Sample records for climate observations compared
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Extra-Tropical Cyclones at Climate Scales: Comparing Models to Observations
Tselioudis, G.; Bauer, M.; Rossow, W.
2009-04-01
Climate is often defined as the accumulation of weather, and weather is not the concern of climate models. Justification for this latter sentiment has long been hidden behind coarse model resolutions and blunt validation tools based on climatological maps. The spatial-temporal resolutions of today's climate models and observations are converging onto meteorological scales, however, which means that with the correct tools we can test the largely unproven assumption that climate model weather is correct enough that its accumulation results in a robust climate simulation. Towards this effort we introduce a new tool for extracting detailed cyclone statistics from observations and climate model output. These include the usual cyclone characteristics (centers, tracks), but also adaptive cyclone-centric composites. We have created a novel dataset, the MAP Climatology of Mid-latitude Storminess (MCMS), which provides a detailed 6 hourly assessment of the areas under the influence of mid-latitude cyclones, using a search algorithm that delimits the boundaries of each system from the outer-most closed SLP contour. Using this we then extract composites of cloud, radiation, and precipitation properties from sources such as ISCCP and GPCP to create a large comparative dataset for climate model validation. A demonstration of the potential usefulness of these tools in process-based climate model evaluation studies will be shown.
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Comparing climate projections to observations up to 2011
International Nuclear Information System (INIS)
Rahmstorf, Stefan; Foster, Grant; Cazenave, Anny
2012-01-01
We analyse global temperature and sea-level data for the past few decades and compare them to projections published in the third and fourth assessment reports of the Intergovernmental Panel on Climate Change (IPCC). The results show that global temperature continues to increase in good agreement with the best estimates of the IPCC, especially if we account for the effects of short-term variability due to the El Niño/Southern Oscillation, volcanic activity and solar variability. The rate of sea-level rise of the past few decades, on the other hand, is greater than projected by the IPCC models. This suggests that IPCC sea-level projections for the future may also be biased low. (letter)
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National Oceanic and Atmospheric Administration, Department of Commerce — Comparative Climatic Data is a publication containing data tables of meteorological elements; the publication outlines the climatic conditions at major weather...
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Challenges of coordinating global climate observations - Role of satellites in climate monitoring
Richter, C.
2017-12-01
Global observation of the Earth's atmosphere, ocean and land is essential for identifying climate variability and change, and for understanding their causes. Observation also provides data that are fundamental for evaluating, refining and initializing the models that predict how the climate system will vary over the months and seasons ahead, and that project how climate will change in the longer term under different assumptions concerning greenhouse gas emissions and other human influences. Long-term observational records have enabled the Intergovernmental Panel on Climate Change to deliver the message that warming of the global climate system is unequivocal. As the Earth's climate enters a new era, in which it is forced by human activities, as well as natural processes, it is critically important to sustain an observing system capable of detecting and documenting global climate variability and change over long periods of time. High-quality climate observations are required to assess the present state of the ocean, cryosphere, atmosphere and land and place them in context with the past. The global observing system for climate is not a single, centrally managed observing system. Rather, it is a composite "system of systems" comprising a set of climate-relevant observing, data-management, product-generation and data-distribution systems. Data from satellites underpin many of the Essential Climate Variables(ECVs), and their historic and contemporary archives are a key part of the global climate observing system. In general, the ECVs will be provided in the form of climate data records that are created by processing and archiving time series of satellite and in situ measurements. Early satellite data records are very valuable because they provide unique observations in many regions which were not otherwise observed during the 1970s and which can be assimilated in atmospheric reanalyses and so extend the satellite climate data records back in time.
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Long-term climate monitoring by the global climate observing system
International Nuclear Information System (INIS)
Karl, T.R.
1995-12-01
Is the climate warming? Is the hydrologic cycle changing? Is the atmospheric/oceanic circulation changing? Is the climate becoming more variable or extreme? Is radiative forcing of the climate changing? are complex questions not only from the standpoint of a multi-variate problem, but because of the various aspects of spatial and temporal sampling that must be considered on a global scale. The development of a Global Climate Observing System (GCOS) offers the opportunity for scientists to do something about existing observing deficiencies in light of the importance of documenting long-term climate changes that may already be affected by anthropogenic changes of atmospheric composition and land use as well as other naturally occurring changes. As an important step toward improving the present inadequacies, a workshop was held to help define the long-term monitoring requirements minimally needed to address the five questions posed above, with special emphasis on detecting anthropogenic climate change and its potential impact on managed and unmanaged systems The workshop focussed on three broad areas related to long-term climate monitoring: (a) the scientific rationale for the long-term climate products (including their accuracy, resolution, and homogeneity) required from our observing systems as related to climate monitoring and climate change detection and attribution; (b) the status of long-term climate products and the observing systems from which these data are derived; and (c) implementation strategies necessary to fulfill item (a) in light of existing systems. Item (c) was treated more in terms of feasibility rather than as a specific implementation plan. figs., tabs., refs
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Designing the Climate Observing System of the Future
Weatherhead, Elizabeth C.; Wielicki, Bruce A.; Ramaswamy, V.; Abbott, Mark; Ackerman, Thomas P.; Atlas, Robert; Brasseur, Guy; Bruhwiler, Lori; Busalacchi, Antonio J.; Butler, James H.; Clack, Christopher T. M.; Cooke, Roger; Cucurull, Lidia; Davis, Sean M.; English, Jason M.; Fahey, David W.; Fine, Steven S.; Lazo, Jeffrey K.; Liang, Shunlin; Loeb, Norman G.; Rignot, Eric; Soden, Brian; Stanitski, Diane; Stephens, Graeme; Tapley, Byron D.; Thompson, Anne M.; Trenberth, Kevin E.; Wuebbles, Donald
2018-01-01
Climate observations are needed to address a large range of important societal issues including sea level rise, droughts, floods, extreme heat events, food security, and freshwater availability in the coming decades. Past, targeted investments in specific climate questions have resulted in tremendous improvements in issues important to human health, security, and infrastructure. However, the current climate observing system was not planned in a comprehensive, focused manner required to adequately address the full range of climate needs. A potential approach to planning the observing system of the future is presented in this article. First, this article proposes that priority be given to the most critical needs as identified within the World Climate Research Program as Grand Challenges. These currently include seven important topics: melting ice and global consequences; clouds, circulation and climate sensitivity; carbon feedbacks in the climate system; understanding and predicting weather and climate extremes; water for the food baskets of the world; regional sea-level change and coastal impacts; and near-term climate prediction. For each Grand Challenge, observations are needed for long-term monitoring, process studies and forecasting capabilities. Second, objective evaluations of proposed observing systems, including satellites, ground-based and in situ observations as well as potentially new, unidentified observational approaches, can quantify the ability to address these climate priorities. And third, investments in effective climate observations will be economically important as they will offer a magnified return on investment that justifies a far greater development of observations to serve society's needs.
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Greenhouse-gas-induced climatic change: A critical appraisal of simulations and observations
International Nuclear Information System (INIS)
Schlesinger, M.E.
1990-01-01
This book is the culmination of a Workshop on Greenhouse-Gas-Induced Climatic Change: A Critical Appraisal of Simulations and Observations which was held at the University of Massachusetts, Amherst, during 8--12 May 1989. The objectives of the Workshop were to: (1) present and evaluate the current status of climate model simulations of greenhouse-gas-induced changes of both the equilibrium and nonequilibrium (transient) climates; (2) present and assess the current status of the observations of global and regional climates from the beginning of the industrial revolution to the present, circa 1850 to 1989; (3) present reconstructions of climatic change during the last millennium to determine the ''natural variability'' of climate on the intra-century time scale; (4) critically evaluate whether or not the climate has changes from circa 1850 to 1989; and (5) compare the observations with the model simulations to ascertain whether a greenhouse-gas-induced climatic change has occurred and, if not, to estimate when in the future such a climatic change will likely become detectable against the background of the ''natural variability.''
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Economic Value of an Advanced Climate Observing System
Wielicki, B. A.; Cooke, R.; Young, D. F.; Mlynczak, M. G.
2013-12-01
) compared the proposed CLARREO advance in satellite absolute calibration for climate change records to an existing system for detecting decadal temperature change using infrared spectra from weather satellites. New results extend this to observational detection of cloud feedback which is the largest uncertainty in determining climate sensitivity and therefore the uncertainty in economic impacts. New results also include the use of multiple societal decision triggers. While CLARREO is used as an example, the value should be considered as relevant to a complete high accuracy climate observing system, as societal decisions are unlikely to be based on one or a few observations. The VOI is found to depend on the required confidence level, the trigger value at which we would abandon the BAU emissions path, the path to which we switch, and the date at which the new system is launched. The VOI of advanced climate observations in this decision context is the surfeit of NPV of averted damages, relative to the existing system. Over all it is in the order of tens of trillions of US dollars in Net Present Value. The results conclude that the economic value of advanced climate observing systems is dramatically larger than their cost, and argues for the continual enhancement of the SCC assessment process.
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Estimating daily climatologies for climate indices derived from climate model data and observations
Mahlstein, Irina; Spirig, Christoph; Liniger, Mark A; Appenzeller, Christof
2015-01-01
Climate indices help to describe the past, present, and the future climate. They are usually closer related to possible impacts and are therefore more illustrative to users than simple climate means. Indices are often based on daily data series and thresholds. It is shown that the percentile-based thresholds are sensitive to the method of computation, and so are the climatological daily mean and the daily standard deviation, which are used for bias corrections of daily climate model data. Sample size issues of either the observed reference period or the model data lead to uncertainties in these estimations. A large number of past ensemble seasonal forecasts, called hindcasts, is used to explore these sampling uncertainties and to compare two different approaches. Based on a perfect model approach it is shown that a fitting approach can improve substantially the estimates of daily climatologies of percentile-based thresholds over land areas, as well as the mean and the variability. These improvements are relevant for bias removal in long-range forecasts or predictions of climate indices based on percentile thresholds. But also for climate change studies, the method shows potential for use. Key Points More robust estimates of daily climate characteristics Statistical fitting approach Based on a perfect model approach PMID:26042192
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Comments on Current Space Systems Observing the Climate
Fisk, L. A.
2016-07-01
The Global Climate Observing System (GCOS), which was established in 1992, has been effective in specifying the observations needed for climate studies, and advocating that these observations be made. As a result, there are essential climate variables being observed, particularly from space, and these have formed the basis for our ever-improving models of how the Earth system functions and the human impact on it. We cannot conclude, however, that the current observing system in space is adequate. Climate change is accelerating, and we need to ensure that our observations capture, with completeness and with proper resolution and cadence, the most important changes. Perhaps of most significance, we need to use observations from space to guide the mitigation and adaptation strategies on which at last our civilization seems prepared to embark. And we need to use our observations to educate particularly policy makers on the reality of climate change, so that none deny the need to act. COSPAR is determined to play its part in highlighting the need to strengthen the climate observing system and notably its research component. This is being accomplished through events like the present roundtable, through the work of its Scientific Commission A, its Task Group on GEO (where COSPAR is serving as a member of its Program Board), and by promoting among space agencies and policy-makers the recently released scientific roadmap on Integrated Earth System Science for the period 2016-2025.
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Ocean Observations of Climate Change
Chambers, Don
2016-01-01
The ocean influences climate by storing and transporting large amounts of heat, freshwater, and carbon, and exchanging these properties with the atmosphere. About 93% of the excess heat energy stored by the earth over the last 50 years is found in the ocean. More than three quarters of the total exchange of water between the atmosphere and the earth's surface through evaporation and precipitation takes place over the oceans. The ocean contains 50 times more carbon than the atmosphere and is at present acting to slow the rate of climate change by absorbing one quarter of human emissions of carbon dioxide from fossil fuel burning, cement production, deforestation and other land use change.Here I summarize the observational evidence of change in the ocean, with an emphasis on basin- and global-scale changes relevant to climate. These include: changes in subsurface ocean temperature and heat content, evidence for regional changes in ocean salinity and their link to changes in evaporation and precipitation over the oceans, evidence of variability and change of ocean current patterns relevant to climate, observations of sea level change and predictions over the next century, and biogeochemical changes in the ocean, including ocean acidification.
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Badr, Hamada S.; Dezfuli, Amin K.; Zaitchik, Benjamin F.; Peters-Lidard, Christa D.
2016-01-01
Many studies have documented dramatic climatic and environmental changes that have affected Africa over different time scales. These studies often raise questions regarding the spatial extent and regional connectivity of changes inferred from observations and proxies and/or derived from climate models. Objective regionalization offers a tool for addressing these questions. To demonstrate this potential, applications of hierarchical climate regionalizations of Africa using observations and GCM historical simulations and future projections are presented. First, Africa is regionalized based on interannual precipitation variability using Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) data for the period 19812014. A number of data processing techniques and clustering algorithms are tested to ensure a robust definition of climate regions. These regionalization results highlight the seasonal and even month-to-month specificity of regional climate associations across the continent, emphasizing the need to consider time of year as well as research question when defining a coherent region for climate analysis. CHIRPS regions are then compared to those of five GCMs for the historic period, with a focus on boreal summer. Results show that some GCMs capture the climatic coherence of the Sahel and associated teleconnections in a manner that is similar to observations, while other models break the Sahel into uncorrelated subregions or produce a Sahel-like region of variability that is spatially displaced from observations. Finally, shifts in climate regions under projected twenty-first-century climate change for different GCMs and emissions pathways are examined. A projected change is found in the coherence of the Sahel, in which the western and eastern Sahel become distinct regions with different teleconnections. This pattern is most pronounced in high-emissions scenarios.
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Carbon cycle observations: gaps threaten climate mitigation policies
Richard Birdsey; Nick Bates; MIke Behrenfeld; Kenneth Davis; Scott C. Doney; Richard Feely; Dennis Hansell; Linda Heath; et al.
2009-01-01
Successful management of carbon dioxide (CO2) requires robust and sustained carbon cycle observations. Yet key elements of a national observation network are lacking or at risk. A U.S. National Research Council review of the U.S. Climate Change Science Program earlier this year highlighted the critical need for a U.S. climate observing system to...
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Sources and Impacts of Modeled and Observed Low-Frequency Climate Variability
Parsons, Luke Alexander
structure of the variance spectrum has important consequences for the probability of multi-year drought. Our lake record suggests there is a significant background threat of multi-year, and even decade-length, drought in western Amazonia, whereas climate model simulations indicate most droughts likely last no longer than one to three years. These findings suggest climate models may underestimate the future risk of extended drought in this important region. In Appendix C, we expand our analysis of climate variability beyond South America. We use observations, well-constrained tropical paleoclimate, and Earth system model data to examine the overall shape of the climate spectrum across interannual to century frequencies. We find a general agreement among observations and models that temperature variability increases with timescale across most of the globe outside the tropics. However, as compared to paleoclimate records, climate models generate too little low-frequency variability in the tropics (e.g., Laepple and Huybers, 2014). When we compare the shape of the simulated climate spectrum to the spectrum of a simple autoregressive process, we find much of the modeled surface temperature variability in the tropics could be explained by ocean smoothing of weather noise. Importantly, modeled precipitation tends to be similar to white noise across much of the globe. By contrast, paleoclimate records of various types from around the globe indicate that both temperature and precipitation variability should experience much more low-frequency variability than a simple autoregressive or white-noise process. In summary, state-of-the-art climate models generate some degree of dynamically driven low-frequency climate variability, especially at high latitudes. However, the latest climate models, observations, and paleoclimate data provide us with drastically different pictures of the background climate system and its associated risks. This research has important consequences for improving
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Armour, K.
2017-12-01
Global energy budget observations have been widely used to constrain the effective, or instantaneous climate sensitivity (ICS), producing median estimates around 2°C (Otto et al. 2013; Lewis & Curry 2015). A key question is whether the comprehensive climate models used to project future warming are consistent with these energy budget estimates of ICS. Yet, performing such comparisons has proven challenging. Within models, values of ICS robustly vary over time, as surface temperature patterns evolve with transient warming, and are generally smaller than the values of equilibrium climate sensitivity (ECS). Naively comparing values of ECS in CMIP5 models (median of about 3.4°C) to observation-based values of ICS has led to the suggestion that models are overly sensitive. This apparent discrepancy can partially be resolved by (i) comparing observation-based values of ICS to model values of ICS relevant for historical warming (Armour 2017; Proistosescu & Huybers 2017); (ii) taking into account the "efficacies" of non-CO2 radiative forcing agents (Marvel et al. 2015); and (iii) accounting for the sparseness of historical temperature observations and differences in sea-surface temperature and near-surface air temperature over the oceans (Richardson et al. 2016). Another potential source of discrepancy is a mismatch between observed and simulated surface temperature patterns over recent decades, due to either natural variability or model deficiencies in simulating historical warming patterns. The nature of the mismatch is such that simulated patterns can lead to more positive radiative feedbacks (higher ICS) relative to those engendered by observed patterns. The magnitude of this effect has not yet been addressed. Here we outline an approach to perform fully commensurate comparisons of climate models with global energy budget observations that take all of the above effects into account. We find that when apples-to-apples comparisons are made, values of ICS in models are
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AIRS Observations Based Evaluation of Relative Climate Feedback Strengths on a GCM Grid-Scale
Molnar, G. I.; Susskind, J.
2012-12-01
Climate feedback strengths, especially those associated with moist processes, still have a rather wide range in GCMs, the primary tools to predict future climate changes associated with man's ever increasing influences on our planet. Here, we make use of the first 10 years of AIRS observations to evaluate interrelationships/correlations of atmospheric moist parameter anomalies computed from AIRS Version 5 Level-3 products, and demonstrate their usefulness to assess relative feedback strengths. Although one may argue about the possible usability of shorter-term, observed climate parameter anomalies for estimating the strength of various (mostly moist processes related) feedbacks, recent works, in particular analyses by Dessler [2008, 2010], have demonstrated their usefulness in assessing global water vapor and cloud feedbacks. First, we create AIRS-observed monthly anomaly time-series (ATs) of outgoing longwave radiation, water vapor, clouds and temperature profile over a 10-year long (Sept. 2002 through Aug. 2012) period using 1x1 degree resolution (a common GCM grid-scale). Next, we evaluate the interrelationships of ATs of the above parameters with the corresponding 1x1 degree, as well as global surface temperature ATs. The latter provides insight comparable with more traditional climate feedback definitions (e. g., Zelinka and Hartmann, 2012) whilst the former is related to a new definition of "local (in surface temperature too) feedback strengths" on a GCM grid-scale. Comparing the correlation maps generated provides valuable new information on the spatial distribution of relative climate feedback strengths. We argue that for GCMs to be trusted for predicting longer-term climate variability, they should be able to reproduce these observed relationships/metrics as closely as possible. For this time period the main climate "forcing" was associated with the El Niño/La Niña variability (e. g., Dessler, 2010), so these assessments may not be descriptive of longer
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A Comparison Between Gravity Wave Momentum Fluxes in Observations and Climate Models
Geller, Marvin A.; Alexadner, M. Joan; Love, Peter T.; Bacmeister, Julio; Ern, Manfred; Hertzog, Albert; Manzini, Elisa; Preusse, Peter; Sato, Kaoru; Scaife, Adam A.;
2013-01-01
For the first time, a formal comparison is made between gravity wave momentum fluxes in models and those derived from observations. Although gravity waves occur over a wide range of spatial and temporal scales, the focus of this paper is on scales that are being parameterized in present climate models, sub-1000-km scales. Only observational methods that permit derivation of gravity wave momentum fluxes over large geographical areas are discussed, and these are from satellite temperature measurements, constant-density long-duration balloons, and high-vertical-resolution radiosonde data. The models discussed include two high-resolution models in which gravity waves are explicitly modeled, Kanto and the Community Atmosphere Model, version 5 (CAM5), and three climate models containing gravity wave parameterizations,MAECHAM5, Hadley Centre Global Environmental Model 3 (HadGEM3), and the Goddard Institute for Space Studies (GISS) model. Measurements generally show similar flux magnitudes as in models, except that the fluxes derived from satellite measurements fall off more rapidly with height. This is likely due to limitations on the observable range of wavelengths, although other factors may contribute. When one accounts for this more rapid fall off, the geographical distribution of the fluxes from observations and models compare reasonably well, except for certain features that depend on the specification of the nonorographic gravity wave source functions in the climate models. For instance, both the observed fluxes and those in the high-resolution models are very small at summer high latitudes, but this is not the case for some of the climate models. This comparison between gravity wave fluxes from climate models, high-resolution models, and fluxes derived from observations indicates that such efforts offer a promising path toward improving specifications of gravity wave sources in climate models.
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Energy Technology Data Exchange (ETDEWEB)
Albani, Samuel [University of Siena, Graduate School in Polar Sciences, Siena (Italy); University of Milano-Bicocca, Department of Environmental Sciences, Milano (Italy); Cornell University, Department of Earth and Atmospheric Sciences, Ithaca, NY (United States); Mahowald, Natalie M. [Cornell University, Department of Earth and Atmospheric Sciences, Ithaca, NY (United States); Delmonte, Barbara; Maggi, Valter [University of Milano-Bicocca, Department of Environmental Sciences, Milano (Italy); Winckler, Gisela [Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY (United States); Columbia University, Department of Earth and Environmental Sciences, New York, NY (United States)
2012-05-15
Mineral dust aerosols represent an active component of the Earth's climate system, by interacting with radiation directly, and by modifying clouds and biogeochemistry. Mineral dust from polar ice cores over the last million years can be used as paleoclimate proxy, and provide unique information about climate variability, as changes in dust deposition at the core sites can be due to changes in sources, transport and/or deposition locally. Here we present results from a study based on climate model simulations using the Community Climate System Model. The focus of this work is to analyze simulated differences in the dust concentration, size distribution and sources in current climate conditions and during the Last Glacial Maximum at specific ice core locations in Antarctica, and compare with available paleodata. Model results suggest that South America is the most important source for dust deposited in Antarctica in current climate, but Australia is also a major contributor and there is spatial variability in the relative importance of the major dust sources. During the Last Glacial Maximum the dominant source in the model was South America, because of the increased activity of glaciogenic dust sources in Southern Patagonia-Tierra del Fuego and the Southernmost Pampas regions, as well as an increase in transport efficiency southward. Dust emitted from the Southern Hemisphere dust source areas usually follow zonal patterns, but southward flow towards Antarctica is located in specific areas characterized by southward displacement of air masses. Observations and model results consistently suggest a spatially variable shift in dust particle sizes. This is due to a combination of relatively reduced en route wet removal favouring a generalized shift towards smaller particles, and on the other hand to an enhanced relative contribution of dry coarse particle deposition in the Last Glacial Maximum. (orig.)
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IPCC Fourth Assessment Report (AR4) Observed Climate Change Impacts Database
National Aeronautics and Space Administration — The Intergovernmental Panel on Climate Change (IPCC) Fourth Assessement Report (AR4) Observed Climate Change Impacts Database contains observed responses to climate...
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Climate, fishery and society interactions: Observations from the North Atlantic
Hamilton, Lawrence C.
2007-11-01
Interdisciplinary studies comparing fisheries-dependent regions across the North Atlantic find a number of broad patterns. Large ecological shifts, disastrous to historical fisheries, have resulted when unfavorable climatic events occur atop overfishing. The "teleconnections" linking fisheries crises across long distances include human technology and markets, as well as climate or migratory fish species. Overfishing and climate-driven changes have led to a shift downwards in trophic levels of fisheries takes in some ecosystems, from dominance by bony fish to crustaceans. Fishing societies adapt to new ecological conditions through social reorganization that have benefited some people and places, while leaving others behind. Characteristic patterns of demographic change are among the symptoms of such reorganization. These general observations emerge from a review of recent case studies of individual fishing communities, such as those conducted for the North Atlantic Arc research project.
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Assessing the observed impact of anthropogenic climate change
Hansen, G; Stone, D
2016-01-01
© 2016 Macmillan Publishers Limited. All rights reserved. Impacts of recent regional changes in climate on natural and human systems are documented across the globe, yet studies explicitly linking these observations to anthropogenic forcing of the climate are scarce. Here we provide a systematic assessment of the role of anthropogenic climate change for the range of impacts of regional climate trends reported in the IPCC's Fifth Assessment Report. We find that almost two-thirds of the impacts...
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Wińska, Małgorzata; Nastula, Jolanta
2017-04-01
Large scale mass redistribution and its transport within the Earth system causes changes in the Earth's rotation in space, gravity field and Earth's ellipsoid shape. These changes are observed in the ΔC21, ΔS21, and ΔC20 spherical harmonics gravity coefficients, which are proportional to the mass load-induced Earth rotational excitations. In this study, linear trend, decadal, inter-annual, and seasonal variations of low degree spherical harmonics coefficients of Earth's gravity field, determined from different space geodetic techniques, Gravity Recovery and Climate Experiment (GRACE), satellite laser ranging (SLR), Global Navigation Satellite System (GNSS), Earth rotation, and climate models, are examined. In this way, the contribution of each measurement technique to interpreting the low degree surface mass density of the Earth is shown. Especially, we evaluate an usefulness of several climate models from the Coupled Model Intercomparison Project phase 5 (CMIP5) to determine the low degree Earth's gravity coefficients using GRACE satellite observations. To do that, Terrestrial Water Storage (TWS) changes from several CMIP5 climate models are determined and then these simulated data are compared with the GRACE observations. Spherical harmonics ΔC21, ΔS21, and ΔC20 changes are calculated as the sum of atmosphere and ocean mass effect (GAC values) taken from GRACE and a land surface hydrological estimate from the selected CMIP5 climate models. Low degree Stokes coefficients of the surface mass density determined from GRACE, SLR, GNSS, Earth rotation measurements and climate models are compared to each other in order to assess their consistency. The comparison is done by using different types of statistical and signal processing methods.
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Parrish, D. D.; Lamarque, J.-F.; Naik, V.; Horowitz, L.; Shindell, D. T.; Staehelin, J.; Derwent, R.; Cooper, O. R.; Tanimoto, H.; Volz-Thomas, A.; Gilge, S.; Scheel, H.-E.; Steinbacher, M.; Fröhlich, M.
2014-05-01
Two recent papers have quantified long-term ozone (O3) changes observed at northern midlatitude sites that are believed to represent baseline (here understood as representative of continental to hemispheric scales) conditions. Three chemistry-climate models (NCAR CAM-chem, GFDL-CM3, and GISS-E2-R) have calculated retrospective tropospheric O3 concentrations as part of the Atmospheric Chemistry and Climate Model Intercomparison Project and Coupled Model Intercomparison Project Phase 5 model intercomparisons. We present an approach for quantitative comparisons of model results with measurements for seasonally averaged O3 concentrations. There is considerable qualitative agreement between the measurements and the models, but there are also substantial and consistent quantitative disagreements. Most notably, models (1) overestimate absolute O3 mixing ratios, on average by 5 to 17 ppbv in the year 2000, (2) capture only 50% of O3 changes observed over the past five to six decades, and little of observed seasonal differences, and (3) capture 25 to 45% of the rate of change of the long-term changes. These disagreements are significant enough to indicate that only limited confidence can be placed on estimates of present-day radiative forcing of tropospheric O3 derived from modeled historic concentration changes and on predicted future O3 concentrations. Evidently our understanding of tropospheric O3, or the incorporation of chemistry and transport processes into current chemical climate models, is incomplete. Modeled O3 trends approximately parallel estimated trends in anthropogenic emissions of NOx, an important O3 precursor, while measured O3 changes increase more rapidly than these emission estimates.
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Assessing the observed impact of anthropogenic climate change
Hansen, G.E.
2015-01-01
Assessing the observed impact of anthropogenic climate change
Gerrit Hansen
Global climate change is unequivocal, and greenhouse gas emissions continue rising despite international mitigation efforts. Hence whether and to what extent the impacts of human induced
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School climate in peer bullying: observers' and active participants' perceptions
Directory of Open Access Journals (Sweden)
Sonja Pečjak
2017-09-01
Full Text Available Peer bullying is a phenomenon present in all schools. The school as an institution has a major role in limiting peer bullying. The primary goal of the study was to determine how different groups of students perceived school climate in relation to peer bullying regarding their role in peer bullying (active participants: bullies, victims, bully-victims and non-active participants: observers. 414 students (from 18 primary and secondary schools responded to The School Climate Bullying Survey (SCBS; Cornell, 2012, which measures the incidence of various forms of peer bullying and three dimensions of school climate (prevalence of teasing and bullying, aggressive attitudes, and willingness to seek help. The results showed that the active participants in peer bullying report a frequent presence of verbal and social bullying (54% and 40%, respectively and a significantly lower frequency of physical and cyber bullying (14%. The largest differences between the groups of students were found in their perceptions of the prevalence of aggressive attitudes and willingness to seek help in a school context. In the perceptions of both of these dimensions we found a high degree of similarity between the groups of bullies and victim-bullies, and between the groups of victims and observers. The first two groups, when compared to the victims and observers, perceived to a greater extent that school allows aggression as a way of affirmation among peers and in school in general, and that neither teachers nor peers do not stop the bullying, which discourages the victims from seeking help from them. The results confirmed the existence of the association between students’ perceived school climate by bullying and their behavior (roles in peer bullying.
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Dante Castellanos-Acuña; Kenneth W. Vance-Borland; J. Bradley St. Clair; Andreas Hamann; Javier López-Upton; Erika Gómez-Pineda; Juan Manuel Ortega-Rodríguez; Cuauhtémoc Sáenz-Romero
2018-01-01
Seed zones for forest tree species are a widely used tool in reforestation programs to ensure that seedlings are well adapted to their planting environments. Here, we propose a climate-based seed zone system for Mexico to address observed and projected climate change. The proposed seed zone classification is based on bands of climate variables often related to genetic...
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Climate Change Observation Accuracy: Requirements and Economic Value
Wielicki, Bruce; Cooke, Roger; Golub, Alexander; Baize, Rosemary; Mlynczak, Martin; Lukashin, Constantin; Thome, Kurt; Shea, Yolanda; Kopp, Greg; Pilewskie, Peter;
2016-01-01
This presentation will summarize a new quantitative approach to determining the required accuracy for climate change observations. Using this metric, most current global satellite observations struggle to meet this accuracy level. CLARREO (Climate Absolute Radiance and Refractivity Observatory) is a new satellite mission designed to resolve this challenge is by achieving advances of a factor of 10 for reflected solar spectra and a factor of 3 to 5 for thermal infrared spectra. The CLARREO spectrometers can serve as SI traceable benchmarks for the Global Satellite Intercalibration System (GSICS) and greatly improve the utility of a wide range of LEO and GEO infrared and reflected solar satellite sensors for climate change observations (e.g. CERES, MODIS, VIIIRS, CrIS, IASI, Landsat, etc). A CLARREO Pathfinder mission for flight on the International Space Station is included in the U.S. Presidentâ€"TM"s fiscal year 2016 budget, with launch in 2019 or 2020. Providing more accurate decadal change trends can in turn lead to more rapid narrowing of key climate science uncertainties such as cloud feedback and climate sensitivity. A new study has been carried out to quantify the economic benefits of such an advance and concludes that the economic value is $9 Trillion U.S. dollars. The new value includes the cost of carbon emissions reductions.
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Europe adapts to climate change: Comparing National Adaptation Strategies
DEFF Research Database (Denmark)
Biesbroek, G. Robbert; Swart, Rob J.; Carter, Timothy R.
2010-01-01
For the last two decades, European climate policy has focused almost exclusively on mitigation of climate change. It was only well after the turn of the century, with impacts of climate change increasingly being observed, that adaptation was added to the policy agenda and EU Member States started...
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Unusual climatic conditions and infectious diseases: observations made by Hippocrates.
Falagas, Matthew E; Bliziotis, Ioannis A; Kosmidis, John; Daikos, George K
2010-12-01
About 2500 years ago, Hippocrates made noteworthy observations about the influence of climate on public health. He believed that people living in cities with different climate may suffer from different diseases. Hippocrates also observed that abrupt climatic changes or unusual weather conditions affect public health, especially the incidence and severity of various infectious diseases, including gastrointestinal infections, tuberculosis, and central nervous system infections. We believe that Hippocrates' scientific observations are great early historic examples that stress to modern infectious diseases researchers and clinicians the need to study intensively the effect of the occurring global climate changes to infectious diseases in order to help in the prevention of possible epidemics of infections. Copyright © 2009 Elsevier España, S.L. All rights reserved.
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Directory of Open Access Journals (Sweden)
A. Loew
2013-09-01
Full Text Available Soil moisture is an essential climate variable (ECV of major importance for land–atmosphere interactions and global hydrology. An appropriate representation of soil moisture dynamics in global climate models is therefore important. Recently, a first multidecadal, observation-based soil moisture dataset has become available that provides information on soil moisture dynamics from satellite observations (ECVSM, essential climate variable soil moisture. The present study investigates the potential and limitations of this new dataset for several applications in climate model evaluation. We compare soil moisture data from satellite observations, reanalysis and simulations from a state-of-the-art land surface model and analyze relationships between soil moisture and precipitation anomalies in the different dataset. Other potential applications like model parameter optimization or model initialization are not investigated in the present study. In a detailed regional study, we show that ECVSM is capable to capture well the interannual and intraannual soil moisture and precipitation dynamics in the Sahelian region. Current deficits of the new dataset are critically discussed and summarized at the end of the paper to provide guidance for an appropriate usage of the ECVSM dataset for climate studies.
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SATELLITE OBSERVATIONS FOR EDUCATION OF CLIMATE CHANGE
Directory of Open Access Journals (Sweden)
ILONA PAJTÓK-TARI
2011-03-01
Full Text Available This paper surveys the key statements of the IPCC (2007 Reportbased mainly on the satellite-borne observations to support teaching climatechange and geography by using the potential of this technology. In theIntroduction we briefly specify the potential and the constraints of remote sensing.Next the key climate variables for indicating the changes are surveyed. Snow andsea-ice changes are displayed as examples for these applications. Testing theclimate models is a two-sided task involving satellites, as well. Validation of theability of reconstructing the present climate is the one side of the coin, whereassensitivity of the climate system is another key task, leading to consequences onthe reality of the projected changes. Finally some concluding remarks arecompiled, including a few ideas on the ways how these approaches can be appliedfor education of climate change.
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International Nuclear Information System (INIS)
Andre, J.C.; Royer, J.F.
1999-01-01
Simulations of future climate made with coupled general circulation models of the atmosphere and ocean predict that the increase of the concentration of greenhouse gases released in the atmosphere by man's activities will have a large influence on the climate of the next century. The identification of the climatic impact produced by the rapid increase in carbon dioxide concentration in the last decades is made difficult by strong inter-annual climate variability, and requires the application of statistical techniques combining several climatic indicators (method of climatic 'fingerprints') so as to improve the detection of a possible anthropogenic perturbation. In this paper we review the evolution through the last decades of several climate indicators showing global warming, its geographical distribution, sea level, the hydrological cycle and the response of vegetation, and we compare them to the model results predicted in climate scenarios. The coherence between model results and observed climatic trends shows that the additional greenhouse effect is starting to become detectable in recent climatic data. (authors)
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Climate-carbon cycle feedbacks under stabilization: uncertainty and observational constraints
International Nuclear Information System (INIS)
Jones, Chris D.; Cox, Peter M.; Huntingford, Chris
2006-01-01
Avoiding 'dangerous climate change' by stabilization of atmospheric CO 2 concentrations at a desired level requires reducing the rate of anthropogenic carbon emissions so that they are balanced by uptake of carbon by the natural terrestrial and oceanic carbon cycles. Previous calculations of profiles of emissions which lead to stabilized CO 2 levels have assumed no impact of climate change on this natural carbon uptake. However, future climate change effects on the land carbon cycle are predicted to reduce its ability to act as a sink for anthropogenic carbon emissions and so quantification of this feedback is required to determine future permissible emissions. Here, we assess the impact of the climate-carbon cycle feedback and attempt to quantify its uncertainty due to both within-model parameter uncertainty and between-model structural uncertainty. We assess the use of observational constraints to reduce uncertainty in the future permissible emissions for climate stabilization and find that all realistic carbon cycle feedbacks consistent with the observational record give permissible emissions significantly less than previously assumed. However, the observational record proves to be insufficient to tightly constrain carbon cycle processes or future feedback strength with implications for climate-carbon cycle model evaluation
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Using Copernicus earth observation services to monitor climate change impacts and adaptations
Becker, Daniel; Zebisch, Marc; Sonnenschein, Ruth; Schönthaler, Konstanze; von Andrian-Werburg, Stefan
2016-04-01
In the last years, earth observation made a big leap towards an operational monitoring of the state of environment. Remote sensing provides for instance information on the dynamics, trends and anomalies of snow and glaciers, vegetation, soil moisture or water temperature. In particular, the European Copernicus initiative offers new opportunities through new satellites with a higher temporal and spatial resolution, operational services for environmental monitoring and an open data access policy. With the Copernicus climate change service and the ESA climate change initiative, specific earth observation programs are in place to address the impacts of climate change. However, such products and services are until now rarely picked up in the field of policy or decision making oriented climate impact or climate risk assessments. In this talk, we will present results of a study, which focus on the question, if and how remote sensing approaches could be integrated into operational monitoring activities of climate impacts and response measures on a national and subnational scale. We assessed all existing and planned Copernicus services regarding their relevance for climate impact monitoring by comparing them against the indication fields from an indicator system for climate impact and response monitoring in Germany, which has lately been developed in the framework of the German national adaptation strategy. For several climate impact or response indicators, an immediate integration of remote sensing data could be identified and been recommended. For these cases, we will show practical examples on the benefit of remote sensing data. For other indication fields, promising approaches were found, which need further development. We argue that remote sensing is a very valuable complement to the existing indicator schemes by contributing with spatial explicit, timely information but not always easy to integrate with classical approaches, which are oriented towards consistent long
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Energy Technology Data Exchange (ETDEWEB)
Di Luca, Alejandro; Laprise, Rene [Universite du Quebec a Montreal (UQAM), Centre ESCER (Etude et Simulation du Climat a l' Echelle Regionale), Departement des Sciences de la Terre et de l' Atmosphere, PK-6530, Succ. Centre-ville, B.P. 8888, Montreal, QC (Canada); De Elia, Ramon [Universite du Quebec a Montreal, Ouranos Consortium, Centre ESCER (Etude et Simulation du Climat a l' Echelle Regionale), Montreal (Canada)
2012-03-15
Regional Climate Models (RCMs) constitute the most often used method to perform affordable high-resolution regional climate simulations. The key issue in the evaluation of nested regional models is to determine whether RCM simulations improve the representation of climatic statistics compared to the driving data, that is, whether RCMs add value. In this study we examine a necessary condition that some climate statistics derived from the precipitation field must satisfy in order that the RCM technique can generate some added value: we focus on whether the climate statistics of interest contain some fine spatial-scale variability that would be absent on a coarser grid. The presence and magnitude of fine-scale precipitation variance required to adequately describe a given climate statistics will then be used to quantify the potential added value (PAV) of RCMs. Our results show that the PAV of RCMs is much higher for short temporal scales (e.g., 3-hourly data) than for long temporal scales (16-day average data) due to the filtering resulting from the time-averaging process. PAV is higher in warm season compared to cold season due to the higher proportion of precipitation falling from small-scale weather systems in the warm season. In regions of complex topography, the orographic forcing induces an extra component of PAV, no matter the season or the temporal scale considered. The PAV is also estimated using high-resolution datasets based on observations allowing the evaluation of the sensitivity of changing resolution in the real climate system. The results show that RCMs tend to reproduce relatively well the PAV compared to observations although showing an overestimation of the PAV in warm season and mountainous regions. (orig.)
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Climate Model Diagnostic and Evaluation: With a Focus on Satellite Observations
Waliser, Duane
2011-01-01
Each year, we host a summer school that brings together the next generation of climate scientists - about 30 graduate students and postdocs from around the world - to engage with premier climate scientists from the Jet Propulsion Laboratory and elsewhere. Our yearly summer school focuses on topics on the leading edge of climate science research. Our inaugural summer school, held in 2011, was on the topic of "Using Satellite Observations to Advance Climate Models," and enabled students to explore how satellite observations can be used to evaluate and improve climate models. Speakers included climate experts from both NASA and the National Oceanic and Atmospheric Administration (NOAA), who provided updates on climate model diagnostics and evaluation and remote sensing of the planet. Details of the next summer school will be posted here in due course.
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Comparing farmers' perception of climate change and variability with ...
African Journals Online (AJOL)
Perception of climate change and variability supported by local knowledge has helped to advance understanding of climate change and its impacts on agricultural land-use systems. This study compares farmers' perception of climate change and variability in four communities of the Upper East Region of Ghana. Using a ...
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A Field Guide to Extra-Tropical Cyclones: Comparing Models to Observations
Bauer, M.
2008-12-01
Climate it is said is the accumulation of weather. And weather is not the concern of climate models. Justification for this latter sentiment has long hidden behind coarse model resolutions and blunt validation tools based on climatological maps and the like. The spatial-temporal resolutions of today's models and observations are converging onto meteorological scales however, which means that with the correct tools we can test the largely unproven assumption that climate model weather is correct enough, or at least lacks perverting biases, such that its accumulation does in fact result in a robust climate prediction. Towards this effort we introduce a new tool for extracting detailed cyclone statistics from climate model output. These include the usual cyclone distribution statistics (maps, histograms), but also adaptive cyclone- centric composites. We have also created a complementary dataset, The MAP Climatology of Mid-latitude Storminess (MCMS), which provides a detailed 6 hourly assessment of the areas under the influence of mid- latitude cyclones based on Reanalysis products. Using this we then extract complimentary composites from sources such as ISCCP and GPCP to create a large comparative dataset for climate model validation. A demonstration of the potential usefulness of these tools will be shown. dime.giss.nasa.gov/mcms/mcms.html
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An observational and modeling study of the August 2017 Florida climate extreme event.
Konduru, R.; Singh, V.; Routray, A.
2017-12-01
A special report on the climate extremes by the Intergovernmental Panel on Climate Change (IPCC) elucidates that the sole cause of disasters is due to the exposure and vulnerability of the human and natural system to the climate extremes. The cause of such a climate extreme could be anthropogenic or non-anthropogenic. Therefore, it is challenging to discern the critical factor of influence for a particular climate extreme. Such kind of perceptive study with reasonable confidence on climate extreme events is possible only if there exist any past case studies. A similar rarest climate extreme problem encountered in the case of Houston floods and extreme rainfall over Florida in August 2017. A continuum of hurricanes like Harvey and Irma targeted the Florida region and caused catastrophe. Due to the rarity of August 2017 Florida climate extreme event, it requires the in-depth study on this case. To understand the multi-faceted nature of the event, a study on the development of the Harvey hurricane and its progression and dynamics is significant. Current article focus on the observational and modeling study on the Harvey hurricane. A global model named as NCUM (The global UK Met office Unified Model (UM) operational at National Center for Medium Range Weather Forecasting, India, was utilized to simulate the Harvey hurricane. The simulated rainfall and wind fields were compared with the observational datasets like Tropical Rainfall Measuring Mission rainfall datasets and Era-Interim wind fields. The National Centre for Environmental Prediction (NCEP) automated tracking system was utilized to track the Harvey hurricane, and the tracks were analyzed statistically for different forecasts concerning the Harvey hurricane track of Joint Typhon Warning Centre. Further, the current study will be continued to investigate the atmospheric processes involved in the August 2017 Florida climate extreme event.
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The Impact of Ocean Observations in Seasonal Climate Prediction
Rienecker, Michele; Keppenne, Christian; Kovach, Robin; Marshak, Jelena
2010-01-01
The ocean provides the most significant memory for the climate system. Hence, a critical element in climate forecasting with coupled models is the initialization of the ocean with states from an ocean data assimilation system. Remotely-sensed ocean surface fields (e.g., sea surface topography, SST, winds) are now available for extensive periods and have been used to constrain ocean models to provide a record of climate variations. Since the ocean is virtually opaque to electromagnetic radiation, the assimilation of these satellite data is essential to extracting the maximum information content. More recently, the Argo drifters have provided unprecedented sampling of the subsurface temperature and salinity. Although the duration of this observation set has been too short to provide solid statistical evidence of its impact, there are indications that Argo improves the forecast skill of coupled systems. This presentation will address the impact these different observations have had on seasonal climate predictions with the GMAO's coupled model.
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Directory of Open Access Journals (Sweden)
Iain Brown
2015-11-01
Full Text Available Risk assessment can potentially provide an objective framework to synthesise and prioritise climate change risks to inform adaptation policy. However, there are significant challenges in the application of comparative risk assessment procedures to climate change, particularly for the natural environment. These challenges are evaluated with particular reference to the first statutory Climate Change Risk Assessment (CCRA and evidence review procedures used to guide policy for the UK government. More progress was achieved on risk identification, screening and prioritisation compared to risk quantification. This was due to the inherent complexity and interdependence of ecological risks and their interaction with socio-economic drivers as well as a climate change. Robust strategies to manage risk were identified as those that coordinate organisational resources to enhance ecosystem resilience, and to accommodate inevitable change, rather than to meet specific species or habitats targets. The assessment also highlighted subjective and contextual components of risk appraisal including ethical issues regarding the level of human intervention in the natural environment and the proposed outcomes of any intervention. This suggests that goals for risk assessment need to be more clearly explicated and assumptions on tolerable risk declared as a primer for further dialogue on expectations for managed outcomes. Ecosystem-based adaptation may mean that traditional habitats and species conservation goals and existing regulatory frameworks no longer provide the best guide for long-term risk management thereby challenging the viability of some existing practices.
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A perspective on sustained marine observations for climate modelling and prediction.
Dunstone, Nick J
2014-09-28
Here, I examine some of the many varied ways in which sustained global ocean observations are used in numerical modelling activities. In particular, I focus on the use of ocean observations to initialize predictions in ocean and climate models. Examples are also shown of how models can be used to assess the impact of both current ocean observations and to simulate that of potential new ocean observing platforms. The ocean has never been better observed than it is today and similarly ocean models have never been as capable at representing the real ocean as they are now. However, there remain important unanswered questions that can likely only be addressed via future improvements in ocean observations. In particular, ocean observing systems need to respond to the needs of the burgeoning field of near-term climate predictions. Although new ocean observing platforms promise exciting new discoveries, there is a delicate balance to be made between their funding and that of the current ocean observing system. Here, I identify the need to secure long-term funding for ocean observing platforms as they mature, from a mainly research exercise to an operational system for sustained observation over climate change time scales. At the same time, considerable progress continues to be made via ship-based observing campaigns and I highlight some that are dedicated to addressing uncertainties in key ocean model parametrizations. The use of ocean observations to understand the prominent long time scale changes observed in the North Atlantic is another focus of this paper. The exciting first decade of monitoring of the Atlantic meridional overturning circulation by the RAPID-MOCHA array is highlighted. The use of ocean and climate models as tools to further probe the drivers of variability seen in such time series is another exciting development. I also discuss the need for a concerted combined effort from climate models and ocean observations in order to understand the current slow
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Sensitivity of climate models: Comparison of simulated and observed patterns for past climates
International Nuclear Information System (INIS)
Prell, W.L.; Webb, T. III.
1992-08-01
Predicting the potential climatic effects of increased concentrations of atmospheric carbon dioxide requires the continuing development of climate models. Confidence in the predictions will be much enhanced once the models are thoroughly tested in terms of their ability to simulate climates that differ significantly from today's climate. As one index of the magnitude of past climate change, the global mean temperature increase during the past 18,000 years is similar to that predicted for carbon dioxide--doubling. Simulating the climatic changes of the past 18,000 years, as well as the warmer-than-present climate of 6000 years ago and the climate of the last interglacial, around 126,000 years ago, provides an excellent opportunity to test the models that are being used in global climate change research. During the past several years, we have used paleoclimatic data to test the accuracy of the National Center for Atmospheric Research, Community Climate Model, Version 0, after changing its boundary conditions to those appropriate for past climates. We have assembled regional and near-global paleoclimatic data sets of pollen, lake level, and marine plankton data and calibrated many of the data in terms of climatic variables. We have also developed methods that permit direct quantitative comparisons between the data and model results. Our research has shown that comparing the model results with the data is an evolutionary process, because the models, the data, and the methods for comparison are continually being improved. During 1992, we have completed new modeling experiments, further analyzed previous model experiments, compiled new paleodata, made new comparisons between data and model results, and participated in workshops on paleoclimatic modeling
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Comparing climate policies to reduce carbon emissions in China
International Nuclear Information System (INIS)
Li, Aijun; Lin, Boqiang
2013-01-01
Currently, China is the largest carbon emitter mainly due to growing consumption of fossil fuels. In 2009, the Chinese government committed itself to reducing domestic carbon emissions per unit of GDP by 40–45% by 2020 compared to 2005 levels. Therefore, it is a top priority for the Chinese government to adopt efficient policy instruments to reduce its carbon intensity. Against this background, this paper develops a general equilibrium model and seeks to provide empirical contributions by comparing the potential impacts of several different policy options to reduce China's carbon emissions. The main findings are as follows. Firstly, these climate policies would affect the structure of economy and contribute to carbon emissions reduction and carbon intensity reduction. Secondly, there would be significant differences in the economic and environmental effects among different climate policies and hence, the government would trade-off among different economic objectives to overcome any potential resistances. Thirdly, there would be considerable differences in the emissions effects of absolute and intensity-based carbon emissions controls, implying that the government might adopt different climate policies for absolute or intensity-based carbon emissions controls. Looking ahead, the government should trade-off among different objectives when designing climate reforms. - Highlights: • We develop a static general equilibrium model to simulate the impacts of climate policies. • We compare the potential impacts of various climate policies in China. • We discuss how to design these policies to make them more effective
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Freeth, D; Sandall, J; Allan, T; Warburton, F; Berridge, E J; Mackintosh, N; Rogers, M; Abbott, S
2012-05-01
Patient safety concerns have focused attention on organisational and safety cultures, in turn directing attention to the measurement of organisational and safety climates. First, to compare levels of agreement between survey- and observation-based measures of organisational and safety climates/cultures and to compare both measures with criterion-based audits of the quality of care, using evidence-based markers drawn from national care standards relating to six common clinical conditions. (This required development of an observation-based instrument.) Second, to examine whether observation-based evaluations could replace or augment survey measurements to mitigate concerns about declining response rates and increasing social desirability bias. Third, to examine mediating factors in safety and organisational climate scores. The study had three strands: (A) a postal questionnaire survey to elicit staff perceptions of organisational and safety climates, using six prevalidated scales; (B) semistructured non-participant observation of clinical teams; and (C) a retrospective criterion-based audit carried out by non-clinical auditors to minimise hindsight bias. Standardised summary scores were created for each strand, and pairs of measurements were compared (strand A with strand B, strand A with strand C, and strand B with strand C) using Bland-Altman plots to evaluate agreement. Correlations were also examined. Multilevel modelling of Strand A scores explored mediating factors. Eight emergency departments and eight maternity units in England, UK. None. Examination of feasibility, correlation and agreement. Strand A: the overall response rate was 27.6%, whereas site-specific rates ranged from 9% to 47%. We identified more mediating factors than previous studies; variable response rates had little effect on the results. Organisational and safety climate scores were strongly correlated (r = 0.845) and exhibited good agreement [standard deviation (SD) differences 0.449; 14 (88
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Satellite lidar and radar: Key components of the future climate observing system
Winker, D. M.
2017-12-01
Cloud feedbacks represent the dominant source of uncertainties in estimates of climate sensitivity and aerosols represent the largest source of uncertainty in climate forcing. Both observation of long-term changes and observational constraints on the processes responsible for those changes are necessary. The existing 30-year record of passive satellite observations has not yet provided constraints to significantly reduce these uncertainties, though. We now have more than a decade of experience with active sensors flying in the A-Train. These new observations have demonstrated the strengths of active sensors and the benefits of continued and more advanced active sensors. This talk will discuss the multiple roles for active sensors as an essential component of a global climate observing system.
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Ecological Assimilation of Land and Climate Observations - the EALCO model
Wang, S.; Zhang, Y.; Trishchenko, A.
2004-05-01
Ecosystems are intrinsically dynamic and interact with climate at a highly integrated level. Climate variables are the main driving factors in controlling the ecosystem physical, physiological, and biogeochemical processes including energy balance, water balance, photosynthesis, respiration, and nutrient cycling. On the other hand, ecosystems function as an integrity and feedback on the climate system through their control on surface radiation balance, energy partitioning, and greenhouse gases exchange. To improve our capability in climate change impact assessment, a comprehensive ecosystem model is required to address the many interactions between climate change and ecosystems. In addition, different ecosystems can have very different responses to the climate change and its variation. To provide more scientific support for ecosystem impact assessment at national scale, it is imperative that ecosystem models have the capability of assimilating the large scale geospatial information including satellite observations, GIS datasets, and climate model outputs or reanalysis. The EALCO model (Ecological Assimilation of Land and Climate Observations) is developed for such purposes. EALCO includes the comprehensive interactions among ecosystem processes and climate, and assimilates a variety of remote sensing products and GIS database. It provides both national and local scale model outputs for ecosystem responses to climate change including radiation and energy balances, water conditions and hydrological cycles, carbon sequestration and greenhouse gas exchange, and nutrient (N) cycling. These results form the foundation for the assessment of climate change impact on ecosystems, their services, and adaptation options. In this poster, the main algorithms for the radiation, energy, water, carbon, and nitrogen simulations were diagrammed. Sample input data layers at Canada national scale were illustrated. Model outputs including the Canada wide spatial distributions of net
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Comparative study on Climate Change Policies in the EU and China
Bray, M.; Han, D.
2012-04-01
Both the EU and China are among the largest CO2 emitters in the world; their climate actions and policies have profound impacts on global climate change and may influence the activities in other countries. Evidence of climate change has been observed across Europe and China. Despite the many differences between the two regions, the European Commission and Chinese government support climate change actions. The EU has three priority areas in climate change: 1) understanding, monitoring and predicting climate change and its impact; 2) providing tools to analyse the effectiveness, cost and benefits of different policy options for mitigating climate change and adapting to its impacts; 3) improving, demonstrating and deploying existing climate friendly technologies and developing the technologies of the future. China is very vulnerable to climate change, because of its vast population, fast economic development, and fragile ecological environment. The priority policies in China are: 1) Carbon Trading Policy; 2) Financing Loan Policy (Special Funds for Renewable Energy Development); 3) Energy Efficiency Labelling Policy; 4) Subsidy Policy. In addition, China has formulated the "Energy Conservation Law", "Renewable Energy Law", "Cleaner Production Promotion Law" and "Circular Economy Promotion Law". Under the present EU Framework Programme FP7 there is a large number of funded research activities linked to climate change research. Current climate change research projects concentrate on the carbon cycle, water quality and availability, climate change predictors, predicting future climate and understanding past climates. Climate change-related scientific and technological projects in China are mostly carried out through national scientific and technological research programs. Areas under investigation include projections and impact of global climate change, the future trends of living environment change in China, countermeasures and supporting technologies of global
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Solving the African Climate Observation Puzzle, and Concurrently Building Capacity
Selker, J. S.; Van De Giesen, N.; Annor, F. O.; Hochreutener, R.; Jachens, E. R.
2017-12-01
The Trans-African Hydro-Meteorological Observatory (TAHMO.org) is directly addressing basic issues of climate observation, climate science, and education through a novel public-private partnership. With 500 stations now reporting from over 20 African countries, TAHMO is the largest single source of continental-scale weather and climate data for Africa. Working directly with national meteorological agencies, TAHMO first builds local human capacity and real-time data to the host country. TAHMO also provides all of these data free of charge to all researchers and teams seeking to develop peer-reviewed scientific contributions. This will be the basis of a whole new level of observation-informed science for the African continent. Most TAHMO stations are housed at African schools, with a local host-teacher who attends to basic day-to-day cleaning. These schools also receive free curricular support providing geographic, mathematical, statistical, hydrologic, and meteorological lessons that connect student to their environment and creates climate-aware citizens, which we believe is the most fundamental element of developing a climate-resilient society. Installation of these stations have been made possible through the support of private companies like IBM and development programmes through the Global Resilience Partnership, World Bank, USAID among others. The availability of these new data sets will help generate more accurate weather forecasts which will be made freely available across the African continent. TAHMO leverages low-cost cell phone data transmission with solid-state sensor technology (provided by the METER corporation) to provide a cost-effective, sustainable, and transformative solution to the climate observation gap in Africa.
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Satellite-derived SIF and CO2 Observations Show Coherent Responses to Interannual Climate Variations
Butterfield, Z.; Hogikyan, A.; Kulawik, S. S.; Keppel-Aleks, G.
2017-12-01
Gross primary production (GPP) is the single largest carbon flux in the Earth system, but its sensitivity to changes in climate is subject to significant uncertainty. Satellite measurements of solar-induced chlorophyll fluorescence (SIF) offer insight into spatial and temporal patterns in GPP at a global scale and, combined with other satellite-derived datasets, provide unprecedented opportunity to explore interactions between atmospheric CO2, GPP, and climate variability. To explore potential drivers of GPP in the Northern Hemisphere (NH), we compare monthly-averaged SIF data from the Global Ozone Monitoring Experiment 2 (GOME-2) with observed anomalies in temperature (T; CRU-TS), liquid water equivalent (LWE) from the Gravity Recovery and Climate Experiment (GRACE), and photosynthetically active radiation (PAR; CERES SYN1deg). Using observations from 2007 through 2015 for several NH regions, we calculate month-specific sensitivities of SIF to variability in T, LWE, and PAR. These sensitivities provide insight into the seasonal progression of how productivity is affected by climate variability and can be used to effectively model the observed SIF signal. In general, we find that high temperatures are beneficial to productivity in the spring, but detrimental in the summer. The influences of PAR and LWE are more heterogeneous between regions; for example, higher LWE in North American temperate forest leads to decreased springtime productivity, while exhibiting a contrasting effect in water-limited regions. Lastly, we assess the influence of variations in terrestrial productivity on atmospheric carbon using a new lower tropospheric CO2 product derived from the Greenhouse Gases Observing Satellite (GOSAT). Together, these data shed light on the drivers of interannual variability in the annual cycle of NH atmospheric CO2, and may provide improved constraints on projections of long-term carbon cycle responses to climate change.
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Brown, Patrick T.; Li, Wenhong; Cordero, Eugene C.; Mauget, Steven A.
2015-01-01
The comparison of observed global mean surface air temperature (GMT) change to the mean change simulated by climate models has received much public and scientific attention. For a given global warming signal produced by a climate model ensemble, there exists an envelope of GMT values representing the range of possible unforced states of the climate system (the Envelope of Unforced Noise; EUN). Typically, the EUN is derived from climate models themselves, but climate models might not accurately simulate the correct characteristics of unforced GMT variability. Here, we simulate a new, empirical, EUN that is based on instrumental and reconstructed surface temperature records. We compare the forced GMT signal produced by climate models to observations while noting the range of GMT values provided by the empirical EUN. We find that the empirical EUN is wide enough so that the interdecadal variability in the rate of global warming over the 20th century does not necessarily require corresponding variability in the rate-of-increase of the forced signal. The empirical EUN also indicates that the reduced GMT warming over the past decade or so is still consistent with a middle emission scenario's forced signal, but is likely inconsistent with the steepest emission scenario's forced signal. PMID:25898351
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Brown, Patrick T; Li, Wenhong; Cordero, Eugene C; Mauget, Steven A
2015-04-21
The comparison of observed global mean surface air temperature (GMT) change to the mean change simulated by climate models has received much public and scientific attention. For a given global warming signal produced by a climate model ensemble, there exists an envelope of GMT values representing the range of possible unforced states of the climate system (the Envelope of Unforced Noise; EUN). Typically, the EUN is derived from climate models themselves, but climate models might not accurately simulate the correct characteristics of unforced GMT variability. Here, we simulate a new, empirical, EUN that is based on instrumental and reconstructed surface temperature records. We compare the forced GMT signal produced by climate models to observations while noting the range of GMT values provided by the empirical EUN. We find that the empirical EUN is wide enough so that the interdecadal variability in the rate of global warming over the 20(th) century does not necessarily require corresponding variability in the rate-of-increase of the forced signal. The empirical EUN also indicates that the reduced GMT warming over the past decade or so is still consistent with a middle emission scenario's forced signal, but is likely inconsistent with the steepest emission scenario's forced signal.
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Climate Outreach Using Regional Coastal Ocean Observing System Portals
Anderson, D. M.; Hernandez, D. L.; Wakely, A.; Bochenek, R. J.; Bickel, A.
2015-12-01
Coastal oceans are dynamic, changing environments affected by processes ranging from seconds to millennia. On the east and west coast of the U.S., regional observing systems have deployed and sustained a remarkable diverse array of observing tools and sensors. Data portals visualize and provide access to real-time sensor networks. Portals have emerged as an interactive tool for educators to help students explore and understand climate. Bringing data portals to outreach events, into classrooms, and onto tablets and smartphones enables educators to address topics and phenomena happening right now. For example at the 2015 Charleston Science Technology Engineering and Math (STEM) Festival, visitors navigated the SECOORA (Southeast Coastal Ocean Observing regional Association) data portal to view the real-time marine meteorological conditions off South Carolina. Map-based entry points provide an intuitive interface for most students, an array of time series and other visualizations depict many of the essential principles of climate science manifest in the coastal zone, and data down-load/ extract options provide access to the data and documentation for further inquiry by advanced users. Beyond the exposition of climate principles, the portal experience reveals remarkable technologies in action and shows how the observing system is enabled by the activity of many different partners.
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The Grand Challenges of WCRP and the Climate Observing System of the Future
Brasseur, G. P.
2017-12-01
The successful implementation the Paris agreement on climate change (COP21) calls for a well-designed global monitoring system of essential climate variables, climate processes and Earth system budgets. The Grand Challenges implemented by the World Climate Research Programme (WCRP) provide an opportunity to investigate issues of high societal relevance, directly related to sea level rise, droughts, floods, extreme heat events, food security, and fresh water availability. These challenges would directly benefit from a well-designed suite of systematic climate observations. Quantification of the evolution of the global energy, water and carbon budgets as well as the development and the production of near-term and regional climate predictions require that a comprehensive, focused, multi-platform observing system (satellites, ground-based and in situ observations) be established in an international context. This system must be accompanied by the development of climate services that should translate and disseminate scientific outcomes as actionable information for users and stakeholders.
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Climatic trends in Estonia during the period of instrumental observations and climate scenarios
International Nuclear Information System (INIS)
Jaagus, J.
1996-01-01
Weather conditions in Estonia are quite variable. Long-term periodical fluctuations have been observed in meteorological values. At the same time, the climate change during the last 100-150 years is marked. As a general tendency, the climate has become more maritime. Air pressure is characterized by an increasing trend in spring and summer, and by a decreasing trend in autumn and winter. Mean air temperature has increased, particularly over the colder half of the year. Precipitation area totals have risen, most of all in autumn and winter. Snow cover duration has decreased significantly. General circulation model-based climate change scenarios expect a general increase in air temperature in Estonia with warming in winter more significant than that in summer. Moreover, they indicate an increase in precipitation, but the results of the individual models are quite variable. The transient scenario shows that the main increase in precipitation will not occur during next decades, but only at the end of the transient period, around 2070. It can be stated that observed tendencies of climate change in Estonia concur with expected changes caused by global warming. According to the long-term fluctuations of meteorological values in Estonia, changes different from general trends can take place during the next decade. An increase in mean air pressure, sunshine duration and snow cover duration, as well as a decrease in mean air temperature and precipitation is expected in the following years
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Shulgina, T.; Genina, E.; Gordov, E.; Nikitchuk, K.
2009-04-01
At present numerous data archives which include meteorological observations as well as climate processes modeling data are available for Earth Science specialists. Methods of mathematical statistics are widely used for their processing and analysis. In many cases they represent the only way of quantitative assessment of the meteorological and climatic information. Unified set of analysis methods allows us to compare climatic characteristics calculated on the basis of different datasets with the purpose of performing more detailed analysis of climate dynamics for both regional and global levels. The report presents the results of comparative analysis of atmosphere temperature behavior for the Northern Eurasia territory for the period from 1979 to 2004 based on the NCEP/NCAR Reanalysis, NCEP/DOE Reanalysis AMIP II, JMA/CRIEPI JRA-25 Reanalysis, ECMWF ERA-40 Reanalysis data and observation data obtained from meteorological stations of the former Soviet Union. Statistical processing of atmosphere temperature data included analysis of time series homogeneity of climate indices approved by WMO, such as "Number of frost days", "Number of summer days", "Number of icing days", "Number of tropical nights", etc. by means of parametric methods of mathematical statistics (Fisher and Student tests). That allowed conducting comprehensive research of spatio-temporal features of the atmosphere temperature. Analysis of the atmosphere temperature dynamics revealed inhomogeneity of the data obtained for large observation intervals. Particularly, analysis performed for the period 1979 - 2004 showed the significant increase of the number of frost and icing days approximately by 1 day for every 2 years and decrease roughly by 1 day for 2 years for the number of summer days. Also it should be mentioned that the growth period mean temperature have increased by 1.5 - 2° C for the time period being considered. The usage of different Reanalysis datasets in conjunction with in-situ observed
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The highs and lows of cloud radiative feedback: Comparing observational data and CMIP5 models
Jenney, A.; Randall, D. A.
2014-12-01
Clouds play a complex role in the climate system, and remain one of the more difficult aspects of the future climate to predict. Over subtropical eastern ocean basins, particularly next to California, Peru, and Southwest Africa, low marine stratocumulus clouds (MSC) help to reduce the amount of solar radiation that reaches the surface by reflecting incident sunlight. The climate feedback associated with these clouds is thought to be positive. This project looks at CMIP5 models and compares them to observational data from CERES and ERA-Interim to try and find observational evidence and model agreement for low, marine stratocumulus cloud feedback. Although current evidence suggests that the low cloud feedback is positive (IPCC, 2014), an analysis of the simulated relationship between July lower tropospheric stability (LTS) and shortwave cloud forcing in MSC regions suggests that this feedback is not due to changes in LTS. IPCC, 2013: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp.
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Directory of Open Access Journals (Sweden)
Ayansina Ayanlade
2017-03-01
Full Text Available This paper examines smallholder farmers’ perceptions of climate change, climate variability and their impacts, and adaptation strategies adopted over the past three decades. We use ethnographic analysis, combined with Cumulative Departure Index (CDI, Rainfall Anomaly Index (RAI analysis, and correlation analysis to compare farmers’ perceptions in Southwestern Nigeria with historical meteorological data, in order to assess the way farmers’ observations mirror the climatic trends. The results show that about 67% of farmers who participated had observed recent changes in climate. Perceptions of rural farmers on climate change and variability are consistent with the climatic trend analysis. RAI and CDI results illustrate that not less than 11 out of 30 years in each study site experienced lower-than-normal rainfall. Climatic trends show fluctuations in both early growing season (EGS and late growing season (LGS rainfall and the 5-year moving average suggests a reduction in rainfall over the 30 years. Climatic trends confirmed farmers’ perceptions that EGS and LGS precipitations are oscillating, that rainfall onset is becoming later, and EGS rainfall is reducing. Overall impacts of climate change on both crops and livestock appear to be highly negative, much more on maize (62.8%, yam (52.2%, poultry (67% and cattle (63.2%. Years of farming experiences and level of income of farmers appear to have a significant relationship with farmers’ choice of adaptation strategies, with r≥0.60@ p<0.05 and r≥0.520@ p<0.05 respectively. The study concluded that farmers’ perceptions of climate change mirror meteorological analysis, though their perceptions were based on local climate parameters. Smallholder farmers are particularly vulnerable to climate change since the majority of them do not have enough resources to cope.
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The role of natural climatic variation in perturbing the observed global mean temperature trend
Energy Technology Data Exchange (ETDEWEB)
Hunt, B.G. [CSIRO Marine and Atmospheric Research, Aspendale, VIC (Australia)
2011-02-15
Controversy continues to prevail concerning the reality of anthropogenically-induced climatic warming. One of the principal issues is the cause of the hiatus in the current global warming trend. There appears to be a widely held view that climatic change warming should exhibit an inexorable upwards trend, a view that implies there is no longer any input by climatic variability in the existing climatic system. The relative roles of climatic change and climatic variability are examined here using the same coupled global climatic model. For the former, the model is run using a specified CO{sub 2} growth scenario, while the latter consisted of a multi-millennial simulation where any climatic variability was attributable solely to internal processes within the climatic system. It is shown that internal climatic variability can produce global mean surface temperature anomalies of {+-}0.25 K and sustained positive and negative anomalies sufficient to account for the anomalous warming of the 1940s as well as the present hiatus in the observed global warming. The characteristics of the internally-induced negative temperature anomalies are such that if this internal natural variability is the cause of the observed hiatus, then a resumption of the observed global warming trend is to be expected within the next few years. (orig.)
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Internal Variability and Disequilibrium Confound Estimates of Climate Sensitivity From Observations
Marvel, Kate; Pincus, Robert; Schmidt, Gavin A.; Miller, Ron L.
2018-02-01
An emerging literature suggests that estimates of equilibrium climate sensitivity (ECS) derived from recent observations and energy balance models are biased low because models project more positive climate feedback in the far future. Here we use simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to show that across models, ECS inferred from the recent historical period (1979-2005) is indeed almost uniformly lower than that inferred from simulations subject to abrupt increases in CO2 radiative forcing. However, ECS inferred from simulations in which sea surface temperatures are prescribed according to observations is lower still. ECS inferred from simulations with prescribed sea surface temperatures is strongly linked to changes to tropical marine low clouds. However, feedbacks from these clouds are a weak constraint on long-term model ECS. One interpretation is that observations of recent climate changes constitute a poor direct proxy for long-term sensitivity.
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Observing climate change trends in ocean biogeochemistry: when and where.
Henson, Stephanie A; Beaulieu, Claudie; Lampitt, Richard
2016-04-01
Understanding the influence of anthropogenic forcing on the marine biosphere is a high priority. Climate change-driven trends need to be accurately assessed and detected in a timely manner. As part of the effort towards detection of long-term trends, a network of ocean observatories and time series stations provide high quality data for a number of key parameters, such as pH, oxygen concentration or primary production (PP). Here, we use an ensemble of global coupled climate models to assess the temporal and spatial scales over which observations of eight biogeochemically relevant variables must be made to robustly detect a long-term trend. We find that, as a global average, continuous time series are required for between 14 (pH) and 32 (PP) years to distinguish a climate change trend from natural variability. Regional differences are extensive, with low latitudes and the Arctic generally needing shorter time series (ocean surface. Our results present a quantitative framework for assessing the adequacy of current and future ocean observing networks for detection and monitoring of climate change-driven responses in the marine ecosystem. © 2016 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.
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Comparing Impact of Climate Science Data Visualized Graphically and in Artwork
Pelto, J. N.; Pelto, M. S.; Zemp, M.
2017-12-01
How significant is the form of scientific data presentation in determining impact on and extent of the audience? This question is investigated by comparing the response to scientific information presented as a traditional data graph versus presented in artwork. Most people will gloss over the graphs in a scientific paper, even though the figures tell an important story. The role as an artist is to engage people emotionally in that story using the uniquely articulate lens of art. The goal of communicating the climate science data in an art format was to reach a broader audience. We compare the social media and media analytics from publication of original glacier data sets in 2015 to that generated by the artwork of the same data also completed in 2015. Glacier annual mass balance, total snow accumulation minus total snow ablation, is recognized as the most sensitive and representative climate parameter observed and reported from glaciers. The World Glacier Monitoring Service (M.Zemp: WGMS) compiles and reports this data. As a key contributor (M. Pelto) to this record and reporter on this record for the annual BAMS State of the Climate (SOTC) report, it became apparent that the data set though a special focus and media highlight of the SOTC report could benefit from a new perspective. J. Pelto completed two pieces of art that feature glacier mass balance as a visually important story of climate change. Decrease in Glacier Mass Balance presents data of average mass balance for a group of North Cascade, WA glaciers 1984-2014. Climate Change Data illustrates global annual glacier mass balance, global sea level rise, and global temperatures. This image conveys how the data sets are linked, and presented together better communicates the fluctuations in Earth's dynamic systems. The numbers on the left y-axis depict quantities of glacial melt and sea level rise, and the suns across the horizon contain global temperature increase values, coinciding with the timeline on the x
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Observations. Surface and Atmospheric Climate Change. Chapter 3
Energy Technology Data Exchange (ETDEWEB)
Trenberth, K.E.; Jones, P.D.; Ambenje, P.; Bojariu, R.; Easterling, D.; Klein Tank, A.; Parker, D.; Rahimzadeh, F.; Renwick, J.A.; Rusticucci, M.; Soden, B.; Zhai, P.
2007-09-15
This chapter assesses the observed changes in surface and atmospheric climate, placing new observations and new analyses made during the past six years (since the Third Assessment Report TAR) in the context of the previous instrumental record. In previous IPCC reports, palaeo-observations from proxy data for the pre-instrumental past and observations from the ocean and ice domains were included within the same chapter. This helped the overall assessment of the consistency among the various variables and their synthesis into a coherent picture of change. A short synthesis and scrutiny of the consistency of all the observations is included here (see Section 3.9). In the TAR, surface temperature trends were examined from 1860 to 2000 globally, for 1901 to 2000 as maps and for three sub-periods (1910-1945, 1946-1975 and 1976-2000). The first and third sub-periods had rising temperatures, while the second sub-period had relatively stable global mean temperatures. The 1976 divide is the date of a widely acknowledged 'climate shift' and seems to mark a time when global mean temperatures began a discernible upward trend that has been at least partly attributed to increases in greenhouse gas concentrations in the atmosphere. The picture prior to 1976 has essentially not changed and is therefore not repeated in detail here. However, it is more convenient to document the sub-period after 1979, rather than 1976, owing to the availability of increased and improved satellite data since then (in particular Television InfraRed Observation Satellite (TIROS) Operational Vertical Sounder (TOVS) data) in association with the Global Weather Experiment (GWE) of 1979. The post-1979 period allows, for the first time, a global perspective on many fields of variables, such as precipitation, that was not previously available. The availability of high-quality data has led to a focus on the post-1978 period, although physically this new regime seems to have begun in 1976
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Observing Human-induced Linkages between Urbanization and Earth's Climate System
Shepherd, J. Marshall; Jin, Menglin
2004-01-01
Urbanization is one of the extreme cases of land use change. Most of world s population has moved to urban areas. Although currently only 1.2% of the land is considered urban, the spatial coverage and density of cities are expected to rapidly increase in the near future. It is estimated that by the year 2025, 60% of the world s population will live in cities. Human activity in urban environments also alters atmospheric composition; impacts components of the water cycle; and modifies the carbon cycle and ecosystems. However, our understanding of urbanization on the total Earth-climate system is incomplete. Better understanding of how the Earth s atmosphere-ocean-land-biosphere components interact as a coupled system and the influence of the urban environment on this climate system is critical. The goal of the 2003 AGU Union session Human-induced climate variations on urban areas: From observations to modeling was to bring together scientists from interdisciplinary backgrounds to discuss the data, scientific approaches and recent results on observing and modeling components of the urban environment with the intent of sampling our current stand and discussing future direction on this topic. Herein, a summary and discussion of the observations component of the session are presented.
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Indigenous observations of climate change in the Lower Yukon River Basin, Alaska
Herman-Mercer, Nicole M.; Schuster, Paul F.; Maracle, Karonhiakt'tie
2011-01-01
Natural science climate change studies have led to an overwhelming amount of evidence that the Arctic and Subarctic are among the world's first locations to begin experiencing climate change. Indigenous knowledge of northern regions is a valuable resource to assess the effects of climate change on the people and the landscape. Most studies, however, have focused on coastal Arctic and Subarctic communities with relatively little focus on inland communities. This paper relates the findings from fieldwork conducted in the Lower Yukon River Basin of Alaska in the spring of 2009. Semi-structured interviews were conducted with hunters and elders in the villages of St. Mary's and Pitka's Point, Alaska to document observations of climate change. This study assumes that scientific findings and indigenous knowledge are complementary and seeks to overcome the false dichotomy that these two ways of knowing are in opposition. The observed changes in the climate communicated by the hunters and elders of St. Mary's and Pitka's Point, Alaska are impacting the community in ways ranging from subsistence (shifting flora and fauna patterns), concerns about safety (unpredictable weather patterns and dangerous ice conditions), and a changing resource base (increased reliance on fossil fuels). Here we attempt to address the challenges of integrating these two ways of knowing while relating indigenous observations as described by elders and hunters of the study area to those described by scientific literature.
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Energy Technology Data Exchange (ETDEWEB)
Mather, James [Pacific Northwest National Laboratory; McCord, Raymond [Oak Ridge National Laboratory; Sisterson, Doug [Argonne National Laboratory; Voyles, Jimmy [Pacific Northwest National Laboratory
2012-11-08
The workshop aimed to identify outstanding climate change science questions and the observational strategies for addressing them. The scientific focus was clouds, aerosols, and precipitation, and the required ground- and aerial-based observations. The workshop findings will be useful input for setting priorities within the Department of Energy (DOE) and the participating European centers. This joint workshop was envisioned as the first step in enhancing the collaboration among these climate research activities needed to better serve the science community.
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Afshin Pourmokhtarian; Charles T. Driscoll; John L. Campbell; Katharine Hayhoe; Anne M. K. Stoner
2016-01-01
Assessments of future climate change impacts on ecosystems typically rely on multiple climate model projections, but often utilize only one downscaling approach trained on one set of observations. Here, we explore the extent to which modeled biogeochemical responses to changing climate are affected by the selection of the climate downscaling method and training...
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Trettin, C.; Dai, Z.; Amatya, D. M.
2014-12-01
Long-term climatic and hydrologic observations on the Santee Experimental Forest in the lower coastal plain of South Carolina were used to estimate long-term changes in hydrology and forest carbon dynamics for a pair of first-order watersheds. Over 70 years of climate data indicated that warming in this forest area in the last decades was faster than the global mean; 35+ years of hydrologic records showed that forest ecosystem succession three years following Hurricane Hugo caused a substantial change in the ratio of runoff to precipitation. The change in this relationship between the paired watersheds was attributed to altered evapotranspiration processes caused by greater abundance of pine in the treatment watershed and regeneration of the mixed hardwood-pine forest on the reference watershed. The long-term records and anomalous observations are highly valuable for reliable calibration and validation of hydrological and biogeochemical models capturing the effects of climate variability. We applied the hydrological model MIKESHE that showed that runoff and water table level are sensitive to global warming, and that the sustained warming trends can be expected to decrease stream discharge and lower the mean water table depth. The spatially-explicit biogeochemical model Forest-DNDC, validated using biomass measurements from the watersheds, was used to assess carbon dynamics in response to high resolution hydrologic observation data and simulation results. The simulations showed that the long-term spatiotemporal carbon dynamics, including biomass and fluxes of soil carbon dioxide and methane were highly regulated by disturbance regimes, climatic conditions and water table depth. The utility of linked-modeling framework demonstrated here to assess biogeochemical responses at the watershed scale suggests applications for assessing the consequences of climate change within an urbanizing forested landscape. The approach may also be applicable for validating large
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Pre-LBA Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) Data
National Aeronautics and Space Administration — The data set presents the principal data from the Anglo-BRazilian Amazonian Climate Observation Study (ABRACOS) (Gash et al. 1996) and provides quality controlled...
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Pre-LBA Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) Data
National Aeronautics and Space Administration — ABSTRACT: The data set presents the principal data from the Anglo-BRazilian Amazonian Climate Observation Study (ABRACOS) (Gash et al. 1996) and provides quality...
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Arctic Climate Variability and Trends from Satellite Observations
Directory of Open Access Journals (Sweden)
Xuanji Wang
2012-01-01
Full Text Available Arctic climate has been changing rapidly since the 1980s. This work shows distinctly different patterns of change in winter, spring, and summer for cloud fraction and surface temperature. Satellite observations over 1982–2004 have shown that the Arctic has warmed up and become cloudier in spring and summer, but cooled down and become less cloudy in winter. The annual mean surface temperature has increased at a rate of 0.34°C per decade. The decadal rates of cloud fraction trends are −3.4%, 2.3%, and 0.5% in winter, spring, and summer, respectively. Correspondingly, annually averaged surface albedo has decreased at a decadal rate of −3.2%. On the annual average, the trend of cloud forcing at the surface is −2.11 W/m2 per decade, indicating a damping effect on the surface warming by clouds. The decreasing sea ice albedo and surface warming tend to modulate cloud radiative cooling effect in spring and summer. Arctic sea ice has also declined substantially with decadal rates of −8%, −5%, and −15% in sea ice extent, thickness, and volume, respectively. Significant correlations between surface temperature anomalies and climate indices, especially the Arctic Oscillation (AO index, exist over some areas, implying linkages between global climate change and Arctic climate change.
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Comparing soil moisture memory in satellite observations and models
Stacke, Tobias; Hagemann, Stefan; Loew, Alexander
2013-04-01
A major obstacle to a correct parametrization of soil processes in large scale global land surface models is the lack of long term soil moisture observations for large parts of the globe. Currently, a compilation of soil moisture data derived from a range of satellites is released by the ESA Climate Change Initiative (ECV_SM). Comprising the period from 1978 until 2010, it provides the opportunity to compute climatological relevant statistics on a quasi-global scale and to compare these to the output of climate models. Our study is focused on the investigation of soil moisture memory in satellite observations and models. As a proxy for memory we compute the autocorrelation length (ACL) of the available satellite data and the uppermost soil layer of the models. Additional to the ECV_SM data, AMSR-E soil moisture is used as observational estimate. Simulated soil moisture fields are taken from ERA-Interim reanalysis and generated with the land surface model JSBACH, which was driven with quasi-observational meteorological forcing data. The satellite data show ACLs between one week and one month for the greater part of the land surface while the models simulate a longer memory of up to two months. Some pattern are similar in models and observations, e.g. a longer memory in the Sahel Zone and the Arabian Peninsula, but the models are not able to reproduce regions with a very short ACL of just a few days. If the long term seasonality is subtracted from the data the memory is strongly shortened, indicating the importance of seasonal variations for the memory in most regions. Furthermore, we analyze the change of soil moisture memory in the different soil layers of the models to investigate to which extent the surface soil moisture includes information about the whole soil column. A first analysis reveals that the ACL is increasing for deeper layers. However, its increase is stronger in the soil moisture anomaly than in its absolute values and the first even exceeds the
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Organizational climate: Comparing private and public hospitals within professional roles
Directory of Open Access Journals (Sweden)
Diana Rojas
2014-11-01
Full Text Available This study compares the organizational climate differences within professional roles in private and public hospitals. We focused on how physicians, administrative, healthcare and non-healthcare staff either in the public or in the private perceived their work environment and each organizational climate dimension. Data came from organizational-climate questionnaires administered in 2010 and 2012 to 19616 and 1276 health employees in public and private hospitals in the Tuscany Region respectively. We applied exploratory factoranalysis to verify the validity and internal consistency between items in the questionnaire and t-test, one-way analysis of variance to compare mean perceptions regarding to the dimensions across different groups of respondents. We measured four dimensions: “training opportunities”, “managerial tools”, “organization” and “management & leadership style” and overall job satisfaction. Hospital status in the professional roles was found significant in the staff's perceptions (p≤0.05.
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Comparative analysis of radiosensitivity of fish eggs from northern and temperate climate
International Nuclear Information System (INIS)
Kryshev, A.; Sazykina, T.
2004-01-01
In the radiobiological studies of aquatic organisms, fish eggs are the favorite subject for experimental work because of easy availability of embryos and the possibility of observing the development of embryos within eggs. Data from Russian/FSU publications concerning the effects of ionizing radiation on fish eggs were compiled in the EPIC database within the framework of the EC Project EPIC. The comparative analysis of radiosensitivity was performed for eggs of two representative fish species from different climatic zones: cold water salmon (Salmo salar), and pike (Esox lucius), a widespread predatory fish in the temperate climate. A special attention was given to data of chronic exposure experiments with incubation of roe in water containing radionuclides. Dose rates on the fish eggs were estimated using appropriate dosimetric methodologies. Dose-effects relationships were constructed for chronic exposures during the periods of fish eggs development. The comparative analysis revealed that effects of ionizing radiation on salmon eggs appeared at lower doses than the effects on pike eggs. For example, first effects on survival of salmon eggs appeared at dose rate (1-2)*10-4 Gy/day, whereas effects on survival of pike eggs were not found at dose rates lower than (5-10)*10-3 Gy/day (chronic exposure); practically total death of roe took place at the chronic dose rates 0.13-0.33 Gy/day for salmon and 0.94 Gy/day for pike. Data on dose-effects relationships for salmon and pike roe defined the range of radiosensitivities between fish species from zones of severe and moderate climate. (author)
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Comparing safety climate in naval aviation and hospitals: implications for improving patient safety.
Singer, Sara J; Rosen, Amy; Zhao, Shibei; Ciavarelli, Anthony P; Gaba, David M
2010-01-01
Evidence of variation in safety climate suggests the need for improvement among at least some hospitals. However, comparisons only among hospitals may underestimate the improvement required. Comparison of hospitals with analogous industries may provide a broader perspective on the safety status of our nation's hospitals. The purpose of this study was to compare safety climate among hospital workers with personnel from naval aviation, an organization that operates with high reliability despite intrinsically hazardous conditions. We surveyed a random sample of health care workers in 67 U.S. hospitals and, for generalizability, 30 veterans affairs hospitals using questions comparable with those posed at approximately the same time (2007) to a census of personnel from 35 squadrons of U.S. naval aviators. We received 13,841 (41%) completed surveys in U.S. hospitals, 5,511 (50%) in veterans affairs hospitals, and 14,854 (82%) among naval aviators. We examined differences in respondents' perceptions of safety climate at their institution overall and for 16 individual items. Safety climate was three times better on average among naval aviators than among hospital personnel. Naval aviators perceived a safer climate (up to seven times safer) than hospital personnel with respect to each of the 16 survey items. Compared with hospital managers, naval commanders perceived climate more like frontline personnel did. When contrasting naval aviators with hospital personnel working in comparably hazardous areas, safety climate discrepancies increased rather than decreased. One individual hospital performed as well as naval aviation on average, and at least one hospital outperformed the Navy benchmark for all but three individual survey items. Results suggest that hospitals have not sufficiently created a uniform priority of safety. However, if each hospital performed as well as the top-performing hospital in each area measured, hospitals could achieve safety climate levels comparable
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Characterization of the Sahelian-Sudan rainfall based on observations and regional climate models
Salih, Abubakr A. M.; Elagib, Nadir Ahmed; Tjernström, Michael; Zhang, Qiong
2018-04-01
The African Sahel region is known to be highly vulnerable to climate variability and change. We analyze rainfall in the Sahelian Sudan in terms of distribution of rain-days and amounts, and examine whether regional climate models can capture these rainfall features. Three regional models namely, Regional Model (REMO), Rossby Center Atmospheric Model (RCA) and Regional Climate Model (RegCM4), are evaluated against gridded observations (Climate Research Unit, Tropical Rainfall Measuring Mission, and ERA-interim reanalysis) and rain-gauge data from six arid and semi-arid weather stations across Sahelian Sudan over the period 1989 to 2008. Most of the observed rain-days are characterized by weak (0.1-1.0 mm/day) to moderate (> 1.0-10.0 mm/day) rainfall, with average frequencies of 18.5% and 48.0% of the total annual rain-days, respectively. Although very strong rainfall events (> 30.0 mm/day) occur rarely, they account for a large fraction of the total annual rainfall (28-42% across the stations). The performance of the models varies both spatially and temporally. RegCM4 most closely reproduces the observed annual rainfall cycle, especially for the more arid locations, but all of the three models fail to capture the strong rainfall events and hence underestimate its contribution to the total annual number of rain-days and rainfall amount. However, excessive moderate rainfall compensates this underestimation in the models in an annual average sense. The present study uncovers some of the models' limitations in skillfully reproducing the observed climate over dry regions, will aid model users in recognizing the uncertainties in the model output and will help climate and hydrological modeling communities in improving models.
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Tropical convection regimes in climate models: evaluation with satellite observations
Directory of Open Access Journals (Sweden)
A. K. Steiner
2018-04-01
Full Text Available High-quality observations are powerful tools for the evaluation of climate models towards improvement and reduction of uncertainty. Particularly at low latitudes, the most uncertain aspect lies in the representation of moist convection and interaction with dynamics, where rising motion is tied to deep convection and sinking motion to dry regimes. Since humidity is closely coupled with temperature feedbacks in the tropical troposphere, a proper representation of this region is essential. Here we demonstrate the evaluation of atmospheric climate models with satellite-based observations from Global Positioning System (GPS radio occultation (RO, which feature high vertical resolution and accuracy in the troposphere to lower stratosphere. We focus on the representation of the vertical atmospheric structure in tropical convection regimes, defined by high updraft velocity over warm surfaces, and investigate atmospheric temperature and humidity profiles. Results reveal that some models do not fully capture convection regions, particularly over land, and only partly represent strong vertical wind classes. Models show large biases in tropical mean temperature of more than 4 K in the tropopause region and the lower stratosphere. Reasonable agreement with observations is given in mean specific humidity in the lower to mid-troposphere. In moist convection regions, models tend to underestimate moisture by 10 to 40 % over oceans, whereas in dry downdraft regions they overestimate moisture by 100 %. Our findings provide evidence that RO observations are a unique source of information, with a range of further atmospheric variables to be exploited, for the evaluation and advancement of next-generation climate models.
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Tropical convection regimes in climate models: evaluation with satellite observations
Steiner, Andrea K.; Lackner, Bettina C.; Ringer, Mark A.
2018-04-01
High-quality observations are powerful tools for the evaluation of climate models towards improvement and reduction of uncertainty. Particularly at low latitudes, the most uncertain aspect lies in the representation of moist convection and interaction with dynamics, where rising motion is tied to deep convection and sinking motion to dry regimes. Since humidity is closely coupled with temperature feedbacks in the tropical troposphere, a proper representation of this region is essential. Here we demonstrate the evaluation of atmospheric climate models with satellite-based observations from Global Positioning System (GPS) radio occultation (RO), which feature high vertical resolution and accuracy in the troposphere to lower stratosphere. We focus on the representation of the vertical atmospheric structure in tropical convection regimes, defined by high updraft velocity over warm surfaces, and investigate atmospheric temperature and humidity profiles. Results reveal that some models do not fully capture convection regions, particularly over land, and only partly represent strong vertical wind classes. Models show large biases in tropical mean temperature of more than 4 K in the tropopause region and the lower stratosphere. Reasonable agreement with observations is given in mean specific humidity in the lower to mid-troposphere. In moist convection regions, models tend to underestimate moisture by 10 to 40 % over oceans, whereas in dry downdraft regions they overestimate moisture by 100 %. Our findings provide evidence that RO observations are a unique source of information, with a range of further atmospheric variables to be exploited, for the evaluation and advancement of next-generation climate models.
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Comparing regional precipitation and temperature extremes in climate model and reanalysis products
Directory of Open Access Journals (Sweden)
Oliver Angélil
2016-09-01
Full Text Available A growing field of research aims to characterise the contribution of anthropogenic emissions to the likelihood of extreme weather and climate events. These analyses can be sensitive to the shapes of the tails of simulated distributions. If tails are found to be unrealistically short or long, the anthropogenic signal emerges more or less clearly, respectively, from the noise of possible weather. Here we compare the chance of daily land-surface precipitation and near-surface temperature extremes generated by three Atmospheric Global Climate Models typically used for event attribution, with distributions from six reanalysis products. The likelihoods of extremes are compared for area-averages over grid cell and regional sized spatial domains. Results suggest a bias favouring overly strong attribution estimates for hot and cold events over many regions of Africa and Australia, and a bias favouring overly weak attribution estimates over regions of North America and Asia. For rainfall, results are more sensitive to geographic location. Although the three models show similar results over many regions, they do disagree over others. Equally, results highlight the discrepancy amongst reanalyses products. This emphasises the importance of using multiple reanalysis and/or observation products, as well as multiple models in event attribution studies.
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Wang, X.; Dessler, A. E.
2017-12-01
The seasonal cycle is one of the key features of the tropical lower stratospheric water vapor, so it is important that the climate models reproduce it. In this analysis, we evaluate how well the Goddard Earth Observing System Chemistry Climate Model (GEOSCCM) and the Whole Atmosphere Community Climate Model (WACCM) reproduce the seasonal cycle of tropical lower stratospheric water vapor. We do this by comparing the models to observations from the Microwave Limb Sounder (MLS) and the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim (ERAi). We also evaluate if the chemistry-climate models (CCMs) reproduce the key transport and dehydration processes that regulate the seasonal cycle using a forward, domain filling, diabatic trajectory model. Finally, we explore the changes of the seasonal cycle during the 21st century in the two CCMs. Our results show general agreement in the seasonal cycles from the MLS, the ERAi, and the CCMs. Despite this agreement, there are some clear disagreements between the models and the observations on the details of transport and dehydration in the TTL. Finally, both the CCMs predict a moister seasonal cycle by the end of the 21st century. But they disagree on the changes of the seasonal amplitude, which is predicted to increase in the GEOSCCM and decrease in the WACCM.
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Directory of Open Access Journals (Sweden)
M. F. Loutre
2011-05-01
Full Text Available Many sources of uncertainty limit the accuracy of climate projections. Among them, we focus here on the parameter uncertainty, i.e. the imperfect knowledge of the values of many physical parameters in a climate model. Therefore, we use LOVECLIM, a global three-dimensional Earth system model of intermediate complexity and vary several parameters within a range based on the expert judgement of model developers. Nine climatic parameter sets and three carbon cycle parameter sets are selected because they yield present-day climate simulations coherent with observations and they cover a wide range of climate responses to doubled atmospheric CO2 concentration and freshwater flux perturbation in the North Atlantic. Moreover, they also lead to a large range of atmospheric CO2 concentrations in response to prescribed emissions. Consequently, we have at our disposal 27 alternative versions of LOVECLIM (each corresponding to one parameter set that provide very different responses to some climate forcings. The 27 model versions are then used to illustrate the range of responses provided over the recent past, to compare the time evolution of climate variables over the time interval for which they are available (the last few decades up to more than one century and to identify the outliers and the "best" versions over that particular time span. For example, between 1979 and 2005, the simulated global annual mean surface temperature increase ranges from 0.24 °C to 0.64 °C, while the simulated increase in atmospheric CO2 concentration varies between 40 and 50 ppmv. Measurements over the same period indicate an increase in global annual mean surface temperature of 0.45 °C (Brohan et al., 2006 and an increase in atmospheric CO2 concentration of 44 ppmv (Enting et al., 1994; GLOBALVIEW-CO2, 2006. Only a few parameter sets yield simulations that reproduce the observed key variables of the climate system over the last
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Historical Phenological Observations: Past Climate Impact Analyses and Climate Reconstructions
Rutishauser, T.; Luterbacher, J.; Meier, N.; Jeanneret, F.; Pfister, C.; Wanner, H.
2007-12-01
Plant phenological observations have been found an important indicator of climate change impacts on seasonal and interannual vegetation development for the late 20th/early 21st century. Our contribution contains three parts that are essential for the understanding (part 1), the analysis (part 2) and the application (part 3) of historical phenological observations in global change research. First, we propose a definition for historical phenonolgy (Rutishauser, 2007). We shortly portray the first appearance of phenological observations in Medieval philosophical and literature sources, the usage and application of this method in the Age of Enlightenment (Carl von Linné, Charles Morren), as well as the development in the 20th century (Schnelle, Lieth) to present-day networks (COST725, USA-NPN) Second, we introduce a methodological approach to estimate 'Statistical plants' from historical phenological observations (Rutishauser et al., JGR-Biogeoscience, in press). We combine spatial averaging methods and regression transfer modeling to estimate 'statistical plant' dates from historical observations that often contain gaps, changing observers and changing locations. We apply the concept to reconstruct a statistical 'Spring plant' as the weighted mean of the flowering date of cherry and apple tree and beech budburst of Switzerland 1702- 2005. Including dating total data uncertainty we estimate 10 at interannual and 3.4 days at decadal time scales. Third, we apply two long-term phenological records to describe plant phenological response to spring temperature and reconstruct warm-season temperatures from grape harvest dates (Rutishauser et al, submitted; Meier et al, GRL, in press).
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International Nuclear Information System (INIS)
Sun, Qiaohong; Miao, Chiyuan; Duan, Qingyun; Kong, Dongxian; Ye, Aizhong; Di, Zhenhua; Gong, Wei
2014-01-01
This research compared and evaluated the spatio-temporal similarities and differences of eight widely used gridded datasets. The datasets include daily precipitation over East Asia (EA), the Climate Research Unit (CRU) product, the Global Precipitation Climatology Centre (GPCC) product, the University of Delaware (UDEL) product, Precipitation Reconstruction over Land (PREC/L), the Asian Precipitation Highly Resolved Observational (APHRO) product, the Institute of Atmospheric Physics (IAP) dataset from the Chinese Academy of Sciences, and the National Meteorological Information Center dataset from the China Meteorological Administration (CN05). The meteorological variables focus on surface air temperature (SAT) or precipitation (PR) in China. All datasets presented general agreement on the whole spatio-temporal scale, but some differences appeared for specific periods and regions. On a temporal scale, EA shows the highest amount of PR, while APHRO shows the lowest. CRU and UDEL show higher SAT than IAP or CN05. On a spatial scale, the most significant differences occur in western China for PR and SAT. For PR, the difference between EA and CRU is the largest. When compared with CN05, CRU shows higher SAT in the central and southern Northwest river drainage basin, UDEL exhibits higher SAT over the Southwest river drainage system, and IAP has lower SAT in the Tibetan Plateau. The differences in annual mean PR and SAT primarily come from summer and winter, respectively. Finally, potential factors impacting agreement among gridded climate datasets are discussed, including raw data sources, quality control (QC) schemes, orographic correction, and interpolation techniques. The implications and challenges of these results for climate research are also briefly addressed. (paper)
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Climate change and Australia’s comparative advantage in broadacre agriculture
Sanderson, Todd; Ahmadi-Esfahani, Fredoun Z.
2010-01-01
Australia has long been a major exporter of the products of broadacre agriculture, a production system well suited to the economic and climatic conditions of the country. According to the conventional wisdom, Australia holds a comparative advantage in these products, among which wheat and livestock products predominate. However, the future validity of this proposition is sensitive to the projected impacts of climate change. This paper develops a framework with which to quantify the future pat...
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Yuan, Tianle; Oreopoulos, Lazaros; Platnick, Steven E.; Meyer, Kerry
2018-05-01
Modeling studies have shown that cloud feedbacks are sensitive to the spatial pattern of sea surface temperature (SST) anomalies, while cloud feedbacks themselves strongly influence the magnitude of SST anomalies. Observational counterparts to such patterned interactions are still needed. Here we show that distinct large-scale patterns of SST and low-cloud cover (LCC) emerge naturally from objective analyses of observations and demonstrate their close coupling in a positive local SST-LCC feedback loop that may be important for both internal variability and climate change. The two patterns that explain the maximum amount of covariance between SST and LCC correspond to the Interdecadal Pacific Oscillation and the Atlantic Multidecadal Oscillation, leading modes of multidecadal internal variability. Spatial patterns and time series of SST and LCC anomalies associated with both modes point to a strong positive local SST-LCC feedback. In many current climate models, our analyses suggest that SST-LCC feedback strength is too weak compared to observations. Modeled local SST-LCC feedback strength affects simulated internal variability so that stronger feedback produces more intense and more realistic patterns of internal variability. To the extent that the physics of the local positive SST-LCC feedback inferred from observed climate variability applies to future greenhouse warming, we anticipate significant amount of delayed warming because of SST-LCC feedback when anthropogenic SST warming eventually overwhelm the effects of internal variability that may mute anthropogenic warming over parts of the ocean. We postulate that many climate models may be underestimating both future warming and the magnitude of modeled internal variability because of their weak SST-LCC feedback.
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Gavazov, Konstantin; Spiegelberger, Thomas; Buttler, Alexandre
2014-04-01
Climate change could impact strongly on cold-adapted mountain ecosystems, but little is known about its interaction with traditional land-use practices. We used an altitudinal gradient to simulate a year-round warmer and drier climate for semi-natural subalpine grasslands across a landscape of contrasting land-use management. Turf mesocosms from three pasture-woodland land-use types-unwooded pasture, sparsely wooded pasture, and densely wooded pasture-spanning a gradient from high to low management intensity were transplanted downslope to test their resistance to two intensities of climate change. We found strong overall effects of intensive (+4 K) experimental climate change (i.e., warming and reduced precipitation) on plant community structure and function, while moderate (+2 K) climate change did not substantially affect the studied land-use types, thus indicating an ecosystem response threshold to moderate climate perturbation. The individual land-use types were affected differently under the +4 K scenario, with a 60% decrease in aboveground biomass (AGB) in unwooded pasture turfs, a 40% decrease in sparsely wooded pasture turfs, and none in densely wooded ones. Similarly, unwooded pasture turfs experienced a 30% loss of species, advanced (by 30 days) phenological development, and a mid-season senescence due to drought stress, while no such effects were recorded for the other land-use types. The observed contrasting effects of climate change across the pasture-woodland landscape have important implications for future decades. The reduced impact of climate change on wooded pastures as compared to unwooded ones should promote the sustainable land use of wooded pastures by maintaining low management intensity and a sparse forest canopy, which buffer the immediate impacts of climate change on herbaceous vegetation.
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Continuity of Climate Data Records derived from Microwave Observations
Mears, C. A.; Wentz, F. J.; Brewer, M.; Meissner, T.; Ricciardulli, L.
2017-12-01
Remote Sensing Systems (www.remss.com) has been producing and distributing microwave climate data products from microwave imagers (SSMI, TMI, AMSR, WindSat, GMI, Aquarius, SMAP) over the global oceans since the launch of the first SSMI in 1987. Interest in these data products has been significant as researchers around the world have downloaded the approximate equivalent of 1 million satellite years of processed data. Users, including NASA, NOAA, US National Laboratories, US Navy, UK Met, ECMWF, JAXA, JMA, CMC, the Australian Bureau of Meteorology, as well as many hundreds of other agencies and universities routinely access these microwave data products. The quality of these data records has increased as more observations have become available and inter-calibration techniques have improved. The impending end of missions for WindSat, AMSR-2, and the remaining SSMIs will have significant impact on the quality and continuity of long term microwave climate data records. In addition to the problem of reduced numbers of observations, there is a real danger of losing overlapping observations. Simultaneous operation of satellites, especially when the observations are at similar local crossing times, provides a significant benefit in the effort to inter-calibrate satellites to yield accurate and stable long-term records. The end of WindSat and AMSR-2 will leave us without microwave SSTs in cold water, as there will be no microwave imagers with C-band channels. Microwave SSTs have a crucial advantage over IR SSTs, which is not able to measure SST in clouds or if aerosols are present. The gap in ocean wind vectors will be somewhat mitigated as the European ASCAT C-band scatterometer mission on MetOp is continuing. Nonetheless, the anticipated cease of several microwave satellite radiometers retrieving ocean winds in the coming years will lead to a significant gap in temporal coverage. Atmospheric water vapor, cloud liquid water, and rain rate are all important climate
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Climate change mitigation: comparative assessment of Malaysian and ASEAN scenarios.
Rasiah, Rajah; Ahmed, Adeel; Al-Amin, Abul Quasem; Chenayah, Santha
2017-01-01
This paper analyses empirically the optimal climate change mitigation policy of Malaysia with the business as usual scenario of ASEAN to compare their environmental and economic consequences over the period 2010-2110. A downscaling empirical dynamic model is constructed using a dual multidisciplinary framework combining economic, earth science, and ecological variables to analyse the long-run consequences. The model takes account of climatic variables, including carbon cycle, carbon emission, climatic damage, carbon control, carbon concentration, and temperature. The results indicate that without optimal climate policy and action, the cumulative cost of climate damage for Malaysia and ASEAN as a whole over the period 2010-2110 would be MYR40.1 trillion and MYR151.0 trillion, respectively. Under the optimal policy, the cumulative cost of climatic damage for Malaysia would fall to MYR5.3 trillion over the 100 years. Also, the additional economic output of Malaysia will rise from MYR2.1 billion in 2010 to MYR3.6 billion in 2050 and MYR5.5 billion in 2110 under the optimal climate change mitigation scenario. The additional economic output for ASEAN would fall from MYR8.1 billion in 2010 to MYR3.2 billion in 2050 before rising again slightly to MYR4.7 billion in 2110 in the business as usual ASEAN scenario.
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Observational uncertainty and regional climate model evaluation: A pan-European perspective
Kotlarski, Sven; Szabó, Péter; Herrera, Sixto; Räty, Olle; Keuler, Klaus; Soares, Pedro M.; Cardoso, Rita M.; Bosshard, Thomas; Pagé, Christian; Boberg, Fredrik; Gutiérrez, José M.; Jaczewski, Adam; Kreienkamp, Frank; Liniger, Mark. A.; Lussana, Cristian; Szepszo, Gabriella
2017-04-01
Local and regional climate change assessments based on downscaling methods crucially depend on the existence of accurate and reliable observational reference data. In dynamical downscaling via regional climate models (RCMs) observational data can influence model development itself and, later on, model evaluation, parameter calibration and added value assessment. In empirical-statistical downscaling, observations serve as predictand data and directly influence model calibration with corresponding effects on downscaled climate change projections. Focusing on the evaluation of RCMs, we here analyze the influence of uncertainties in observational reference data on evaluation results in a well-defined performance assessment framework and on a European scale. For this purpose we employ three different gridded observational reference grids, namely (1) the well-established EOBS dataset (2) the recently developed EURO4M-MESAN regional re-analysis, and (3) several national high-resolution and quality-controlled gridded datasets that recently became available. In terms of climate models five reanalysis-driven experiments carried out by five different RCMs within the EURO-CORDEX framework are used. Two variables (temperature and precipitation) and a range of evaluation metrics that reflect different aspects of RCM performance are considered. We furthermore include an illustrative model ranking exercise and relate observational spread to RCM spread. The results obtained indicate a varying influence of observational uncertainty on model evaluation depending on the variable, the season, the region and the specific performance metric considered. Over most parts of the continent, the influence of the choice of the reference dataset for temperature is rather small for seasonal mean values and inter-annual variability. Here, model uncertainty (as measured by the spread between the five RCM simulations considered) is typically much larger than reference data uncertainty. For
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Observed climate variability over Chad using multiple observational and reanalysis datasets
Maharana, Pyarimohan; Abdel-Lathif, Ahmat Younous; Pattnayak, Kanhu Charan
2018-03-01
Chad is the largest of Africa's landlocked countries and one of the least studied region of the African continent. The major portion of Chad lies in the Sahel region, which is known for its rapid climate change. In this study, multiple observational datasets are analyzed from 1950 to 2014, in order to examine the trend of precipitation and temperature along with their variability over Chad to understand possible impacts of climate change over this region. Trend analysis of the climatic fields has been carried out using Mann-Kendall test. The precipitation over Chad is mostly contributed during summer by West African Monsoon, with maximum northward limit of 18° N. The Atlantic Ocean as well as the Mediterranean Sea are the major source of moisture for the summer rainfall over Chad. Based on the rainfall time series, the entire study period has been divided in to wet (1950 to 1965), dry (1966 to 1990) and recovery period (1991 to 2014). The rainfall has decreased drastically for almost 3 decades during the dry period resulted into various drought years. The temperature increases at a rate of 0.15 °C/decade during the entire period of analysis. The seasonal rainfall as well as temperature plays a major role in the change of land use/cover. The decrease of monsoon rainfall during the dry period reduces the C4 cover drastically; this reduction of C4 grass cover leads to increase of C3 grass cover. The slow revival of rainfall is still not good enough for the increase of shrub cover but it favors the gradual reduction of bare land over Chad.
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Gerald E. Rehfeldt; Barry C. Jaquish; Javier Lopez-Upton; Cuauhtemoc Saenz-Romero; J. Bradley St Clair; Laura P. Leites; Dennis G. Joyce
2014-01-01
The Random Forests classification algorithm was used to predict the occurrence of the realized climate niche for two sub-specific varieties of Pinus ponderosa and three varieties of Pseudotsuga menziesii from presence-absence data in forest inventory ground plots. Analyses were based on ca. 271,000 observations for P. ponderosa and ca. 426,000 observations for P....
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Directory of Open Access Journals (Sweden)
Y. Zhao
2017-11-01
Full Text Available Climate signals are the results of interactions of multiple timescale media such as the atmosphere and ocean in the coupled earth system. Coupled data assimilation (CDA pursues balanced and coherent climate analysis and prediction initialization by incorporating observations from multiple media into a coupled model. In practice, an observational time window (OTW is usually used to collect measured data for an assimilation cycle to increase observational samples that are sequentially assimilated with their original error scales. Given different timescales of characteristic variability in different media, what are the optimal OTWs for the coupled media so that climate signals can be most accurately recovered by CDA? With a simple coupled model that simulates typical scale interactions in the climate system and twin CDA experiments, we address this issue here. Results show that in each coupled medium, an optimal OTW can provide maximal observational information that best fits the characteristic variability of the medium during the data blending process. Maintaining correct scale interactions, the resulting CDA improves the analysis of climate signals greatly. These simple model results provide a guideline for when the real observations are assimilated into a coupled general circulation model for improving climate analysis and prediction initialization by accurately recovering important characteristic variability such as sub-diurnal in the atmosphere and diurnal in the ocean.
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Hughes, Sheryl O; Power, Thomas G; Papaioannou, Maria A; Cross, Matthew B; Nicklas, Theresa A; Hall, Sharon K; Shewchuk, Richard M
2011-06-10
A number of studies conducted with ethnically diverse, low-income samples have found that parents with indulgent feeding styles had children with a higher weight status. Indulgent parents are those who are responsive to their child's emotional states but have problems setting appropriate boundaries with their child. Because the processes through which styles impact child weight are poorly understood, the aim of this study was to observe differences in the emotional climate created by parents (including affect, tone of voice, and gestures) and behavioral feeding practices among those reporting different feeding styles on the Caregiver's Feeding Styles Questionnaire. A secondary aim was to examine differences on child weight status across the feeding styles. Participants were 177 Head Start families from Houston, Texas (45% African-American; 55% Hispanic). Using an observational approach, the relationship between the observed emotional climate of the meal, behavioral feeding practices, and self-reported parent feeding styles were examined. Mean age of the children was 4.4 years (SD = 0.7) equally distributed across gender. Families were observed on 3 separate dinner occasions. Heights and weight were measured on the parents and children. Parents with self-reported indulgent feeding styles made fewer demands on their children to eat during dinner and showed lower levels of negative affect and intrusiveness. Surprisingly, these parents also showed higher levels of emotional detachment with their children during dinner. Hispanic boys with indulgent parents had significantly higher BMI z scores compared to Hispanic boys in the other three feeding style groups. No other differences were found on child weight status. Results suggest that the emotional climate created by indulgent parents during dinner and their lack of demands on their children to eat may play an important role in how young children become overweight. Numerous observed emotional climate and behavioral
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Palacios-Peña, Laura; Baró, Rocío; Baklanov, Alexander; Balzarini, Alessandra; Brunner, Dominik; Forkel, Renate; Hirtl, Marcus; Honzak, Luka; María López-Romero, José; Montávez, Juan Pedro; Pérez, Juan Luis; Pirovano, Guido; San José, Roberto; Schröder, Wolfram; Werhahn, Johannes; Wolke, Ralf; Žabkar, Rahela; Jiménez-Guerrero, Pedro
2018-04-01
Atmospheric aerosols modify the radiative budget of the Earth due to their optical, microphysical and chemical properties, and are considered one of the most uncertain climate forcing agents. In order to characterise the uncertainties associated with satellite and modelling approaches to represent aerosol optical properties, mainly aerosol optical depth (AOD) and Ångström exponent (AE), their representation by different remote-sensing sensors and regional online coupled chemistry-climate models over Europe are evaluated. This work also characterises whether the inclusion of aerosol-radiation (ARI) or/and aerosol-cloud interactions (ACI) help improve the skills of modelling outputs.Two case studies were selected within the EuMetChem COST Action ES1004 framework when important aerosol episodes in 2010 all over Europe took place: a Russian wildfire episode and a Saharan desert dust outbreak that covered most of the Mediterranean Sea. The model data came from different regional air-quality-climate simulations performed by working group 2 of EuMetChem, which differed according to whether ARI or ACI was included or not. The remote-sensing data came from three different sensors: MODIS, OMI and SeaWIFS. The evaluation used classical statistical metrics to first compare satellite data versus the ground-based instrument network (AERONET) and then to evaluate model versus the observational data (both satellite and ground-based data).Regarding the uncertainty in the satellite representation of AOD, MODIS presented the best agreement with the AERONET observations compared to other satellite AOD observations. The differences found between remote-sensing sensors highlighted the uncertainty in the observations, which have to be taken into account when evaluating models. When modelling results were considered, a common trend for underestimating high AOD levels was observed. For the AE, models tended to underestimate its variability, except when considering a sectional approach in
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Pitts, K.; Little, M.; Loewenstein, M.; Iraci, L. T.; Milesi, C.; Schmidt, C.; Skiles, J. W.
2011-12-01
The projected impacts of climate change on Northern California ecosystems using model outputs from the Terrestrial Observation and Prediction System (TOPS) for the period 1950-2099 based on 1km downscaled climate data from the Geophysical Fluid Dynamics Laboratory (GFDL) model are analyzed in this study. The impacts are analyzed for the Special Report Emissions Scenarios (SRES) A1B and A2, both maintaining present levels of urbanization constant and under projected urban expansion. The analysis is in support of the Climate Adaptation Science Investigation at NASA Ames Research Center. A statistical analysis is completed for time series of temperature, precipitation, gross primary productivity (GPP), evapotranspiration, soil runoff, and vapor pressure deficit. Trends produced from this analysis show that increases in maximum and minimum temperatures lead to declines in peak GPP, length of growing seasons, and overall declines in runoff within the watershed. For Northern California, GPP is projected under the A2 scenario to decrease by 18-25% by the 2090 decade as compared to the 2000 decade. These trends indicate a higher risk to crop production and other ecosystem services, as conditions would be less hospitable to vegetation growth. The increase in dried out vegetation would then lead to a higher risk of wildfire and mudslides in the mountainous regions.
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Köppen climate types in observed and simulated climates
Czech Academy of Sciences Publication Activity Database
Kalvová, J.; Halenka, T.; Bezpalcová, K.; Nemešová, Ivana
2003-01-01
Roč. 47, - (2003), s. 185-202 ISSN 0039-3169 R&D Projects: GA ČR GA205/99/1561; GA AV ČR IAA3042903; GA MŽP SJ/740/1/00 Institutional research plan: CEZ:AV0Z3042911 Keywords : Köppen climate classification * general circulation models * ECHAM4 * HadCM2 * climate projections Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 0.426, year: 2003
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Uncertainty information in climate data records from Earth observation
Merchant, Christopher J.; Paul, Frank; Popp, Thomas; Ablain, Michael; Bontemps, Sophie; Defourny, Pierre; Hollmann, Rainer; Lavergne, Thomas; Laeng, Alexandra; de Leeuw, Gerrit; Mittaz, Jonathan; Poulsen, Caroline; Povey, Adam C.; Reuter, Max; Sathyendranath, Shubha; Sandven, Stein; Sofieva, Viktoria F.; Wagner, Wolfgang
2017-07-01
The question of how to derive and present uncertainty information in climate data records (CDRs) has received sustained attention within the European Space Agency Climate Change Initiative (CCI), a programme to generate CDRs addressing a range of essential climate variables (ECVs) from satellite data. Here, we review the nature, mathematics, practicalities, and communication of uncertainty information in CDRs from Earth observations. This review paper argues that CDRs derived from satellite-based Earth observation (EO) should include rigorous uncertainty information to support the application of the data in contexts such as policy, climate modelling, and numerical weather prediction reanalysis. Uncertainty, error, and quality are distinct concepts, and the case is made that CDR products should follow international metrological norms for presenting quantified uncertainty. As a baseline for good practice, total standard uncertainty should be quantified per datum in a CDR, meaning that uncertainty estimates should clearly discriminate more and less certain data. In this case, flags for data quality should not duplicate uncertainty information, but instead describe complementary information (such as the confidence in the uncertainty estimate provided or indicators of conditions violating the retrieval assumptions). The paper discusses the many sources of error in CDRs, noting that different errors may be correlated across a wide range of timescales and space scales. Error effects that contribute negligibly to the total uncertainty in a single-satellite measurement can be the dominant sources of uncertainty in a CDR on the large space scales and long timescales that are highly relevant for some climate applications. For this reason, identifying and characterizing the relevant sources of uncertainty for CDRs is particularly challenging. The characterization of uncertainty caused by a given error effect involves assessing the magnitude of the effect, the shape of the
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Climate sciences, observation and modelling: an historical perspective
International Nuclear Information System (INIS)
Morel, P.; Le Treut, H.; Charles, L.
2013-01-01
At a time when the public perception of climate change is recovering from the controversies and vocal dissent aired during the recent years, we thought it would be interesting to begin this special issue with an interview of Pierre Morel. As the originator of physical climate studies in France, he established and led (until 1975) the Dynamic Meteorology Laboratory of CNRS, a component of the Pierre-Simon Laplace Institute (IPSL), which has become the focus of climate research in France. However his professional activities were pursued largely in an international context. Alumnus of Ecole Normale Superieure in Paris, physicist, first director of scientific research and advanced technology programs in the French space agency CNES from 1962 to 1964 and then Professor at the University of Paris, he specialized in the field of geophysical fluid dynamics. In 1967, he became a member of the international Joint Organizing Committee for the Global Atmospheric Research Programme (GARP) and eventually vice-chairman of the Committee until 1982. He conceived and promoted a number of satellite projects, in particular the operational ARGOS navigation and data collection System on NOAA polar-orbiting meteorological satellites and the European geostationary meteorological satellite Meteosat. In 1982, he became the first director of the international World Climate Research Programme that followed upon GARP and continued in this function until 1994. He then joined NASA Headquarters in the capacity as Senior Visiting Scientist in the Office of Mission to Planet Earth. This unorthodox professional career gave Pierre Morel an exceptionally broad, possibly unmatched, view of all facets of climate science and global observations. Herve Le Treut, with whom this interview was prepared and conducted, is the current director of IPSL, a member of the French Academy of Sciences, and professor at Ecole Polytechnique and University Pierre and Marie Curie of Paris. We are grateful to both for
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International Nuclear Information System (INIS)
Gachon, P.; Radojevic, M.; Harding, A.; Saad, C.; Nguyen, V.T.V.
2008-01-01
The changes in the characteristics of extreme climate conditions are one of the most critical challenges for all ecosystems, human being and infrastructure, in the context of the on-going global climate change. However, extremes information needed for impacts studies cannot be obtained directly from coarse scale global climate models (GCMs), due mainly to their difficulties to incorporate regional scale feedbacks and processes responsible in part for the occurrence, intensity and duration of extreme events. Downscaling approaches, namely statistical and dynamical downscaling techniques (i.e. SD and RCM), have emerged as useful tools to develop high resolution climate change information, in particular for extremes, as those are theoretically more capable to take into account regional/local forcings and their feedbacks from large scale influences as they are driven with GCM synoptic variables. Nevertheless, in spite of the potential added values from downscaling methods (statistical and dynamical), a rigorous assessment of these methods are needed as inherent difficulties to simulate extremes are still present. In this paper, different series of RCM and SD simulations using three different GCMs are presented and evaluated with respect to observed values over the current period and over a river basin in southern Quebec, with future ensemble runs, i.e. centered over 2050s (i.e. 2041-2070 period using the SRES A2 emission scenario). Results suggest that the downscaling performance over the baseline period significantly varies between the two downscaling techniques and over various seasons with more regular reliable simulated values with SD technique for temperature than for RCM runs, while both approaches produced quite similar temperature changes in the future from median values with more divergence for extremes. For precipitation, less accurate information is obtained compared to observed data, and with more differences among models with higher uncertainties in the
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Pan-Arctic observations in GRENE Arctic Climate Change Research Project and its successor
Yamanouchi, Takashi
2016-04-01
We started a Japanese initiative - "Arctic Climate Change Research Project" - within the framework of the Green Network of Excellence (GRENE) Program, funded by the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT), in 2011. This Project targeted understanding and forecasting "Rapid Change of the Arctic Climate System and its Global Influences." Four strategic research targets are set by the Ministry: 1. Understanding the mechanism of warming amplification in the Arctic; 2. Understanding the Arctic climate system for global climate and future change; 3. Evaluation of the impacts of Arctic change on the weather and climate in Japan, marine ecosystems and fisheries; 4. Projection of sea ice distribution and Arctic sea routes. Through a network of universities and institutions in Japan, this 5-year Project involves more than 300 scientists from 39 institutions and universities. The National Institute of Polar Research (NIPR) works as the core institute and The Japan Agency for Marine- Earth Science and Technology (JAMSTEC) joins as the supporting institute. There are 7 bottom up research themes approved: the atmosphere, terrestrial ecosystems, cryosphere, greenhouse gases, marine ecology and fisheries, sea ice and Arctic sea routes and climate modeling, among 22 applications. The Project will realize multi-disciplinal study of the Arctic region and connect to the projection of future Arctic and global climatic change by modeling. The project has been running since the beginning of 2011 and in those 5 years pan-Arctic observations have been carried out in many locations, such as Svalbard, Russian Siberia, Alaska, Canada, Greenland and the Arctic Ocean. In particular, 95 GHz cloud profiling radar in high precision was established at Ny-Ålesund, Svalbard, and intensive atmospheric observations were carried out in 2014 and 2015. In addition, the Arctic Ocean cruises by R/V "Mirai" (belonging to JAMSTEC) and other icebreakers belonging to other
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Adaptation to Climate Change: A Comparative Analysis of Modeling Methods for Heat-Related Mortality.
Gosling, Simon N; Hondula, David M; Bunker, Aditi; Ibarreta, Dolores; Liu, Junguo; Zhang, Xinxin; Sauerborn, Rainer
2017-08-16
Multiple methods are employed for modeling adaptation when projecting the impact of climate change on heat-related mortality. The sensitivity of impacts to each is unknown because they have never been systematically compared. In addition, little is known about the relative sensitivity of impacts to "adaptation uncertainty" (i.e., the inclusion/exclusion of adaptation modeling) relative to using multiple climate models and emissions scenarios. This study had three aims: a ) Compare the range in projected impacts that arises from using different adaptation modeling methods; b ) compare the range in impacts that arises from adaptation uncertainty with ranges from using multiple climate models and emissions scenarios; c ) recommend modeling method(s) to use in future impact assessments. We estimated impacts for 2070-2099 for 14 European cities, applying six different methods for modeling adaptation; we also estimated impacts with five climate models run under two emissions scenarios to explore the relative effects of climate modeling and emissions uncertainty. The range of the difference (percent) in impacts between including and excluding adaptation, irrespective of climate modeling and emissions uncertainty, can be as low as 28% with one method and up to 103% with another (mean across 14 cities). In 13 of 14 cities, the ranges in projected impacts due to adaptation uncertainty are larger than those associated with climate modeling and emissions uncertainty. Researchers should carefully consider how to model adaptation because it is a source of uncertainty that can be greater than the uncertainty in emissions and climate modeling. We recommend absolute threshold shifts and reductions in slope. https://doi.org/10.1289/EHP634.
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Regional-Scale Climate Change: Observations and Model Simulations
Energy Technology Data Exchange (ETDEWEB)
Bradley, Raymond S; Diaz, Henry F
2010-12-14
This collaborative proposal addressed key issues in understanding the Earth's climate system, as highlighted by the U.S. Climate Science Program. The research focused on documenting past climatic changes and on assessing future climatic changes based on suites of global and regional climate models. Geographically, our emphasis was on the mountainous regions of the world, with a particular focus on the Neotropics of Central America and the Hawaiian Islands. Mountain regions are zones where large variations in ecosystems occur due to the strong climate zonation forced by the topography. These areas are particularly susceptible to changes in critical ecological thresholds, and we conducted studies of changes in phonological indicators based on various climatic thresholds.
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Directory of Open Access Journals (Sweden)
Hall Sharon K
2011-06-01
Full Text Available Abstract Background A number of studies conducted with ethnically diverse, low-income samples have found that parents with indulgent feeding styles had children with a higher weight status. Indulgent parents are those who are responsive to their child's emotional states but have problems setting appropriate boundaries with their child. Because the processes through which styles impact child weight are poorly understood, the aim of this study was to observe differences in the emotional climate created by parents (including affect, tone of voice, and gestures and behavioral feeding practices among those reporting different feeding styles on the Caregiver's Feeding Styles Questionnaire. A secondary aim was to examine differences on child weight status across the feeding styles. Methods Participants were 177 Head Start families from Houston, Texas (45% African-American; 55% Hispanic. Using an observational approach, the relationship between the observed emotional climate of the meal, behavioral feeding practices, and self-reported parent feeding styles were examined. Mean age of the children was 4.4 years (SD = 0.7 equally distributed across gender. Families were observed on 3 separate dinner occasions. Heights and weight were measured on the parents and children. Results Parents with self-reported indulgent feeding styles made fewer demands on their children to eat during dinner and showed lower levels of negative affect and intrusiveness. Surprisingly, these parents also showed higher levels of emotional detachment with their children during dinner. Hispanic boys with indulgent parents had significantly higher BMI z scores compared to Hispanic boys in the other three feeding style groups. No other differences were found on child weight status. Conclusions Results suggest that the emotional climate created by indulgent parents during dinner and their lack of demands on their children to eat may play an important role in how young children become
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Observational Quantification of Climatic and Human Influences on Vegetation Greening in China
Directory of Open Access Journals (Sweden)
Wenjian Hua
2017-04-01
Full Text Available This study attempts to quantify the relative contributions of vegetation greening in China due to climatic and human influences from multiple observational datasets. Satellite measured vegetation greenness, Normalized Difference Vegetation Index (NDVI, and relevant climate, land cover, and socioeconomic data since 1982 are analyzed using a multiple linear regression (MLR method. A statistically significant positive trend of average growing-season (April–October NDVI is found over more than 34% of the vegetated areas, mainly in North China, while significant decreases in NDVI are only seen in less than 5% of the areas. The relationships between vegetation and climate (temperature, precipitation, and radiation vary by geographical location and vegetation type. We estimate the NDVI changes in association with the non-climatic effects by removing the climatic effects from the original NDVI time series using the MLR analysis. Our results indicate that land use change is the dominant factor driving the long-term changes in vegetation greenness. The significant greening in North China is due to the increase in crops, grasslands, and forests. The socioeconomic datasets provide consistent and supportive results for the non-climatic effects at the provincial level that afforestation and reduced fire events generally have a major contribution. This study provides a basis for quantifying the non-climatic effects due to possible human influences on the vegetation greening in China.
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Human Impacts on the Hydrologic Cycle: Comparing Global Climate Change and Local Water Management
Ferguson, I. M.; Maxwell, R. M.
2010-12-01
Anthropogenic climate change is significantly altering the hydrologic cycle at global and regional scales, with potentially devastating impacts on water resources. Recent studies demonstrate that hydrologic response to climate change will depend on local-scale feedbacks between groundwater, surface water, and land surface processes. These studies suggest that local water management practices that alter the quantity and distribution of water in the terrestrial system—e.g., groundwater pumping and irrigation—may also feed back across the hydrologic cycle, with impacts on land-atmosphere fluxes and thus weather and climate. Here we use an integrated hydrologic model to compare the impacts of large-scale climate change and local water management practices on water and energy budgets at local and watershed scales. We consider three climate scenarios (hot, hot+wet, and hot+dry) and three management scenarios (pumping only, irrigation only, and pumping+irrigation). Results demonstrate that impacts of local water management on basin-integrated groundwater storage, evapotranspiration, and stream discharge are comparable to those of changing climate conditions. However, impacts of climate change are shown to have a smaller magnitude and greater spatial extent, while impacts of pumping and irrigation are shown to have a greater magnitude but are local to areas where pumping and irrigation occur. These results have important implications regarding the scales of human impacts on both water resources and climate and the sustainability of water resources.
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Quetin, Gregory R.
The natural composition of terrestrial ecosystems can be shaped by climate to take advantage of local environmental conditions. Ecosystem functioning, e.g. interaction between photosynthesis and temperature, can also acclimate to different climatological states. The combination of these two factors thus determines ecological-climate interactions. The ecosystem functioning also plays a key role in predicting the carbon cycle, hydrological cycle, terrestrial surface energy balance, and the feedbacks in the climate system. Predicting the response of the Earth's biosphere to global warming requires the ability to mechanistically represent the processes controlling ecosystem functioning through photosynthesis, respiration, and water use. The physical environment in a place shapes the vegetation there, but vegetation also has the potential to shape the environment, e.g. increased photosynthesis and transpiration moisten the atmosphere. These two-way ecoclimate interactions create the potential for feedbacks between vegetation at the physical environment that depend on the vegetation and the climate of a place, and can change throughout the year. In Chapter 1, we derive a global empirical map of the sensitivity of vegetation to climate using the response of satellite-observed greenness to interannual variations in temperature and precipitation. We infer mechanisms constraining ecosystem functioning by analyzing how the sensitivity of vegetation to climate varies across climate space. Our analysis yields empirical evidence for multiple physical and biological mediators of the sensitivity of vegetation to climate at large spatial scales. In hot and wet locations, vegetation is greener in warmer years despite temperatures likely exceeding thermally optimum conditions. However, sunlight generally increases during warmer years, suggesting that the increased stress from higher atmospheric water demand is offset by higher rates of photosynthesis. The sensitivity of vegetation
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Developing and Validating a New Classroom Climate Observation Assessment Tool.
Leff, Stephen S; Thomas, Duane E; Shapiro, Edward S; Paskewich, Brooke; Wilson, Kim; Necowitz-Hoffman, Beth; Jawad, Abbas F
2011-01-01
The climate of school classrooms, shaped by a combination of teacher practices and peer processes, is an important determinant for children's psychosocial functioning and is a primary factor affecting bullying and victimization. Given that there are relatively few theoretically-grounded and validated assessment tools designed to measure the social climate of classrooms, our research team developed an observation tool through participatory action research (PAR). This article details how the assessment tool was designed and preliminarily validated in 18 third-, fourth-, and fifth-grade classrooms in a large urban public school district. The goals of this study are to illustrate the feasibility of a PAR paradigm in measurement development, ascertain the psychometric properties of the assessment tool, and determine associations with different indices of classroom levels of relational and physical aggression.
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Timuhins, Andrejs; Bethers, Uldis; Bethers, Peteris; Klints, Ilze; Sennikovs, Juris; Frishfelds, Vilnis
2017-04-01
In a changing climate it is essential to estimate its impacts on different economic fields. In our study we tried to create a framework for climate change assessment and climate change impact estimation for the territory of Latvia and to create results which are also understandable for non-scientists (stakeholder, media and public). This approach allowed us to more carefully assess the presentation and interpretation of results and their validation, for public viewing. For the presentation of our work a website was created (www.modlab.lv/klimats) containing two types of documents in a unified framework, meteorological parameter analysis of different easily interpretable derivative values. Both of these include analysis of the current situation as well as illustrate the projection for future time periods. Derivate values are calculated using two data sources: the bias corrected regional climate data and meteorological observation data. Derivative documents contain description of derived value, some interesting facts and conclusions. Additionally, all results may be viewed in temporal and spatial graphs and maps, for different time periods as well as different seasons. Bias correction (Sennikovs and Bethers, 2009) for the control period 1961-1990 is applied to RCM data series. Meteorological observation data of the Latvian Environment, Geology, and Meteorology Agency and ENSEMBLES project daily data of 13 RCM runs for the period 1960-2100 are used. All the documents are prepared in python notebooks, which allow for flexible changes. At the moment following derivative values have been published: forest fire risk index, wind energy, phenology (Degree days), road condition (friction, ice conditions), daily minimal meteorological visibility, headache occurrence rate, firs snow date and meteorological parameter analysis: temperature, precipitation, wind speed, relative humidity, and cloudiness. While creating these products RCM ability to represent the actual climate was
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Energy Technology Data Exchange (ETDEWEB)
Bhatt, Uma S. [Univ. of Alaska, Fairbanks, AK (United States). Dept. of Atmospheric Sciences; Wackerbauer, Renate [Univ. of Alaska, Fairbanks, AK (United States). Dept. of Physics; Polyakov, Igor V. [Univ. of Alaska, Fairbanks, AK (United States). Dept. of Atmospheric Sciences; Newman, David E. [Univ. of Alaska, Fairbanks, AK (United States). Dept. of Physics; Sanchez, Raul E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fusion Energy Division; Univ. Carlos III de Madrid (Spain)
2015-11-13
The goal of this research was to apply fractional and non-linear analysis techniques in order to develop a more complete characterization of climate change and variability for the oceanic, sea ice and atmospheric components of the Earth System. This research applied two measures of dynamical characteristics of time series, the R/S method of calculating the Hurst exponent and Renyi entropy, to observational and modeled climate data in order to evaluate how well climate models capture the long-term dynamics evident in observations. Fractional diffusion analysis was applied to ARGO ocean buoy data to quantify ocean transport. Self organized maps were applied to North Pacific sea level pressure and analyzed in ways to improve seasonal predictability for Alaska fire weather. This body of research shows that these methods can be used to evaluate climate models and shed light on climate mechanisms (i.e., understanding why something happens). With further research, these methods show promise for improving seasonal to longer time scale forecasts of climate.
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Changes in observed climate extremes in global urban areas
International Nuclear Information System (INIS)
Mishra, Vimal; Ganguly, Auroop R; Nijssen, Bart; Lettenmaier, Dennis P
2015-01-01
Climate extremes have profound implications for urban infrastructure and human society, but studies of observed changes in climate extremes over the global urban areas are few, even though more than half of the global population now resides in urban areas. Here, using observed station data for 217 urban areas across the globe, we show that these urban areas have experienced significant increases (p-value <0.05) in the number of heat waves during the period 1973–2012, while the frequency of cold waves has declined. Almost half of the urban areas experienced significant increases in the number of extreme hot days, while almost 2/3 showed significant increases in the frequency of extreme hot nights. Extreme windy days declined substantially during the last four decades with statistically significant declines in about 60% in the urban areas. Significant increases (p-value <0.05) in the frequency of daily precipitation extremes and in annual maximum precipitation occurred at smaller fractions (17 and 10% respectively) of the total urban areas, with about half as many urban areas showing statistically significant downtrends as uptrends. Changes in temperature and wind extremes, estimated as the result of a 40 year linear trend, differed for urban and non-urban pairs, while changes in indices of extreme precipitation showed no clear differentiation for urban and selected non-urban stations. (letter)
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Climate change: Conflict of observational science, theory, and politics
Gerhard, L.C.
2004-01-01
Debate over whether human activity causes Earth climate change obscures the immensity of the dynamic systems that create and maintain climate on the planet. Anthropocentric debate leads people to believe that they can alter these planetary dynamic systems to prevent that they perceive as negative climate impacts on human civilization. Although politicians offer simplistic remedies, such as the Kyoto Protocol, global climate continues to change naturally. Better planning for the inevitable dislocations that have followed natural global climate changes throughout human history requires us to accept the fact that climate will change, and that human society must adapt to the changes. Over the last decade, the scientific literature reported a shift in emphasis from attempting to build theoretical models of putative human impacts on climate to understanding the planetwide dynamic processes that are the natural climate drivers. The current scientific literature is beginning to report the history of past climate change, the extent of natural climate variability, natural system drivers, and the episodicity of many climate changes. The scientific arguments have broadened from focus upon human effects on climate to include the array of natural phenomena that have driven global climate change for eons. However, significant political issues with long-term social consequences continue their advance. This paper summarizes recent scientific progress in climate science and arguments about human influence on climate. ?? 2004. The American Association of Petroleum Geologists. All rights reserved.
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Investing in Climate Change. Dutch Banks Compared
International Nuclear Information System (INIS)
Buurgaard Nielsen, J.; Pols, D.; Van Gelder, J.W.; Denie, S.; Scheire, C.
2007-06-01
This report is the first comparison of the climate change performance of Dutch banks that analyses the actual investments of these banks. It reviews a substantial share of each bank's portfolio, according to three criteria: how much they invest in the main cause of climate change, fossil fuels; how much they invest in the main alternative to fossil fuels, renewable energy; the bank's plans and policies to limit their contribution to climate change
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Energy Technology Data Exchange (ETDEWEB)
Lindroos, T. J.; Ekholm, T.; Savolainen, I.
2012-11-15
Climate policy needs a relatively simple method to compare the warming effect of different greenhouse gases (GHGs). Otherwise it would be necessary to negotiate a different reduction target for each gas. At the moment, Global Warming Potential (GWP) concept is used to compare different GHGs. Numerical values of GWP factors have been updated alongside with scientific understanding and majority seems content to the GWP. From 2005 onwards there have been many proposals of optional metrics. The most well known is Global Temperature change Potential (GTP) concept which measures the change of temperature as does global climate policies. The decision between metrics is a multicriteria decision which should include at least the coherence with climate policy and cost efficiency. The GWP concept may be a little more difficult to understand than the GTP but it is more cost efficient. Alongside with new metrics, scientists and politicians have started to discuss of new emission which have an effect on warming. These Short Lived Climate Forcers (SLCFs) have either warming or cooling effect. Their effect can be presented with GWP and GTP but the uncertainties in the emission factors are large. In total, SLCFs reduce overall emissions of EU approximately 1% in year 2000. NO{sub x}, SO{sub x} (cooling) and black carbon (warming) emissions were the biggest factors. EU is planning to reduce the SLCF emissions to achieve health and environmental benefits, but at the same time this reduces the effect of EU's climate policies by approximately 10%. Uncertainties in the estimates are large. (orig.)
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Developing a Comparative Measure of the Learning Climate in Professional Schools
Bowen, Donald D.; Kilmann, Ralph H.
1975-01-01
The Learning Climate Questionnaire (LCQ) compares the objective properties of schools with measures of overall student satisfaction. The validity of the instrument suggests its use for substantive research investigations into the organizational dynamics of professional schools. (Author/JR)
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Current climate and climate change over India as simulated by the Canadian Regional Climate Model
Alexandru, Adelina; Sushama, Laxmi
2015-08-01
The performance of the fifth generation of the Canadian Regional Climate Model (CRCM5) in reproducing the main climatic characteristics over India during the southwest (SW)-, post- and pre-monsoon seasons are presented in this article. To assess the performance of CRCM5, European Centre for Medium- Range Weather Forecasts (ECMWF) Re- Analysis (ERA- 40) and Interim re-analysis (ERA-Interim) driven CRCM5 simulation is compared against independent observations and reanalysis data for the 1971-2000 period. Projected changes for two future periods, 2041-2070 and 2071-2100, with respect to the 1971-2000 current period are assessed based on two transient climate change simulations of CRCM5 spanning the 1950-2100 period. These two simulations are driven by the Canadian Earth System Model version 2 (CanESM2) and the Max Planck Institute for Meteorology's Earth System Low Resolution Model (MPI-ESM-LR), respectively. The boundary forcing errors associated with errors in the driving global climate models are also studied by comparing the 1971-2000 period of the CanESM2 and MPI-ESM-LR driven simulations with that of the CRCM5 simulation driven by ERA-40/ERA-Interim. Results show that CRCM5 driven by ERA-40/ERA-Interim is in general able to capture well the temporal and spatial patterns of 2 m-temperature, precipitation, wind, sea level pressure, total runoff and soil moisture over India in comparison with available reanalysis and observations. However, some noticeable differences between the model and observational data were found during the SW-monsoon season within the domain of integration. CRCM5 driven by ERA-40/ERA-Interim is 1-2 °C colder than CRU observations and generates more precipitation over the Western Ghats and central regions of India, and not enough in the northern and north-eastern parts of India and along the Konkan west coast in comparison with the observed precipitation. The monsoon onset seems to be relatively well captured over the southwestern coast of
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Beranová, Romana; Kyselý, Jan; Hanel, Martin
2018-04-01
The study compares characteristics of observed sub-daily precipitation extremes in the Czech Republic with those simulated by Hadley Centre Regional Model version 3 (HadRM3) and Rossby Centre Regional Atmospheric Model version 4 (RCA4) regional climate models (RCMs) driven by reanalyses and examines diurnal cycles of hourly precipitation and their dependence on intensity and surface temperature. The observed warm-season (May-September) maxima of short-duration (1, 2 and 3 h) amounts show one diurnal peak in the afternoon, which is simulated reasonably well by RCA4, although the peak occurs too early in the model. HadRM3 provides an unrealistic diurnal cycle with a nighttime peak and an afternoon minimum coinciding with the observed maximum for all three ensemble members, which suggests that convection is not captured realistically. Distorted relationships of the diurnal cycles of hourly precipitation to daily maximum temperature in HadRM3 further evidence that underlying physical mechanisms are misrepresented in this RCM. Goodness-of-fit tests indicate that generalised extreme value distribution is an applicable model for both observed and RCM-simulated precipitation maxima. However, the RCMs are not able to capture the range of the shape parameter estimates of distributions of short-duration precipitation maxima realistically, leading to either too many (nearly all for HadRM3) or too few (RCA4) grid boxes in which the shape parameter corresponds to a heavy tail. This means that the distributions of maxima of sub-daily amounts are distorted in the RCM-simulated data and do not match reality well. Therefore, projected changes of sub-daily precipitation extremes in climate change scenarios based on RCMs not resolving convection need to be interpreted with caution.
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Shifts in comparative advantages for maize, oat, and wheat cropping under climate change in Europe
DEFF Research Database (Denmark)
Elsgaard, Lars; Børgesen, Christen Duus; Olesen, Jørgen E
2012-01-01
as projected for the time period around 2040 by two regional climate models (RCM) with a moderate and a strong climate change signal, respectively. The projected cropping shares are based on the output from the two RCMs and on algorithms derived for the relation between meteorological data and observed...
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Comparative response of Rangifer tarandus and other northern ungulates to climatic variability
Directory of Open Access Journals (Sweden)
Robert B. Weladji
2002-06-01
Full Text Available To understand the factors influencing life history traits and population dynamics, attention is increasingly being given to the importance of environmental stochasticity. In this paper, we review and discuss aspects of current knowledge concerning the effect of climatic variation (local and global on population parameters of northern ungu¬lates, with special emphasis on reindeer/caribou (Rangifer tarandus. We also restrict ourselves to indirect effects of climate through both forage availability and quality, and insect activity. Various authors have used different weather variables; with sometime opposite trends in resulting life history traits of ungulates, and few studies show consistent effects to the same climatic variables. There is thus little consensus about which weather variables play the most sig¬nificant role influencing ungulate population parameters. This may be because the effects of weather on ungulate pop¬ulation dynamics and life history traits are scale dependent and it is difficult to isolate climatic effects from density dependent factors. This confirms the complexity of the relationship between environment and ecosystem. We point out limits of comparability between systems and the difficulty of generalizing about the effect of climate change broadly across northern systems, across species and even within species. Furthermore, insect harassment appears to be a key climate-related factor for the ecology of reindeer/caribou that has been overlooked in the literature of climatic effects on large herbivores. In light of this, there is a need for further studies of long time series in assessing effects of climate variability on reindeer/caribou.
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What climate changes could be observed by two generations of Poles?
Szwed, M.
2010-09-01
For many years, numerous scientific papers in different disciplines have been published on different aspects of the global warming. The issue of climate change and its impacts has become certainly a "fashionable" research area. In Poland, for example, the issue was tackled by one of the greatest hydro-climatological research projects, namely: "Extreme meteorological and hydrological events in Poland (the evaluation of forecasting events and their effects on human environment)". However, for several years, and certainly since 2007, when Al Gore, former U.S. vice-president, and the Intergovernmental Panel on Climate Change (IPCC) won the Nobel Peace Prize, this topic has started to be increasingly more frequently raised by the Polish media. The average Polish citizen increasingly more often learns from the press, radio and television about the global warming. There are also those skeptical of the climate change who loudly express their opinions in the media. Can the average Pole not get lost in the thicket of information? Can they refer to their own memory or the memory of their parents or grandparents on issues of climate change? How is the typical summer or winter perceived the previous generations? Is it possible to observe such changes without reference to extreme events? This article is to try to answer the question whether the average Pole could see climate change, most simply understood as changes in the thermal conditions and precipitations. If yes, then what seasons or months see the biggest changes. Which parts of the country witness the biggest changes? The starting point of the analysis are the 58-years time series of real monthly temperature and precipitation in the period of 1951-2008 for 20 stations across Poland. However, they will not be analyzed in more detail. In order to smooth the data sequences and thus to reject the short-term fluctuations, the long-term moving averages in different sequences (individual months, seasons and years) will be
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Observations of climate, albedo, and surface radiation over cleared and undisturbed Amazonian forest
International Nuclear Information System (INIS)
Bastable, H.G.; Shuttleworth, W.J.; Dallarosa, R.L.G.; Fisch, G.; Nobre, C.A.
1993-01-01
Measurements from the first comparative study of climate over Amazonian tropical forest and an embedded deforested clearing are presented. Observations comprise a continuous 60-day run of data from mid-October to mid-December 1990, covering the end of the dry season and the beginning of the wet season. Mean hourly observations are calculated for the whole period; and for two 10-day periods, one in the dry season and one at the start of the wet season. Much greater variation in weather variables was observed at the clearing compared with over the forest. While the mean values of temperature and specific humidity deficit differed by less than 1°C and 1 g kg −1 respectively, their daily ranges at the clearing were twice those at the forest. Mean daily albedo of the forest was 13.1 per cent, agreeing well with other tropical forest measurements, and of the clearing was 16.3 per cent, somewhat lower than the values currently being used in GCMs. The surface energy balance was investigated and mean available energy calculated for each site. The significant difference in the daily pattern of net radiation between the sites was found to be at least as much due to differences in the longwave radiation balance as to differences in albedo. The diurnal pattern of net radiation therefore changed between dry and wet periods as the higher plant water stress experienced by clearing vegetation altered the daily temperature cycle
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Celaya, Michael A.; Wahr, John M.; Bryan, Frank O.
1999-06-01
The output of a coupled climate system model provides a synthetic climate record with temporal and spatial coverage not attainable with observational data, allowing evaluation of climatic excitation of polar motion on timescales of months to decades. Analysis of the geodetically inferred Chandler excitation power shows that it has fluctuated by up to 90% since 1900 and that it has characteristics representative of a stationary Gaussian process. Our model-predicted climate excitation of the Chandler wobble also exhibits variable power comparable to the observed. Ocean currents and bottom pressure shifts acting together can alone drive the 14-month wobble. The same is true of the excitation generated by the combined effects of barometric pressure and winds. The oceanic and atmospheric contributions are this large because of a relatively high degree of constructive interference between seafloor pressure and currents and between atmospheric pressure and winds. In contrast, excitation by the redistribution of water on land appears largely insignificant. Not surprisingly, the full climate effect is even more capable of driving the wobble than the effects of the oceans or atmosphere alone are. Our match to the observed annual excitation is also improved, by about 17%, over previous estimates made with historical climate data. Efforts to explain the 30-year Markowitz wobble meet with less success. Even so, at periods ranging from months to decades, excitation generated by a model of a coupled climate system makes a close approximation to the amplitude of what is geodetically observed.
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The comparison of observed global mean surface air temperature (GMT) change to the mean change simulated by climate models has received much attention. For a given global warming signal produced by a climate model ensemble, there exists an envelope of GMT values representing the range of possible un...
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Fisher, Jeremy Isaac
Important systematic shifts in ecosystem function are often masked by natural variability. The rich legacy of over two decades of continuous satellite observations provides an important database for distinguishing climatological and anthropogenic ecosystem changes. Examples from semi-arid Sudanian West Africa and New England (USA) illustrate the response of vegetation to climate and land-use. In Burkina Faso, West Africa, pastoral and agricultural practices compete for land area, while degradation may follow intensification. The Nouhao Valley is a natural experiment in which pastoral and agricultural land uses were allocated separate, coherent reserves. Trajectories of annual net primary productivity were derived from 18 years of coarse-grain (AVHRR) satellite data. Trends suggested that pastoral lands had responded rigorously to increasing rainfall after the 1980's droughts. A detailed analysis at Landsat resolution (30m) indicated that the increased vegetative cover was concentrated in the river basins of the pastoral region, implying a riparian wood expansion. In comparison, riparian cover was reduced in agricultural regions. We suggest that broad-scale patterns of increasing semi-arid West African greenness may be indicative of climate variability, whereas local losses may be anthropogenic in nature. The contiguous deciduous forests, ocean proximity, topography, and dense urban developments of New England provide an ideal landscape to examine influences of climate variability and the impact of urban development vegetation response. Spatial and temporal patterns of interannual climate variability were examined via green leaf phenology. Phenology, or seasonal growth and senescence, is driven by deficits of light, temperature, and water. In temperate environments, phenology variability is driven by interannual temperature and precipitation shifts. Average and interannual phenology analyses across southern New England were conducted at resolutions of 30m (Landsat
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The ARM Cloud Radar Simulator for Global Climate Models: Bridging Field Data and Climate Models
Energy Technology Data Exchange (ETDEWEB)
Zhang, Yuying [Lawrence Livermore National Laboratory, Livermore, California; Xie, Shaocheng [Lawrence Livermore National Laboratory, Livermore, California; Klein, Stephen A. [Lawrence Livermore National Laboratory, Livermore, California; Marchand, Roger [University of Washington, Seattle, Washington; Kollias, Pavlos [Stony Brook University, Stony Brook, New York; Clothiaux, Eugene E. [The Pennsylvania State University, University Park, Pennsylvania; Lin, Wuyin [Brookhaven National Laboratory, Upton, New York; Johnson, Karen [Brookhaven National Laboratory, Upton, New York; Swales, Dustin [CIRES and NOAA/Earth System Research Laboratory, Boulder, Colorado; Bodas-Salcedo, Alejandro [Met Office Hadley Centre, Exeter, United Kingdom; Tang, Shuaiqi [Lawrence Livermore National Laboratory, Livermore, California; Haynes, John M. [Cooperative Institute for Research in the Atmosphere/Colorado State University, Fort Collins, Colorado; Collis, Scott [Argonne National Laboratory, Argonne, Illinois; Jensen, Michael [Brookhaven National Laboratory, Upton, New York; Bharadwaj, Nitin [Pacific Northwest National Laboratory, Richland, Washington; Hardin, Joseph [Pacific Northwest National Laboratory, Richland, Washington; Isom, Bradley [Pacific Northwest National Laboratory, Richland, Washington
2018-01-01
Clouds play an important role in Earth’s radiation budget and hydrological cycle. However, current global climate models (GCMs) have had difficulties in accurately simulating clouds and precipitation. To improve the representation of clouds in climate models, it is crucial to identify where simulated clouds differ from real world observations of them. This can be difficult, since significant differences exist between how a climate model represents clouds and what instruments observe, both in terms of spatial scale and the properties of the hydrometeors which are either modeled or observed. To address these issues and minimize impacts of instrument limitations, the concept of instrument “simulators”, which convert model variables into pseudo-instrument observations, has evolved with the goal to improve and to facilitate the comparison of modeled clouds with observations. Many simulators have (and continue to be developed) for a variety of instruments and purposes. A community satellite simulator package, the Cloud Feedback Model Intercomparison Project (CFMIP) Observation Simulator Package (COSP; Bodas-Salcedo et al. 2011), contains several independent satellite simulators and is being widely used in the global climate modeling community to exploit satellite observations for model cloud evaluation (e.g., Klein et al. 2013; Zhang et al. 2010). This article introduces a ground-based cloud radar simulator developed by the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program for comparing climate model clouds with ARM observations from its vertically pointing 35-GHz radars. As compared to CloudSat radar observations, ARM radar measurements occur with higher temporal resolution and finer vertical resolution. This enables users to investigate more fully the detailed vertical structures within clouds, resolve thin clouds, and quantify the diurnal variability of clouds. Particularly, ARM radars are sensitive to low-level clouds, which are
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Directory of Open Access Journals (Sweden)
Manfred A. Lange
2013-11-01
Full Text Available A new methodology to extract crop yield response to climate variability and change from long-term crop yield observations is presented in this study. In contrast to the existing first-difference approach (FDA, the proposed methodology considers that the difference in value between crop yields of two consecutive years reflects necessarily the contributions of climate and management conditions, especially at large spatial scales where both conditions may vary significantly from one year to the next. Our approach was applied to remove the effect of non-climatic factors on crop yield and, hence, to isolate the effect of the observed climate change between 1961 and 2006 on three widely crops grown in three Mediterranean countries—namely wheat, corn and potato—using national-level crop yield observations’ time-series. Obtained results show that the proposed methodology provides us with a ground basis to improve substantially our understanding of crop yield response to climate change at a scale that is relevant to large-scale estimations of agricultural production and to food security analyses; and therefore to reduce uncertainties in estimations of potential climate change effects on agricultural production. Furthermore, a comparison of outputs of our methodology and FDA outputs yielded a difference in terms of maize production in Egypt, for example, that exceeds the production of some neighbouring countries.
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Directory of Open Access Journals (Sweden)
Edlund Stefan
2012-09-01
Full Text Available Abstract Background The role of the Anopheles vector in malaria transmission and the effect of climate on Anopheles populations are well established. Models of the impact of climate change on the global malaria burden now have access to high-resolution climate data, but malaria surveillance data tends to be less precise, making model calibration problematic. Measurement of malaria response to fluctuations in climate variables offers a way to address these difficulties. Given the demonstrated sensitivity of malaria transmission to vector capacity, this work tests response functions to fluctuations in land surface temperature and precipitation. Methods This study of regional sensitivity of malaria incidence to year-to-year climate variations used an extended Macdonald Ross compartmental disease model (to compute malaria incidence built on top of a global Anopheles vector capacity model (based on 10 years of satellite climate data. The predicted incidence was compared with estimates from the World Health Organization and the Malaria Atlas. The models and denominator data used are freely available through the Eclipse Foundation’s Spatiotemporal Epidemiological Modeller (STEM. Results Although the absolute scale factor relating reported malaria to absolute incidence is uncertain, there is a positive correlation between predicted and reported year-to-year variation in malaria burden with an averaged root mean square (RMS error of 25% comparing normalized incidence across 86 countries. Based on this, the proposed measure of sensitivity of malaria to variations in climate variables indicates locations where malaria is most likely to increase or decrease in response to specific climate factors. Bootstrapping measures the increased uncertainty in predicting malaria sensitivity when reporting is restricted to national level and an annual basis. Results indicate a potential 20x improvement in accuracy if data were available at the level ISO 3166–2
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Choice of baseline climate data impacts projected species' responses to climate change.
Baker, David J; Hartley, Andrew J; Butchart, Stuart H M; Willis, Stephen G
2016-07-01
Climate data created from historic climate observations are integral to most assessments of potential climate change impacts, and frequently comprise the baseline period used to infer species-climate relationships. They are often also central to downscaling coarse resolution climate simulations from General Circulation Models (GCMs) to project future climate scenarios at ecologically relevant spatial scales. Uncertainty in these baseline data can be large, particularly where weather observations are sparse and climate dynamics are complex (e.g. over mountainous or coastal regions). Yet, importantly, this uncertainty is almost universally overlooked when assessing potential responses of species to climate change. Here, we assessed the importance of historic baseline climate uncertainty for projections of species' responses to future climate change. We built species distribution models (SDMs) for 895 African bird species of conservation concern, using six different climate baselines. We projected these models to two future periods (2040-2069, 2070-2099), using downscaled climate projections, and calculated species turnover and changes in species-specific climate suitability. We found that the choice of baseline climate data constituted an important source of uncertainty in projections of both species turnover and species-specific climate suitability, often comparable with, or more important than, uncertainty arising from the choice of GCM. Importantly, the relative contribution of these factors to projection uncertainty varied spatially. Moreover, when projecting SDMs to sites of biodiversity importance (Important Bird and Biodiversity Areas), these uncertainties altered site-level impacts, which could affect conservation prioritization. Our results highlight that projections of species' responses to climate change are sensitive to uncertainty in the baseline climatology. We recommend that this should be considered routinely in such analyses. © 2016 John Wiley
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Using climate model simulations to assess the current climate risk to maize production
Kent, Chris; Pope, Edward; Thompson, Vikki; Lewis, Kirsty; Scaife, Adam A.; Dunstone, Nick
2017-05-01
The relationship between the climate and agricultural production is of considerable importance to global food security. However, there has been relatively little exploration of climate-variability related yield shocks. The short observational yield record does not adequately sample natural inter-annual variability thereby limiting the accuracy of probability assessments. Focusing on the United States and China, we present an innovative use of initialised ensemble climate simulations and a new agro-climatic indicator, to calculate the risk of severe water stress. Combined, these regions provide 60% of the world’s maize, and therefore, are crucial to global food security. To probe a greater range of inter-annual variability, the indicator is applied to 1400 simulations of the present day climate. The probability of severe water stress in the major maize producing regions is quantified, and in many regions an increased risk is found compared to calculations from observed historical data. Analysis suggests that the present day climate is also capable of producing unprecedented severe water stress conditions. Therefore, adaptation plans and policies based solely on observed events from the recent past may considerably under-estimate the true risk of climate-related maize shocks. The probability of a major impact event occurring simultaneously across both regions—a multi-breadbasket failure—is estimated to be up to 6% per decade and arises from a physically plausible climate state. This novel approach highlights the significance of climate impacts on crop production shocks and provides a platform for considerably improving food security assessments, in the present day or under a changing climate, as well as development of new risk based climate services.
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CONTRIBUTION OF SATELLITE-BORN INFORMATION TO CLIMATE SCIENCE
Directory of Open Access Journals (Sweden)
MIKA J.
2015-03-01
Full Text Available Observed climate processes play important role in understanding the ongoing changes in the climate system. Our paper intends to present this cross-section of climate science illustrated by selected satellite images and diagrams in four parts. (i. Technical possibilities of the observations are briefly surveyed first. Many satellite platforms and devices started working in the 1980 and 1990s, definitely for climate purposes. (ii. Climate forcing factors and their radiation effects are comprehended, including direct observation of solar irradiance and volcanic aerosol concentration allowing us to compare natural factors to the anthropogenic ones. (iii. Detection of changes in the Earth climate system follows next, including the atmosphere, the oceans and the cryosphere, as well. (iv. Finally, satellite-born results in validation of climate models are presented in three aspects: reconstruction of present climate, validation of simulated changes and investigation of feedback mechanisms driving climate sensitivity to the external forcing factors. The above possibilities of using satellite information in climate science are mostly illustrated by key figures of the IPCC AR5 Report (2013.
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Observed 20th Century Desert Dust Variability: Impact on Climate and Biogeochemistry
Energy Technology Data Exchange (ETDEWEB)
Mahowald, Natalie [Cornell University; Kloster, Silvia [Cornell University; Engelstaedter, S. [Cornell University; Moore, Jefferson Keith [University of California, Irvine; Mukhopadhyay, S. [Harvard University; McConnell, J. R. [Desert Research Institute, Reno, NV; Albani, S. [Cornell University; Doney, Scott C. [Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA; Bhattacharya, A. [Harvard University; Curran, M. A. J. [Antarctic Climate and Ecosystems Cooperative Research Centre; Flanner, Mark G. [University of Michigan; Hoffman, Forrest M [ORNL; Lawrence, David M. [National Center for Atmospheric Research (NCAR); Lindsay, Keith [National Center for Atmospheric Research (NCAR); Mayewski, P. A. [University of Maine; Neff, Jason [University of Colorado, Boulder; Rothenberg, D. [Cornell University; Thomas, E. [British Antarctic Survey, Cambridge, UK; Thornton, Peter E [ORNL; Zender, Charlie S. [University of California, Irvine
2010-01-01
Desert dust perturbs climate by directly and indirectly interacting with incoming solar and outgoing long wave radiation, thereby changing precipitation and temperature, in addition to modifying ocean and land biogeochemistry. While we know that desert dust is sensitive to perturbations in climate and human land use, previous studies have been unable to determine whether humans were increasing or decreasing desert dust in the global average. Here we present observational estimates of desert dust based on paleodata proxies showing a doubling of desert dust during the 20th century over much, but not all the globe. Large uncertainties remain in estimates of desert dust variability over 20th century due to limited data. Using these observational estimates of desert dust change in combination with ocean, atmosphere and land models, we calculate the net radiative effect of these observed changes (top of atmosphere) over the 20th century to be -0.14 {+-} 0.11 W/m{sup 2} (1990-1999 vs. 1905-1914). The estimated radiative change due to dust is especially strong between the heavily loaded 1980-1989 and the less heavily loaded 1955-1964 time periods (-0.57 {+-} 0.46 W/m{sup 2}), which model simulations suggest may have reduced the rate of temperature increase between these time periods by 0.11 C. Model simulations also indicate strong regional shifts in precipitation and temperature from desert dust changes, causing 6 ppm (12 PgC) reduction in model carbon uptake by the terrestrial biosphere over the 20th century. Desert dust carries iron, an important micronutrient for ocean biogeochemistry that can modulate ocean carbon storage; here we show that dust deposition trends increase ocean productivity by an estimated 6% over the 20th century, drawing down an additional 4 ppm (8 PgC) of carbon dioxide into the oceans. Thus, perturbations to desert dust over the 20th century inferred from observations are potentially important for climate and biogeochemistry, and our understanding
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Directory of Open Access Journals (Sweden)
Mario Liebergesell
Full Text Available Future global change scenarios predict a dramatic loss of biodiversity for many regions in the world, potentially reducing the resistance and resilience of ecosystem functions. Once before, during Plio-Pleistocene glaciations, harsher climatic conditions in Europe as compared to North America led to a more depauperate tree flora. Here we hypothesize that this climate driven species loss has also reduced functional diversity in Europe as compared to North America. We used variation in 26 traits for 154 North American and 66 European tree species and grid-based co-occurrences derived from distribution maps to compare functional diversity patterns of the two continents. First, we identified similar regions with respect to contemporary climate in the temperate zone of North America and Europe. Second, we compared the functional diversity of both continents and for the climatically similar sub-regions using the functional dispersion-index (FDis and the functional richness index (FRic. Third, we accounted in these comparisons for grid-scale differences in species richness, and, fourth, investigated the associated trait spaces using dimensionality reduction. For gymnosperms we find similar functional diversity on both continents, whereas for angiosperms functional diversity is significantly greater in Europe than in North America. These results are consistent across different scales, for climatically similar regions and considering species richness patterns. We decomposed these differences in trait space occupation into differences in functional diversity vs. differences in functional identity. We show that climate-driven species loss on a continental scale might be decoupled from or at least not linearly related to changes in functional diversity. This might be important when analyzing the effects of climate-driven biodiversity change on ecosystem functioning.
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The Canadian Centre for Climate Modelling and Analysis global coupled model and its climate
Energy Technology Data Exchange (ETDEWEB)
Flato, G.M.; Boer, G.J.; Lee, W.G.; McFarlane, N.A.; Ramsden, D.; Reader, M.C. [Canadian Centre for Climate Modelling and Analysis, Victoria, BC (Canada); Weaver, A.J. [School of Earth and Ocean Sciences, University of Victoria, BC (Canada)
2000-06-01
A global, three-dimensional climate model, developed by coupling the CCCma second-generation atmospheric general circulation model (GCM2) to a version of the GFDL modular ocean model (MOM1), forms the basis for extended simulations of past, current and projected future climate. The spin-up and coupling procedures are described, as is the resulting climate based on a 200 year model simulation with constant atmospheric composition and external forcing. The simulated climate is systematically compared to available observations in terms of mean climate quantities and their spatial patterns, temporal variability, and regional behavior. Such comparison demonstrates a generally successful reproduction of the broad features of mean climate quantities, albeit with local discrepancies. Variability is generally well-simulated over land, but somewhat underestimated in the tropical ocean and the extratropical storm-track regions. The modelled climate state shows only small trends, indicating a reasonable level of balance at the surface, which is achieved in part by the use of heat and freshwater flux adjustments. The control simulation provides a basis against which to compare simulated climate change due to historical and projected greenhouse gas and aerosol forcing as described in companion publications. (orig.)
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Climate Trends and Farmers' Perceptions of Climate Change in Zambia.
Mulenga, Brian P; Wineman, Ayala; Sitko, Nicholas J
2017-02-01
A number of studies use meteorological records to analyze climate trends and assess the impact of climate change on agricultural yields. While these provide quantitative evidence on climate trends and the likely effects thereof, they incorporate limited qualitative analysis of farmers' perceptions of climate change and/or variability. The present study builds on the quantitative methods used elsewhere to analyze climate trends, and in addition compares local narratives of climate change with evidence found in meteorological records in Zambia. Farmers offer remarkably consistent reports of a rainy season that is growing shorter and less predictable. For some climate parameters-notably, rising average temperature-there is a clear overlap between farmers' observations and patterns found in the meteorological records. However, the data do not support the perception that the rainy season used to begin earlier, and we generally do not detect a reported increase in the frequency of dry spells. Several explanations for these discrepancies are offered. Further, we provide policy recommendations to help farmers adapt to climate change/variability, as well as suggestions to shape future climate change policies, programs, and research in developing countries.
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Panchen, Zoe A; Primack, Richard B; Anisko, Tomasz; Lyons, Robert E
2012-04-01
The global climate is changing rapidly and is expected to continue changing in coming decades. Studying changes in plant flowering times during a historical period of warming temperatures gives us a way to examine the impacts of climate change and allows us to predict further changes in coming decades. The Greater Philadelphia region has a long and rich history of botanical study and documentation, with abundant herbarium specimens, field observations, and botanical photographs from the mid-1800s onward. These extensive records also provide an opportunity to validate methodologies employed by other climate change researchers at a different biogeographical area and with a different group of species. Data for 2539 flowering records from 1840 to 2010 were assessed to examine changes in flowering response over time and in relation to monthly minimum temperatures of 28 Piedmont species native to the Greater Philadelphia region. Regression analysis of the date of flowering with year or with temperature showed that, on average, the Greater Philadelphia species studied are flowering 16 d earlier over the 170-yr period and 2.7 d earlier per 1°C rise in monthly minimum temperature. Of the species studied, woody plants with short flowering duration are the best indicators of a warming climate. For monthly minimum temperatures, temperatures 1 or 2 mo prior to flowering are most significantly correlated with flowering time. Studies combining herbarium specimens, photographs, and field observations are an effective method for detecting the effects of climate change on flowering times.
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Improved Analysis of Earth System Models and Observations using Simple Climate Models
Nadiga, B. T.; Urban, N. M.
2016-12-01
both ESM experiments and actual observations are presented. One such result points to the importance of direct sequestration of heat below 700 m, a process that is not allowed for in the simple models that have been traditionally used to deduce climate sensitivity.
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Energy Technology Data Exchange (ETDEWEB)
Dios, N.; Szenteleki, K.; Ferenczy, A.; Petranyl, G. [Corvinus Univ. of Budapest (Hungary). Dept. of Mathematics and Informatics; Hufnagel, L. [Hungarian Academy of Sciences, Budapest (Hungary). Adaptation to Climate Change Research Group
2009-07-01
Recent research results let us conclude that climate change might have a significant effect on the yield of wheat, barley, rye, potato and maize, and the borderlines of their area of cultivation might shift 100--150 kilometers to the north. The possible mass occurrence of new aggressive pest, pathogen and weed species in Hungary might also create a problem from plant protection. Maize is one of the most important fodder-plants. Hungary has close to the largest total cultivating area in Europe. Maize is used in many ways, thus being of outstanding economic importance. In Hungary the conditions of maize cultivation are -- except for dry years -- quite favorable in most cultural regions and complex cultivating technologies are available. It also might gain a significant role in the line of new environment-friendly alternative sources of energy. For these reasons, it is important to examine the influence of meteorological factors on maize ecosystems and this examination should include as many climate change scenarios and as long a time series as possible. Using ecological data compiled from scientific literature on pest, pathogen and weed species characteristic in maize cultures in Hungary, we defined monthly climate profile indicators and applied them to complete a comparative analysis of the historical and modelled climate change scenario meteorological data of the city of Debrecen. Our results call attention to a drastic decline of the competitive ability of maize as compared to several C{sub 4} and especially C{sub 3} plants. According to the stricter scenarios, the frequency of potential pest and pathogen damage emergency situations will grow significantly by the end of the century.
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Comparing NICU teamwork and safety climate across two commonly used survey instruments.
Profit, Jochen; Lee, Henry C; Sharek, Paul J; Kan, Peggy; Nisbet, Courtney C; Thomas, Eric J; Etchegaray, Jason M; Sexton, Bryan
2016-12-01
Measurement and our understanding of safety culture are still evolving. The objectives of this study were to assess variation in safety and teamwork climate and in the neonatal intensive care unit (NICU) setting, and compare measurement of safety culture scales using two different instruments (Safety Attitudes Questionnaire (SAQ) and Hospital Survey on Patient Safety Culture (HSOPSC)). Cross-sectional survey study of a voluntary sample of 2073 (response rate 62.9%) health professionals in 44 NICUs. To compare survey instruments, we used Spearman's rank correlation coefficients. We also compared similar scales and items across the instruments using t tests and changes in quartile-level performance. We found significant variation across NICUs in safety and teamwork climate scales of SAQ and HSOPSC (pteamwork scales (teamwork climate and teamwork within units) of the two instruments correlated strongly (safety r=0.72, pteamwork r=0.67, p<0.001). However, the means and per cent agreements for all scale scores and even seemingly similar item scores were significantly different. In addition, comparisons of scale score quartiles between the two instruments revealed that half of the NICUs fell into different quartiles when translating between the instruments. Large variation and opportunities for improvement in patient safety culture exist across NICUs. Important systematic differences exist between SAQ and HSOPSC such that these instruments should not be used interchangeably. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
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Observed climatic changes in Shanghai during 1873-2002
Institute of Scientific and Technical Information of China (English)
ZHANGQiang; CHENJiaqi; ZHANGZengxin
2005-01-01
Variation characteristics of temperature and precipitation in January and July and annual mean temperature and annual precipitation are analyzed with the help of cumulative anomalies,Mann-Kendall analysis and wavelet analysis. The research results indicate that January precipitation presents an increasing trend after 1990, wavelet analysis result suggests that this increasing trend will continue in the near future. The changes of July precipitation present different features. During 1900-1960, July precipitation is in a rising trend, but is in a declining trend after 1960. Wavelet analysis shows that this declining trend will go on in the near future. Temperature variations in Shanghai are in fluctuations with 2 to 3 temperature rising periods. Mann-Kendall analysis indicates that temperature variations have the obvious abrupt change time when compared with precipitation changes in Shanghai during the past 100 years. The abrupt change time of January temperature lies in 1985, and that of July temperature lies in 1931-1933 and annual mean temperature has the abrupt change time in 1923-1930. Except July precipitation, the precipitation in January, temperature in January, July and annual mean temperature, and annual precipitation are also in a rising trend in the near future. The research results in this paper may be meaningful for future further climatic changes of Shanghai and social mitigation of climatic disasters in the future.
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Emotional climate and feeding styles: observational analysis of dinner in low-income families
Indulgent feeding styles have been associated with a higher risk for childhood overweight. The processes through which feeding styles impact child weight are poorly understood. The aim of this study was to observe differences in the emotional climate created by parents (affect, tone of voice, gest...
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Bröde, Peter; Błazejczyk, Krzysztof; Fiala, Dusan; Havenith, George; Holmér, Ingvar; Jendritzky, Gerd; Kuklane, Kalev; Kampmann, Bernhard
2013-01-01
The growing need for valid assessment procedures of the outdoor thermal environment in the fields of public weather services, public health systems, urban planning, tourism & recreation and climate impact research raised the idea to develop the Universal Thermal Climate Index UTCI based on the most recent scientific progress both in thermo-physiology and in heat exchange theory. Following extensive validation of accessible models of human thermoregulation, the advanced multi-node 'Fiala' model was selected to form the basis of UTCI. This model was coupled with an adaptive clothing model which considers clothing habits by the general urban population and behavioral changes in clothing insulation related to actual environmental temperature. UTCI was developed conceptually as an equivalent temperature. Thus, for any combination of air temperature, wind, radiation, and humidity, UTCI is defined as the air temperature in the reference condition which would elicit the same dynamic response of the physiological model. This review analyses the sensitivity of UTCI to humidity and radiation in the heat and to wind in the cold and compares the results with observational studies and internationally standardized assessment procedures. The capabilities, restrictions and potential future extensions of UTCI are discussed.
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Uncertainty information in climate data records from Earth observation
Merchant, C. J.
2017-12-01
How to derive and present uncertainty in climate data records (CDRs) has been debated within the European Space Agency Climate Change Initiative, in search of common principles applicable across a range of essential climate variables. Various points of consensus have been reached, including the importance of improving provision of uncertainty information and the benefit of adopting international norms of metrology for language around the distinct concepts of uncertainty and error. Providing an estimate of standard uncertainty per datum (or the means to readily calculate it) emerged as baseline good practice, and should be highly relevant to users of CDRs when the uncertainty in data is variable (the usual case). Given this baseline, the role of quality flags is clarified as being complementary to and not repetitive of uncertainty information. Data with high uncertainty are not poor quality if a valid estimate of the uncertainty is available. For CDRs and their applications, the error correlation properties across spatio-temporal scales present important challenges that are not fully solved. Error effects that are negligible in the uncertainty of a single pixel may dominate uncertainty in the large-scale and long-term. A further principle is that uncertainty estimates should themselves be validated. The concepts of estimating and propagating uncertainty are generally acknowledged in geophysical sciences, but less widely practised in Earth observation and development of CDRs. Uncertainty in a CDR depends in part (and usually significantly) on the error covariance of the radiances and auxiliary data used in the retrieval. Typically, error covariance information is not available in the fundamental CDR (FCDR) (i.e., with the level-1 radiances), since provision of adequate level-1 uncertainty information is not yet standard practice. Those deriving CDRs thus cannot propagate the radiance uncertainty to their geophysical products. The FIDUCEO project (www.fiduceo.eu) is
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The climate - Observing the past, conserving the future
International Nuclear Information System (INIS)
Klotz, G.; Mazaud, A.; Saint-Jalm, F.
2011-01-01
Before we begin, we need to define the difference between meteorology and climatology. Meteorology is the study and forecasting of atmospheric phenomena over short periods of time, for specific geographic areas. The information dealt with is, therefore, temporary. Climatology investigates sets of meteorological conditions which are likely to affect different regions over long periods of time. The subject is built upon the foundations of various natural sciences: geography, geology, physics, chemistry... 'Climate involves changes in meteorological conditions considered over the entire planet'. The word 'climate' is used to refer to two distinct ideas. The more traditional meaning, which we learnt in our geography classes, is a property of a given location: the Earth is divided into climatic areas as a function of the meteorological conditions which dominate the various seasons in those regions. The second meaning of the word 'climate' refers to a global approach with respect to time: in this case, we are interested in changes in meteorological conditions considered over the entire planet and over long time periods (at least 30 years). It is this second meaning of the word that forms the subject of this leaflet, a leaflet which aims to explain how the global climate functions. (authors)
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Comparing the sensitivity of permafrost and marine gas hydrate to climate warming
International Nuclear Information System (INIS)
Taylor, A.E.; Dallimore, S.R.; Hyndman, R.D.; Wright, F.
2005-01-01
The sensitivity of Arctic subpermafrost gas hydrate at the Mallik borehole was compared to temperate marine gas hydrate located offshore southwestern Canada. In particular, a finite element geothermal model was used to determine the sensitivity to the end of the ice age, and contemporary climate warming of a 30 m thick methane hydrate layer lying at the base of a gas hydrate stability zone prior to 13.5 kiloannum (ka) before present (BP). It was suggested that the 30 m gas-hydrate-bearing layer would have disappeared by now, according to the thermal signal alone. However, the same gas-hydrate-bearing layer underlying permafrost would persist until at least 4 ka after present, even with contemporary climate warming. The longer time for subpermafrost gas hydrate comes from the thawing pore ice at the base of permafrost, at the expense of dissociation of the deeper gas hydrate. The dissociation of underlying gas hydrate from climate surface warming is buffered by the overlying permafrost
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Modelling and observing urban climate in the Netherlands
International Nuclear Information System (INIS)
Van Hove, B.; Steeneveld, G.J.; Heusinkveld, B.; Holtslag, B.; Jacobs, C.; Ter Maat, H.; Elbers, J.; Moors, E.
2011-06-01
The main aims of the present study are: (1) to evaluate the performance of two well-known mesoscale NWP (numerical weather prediction) models coupled to a UCM (Urban Canopy Models), and (2) to develop a proper measurement strategy for obtaining meteorological data that can be used in model evaluation studies. We choose the mesoscale models WRF (Weather Research and Forecasting Model) and RAMS (Regional Atmospheric Modeling System), respectively, because the partners in the present project have a large expertise with respect to these models. In addition WRF and RAMS have been successfully used in the meteorology and climate research communities for various purposes, including weather prediction and land-atmosphere interaction research. Recently, state-of-the-art UCM's were embedded within the land surface scheme of the respective models, in order to better represent the exchange of heat, momentum, and water vapour in the urban environment. Key questions addressed here are: What is the general model performance with respect to the urban environment?; How can useful and observational data be obtained that allow sensible validation and further parameterization of the models?; and Can the models be easily modified to simulate the urban climate under Dutch climatic conditions, urban configuration and morphology? Chapter 2 reviews the available Urban Canopy Models; we discuss their theoretical basis, the different representations of the urban environment, the required input and the output. Much of the information was obtained from the Urban Surface Energy Balance: Land Surface Scheme Comparison project (PILPS URBAN, PILPS stands for Project for Inter-comparison of Land-Surface Parameterization Schemes). This project started in March 2008 and was coordinated by the Department of Geography, King's College London. In order to test the performance of our models we participated in this project. Chapter 3 discusses the main results of the first phase of PILPS URBAN. A first
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Comparing climate change and species invasions as drivers of coldwater fish population extirpations.
Directory of Open Access Journals (Sweden)
Sapna Sharma
Full Text Available Species are influenced by multiple environmental stressors acting simultaneously. Our objective was to compare the expected effects of climate change and invasion of non-indigenous rainbow smelt (Osmerus mordax on cisco (Coregonus artedii population extirpations at a regional level. We assembled a database of over 13,000 lakes in Wisconsin, USA, summarising fish occurrence, lake morphology, water chemistry, and climate. We used A1, A2, and B1 scenarios from the Intergovernmental Panel on Climate Change (IPCC of future temperature conditions for 15 general circulation models in 2046-2065 and 2081-2100 totalling 78 projections. Logistic regression indicated that cisco tended to occur in cooler, larger, and deeper lakes. Depending upon the amount of warming, 25-70% of cisco populations are predicted to be extirpated by 2100. In addition, cisco are influenced by the invasion of rainbow smelt, which prey on young cisco. Projecting current estimates of rainbow smelt spread and impact into the future will result in the extirpation of about 1% of cisco populations by 2100 in Wisconsin. Overall, the effect of climate change is expected to overshadow that of species invasion as a driver of coldwater fish population extirpations. Our results highlight the potentially dominant role of climate change as a driver of biotic change.
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Climate warming drives local extinction: Evidence from observation and experimentation.
Panetta, Anne Marie; Stanton, Maureen L; Harte, John
2018-02-01
Despite increasing concern about elevated extinction risk as global temperatures rise, it is difficult to confirm causal links between climate change and extinction. By coupling 25 years of in situ climate manipulation with experimental seed introductions and both historical and current plant surveys, we identify causal, mechanistic links between climate change and the local extinction of a widespread mountain plant ( Androsace septentrionalis ). Climate warming causes precipitous declines in population size by reducing fecundity and survival across multiple life stages. Climate warming also purges belowground seed banks, limiting the potential for the future recovery of at-risk populations under ameliorated conditions. Bolstered by previous reports of plant community shifts in this experiment and in other habitats, our findings not only support the hypothesis that climate change can drive local extinction but also foreshadow potentially widespread species losses in subalpine meadows as climate warming continues.
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An observational and modeling study of the regional impacts of climate variability
Horton, Radley M.
Climate variability has large impacts on humans and their agricultural systems. Farmers are at the center of this agricultural network, but it is often agricultural planners---regional planners, extension agents, commodity groups and cooperatives---that translate climate information for users. Global climate models (GCMs) are a leading tool for understanding and predicting climate and climate change. Armed with climate projections and forecasts, agricultural planners adapt their decision-making to optimize outcomes. This thesis explores what GCMs can, and cannot, tell us about climate variability and change at regional scales. The question is important, since high-quality regional climate projections could assist farmers and regional planners in key management decisions, contributing to better agricultural outcomes. To answer these questions, climate variability and its regional impacts are explored in observations and models for the current and future climate. The goals are to identify impacts of observed variability, assess model simulation of variability, and explore how climate variability and its impacts may change under enhanced greenhouse warming. Chapter One explores how well Goddard Institute for Space Studies (GISS) atmospheric models, forced by historical sea surface temperatures (SST), simulate climatology and large-scale features during the exceptionally strong 1997--1999 El Nino Southern Oscillation (ENSO) cycle. Reasonable performance in this 'proof of concept' test is considered a minimum requirement for further study of variability in models. All model versions produce appropriate local changes with ENSO, indicating that with correct ocean temperatures these versions are capable of simulating the large-scale effects of ENSO around the globe. A high vertical resolution model (VHR) provides the best simulation. Evidence is also presented that SST anomalies outside the tropical Pacific may play a key role in generating remote teleconnections even
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Comparative analysis of climate change vulnerability assessments. Lessons from Tunisia and Indonesia
Energy Technology Data Exchange (ETDEWEB)
Hammill, Anne; Bizikova, Livia; Dekens, Julie; McCandless, Matthew
2013-03-15
Vulnerability assessments (VAs) are central to shaping climate change adaptation decisions. They help to define the nature and extent of the threat that may harm a given human or ecological system, providing a basis for devising measures that will minimize or avoid this harm. Yet the wide variety of VA approaches can be confusing for practitioners, creating uncertainty about the ''right'' way to assess vulnerability. In an effort to provide some guidance on designing and conducting VAs, this paper reviews and compares VAs undertaken in Indonesia and Tunisia to distill key approaches, components and lessons. It begins with a general overview of definitions, approaches and challenges with conducting VAs, and then proposes a framework for analyzing and comparing them. The framework looks at four components of VAs: (1) Framing: where do we come from? (2) Process of conducting the VAs: how does it work? (3) Inputs: what is needed? (4) Outputs: what does it tell us? The framework is then applied to analyze the assessments carried out in Tunisia and Indonesia, from their respective framings of vulnerability to the outputs of the process. The report then concludes with observations on differences and similarities between the VAs, as well as lessons learned that can inform the design and execution of future assessments.
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Comparative analysis of climate change vulnerability assessments. Lessons from Tunisia and Indonesia
International Nuclear Information System (INIS)
Hammill, Anne; Bizikova, Livia; Dekens, Julie; McCandless, Matthew
2013-03-01
Vulnerability assessments (VAs) are central to shaping climate change adaptation decisions. They help to define the nature and extent of the threat that may harm a given human or ecological system, providing a basis for devising measures that will minimize or avoid this harm. Yet the wide variety of VA approaches can be confusing for practitioners, creating uncertainty about the ''right'' way to assess vulnerability. In an effort to provide some guidance on designing and conducting VAs, this paper reviews and compares VAs undertaken in Indonesia and Tunisia to distill key approaches, components and lessons. It begins with a general overview of definitions, approaches and challenges with conducting VAs, and then proposes a framework for analyzing and comparing them. The framework looks at four components of VAs: (1) Framing: where do we come from? (2) Process of conducting the VAs: how does it work? (3) Inputs: what is needed? (4) Outputs: what does it tell us? The framework is then applied to analyze the assessments carried out in Tunisia and Indonesia, from their respective framings of vulnerability to the outputs of the process. The report then concludes with observations on differences and similarities between the VAs, as well as lessons learned that can inform the design and execution of future assessments.
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Glotter, Michael J.; Ruane, Alex C.; Moyer, Elisabeth J.; Elliott, Joshua W.
2015-01-01
Projections of future food production necessarily rely on models, which must themselves be validated through historical assessments comparing modeled and observed yields. Reliable historical validation requires both accurate agricultural models and accurate climate inputs. Problems with either may compromise the validation exercise. Previous studies have compared the effects of different climate inputs on agricultural projections but either incompletely or without a ground truth of observed yields that would allow distinguishing errors due to climate inputs from those intrinsic to the crop model. This study is a systematic evaluation of the reliability of a widely used crop model for simulating U.S. maize yields when driven by multiple observational data products. The parallelized Decision Support System for Agrotechnology Transfer (pDSSAT) is driven with climate inputs from multiple sources reanalysis, reanalysis that is bias corrected with observed climate, and a control dataset and compared with observed historical yields. The simulations show that model output is more accurate when driven by any observation-based precipitation product than when driven by non-bias-corrected reanalysis. The simulations also suggest, in contrast to previous studies, that biased precipitation distribution is significant for yields only in arid regions. Some issues persist for all choices of climate inputs: crop yields appear to be oversensitive to precipitation fluctuations but under sensitive to floods and heat waves. These results suggest that the most important issue for agricultural projections may be not climate inputs but structural limitations in the crop models themselves.
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Observed 20th century desert dust variability: impact on climate and biogeochemistry
Directory of Open Access Journals (Sweden)
N. M. Mahowald
2010-11-01
Full Text Available Desert dust perturbs climate by directly and indirectly interacting with incoming solar and outgoing long wave radiation, thereby changing precipitation and temperature, in addition to modifying ocean and land biogeochemistry. While we know that desert dust is sensitive to perturbations in climate and human land use, previous studies have been unable to determine whether humans were increasing or decreasing desert dust in the global average. Here we present observational estimates of desert dust based on paleodata proxies showing a doubling of desert dust during the 20th century over much, but not all the globe. Large uncertainties remain in estimates of desert dust variability over 20th century due to limited data. Using these observational estimates of desert dust change in combination with ocean, atmosphere and land models, we calculate the net radiative effect of these observed changes (top of atmosphere over the 20th century to be −0.14 ± 0.11 W/m2 (1990–1999 vs. 1905–1914. The estimated radiative change due to dust is especially strong between the heavily loaded 1980–1989 and the less heavily loaded 1955–1964 time periods (−0.57 ± 0.46 W/m2, which model simulations suggest may have reduced the rate of temperature increase between these time periods by 0.11 °C. Model simulations also indicate strong regional shifts in precipitation and temperature from desert dust changes, causing 6 ppm (12 PgC reduction in model carbon uptake by the terrestrial biosphere over the 20th century. Desert dust carries iron, an important micronutrient for ocean biogeochemistry that can modulate ocean carbon storage; here we show that dust deposition trends increase ocean productivity by an estimated 6% over the 20th century, drawing down an additional 4 ppm (8 PgC of carbon dioxide into the oceans. Thus, perturbations to desert dust over the 20th century inferred from observations are potentially important for climate and
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Human-Induced Climate Variations Linked to Urbanization: From Observations to Modeling
Shepherd, J. Marshall; Jin, Menglin
2004-01-01
The goal of this session is to bring together scientists from interdisciplinary backgrounds to discuss the data, scientific approaches and recent results focusing on the impact of urbanization on the climate. The discussion will highlight current observational and modeling capabilities being employed for investigating the urban environment and its linkage to the change in the Earth's climate system. The goal of the session is to identify our current stand and the future direction on the topic. Urbanization is one of the extreme cases of land use change. Most of population of the world has moved to urban areas. By 1995, more than 70% of population of North America and Europe were living in cities. By 2025, the United Nations estimates that 60% of the worlds population will live in cities. Although currently only 1.2% of the land is urban, better understanding of how the atmosphere-ocean-land-biosphere components interact as a coupled system and the influence of human activities on this system is critical. Our understanding of urbanization effect is incomplete, partly because human activities induce new changes on climate in addition to the original natural variations, and partly because previously few data available for study urban effect globally. Urban construction changes surface roughness, albedo, heat capacity and vegetation coverage. Traffic and industry increase atmospheric aerosol. It is suggested that urbanization may modify rainfall processes through aerosol-cloud interactions or dynamic feedbacks. Because urbanization effect on climate is determined by many factors including land cover, the city's microscale features, population density, and human lifestyle patterns, it is necessary to study urban areas over globe.
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Extreme temperature events on Greenland in observations and the MAR regional climate model
Leeson, Amber A.; Eastoe, Emma; Fettweis, Xavier
2018-03-01
Meltwater from the Greenland Ice Sheet contributed 1.7-6.12 mm to global sea level between 1993 and 2010 and is expected to contribute 20-110 mm to future sea level rise by 2100. These estimates were produced by regional climate models (RCMs) which are known to be robust at the ice sheet scale but occasionally miss regional- and local-scale climate variability (e.g. Leeson et al., 2017; Medley et al., 2013). To date, the fidelity of these models in the context of short-period variability in time (i.e. intra-seasonal) has not been fully assessed, for example their ability to simulate extreme temperature events. We use an event identification algorithm commonly used in extreme value analysis, together with observations from the Greenland Climate Network (GC-Net), to assess the ability of the MAR (Modèle Atmosphérique Régional) RCM to reproduce observed extreme positive-temperature events at 14 sites around Greenland. We find that MAR is able to accurately simulate the frequency and duration of these events but underestimates their magnitude by more than half a degree Celsius/kelvin, although this bias is much smaller than that exhibited by coarse-scale Era-Interim reanalysis data. As a result, melt energy in MAR output is underestimated by between 16 and 41 % depending on global forcing applied. Further work is needed to precisely determine the drivers of extreme temperature events, and why the model underperforms in this area, but our findings suggest that biases are passed into MAR from boundary forcing data. This is important because these forcings are common between RCMs and their range of predictions of past and future ice sheet melting. We propose that examining extreme events should become a routine part of global and regional climate model evaluation and that addressing shortcomings in this area should be a priority for model development.
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Charney, Noah D; Babst, Flurin; Poulter, Benjamin; Record, Sydne; Trouet, Valerie M; Frank, David; Enquist, Brian J; Evans, Margaret E K
2016-09-01
Predicting long-term trends in forest growth requires accurate characterisation of how the relationship between forest productivity and climatic stress varies across climatic regimes. Using a network of over two million tree-ring observations spanning North America and a space-for-time substitution methodology, we forecast climate impacts on future forest growth. We explored differing scenarios of increased water-use efficiency (WUE) due to CO2 -fertilisation, which we simulated as increased effective precipitation. In our forecasts: (1) climate change negatively impacted forest growth rates in the interior west and positively impacted forest growth along the western, southeastern and northeastern coasts; (2) shifting climate sensitivities offset positive effects of warming on high-latitude forests, leaving no evidence for continued 'boreal greening'; and (3) it took a 72% WUE enhancement to compensate for continentally averaged growth declines under RCP 8.5. Our results highlight the importance of locally adapted forest management strategies to handle regional differences in growth responses to climate change. © 2016 John Wiley & Sons Ltd/CNRS.
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Climate warming drives local extinction: Evidence from observation and experimentation
Panetta, Anne Marie; Stanton, Maureen L.; Harte, John
2018-01-01
Despite increasing concern about elevated extinction risk as global temperatures rise, it is difficult to confirm causal links between climate change and extinction. By coupling 25 years of in situ climate manipulation with experimental seed introductions and both historical and current plant surveys, we identify causal, mechanistic links between climate change and the local extinction of a widespread mountain plant (Androsace septentrionalis). Climate warming causes precipitous declines in population size by reducing fecundity and survival across multiple life stages. Climate warming also purges belowground seed banks, limiting the potential for the future recovery of at-risk populations under ameliorated conditions. Bolstered by previous reports of plant community shifts in this experiment and in other habitats, our findings not only support the hypothesis that climate change can drive local extinction but also foreshadow potentially widespread species losses in subalpine meadows as climate warming continues. PMID:29507884
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Effects of increasing aerosol on regional climate change in China: Observation and modeling
Qian, Y.; Leung, L.; Ghan, S. J.
2002-12-01
We present regional simulations of climate, aerosol properties, and direct radiative forcing and climatic effects of aerosol and analyze the pollutant emissions and observed climatic data during the latter decades of last century in China. The regional model generally captures the spatial distributions and seasonal pattern of temperature and precipitation. Aerosol extinction coefficient and aerosol optical depth are generally well simulated in both magnitude and spatial distribution, which provides a reliable foundation for estimating the radiative forcing and climatic effects of aerosol. The radiative forcing of aerosol is in the range of -1 to -14 W m-2 in autumn and summer and -1 to -9 W m-2 in spring and winter, with substantial spatial variability at the sub-regional scale. A strong maximum in negative radiative forcing corresponding to the maximum optical depth is found over the Sichuan Basin, where emission as well as relative humidity are high, and stagnant atmospheric conditions inhibit pollutants dispersion. Negative radiative forcing of aerosol induces a surface cooling, which is stronger in the range of -0.6 to -1.2oC in autumn and winter than in spring (-0.3 to -0.6oC) and summer (0.0 to -0.9oC) over the Sichuan Basin and East China due to more significant effects of cloud and precipitation in the summer and spring. Aerosol-induced cooling is mainly contributed by cooling in the daytime temperature. The cooling reaches a maximum and is statistically significant in the Sichuan Basin. The effect of aerosol on precipitation is not evident in our simulations. The temporal and spatial patterns of temperature trends observed in the second half of the twentieth century, including the asymmetric daily maximum and minimum temperature trends, are at least qualitatively consistent with the simulated aerosol-induced cooling over the Sichuan Basin and East China. It supports the hypothesis that the observed temperature trends during the latter decades of the
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Energy Technology Data Exchange (ETDEWEB)
Sierra, Katherine; Roberts, Timmons; de Nevers, Michele; Langley, Claire; Smith, Cory
2013-06-15
Are climate finance contributor countries, multilateral aid agencies and specialized funds using widely accepted best practices in foreign assistance? How is it possible to measure and compare international climate finance contributions when there are as yet no established metrics or agreed definitions of the quality of climate finance? As a subjective metric, quality can mean different things to different stakeholders, while of donor countries, recipients and institutional actors may place quality across a broad spectrum of objectives. This subjectivity makes the assessment of the quality of climate finance contributions a useful and necessary exercise, but one that has many challenges. This work seeks to enhance the development of common definitions and metrics of the quality of climate finance, to understand what we can about those areas where climate finance information is available and shine a light on the areas where there is a severe dearth of data. Allowing for comparisons of the use of best practices across funding institutions in the climate sector could begin a process of benchmarking performance, fostering learning across institutions and driving improvements when incorporated in internal evaluation protocols of those institutions. In the medium term, this kind of benchmarking and transparency could support fundraising in contributor countries and help build trust with recipient countries. As a feasibility study, this paper attempts to outline the importance of assessing international climate finance contributions while describing the difficulties in arriving at universally agreed measurements and indicators for assessment. In many cases, data are neither readily available nor complete, and there is no consensus on what should be included. A number of indicators are proposed in this study as a starting point with which to analyze voluntary contributions, but in some cases their methodologies are not complete, and further research is required for a
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Dirmeyer, Paul A.; Wu, Jiexia; Norton, Holly E.; Dorigo, Wouter A.; Quiring, Steven M.; Ford, Trenton W.; Santanello, Joseph A., Jr.; Bosilovich, Michael G.; Ek, Michael B.; Koster, Randal Dean;
2016-01-01
Four land surface models in uncoupled and coupled configurations are compared to observations of daily soil moisture from 19 networks in the conterminous United States to determine the viability of such comparisons and explore the characteristics of model and observational data. First, observations are analyzed for error characteristics and representation of spatial and temporal variability. Some networks have multiple stations within an area comparable to model grid boxes; for those we find that aggregation of stations before calculation of statistics has little effect on estimates of variance, but soil moisture memory is sensitive to aggregation. Statistics for some networks stand out as unlike those of their neighbors, likely due to differences in instrumentation, calibration and maintenance. Buried sensors appear to have less random error than near-field remote sensing techniques, and heat dissipation sensors show less temporal variability than other types. Model soil moistures are evaluated using three metrics: standard deviation in time, temporal correlation (memory) and spatial correlation (length scale). Models do relatively well in capturing large-scale variability of metrics across climate regimes, but poorly reproduce observed patterns at scales of hundreds of kilometers and smaller. Uncoupled land models do no better than coupled model configurations, nor do reanalyses out perform free-running models. Spatial decorrelation scales are found to be difficult to diagnose. Using data for model validation, calibration or data assimilation from multiple soil moisture networks with different types of sensors and measurement techniques requires great caution. Data from models and observations should be put on the same spatial and temporal scales before comparison.
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Koslow, J. A.; Brodeur, R.; Duffy-Anderson, J. T.; Perry, I.; jimenez Rosenberg, S.; Aceves, G.
2016-02-01
Ichthyoplankton time series available from the Bering Sea, Gulf of Alaska and California Current (Oregon to Baja California) provide a potential ocean observing network to assess climate impacts on fish communities along the west coast of North America. Larval fish abundance reflects spawning stock biomass, so these data sets provide indicators of the status of a broad range of exploited and unexploited fish populations. Analyses to date have focused on individual time series, which generally exhibit significant change in relation to climate. Off California, a suite of 24 midwater fish taxa have declined > 60%, correlated with declining midwater oxygen concentrations, and overall larval fish abundance has declined 72% since 1969, a trend based on the decline of predominantly cool-water affinity taxa in response to warming ocean temperatures. Off Oregon, there were dramatic differences in community structure and abundance of larval fishes between warm and cool ocean conditions. Midwater deoxygenation and warming sea surface temperature trends are predicted to continue as a result of global climate change. US, Canadian, and Mexican fishery scientists are now collaborating in a virtual ocean observing network to synthesize available ichthyoplankton time series and compare patterns of change in relation to climate. This will provide regional indicators of populations and groups of taxa sensitive to warming, deoxygenation and potentially other stressors, establish the relevant scales of coherence among sub-regions and across Large Marine Ecosystems, and provide the basis for predicting future climate change impacts on these ecosystems.
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International Nuclear Information System (INIS)
Chen, Liang; Dirmeyer, Paul A
2016-01-01
To assess the biogeophysical impacts of land cover/land use change (LCLUC) on surface temperature, two observation-based metrics and their applicability in climate modeling were explored in this study. Both metrics were developed based on the surface energy balance, and provided insight into the contribution of different aspects of land surface change (such as albedo, surface roughness, net radiation and surface heat fluxes) to changing climate. A revision of the first metric, the intrinsic biophysical mechanism, can be used to distinguish the direct and indirect effects of LCLUC on surface temperature. The other, a decomposed temperature metric, gives a straightforward depiction of separate contributions of all components of the surface energy balance. These two metrics well capture observed and model simulated surface temperature changes in response to LCLUC. Results from paired FLUXNET sites and land surface model sensitivity experiments indicate that surface roughness effects usually dominate the direct biogeophysical feedback of LCLUC, while other effects play a secondary role. However, coupled climate model experiments show that these direct effects can be attenuated by large scale atmospheric changes (indirect feedbacks). When applied to real-time transient LCLUC experiments, the metrics also demonstrate usefulness for assessing the performance of climate models and quantifying land–atmosphere interactions in response to LCLUC. (letter)
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A Climate Benchmark of Upper Air Temperature Observations from GNSS Radio Occultation
Ao, C. O.; Mannucci, A. J.; Leroy, S. S.; Verkhoglyadova, O. P.
2017-12-01
GPS (Global Positioning System), or more generally Global Navigation Satellite System (GNSS), radio occultation (RO) is a remote sensing technique that produces highly accurate temperature in the upper troposphere and lower stratosphere across the globe with fine vertical resolution. Its fundamental measurement is the time delay of the microwave signal as it travels from a GNSS satellite to the receiver in low Earth orbit. With a relatively simple physical retrieval, the uncertainty in the derived temperature can be traced rigorously through the retrieval chain back to the raw measurements. The high absolute accuracy of RO allows these observations to be assimilated without bias correction in numerical weather prediction models and provides an anchor for assimilating other types of observations. The high accuracy, coupled with long-term stability, makes RO valuable in detecting decadal temperature trends. In this presentation, we will summarize the current state of RO observations and show temperature trends derived from 15 years of RO data in the upper troposphere and lower stratosphere. We will discuss our recent efforts in developing retrieval algorithms that are more tailored towards climate applications. Despite the relatively robust "self-calibrating" nature of RO observations, disparity in receiver hardware and software may introduce subtle differences that need to be carefully addressed. While the historic RO data record came from relatively homogeneous hardware based largely on NASA/JPL design (e.g., CHAMP and COSMIC), the future data will likely be comprised of a diverse set of observations from Europe, China, and various commercial data providers. In addition, the use of non-GPS navigation systems will become more prevalent. We will discuss the challenges involved in establishing a long-term RO climate data record from a suite of research and operational weather satellites with changes in instrumentation and coverage.
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Energy Technology Data Exchange (ETDEWEB)
Schoenwiese, C D [J.W. Goethe Univ., Frankfurt (Germany). Inst. for Meteorology and Geophysics
1996-12-31
It is a well-known fact that human activities lead to an atmospheric concentration increase of some IR-active trace gases (greenhouse gases GHG) and that this influence enhances the `greenhouse effect`. However, there are major quantitative and regional uncertainties in the related climate model projections and the observational data reflect the whole complex of both anthropogenic and natural forcing of the climate system. This contribution aims at the separation of the anthropogenic enhanced greenhouse signal in observed global surface air temperature data versus other forcing using statistical methods such as multiple (multiforced) regressions and neural networks. The competitive natural forcing considered are volcanic and solar activity, in addition the ENSO (El Nino/Southern Oscillation) mechanism. This analysis will be extended also to the NAO (North Atlantic Oscillation) and anthropogenic sulfate formation in the troposphere
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Energy Technology Data Exchange (ETDEWEB)
Schoenwiese, C.D. [J.W. Goethe Univ., Frankfurt (Germany). Inst. for Meteorology and Geophysics
1995-12-31
It is a well-known fact that human activities lead to an atmospheric concentration increase of some IR-active trace gases (greenhouse gases GHG) and that this influence enhances the `greenhouse effect`. However, there are major quantitative and regional uncertainties in the related climate model projections and the observational data reflect the whole complex of both anthropogenic and natural forcing of the climate system. This contribution aims at the separation of the anthropogenic enhanced greenhouse signal in observed global surface air temperature data versus other forcing using statistical methods such as multiple (multiforced) regressions and neural networks. The competitive natural forcing considered are volcanic and solar activity, in addition the ENSO (El Nino/Southern Oscillation) mechanism. This analysis will be extended also to the NAO (North Atlantic Oscillation) and anthropogenic sulfate formation in the troposphere
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Implications for Climate Sensitivity from the Response to Individual Forcings
Marvel, Kate; Schmidt, Gavin A.; Miller, Ron L.; Nazarenko, Larissa
2015-01-01
Climate sensitivity to doubled CO2 is a widely-used metric of the large-scale response to external forcing. Climate models predict a wide range for two commonly used definitions: the transient climate response (TCR: the warming after 70 years of CO2 concentrations that riseat 1 per year), and the equilibrium climate sensitivity (ECS: the equilibrium temperature change following a doubling of CO2 concentrations). Many observational datasets have been used to constrain these values, including temperature trends over the recent past 16, inferences from paleo-climate and process-based constraints from the modern satellite eras. However, as the IPCC recently reported different classes of observational constraints produce somewhat incongruent ranges. Here we show that climate sensitivity estimates derived from recent observations must account for the efficacy of each forcing active during the historical period. When we use single forcing experiments to estimate these efficacies and calculate climate sensitivity from the observed twentieth-century warming, our estimates of both TCR and ECS are revised upward compared to previous studies, improving the consistency with independent constraints.
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Observations from old forests underestimate climate change effects on tree mortality.
Luo, Yong; Chen, Han Y H
2013-01-01
Understanding climate change-associated tree mortality is central to linking climate change impacts and forest structure and function. However, whether temporal increases in tree mortality are attributed to climate change or stand developmental processes remains uncertain. Furthermore, interpreting the climate change-associated tree mortality estimated from old forests for regional forests rests on an un-tested assumption that the effects of climate change are the same for young and old forests. Here we disentangle the effects of climate change and stand developmental processes on tree mortality. We show that both climate change and forest development processes influence temporal mortality increases, climate change-associated increases are significantly higher in young than old forests, and higher increases in younger forests are a result of their higher sensitivity to regional warming and drought. We anticipate our analysis to be a starting point for more comprehensive examinations of how forest ecosystems might respond to climate change.
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Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M.; McCarty, Gregory W.; Hively, Wells; Lang, Megan W.; Sharifi, Amir
2018-01-01
Water quality problems in the Chesapeake Bay Watershed (CBW) are expected to be exacerbated by climate variability and change. However, climate impacts on agricultural lands and resultant nutrient loads into surface water resources are largely unknown. This study evaluated the impacts of climate variability and change on two adjacent watersheds in the Coastal Plain of the CBW, using the Soil and Water Assessment Tool (SWAT) model. We prepared six climate sensitivity scenarios to assess the individual impacts of variations in CO2concentration (590 and 850 ppm), precipitation increase (11 and 21 %), and temperature increase (2.9 and 5.0 °C), based on regional general circulation model (GCM) projections. Further, we considered the ensemble of five GCM projections (2085–2098) under the Representative Concentration Pathway (RCP) 8.5 scenario to evaluate simultaneous changes in CO2, precipitation, and temperature. Using SWAT model simulations from 2001 to 2014 as a baseline scenario, predicted hydrologic outputs (water and nitrate budgets) and crop growth were analyzed. Compared to the baseline scenario, a precipitation increase of 21 % and elevated CO2 concentration of 850 ppm significantly increased streamflow and nitrate loads by 50 and 52 %, respectively, while a temperature increase of 5.0 °C reduced streamflow and nitrate loads by 12 and 13 %, respectively. Crop biomass increased with elevated CO2 concentrations due to enhanced radiation- and water-use efficiency, while it decreased with precipitation and temperature increases. Over the GCM ensemble mean, annual streamflow and nitrate loads showed an increase of ∼ 70 % relative to the baseline scenario, due to elevated CO2 concentrations and precipitation increase. Different hydrological responses to climate change were observed from the two watersheds, due to contrasting land use and soil characteristics. The watershed with a larger percent of croplands demonstrated a greater
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Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M.; McCarty, Gregory W.; Hively, Wells D.; Lang, Megan W.; Sharifi, Amir
2018-01-01
Water quality problems in the Chesapeake Bay Watershed (CBW) are expected to be exacerbated by climate variability and change. However, climate impacts on agricultural lands and resultant nutrient loads into surface water resources are largely unknown. This study evaluated the impacts of climate variability and change on two adjacent watersheds in the Coastal Plain of the CBW, using the Soil and Water Assessment Tool (SWAT) model. We prepared six climate sensitivity scenarios to assess the individual impacts of variations in CO2 concentration (590 and 850 ppm), precipitation increase (11 and 21 %), and temperature increase (2.9 and 5.0 °C), based on regional general circulation model (GCM) projections. Further, we considered the ensemble of five GCM projections (2085-2098) under the Representative Concentration Pathway (RCP) 8.5 scenario to evaluate simultaneous changes in CO2, precipitation, and temperature. Using SWAT model simulations from 2001 to 2014 as a baseline scenario, predicted hydrologic outputs (water and nitrate budgets) and crop growth were analyzed. Compared to the baseline scenario, a precipitation increase of 21 % and elevated CO2 concentration of 850 ppm significantly increased streamflow and nitrate loads by 50 and 52 %, respectively, while a temperature increase of 5.0 °C reduced streamflow and nitrate loads by 12 and 13 %, respectively. Crop biomass increased with elevated CO2 concentrations due to enhanced radiation- and water-use efficiency, while it decreased with precipitation and temperature increases. Over the GCM ensemble mean, annual streamflow and nitrate loads showed an increase of ˜ 70 % relative to the baseline scenario, due to elevated CO2 concentrations and precipitation increase. Different hydrological responses to climate change were observed from the two watersheds, due to contrasting land use and soil characteristics. The watershed with a larger percent of croplands demonstrated a greater increased rate of 5.2 kg N ha-1 in
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CERN. Geneva
2009-01-01
The current understanding of climate change in the industrial age is that it is predominantly caused by anthropogenic greenhouse gases, with relatively small natural contributions due to solar irradiance and volcanoes. However, palaeoclimatic reconstructions show that the climate has frequently varied on 100-year time scales during the Holocene (last 10 kyr) by amounts comparable to the present warming - and yet the mechanism or mechanisms are not understood. Some of these reconstructions show clear associations with solar variability, which is recorded in the light radio-isotope archives that measure past variations of cosmic ray intensity. However, despite the increasing evidence of its importance, solar-climate variability is likely to remain controversial until a physical mechanism is established. Estimated changes of solar irradiance on these time scales appear to be too small to account for the climate observations. This raises the question of whether cosmic rays may directly affect the climate, provi...
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Climate simulations for 1880-2003 with GISS modelE
International Nuclear Information System (INIS)
Hansen, J.; Lacis, A.; Miller, R.; Schmidt, G.A.; Russell, G.; Canuto, V.; Del Genio, A.; Hall, T.; Hansen, J.; Sato, M.; Kharecha, P.; Nazarenko, L.; Aleinov, I.; Bauer, S.; Chandler, M.; Faluvegi, G.; Jonas, J.; Ruedy, R.; Lo, K.; Cheng, Y.; Lacis, A.; Schmidt, G.A.; Del Genio, A.; Miller, R.; Cairns, B.; Hall, T.; Baum, E.; Cohen, A.; Fleming, E.; Jackman, C.; Friend, A.; Kelley, M.
2007-01-01
We carry out climate simulations for 1880-2003 with GISS modelE driven by ten measured or estimated climate forcing. An ensemble of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together. We compare side-by-side simulated climate change for each forcing, all forcing, observations, unforced variability among model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all forcing are due to model deficiencies, inaccurate or incomplete forcing, and imperfect observations. Although there are notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations of future climate change. By using a fixed well-documented model and accurately defining the 1880-2003 forcing, we aim to provide a benchmark against which the effect of improvements in the model, climate forcing, and observations can be tested. Principal model deficiencies include unrealistic weak tropical El Nino-like variability and a poor distribution of sea ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. Greatest uncertainties in the forcing are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds. (authors)
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Climate Informatics: Accelerating Discovering in Climate Science with Machine Learning
Monteleoni, Claire; Schmidt, Gavin A.; McQuade, Scott
2014-01-01
The goal of climate informatics, an emerging discipline, is to inspire collaboration between climate scientists and data scientists, in order to develop tools to analyze complex and ever-growing amounts of observed and simulated climate data, and thereby bridge the gap between data and understanding. Here, recent climate informatics work is presented, along with details of some of the field's remaining challenges. Given the impact of climate change, understanding the climate system is an international priority. The goal of climate informatics is to inspire collaboration between climate scientists and data scientists, in order to develop tools to analyze complex and ever-growing amounts of observed and simulated climate data, and thereby bridge the gap between data and understanding. Here, recent climate informatics work is presented, along with details of some of the remaining challenges.
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Comparing farmers' perception of climate change and varia- bility ...
African Journals Online (AJOL)
adopt adaptation measures to climate change, more attention should be given to the role ... known about how climate interacts with other drivers of change in agricultural systems and ..... ta series divided by the standard deviation (Equation 1).
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DEFF Research Database (Denmark)
Van Roosmalen, Lieke Petronella G; Sonnenborg, Torben; Jensen, Karsten Høgh
2011-01-01
of the HIRHAM4 regional climate model (RCM). The aim of this study was to determine whether the choice of bias-correction method, applied to the RCM data, aff ected the projected hydrological changes. One method consisted of perturbation of observed data (POD) using climate change signals derived from the RCM......Projected climate change eff ects on groundwater and stream discharges were investigated through simulations with a distributed, physically based, surface water–groundwater model. Input to the hydrological model includes precipitation, reference evapotranspiration, and temperature data...... the simulations using both methods, only small differences between the projected changes in hydrological variables for the scenario period were found. Mean annual recharge increased by 15% for the DBS method and 12% for POD, and drain flow increased by 24 and 19%, respectively, while the increases in base flow...
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Effects of climate change on groundwater: observed and forecasted trends on Italian systems
Doveri, Marco; Menichini, Matia; Provenzale, Antonello; Scozzari, Andrea
2017-04-01
Groundwater represents the main source of water supply at global level. In Italy, as well as in most European countries, water needs are mainly covered by groundwater exploitation. The reliance on this resource is continuously growing, given the key role that groundwater plays for mitigating the climate change/variability and for addressing the significant increase in the global water demand. Despite this, and unlike surface waters, groundwater bodies have not been widely studied, and there is a general paucity of quantitative information, especially in relation to climate change. Although groundwater systems are more resilient to climate change than surface waters, they are affected both directly and indirectly. The estimation of the entity of these effects is mandatory for a reliable management of this crucial resource. The analysis of hydro-meteorological data over a few decades highlights that also the Italian territory is experiencing a change of the climate regime. Besides the increase of mean annual temperature, observed in particular since the early 1980s, longer and more frequent drought periods have been registered, as well as an increase of extreme events characterized by heavy rainfall. It is also noticeable a decrease in total rainfall, that is much more evident in the period from January to June. In addition to the reduced yearly inputs from precipitation, such trends determine also a lower snow accumulation and earlier snow melt in mountain areas, a general increase of evapotranspiration rates and an increased runoff fraction of the effective rainfall amount. As flood hydrographs of several major Italian rivers (e.g., Po, Brenta and Arno rivers) confirm, evident effects concern surface water resources. The main observed phenomena consist in the decline of mean annual discharge, the increase of extreme events with high discharge concentrated in short periods, and longer and earlier periods of low base flow. Impacts on groundwater recharge are not well
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Carbonaceous aerosols over China--review of observations, emissions, and climate forcing.
Wang, Linpeng; Zhou, Xuehua; Ma, Yujie; Cao, Zhaoyu; Wu, Ruidong; Wang, Wenxing
2016-01-01
Carbonaceous aerosols have been attracting attention due to the influence on visibility, air quality, and regional climate. Statistical analyses based on concentration levels, spatial-temporal variations, correlations, and organic carbon (OC) to element carbon (EC) ratios from published data of OC and EC in particulate matter (PM2.5 and PM10) were carried out in order to give a carbonaceous aerosol profile in China. The results showed maxima for OC of 29.5 ± 18.2 μg C m(-3) and for EC of 8.4 ± 6.3 μg C m(-3) in winter and minima for OC of 12.9 ± 7.7 μg C m(-3) in summer and for EC of 4.6 ± 2.8 μg C m(-3) in spring. In addition, OC and EC both had higher concentrations in urban than those in rural sites. Carbonaceous aerosol levels in China are about three to seven times higher compared to those in the USA and Europe. OC and EC occupied 20 ± 6 and 7 ± 3% of PM2.5 mass and 17 ± 7 and 5 ± 3% of PM10 mass, respectively, implying that carbonaceous aerosols are the main component of PM, especially OC. Secondary organic carbon (SOC) was a significant portion of PM and contributed 41 ± 26% to OC and 8 ± 6% to PM2.5 mass. The OC/EC ratio was 3.63 ± 1.73, which, along with the good correlation between OC and EC and the OC to EC slope of 2.29, signifies that coal combustion and/or vehicular exhaust is the dominated carbonaceous aerosol source in China. These provide a primary observation-based understanding of carbonaceous aerosol pollution in China and have a great significance in improving the emission inventory and climate forcing evaluation.
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DEFF Research Database (Denmark)
Ghoreishi, Newsha; Sørensen, Jan Corfixen; Jørgensen, Bo Nørregaard
2015-01-01
Non-trivial real world decision-making processes usually involve multiple parties having potentially conflicting interests over a set of issues. State-of-the-art multi-objective evolutionary algorithms (MOEA) are well known to solve this class of complex real-world problems. In this paper, we...... compare the performance of state-of-the-art multi-objective evolutionary algorithms to solve a non-linear multi-objective multi-issue optimisation problem found in Greenhouse climate control. The chosen algorithms in the study includes NSGAII, eNSGAII, eMOEA, PAES, PESAII and SPEAII. The performance...... of all aforementioned algorithms is assessed and compared using performance indicators to evaluate proximity, diversity and consistency. Our insights to this comparative study enhanced our understanding of MOEAs performance in order to solve a non-linear complex climate control problem. The empirical...
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Prettenthaler, Franz; Köberl, Judith; Bird, David Neil
2016-02-01
We extend the concept of 'Weather Value at Risk' - initially introduced to measure the economic risks resulting from current weather fluctuations - to describe and compare sectoral income risks from climate change. This is illustrated using the examples of wheat cultivation and summer tourism in (parts of) Sardinia. Based on climate scenario data from four different regional climate models we study the change in the risk of weather-related income losses between some reference (1971-2000) and some future (2041-2070) period. Results from both examples suggest an increase in weather-related risks of income losses due to climate change, which is somewhat more pronounced for summer tourism. Nevertheless, income from wheat cultivation is at much higher risk of weather-related losses than income from summer tourism, both under reference and future climatic conditions. A weather-induced loss of at least 5% - compared to the income associated with average reference weather conditions - shows a 40% (80%) probability of occurrence in the case of wheat cultivation, but only a 0.4% (16%) probability of occurrence in the case of summer tourism, given reference (future) climatic conditions. Whereas in the agricultural example increases in the weather-related income risks mainly result from an overall decrease in average wheat yields, the heightened risk in the tourism example stems mostly from a change in the weather-induced variability of tourism incomes. With the extended 'Weather Value at Risk' concept being able to capture both, impacts from changes in the mean and the variability of the climate, it is a powerful tool for presenting and disseminating the results of climate change impact assessments. Due to its flexibility, the concept can be applied to any economic sector and therefore provides a valuable tool for cross-sectoral comparisons of climate change impacts, but also for the assessment of the costs and benefits of adaptation measures. Copyright © 2015 Elsevier B
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Comparing Forecasts of the Global Impacts of Climate Change
International Nuclear Information System (INIS)
Mendelsohn, R.; Williams, L.
2004-01-01
This paper utilizes the predictions of several Atmosphere-Ocean General Circulation Models and the Global Impact Model to create forecasts of the global market impacts from climate change. The forecasts of market impacts in 2100 vary considerably depending on climate scenarios and climate impact sensitivity. The models do concur that tropical nations will be hurt, temperate nations will be barely affected, and high latitude nations will benefit. Although the size of these effects varies a great deal across models, the beneficial and harmful effects are offsetting, so that the net impact on the globe is relatively small in almost all outcomes. Looking only at market impacts, the forecasts suggest that while the global net benefits of abatement are small, the distribution of damages suggests a large equity problem that could be addressed through a compensation program. The large uncertainty surrounding these forecasts further suggests that continued monitoring of both the climate and impacts is worthwhile
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Energy Technology Data Exchange (ETDEWEB)
Alberti, Tommaso; Carbone, Vincenzo; Lepreti, Fabio [Dipartimento di Fisica, Università della Calabria, Ponte P. Bucci, Cubo 31C, I-87036, Rende (CS) (Italy); Vecchio, Antonio, E-mail: tommaso.alberti@unical.it, E-mail: tommasoalberti89@gmail.com [LESIA—Observatoire de Paris, PSL Research University, 5 place Jules Janssen, F-92190, Meudon (France)
2017-07-20
The recent discovery of the planetary system hosted by the ultracool dwarf star TRAPPIST-1 could open new paths for investigations of the planetary climates of Earth-sized exoplanets, their atmospheres, and their possible habitability. In this paper, we use a simple climate-vegetation energy-balance model to study the climate of the seven TRAPPIST-1 planets and the climate dependence on various factors: the global albedo, the fraction of vegetation that could cover their surfaces, and the different greenhouse conditions. The model allows us to investigate whether liquid water could be maintained on the planetary surfaces (i.e., by defining a “surface water zone (SWZ)”) in different planetary conditions, with or without the presence of a greenhouse effect. It is shown that planet TRAPPIST-1d seems to be the most stable from an Earth-like perspective, since it resides in the SWZ for a wide range of reasonable values of the model parameters. Moreover, according to the model, outer planets (f, g, and h) cannot host liquid water on their surfaces, even with Earth-like conditions, entering a snowball state. Although very simple, the model allows us to extract the main features of the TRAPPIST-1 planetary climates.
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International Nuclear Information System (INIS)
Alberti, Tommaso; Carbone, Vincenzo; Lepreti, Fabio; Vecchio, Antonio
2017-01-01
The recent discovery of the planetary system hosted by the ultracool dwarf star TRAPPIST-1 could open new paths for investigations of the planetary climates of Earth-sized exoplanets, their atmospheres, and their possible habitability. In this paper, we use a simple climate-vegetation energy-balance model to study the climate of the seven TRAPPIST-1 planets and the climate dependence on various factors: the global albedo, the fraction of vegetation that could cover their surfaces, and the different greenhouse conditions. The model allows us to investigate whether liquid water could be maintained on the planetary surfaces (i.e., by defining a “surface water zone (SWZ)”) in different planetary conditions, with or without the presence of a greenhouse effect. It is shown that planet TRAPPIST-1d seems to be the most stable from an Earth-like perspective, since it resides in the SWZ for a wide range of reasonable values of the model parameters. Moreover, according to the model, outer planets (f, g, and h) cannot host liquid water on their surfaces, even with Earth-like conditions, entering a snowball state. Although very simple, the model allows us to extract the main features of the TRAPPIST-1 planetary climates.
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Gaur, Mahendra; Das, Aradhana; Sahoo, Rajesh Kumar; Mohanty, Sujata; Joshi, Raj Kumar; Subudhi, Enketeswara
2016-09-01
Ginger (Zingiber officinale Rosc.), a well-known member of family Zingiberaceae, is bestowed with number of medicinal properties which is because of the secondary metabolites, essential oil and oleoresin, it contains in its rhizome. The drug yielding potential is known to depend on agro-climatic conditions prevailing at the place cultivation. Present study deals with comparative transcriptome analysis of two sample of elite ginger variety Suprabha collected from two different agro-climatic zones of Odisha. Transcriptome assembly for both the samples was done using next generation sequencing methodology. The raw data of size 10.8 and 11.8 GB obtained from analysis of two rhizomes S1Z4 and S2Z5 collected from Bhubaneswar and Koraput and are available in NCBI accession number SAMN03761169 and SAMN03761176 respectively. We identified 60,452 and 54,748 transcripts using trinity tool respectively from ginger rhizome of S1Z4 and S2Z5. The transcript length varied from 300 bp to 15,213 bp and 8988 bp and N50 value of 1415 bp and 1334 bp respectively for S1Z4 and S2Z5. To the best of our knowledge, this is the first comparative transcriptome analysis of elite ginger cultivars Suprabha from two different agro-climatic conditions of Odisha, India which will help to understand the effect of agro-climatic conditions on differential expression of secondary metabolites.
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The Economic Value of Climate Science
Wielicki, B. A.; Cooke, R.; Young, D. F.; Mlynczak, M. G.
2012-12-01
, exceeds the NPV of the system costs. We present illustrative results comparing the proposed CLARREO advance in satellite absolute calibration for climate change records to an existing system for detecting decadal temperature change and cloud feedback (i.e. climate sensitivity uncertainty). While CLARREO is used as an example, the value should be considered as relevant to an improved climate observing system, since societal decisions are unlikely to be based on one or a few observations. The VOI is found to depend on the required confidence level, the trigger value at which we would abandon the BAU emissions path, the path to which we switch, and the date at which the new system is launched. The VOI of CLARREO in this decision context is the surfeit of NPV of averted damages, relative to the existing system. Over all it is in the order of tens of trillions of US dollars. Among the noteworthy conclusions are (1) switching to either the DICE optimal or Stern emissions paths makes only a modest difference in the VOI of CLARREO, (2) raising the trigger value from 0.2C to 0.3C/decade, increases the VOI of CLARREO, while increasing the total NPV of climate damages, and (3) the choice of discount rate affects the VOI by a factor ~ 5. The results conclude that the economic value of advanced climate observing systems is dramatically larger than their cost, and argues for the continual enhancement of the SCC assessment process.
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International Nuclear Information System (INIS)
Alexander, Lisa
2007-01-01
Full text: Nine global coupled climate models were assessed for their ability to reproduce observed trends in a set of indices representing temperature and precipitation extremes over Australia. Observed trends for 1957-1999 were compared with individual and multi-modelled trends calculated over the same period. When averaged across Australia the magnitude of trends and interannual variability of temperature extremes were well simulated by most models, particularly for the warm nights index. Except for consecutive dry days, the majority of models also reproduced the correct sign of trend for precipitation extremes. A bootstrapping technique was used to show that most models produce plausible trends when averaged over Australia, although only heavy precipitation days simulated from the multi-model ensemble showed significant skill at reproducing the observed spatial pattern of trends. Two of the models with output from different forcings showed that only with anthropogenic forcing included could the models capture the observed areally averaged trend for some of the temperature indices, but the forcing made little difference to the models' ability to reproduce the spatial pattern of trends over Australia. Future projected changes in extremes using three emissions scenarios were also analysed. Australia shows a shift towards significant warming of temperature extremes with much longer dry spells interspersed with periods of increased extreme precipitation irrespective of the scenario used. More work is required to determine whether regional projected changes over Australia are robust
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NASA's Earth Observing System: The Transition from Climate Monitoring to Climate Change Prediction
King, Michael D.; Herring, David D.
1998-01-01
Earth's 4.5 billion year history is a study in change. Natural geological forces have been rearranging the surface features and climatic conditions of our planet since its beginning. There is scientific evidence that some of these natural changes have not only led to mass extinctions of species (e.g., dinosaurs), but have also severely impacted human civilizations. For instance, there is evidence that a relatively sudden climate change caused a 300-year drought that contributed to the downfall of Akkadia, one of the most powerful empires in the Middle-East region around 2200 BC. More recently, the "little ice age" from 1200-1400 AD forced the Vikings to abandon Greenland when temperatures there dropped by about 1.5 C, rendering it too difficult to grow enough crops to sustain the population. Today, there is compelling scientific evidence that human activities have attained the magnitude of a geological force and are speeding up the rate of global change. For example, carbon dioxide levels have risen 30 percent since the industrial revolution and about 40 percent of the world's land surface has been transformed by humans. We don't understand the cause-and-effect relationships among Earth's land, ocean, and atmosphere well enough to predict what, if any, impacts these rapid changes will have on future climate conditions. We need to make many measurements all over the world, over a long period of time, in order to assemble the information needed to construct accurate computer models that will enable us to forecast climate change. In 1988, the Earth System Sciences Committee, sponsored by NASA, issued a report calling for an integrated, long-term strategy for measuring the vital signs of Earth's climate system. The report urged that the measurements must all be intimately coupled with focused process studies, they must facilitate development of Earth system models, and they must be stored in an information system that ensures open access to consistent, long-term data
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Kasoar, M.; Voulgarakis, Apostolos; Lamarque, Jean-Francois; Shindell, Drew T.; Bellouin, Nicholas; Collins, William J.; Faluvegi, Greg; Tsigaridis, Kostas
2016-01-01
We use the HadGEM3-GA4, CESM1, and GISS ModelE2 climate models to investigate the global and regional aerosol burden, radiative flux, and surface temperature responses to removing anthropogenic sulfur dioxide (SO2) emissions from China. We find that the models differ by up to a factor of 6 in the simulated change in aerosol optical depth (AOD) and shortwave radiative flux over China that results from reduced sulfate aerosol, leading to a large range of magnitudes in the regional and global temperature responses. Two of the three models simulate a near-ubiquitous hemispheric warming due to the regional SO2 removal, with similarities in the local and remote pattern of response, but overall with a substantially different magnitude. The third model simulates almost no significant temperature response. We attribute the discrepancies in the response to a combination of substantial differences in the chemical conversion of SO2 to sulfate, translation of sulfate mass into AOD, cloud radiative interactions, and differences in the radiative forcing efficiency of sulfate aerosol in the models. The model with the strongest response (HadGEM3-GA4) compares best with observations of AOD regionally, however the other two models compare similarly (albeit poorly) and still disagree substantially in their simulated climate response, indicating that total AOD observations are far from sufficient to determine which model response is more plausible. Our results highlight that there remains a large uncertainty in the representation of both aerosol chemistry as well as direct and indirect aerosol radiative effects in current climate models, and reinforces that caution must be applied when interpreting the results of modelling studies of aerosol influences on climate. Model studies that implicate aerosols in climate responses should ideally explore a range of radiative forcing strengths representative of this uncertainty, in addition to thoroughly evaluating the models used against
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How well are the climate indices related to the GRACE-observed total water storage changes in China?
Devaraju, B.; Vishwakarma, B.; Sneeuw, N. J.
2017-12-01
The fresh water availability over land masses is changing rapidly under the influence of climate change and human intervention. In order to manage our water resources and plan for a better future, we need to demarcate the role of climate change. The total water storage change in a region can be obtained from the GRACE satellite mission. On the other hand, many climate change indicators, for example ENSO, are derived from sea surface temperature. In this contribution we investigate the relationship between the total water storage change over China with the climate indices using statistical time-series decomposition techniques, such as Seasonal and Trend decomposition using Loess (STL), Principal Component Analysis (PCA) and Canonical Correlation Analysis (CCA). The anomalies in climate variables, such as sea surface temperature, are responsible for anomalous precipitation and thus an anomalous total water storage change over land. Therefore, it is imperative that we use a GRACE product that can capture anomalous water storage changes with unprecedented accuracy. Since filtering decreases the sensitivity of GRACE products substantially, we use the data-driven method of deviation for recovering the signal lost due to filtering. To this end, we are able to obtain the spatial fingerprint of individual climate index on total water storage change observed over China.
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Shabani, Farzin; Shafapour Tehrany, Mahyat; Solhjouy-Fard, Samaneh; Kumar, Lalit
2018-01-01
Aedes albopictus , the Asian Tiger Mosquito, vector of Chikungunya, Dengue Fever and Zika viruses, has proven its hardy adaptability in expansion from its natural Asian, forest edge, tree hole habitat on the back of international trade transportation, re-establishing in temperate urban surrounds, in a range of water receptacles and semi-enclosures of organic matter. Conventional aerial spray mosquito vector controls focus on wetland and stagnant water expanses, proven to miss the protected hollows and crevices favoured by Ae. albopictus. New control or eradication strategies are thus essential, particular in light of potential expansions in the southeastern and eastern USA. Successful regional vector control strategies require risk level analysis. Should strategies prioritize regions with non-climatic or climatic suitability parameters for Ae. albopictus ? Our study used current Ae. albopictus distribution data to develop two independent models: (i) regions with suitable non-climatic factors, and (ii) regions with suitable climate for Ae. albopictus in southeastern USA. Non-climatic model processing used Evidential Belief Function (EBF), together with six geographical conditioning factors (raster data layers), to establish the probability index. Validation of the analysis results was estimated with area under the curve (AUC) using Ae. albopictus presence data. Climatic modeling was based on two General Circulation Models (GCMs), Miroc3.2 and CSIRO-MK30 running the RCP 8.5 scenario in MaxEnt software. EBF non-climatic model results achieved a 0.70 prediction rate and 0.73 success rate, confirming suitability of the study site regions for Ae. albopictus establishment. The climatic model results showed the best-fit model comprised Coldest Quarter Mean Temp, Precipitation of Wettest Quarter and Driest Quarter Precipitation factors with mean AUC value of 0.86. Both GCMs showed that the whole study site is highly suitable and will remain suitable climatically, according
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Directory of Open Access Journals (Sweden)
Farzin Shabani
2018-03-01
Full Text Available Aedes albopictus, the Asian Tiger Mosquito, vector of Chikungunya, Dengue Fever and Zika viruses, has proven its hardy adaptability in expansion from its natural Asian, forest edge, tree hole habitat on the back of international trade transportation, re-establishing in temperate urban surrounds, in a range of water receptacles and semi-enclosures of organic matter. Conventional aerial spray mosquito vector controls focus on wetland and stagnant water expanses, proven to miss the protected hollows and crevices favoured by Ae. albopictus. New control or eradication strategies are thus essential, particular in light of potential expansions in the southeastern and eastern USA. Successful regional vector control strategies require risk level analysis. Should strategies prioritize regions with non-climatic or climatic suitability parameters for Ae. albopictus? Our study used current Ae. albopictus distribution data to develop two independent models: (i regions with suitable non-climatic factors, and (ii regions with suitable climate for Ae. albopictus in southeastern USA. Non-climatic model processing used Evidential Belief Function (EBF, together with six geographical conditioning factors (raster data layers, to establish the probability index. Validation of the analysis results was estimated with area under the curve (AUC using Ae. albopictus presence data. Climatic modeling was based on two General Circulation Models (GCMs, Miroc3.2 and CSIRO-MK30 running the RCP 8.5 scenario in MaxEnt software. EBF non-climatic model results achieved a 0.70 prediction rate and 0.73 success rate, confirming suitability of the study site regions for Ae. albopictus establishment. The climatic model results showed the best-fit model comprised Coldest Quarter Mean Temp, Precipitation of Wettest Quarter and Driest Quarter Precipitation factors with mean AUC value of 0.86. Both GCMs showed that the whole study site is highly suitable and will remain suitable climatically
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Introduction to the special issue: Observed and projected changes in weather and climate extremes
Directory of Open Access Journals (Sweden)
John E. Hay
2016-03-01
Full Text Available This Special Issue documents not only the more recent progress made in detecting and attributing changes in temperature and precipitation extremes in the observational record, but also in projecting changes in such extremes at regional and local scales. It also deals with the impacts and other consequences and implications of both the historic and anticipated changes in extreme weather and climate events. Impact assessments using both dynamical downscaling and statistical modelling for two tropical cyclones are reported, as well as for storm surge and extreme wave changes. The Special Issue concludes with a consideration of some policy implications and practical applications arising from our relatively robust understanding of how the build up of greenhouse gases in the Earth’s atmosphere affects weather and climate extremes.
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Li, D.
2017-12-01
Fingerprints of anthropogenic climate change can be most readily detected in the high latitudes of Northern Hemisphere, where temperature has been rising faster than the rest of the globe and sea ice cover has shrunk dramatically over recent decades. Reducing the meridional temperature gradient, this amplified warming over the high latitudes influences weather in the middle latitudes by modulating the jet stream, storms, and atmospheric blocking activities. Whether observational records have revealed significant changes in mid-latitude storms and blocking activities, however, has remained a subject of much debate. Buried deep in strong year-to-year variations, the long-term dynamic responses of the atmosphere are more difficult to identify, compared with its thermodynamic responses. Variabilities of decadal and longer timescales further obscure any trends diagnosed from satellite observations, which are often shorter than 40 years. Here, new metrics reflecting storm and blocking activities are developed using surface air temperature and pressure records, and their variations and long-term trends are examined. This approach gives an inkling of the changes in storm and blocking activities since the Industrial Revolution in regions with abundant long-term observational records, e.g. Europe and North America. The relationship between Atlantic Multi-decadal Oscillation and variations in storm and blocking activities across the Atlantic is also scrutinized. The connection between observed centennial trends and anthropogenic forcings is investigated using a hierarchy of numerical tools, from highly idealized to fully coupled atmosphere-ocean models. Pre-industrial control simulations and a set of large ensemble simulations forced by increased CO2 are analyzed to evaluate the range of natural variabilities, which paves the way to singling out significant anthropogenic changes from observational records, as well as predicting future changes in mid-latitude storm and
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Redemann, Jens; Wood, R.; Zuidema, P.; Haywood, J.; Luna, B.; Abel, S.
2015-01-01
Southern Africa produces almost a third of the Earth's biomass burning (BB) aerosol particles, yet the fate of these particles and their influence on regional and global climate is poorly understood. Particles lofted into the mid-troposphere are transported westward over the South-East (SE) Atlantic, home to one of the three permanent subtropical Stratocumulus (Sc) cloud decks in the world. The stratocumulus "climate radiators" are critical to the regional and global climate system. They interact with dense layers of BB aerosols that initially overlay the cloud deck, but later subside and are mixed into the clouds. These interactions include adjustments to aerosol-induced solar heating and microphysical effects. As emphasized in the latest IPCC report, the global representation of these aerosol-cloud interaction processes in climate models is one of the largest uncertainty in estimates of future climate. Hence, new observations over the SE Atlantic have significant implications for global climate change scenarios. We discuss the current knowledge of aerosol and cloud property distributions based on satellite observations and sparse suborbital sampling, and describe planned field campaigns in the region. Specifically, we describe the scientific objectives and implementation of the following four synergistic, international research activities aimed at providing a process-level understanding of aerosol-cloud interactions over the SE Atlantic: 1) ORACLES (Observations of Aerosols above Clouds and their interactions), a five-year investigation between 2015 and 2019 with three Intensive Observation Periods (IOP), recently funded by the NASA Earth-Venture Suborbital Program, 2) CLARIFY-2016 (Cloud-Aerosol-Radiation Interactions and Forcing: Year 2016), a comprehensive observational and modeling programme funded by the UK's Natural Environment Research Council (NERC), and supported by the UK Met Office. 3) LASIC (Layered Atlantic Smoke Interactions with Clouds), a funded
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An assessment of the surface climate in the NCEP climate forecast system reanalysis
Energy Technology Data Exchange (ETDEWEB)
Wang, Wanqiu; Xie, Pingping; Yoo, Soo-Hyun; Xue, Yan; Kumar, Arun [Climate Prediction Center, NCEP/NWS/NOAA, Camp Springs, MD (United States); Wu, Xingren [Environmental Modeling Center, NCEP/NWS/NOAA, Camp Springs, MD (United States)
2011-10-15
This paper analyzes surface climate variability in the climate forecast system reanalysis (CFSR) recently completed at the National Centers for Environmental Prediction (NCEP). The CFSR represents a new generation of reanalysis effort with first guess from a coupled atmosphere-ocean-sea ice-land forecast system. This study focuses on the analysis of climate variability for a set of surface variables including precipitation, surface air 2-m temperature (T2m), and surface heat fluxes. None of these quantities are assimilated directly and thus an assessment of their variability provides an independent measure of the accuracy. The CFSR is compared with observational estimates and three previous reanalyses (the NCEP/NCAR reanalysis or R1, the NCEP/DOE reanalysis or R2, and the ERA40 produced by the European Centre for Medium-Range Weather Forecasts). The CFSR has improved time-mean precipitation distribution over various regions compared to the three previous reanalyses, leading to a better representation of freshwater flux (evaporation minus precipitation). For interannual variability, the CFSR shows improved precipitation correlation with observations over the Indian Ocean, Maritime Continent, and western Pacific. The T2m of the CFSR is superior to R1 and R2 with more realistic interannual variability and long-term trend. On the other hand, the CFSR overestimates downward solar radiation flux over the tropical Western Hemisphere warm pool, consistent with a negative cloudiness bias and a positive sea surface temperature bias. Meanwhile, the evaporative latent heat flux in CFSR appears to be larger than other observational estimates over most of the globe. A few deficiencies in the long-term variations are identified in the CFSR. Firstly, dramatic changes are found around 1998-2001 in the global average of a number of variables, possibly related to the changes in the assimilated satellite observations. Secondly, the use of multiple streams for the CFSR induces spurious
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The atmospheric boundary layer in the CSIRO global climate model: simulations versus observations
Garratt, J. R.; Rotstayn, L. D.; Krummel, P. B.
2002-07-01
A 5-year simulation of the atmospheric boundary layer in the CSIRO global climate model (GCM) is compared with detailed boundary-layer observations at six locations, two over the ocean and four over land. Field observations, in the form of surface fluxes and vertical profiles of wind, temperature and humidity, are generally available for each hour over periods of one month or more in a single year. GCM simulations are for specific months corresponding to the field observations, for each of five years. At three of the four land sites (two in Australia, one in south-eastern France), modelled rainfall was close to the observed climatological values, but was significantly in deficit at the fourth (Kansas, USA). Observed rainfall during the field expeditions was close to climatology at all four sites. At the Kansas site, modelled screen temperatures (Tsc), diurnal temperature amplitude and sensible heat flux (H) were significantly higher than observed, with modelled evaporation (E) much lower. At the other three land sites, there is excellent correspondence between the diurnal amplitude and phase and absolute values of each variable (Tsc, H, E). Mean monthly vertical profiles for specific times of the day show strong similarities: over land and ocean in vertical shape and absolute values of variables, and in the mixed-layer and nocturnal-inversion depths (over land) and the height of the elevated inversion or height of the cloud layer (over the sea). Of special interest is the presence climatologically of early morning humidity inversions related to dewfall and of nocturnal low-level jets; such features are found in the GCM simulations. The observed day-to-day variability in vertical structure is captured well in the model for most sites, including, over a whole month, the temperature range at all levels in the boundary layer, and the mix of shallow and deep mixed layers. Weaknesses or unrealistic structure include the following, (a) unrealistic model mixed
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Climate and oceanic fisheries: recent observations and projections and future needs
DEFF Research Database (Denmark)
Salinger, M.J.; Bell, Johan D.; Evans, Karen
2013-01-01
Several lines of evidence show that climatic variation and global warming can have a major effect on fisheries production and replenishment. To prevent overfishing and rebuild overfished stocks under changing and uncertain environmental conditions, new research partnerships between fisheries scie...... scientists and climate change experts are required. The International Workshop on Climate and Oceanic Fisheries held in Rarotonga, Cook Islands, 3–5......Several lines of evidence show that climatic variation and global warming can have a major effect on fisheries production and replenishment. To prevent overfishing and rebuild overfished stocks under changing and uncertain environmental conditions, new research partnerships between fisheries...
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The Greenhouse Effect and Climate Feedbacks
Covey, C.; Haberle, R. M.; McKay, C. P.; Titov, D. V.
This chapter reviews the theory of the greenhouse effect and climate feedback. It also compares the theory with observations, using examples taken from all four known terrestrial worlds with substantial atmospheres: Venus, Earth, Mars, and Titan. The greenhouse effect traps infrared radiation in the atmosphere, thereby increasing surface temperature. It is one of many factors that affect a world's climate. (Others include solar luminosity and the atmospheric scattering and absorption of solar radiation.) A change in these factors — defined as climate forcing — may change the climate in a way that brings other processes — defined as feedbacks — into play. For example, when Earth's atmospheric carbon dioxide increases, warming the surface, the water vapor content of the atmosphere increases. This is a positive feedback on global warming because water vapor is itself a potent greenhouse gas. Many positive and negative feedback processes are significant in determining Earth's climate, and probably the climates of our terrestrial neighbors.
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Ruane, Alex C.; Goldberg, Richard; Chryssanthacopoulos, James
2014-01-01
The AgMERRA and AgCFSR climate forcing datasets provide daily, high-resolution, continuous, meteorological series over the 1980-2010 period designed for applications examining the agricultural impacts of climate variability and climate change. These datasets combine daily resolution data from retrospective analyses (the Modern-Era Retrospective Analysis for Research and Applications, MERRA, and the Climate Forecast System Reanalysis, CFSR) with in situ and remotely-sensed observational datasets for temperature, precipitation, and solar radiation, leading to substantial reductions in bias in comparison to a network of 2324 agricultural-region stations from the Hadley Integrated Surface Dataset (HadISD). Results compare favorably against the original reanalyses as well as the leading climate forcing datasets (Princeton, WFD, WFD-EI, and GRASP), and AgMERRA distinguishes itself with substantially improved representation of daily precipitation distributions and extreme events owing to its use of the MERRA-Land dataset. These datasets also peg relative humidity to the maximum temperature time of day, allowing for more accurate representation of the diurnal cycle of near-surface moisture in agricultural models. AgMERRA and AgCFSR enable a number of ongoing investigations in the Agricultural Model Intercomparison and Improvement Project (AgMIP) and related research networks, and may be used to fill gaps in historical observations as well as a basis for the generation of future climate scenarios.
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Observed trends in climate over Southern Africa
CSIR Research Space (South Africa)
Davis-Reddy, Claire L
2017-10-01
Full Text Available The body of work on historical climate trends has been steadily increasing during the last decade. Global mean annual temperatures have increased by 0.85°C since 1880 and are projected to increase by 0.3 to 2.5 °C by 2050, relative to the 1985...
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Regional climate model downscaling may improve the prediction of alien plant species distributions
Liu, Shuyan; Liang, Xin-Zhong; Gao, Wei; Stohlgren, Thomas J.
2014-12-01
Distributions of invasive species are commonly predicted with species distribution models that build upon the statistical relationships between observed species presence data and climate data. We used field observations, climate station data, and Maximum Entropy species distribution models for 13 invasive plant species in the United States, and then compared the models with inputs from a General Circulation Model (hereafter GCM-based models) and a downscaled Regional Climate Model (hereafter, RCM-based models).We also compared species distributions based on either GCM-based or RCM-based models for the present (1990-1999) to the future (2046-2055). RCM-based species distribution models replicated observed distributions remarkably better than GCM-based models for all invasive species under the current climate. This was shown for the presence locations of the species, and by using four common statistical metrics to compare modeled distributions. For two widespread invasive taxa ( Bromus tectorum or cheatgrass, and Tamarix spp. or tamarisk), GCM-based models failed miserably to reproduce observed species distributions. In contrast, RCM-based species distribution models closely matched observations. Future species distributions may be significantly affected by using GCM-based inputs. Because invasive plants species often show high resilience and low rates of local extinction, RCM-based species distribution models may perform better than GCM-based species distribution models for planning containment programs for invasive species.
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Less favourable climates constrain demographic strategies in plants.
Csergő, Anna M; Salguero-Gómez, Roberto; Broennimann, Olivier; Coutts, Shaun R; Guisan, Antoine; Angert, Amy L; Welk, Erik; Stott, Iain; Enquist, Brian J; McGill, Brian; Svenning, Jens-Christian; Violle, Cyrille; Buckley, Yvonne M
2017-08-01
Correlative species distribution models are based on the observed relationship between species' occurrence and macroclimate or other environmental variables. In climates predicted less favourable populations are expected to decline, and in favourable climates they are expected to persist. However, little comparative empirical support exists for a relationship between predicted climate suitability and population performance. We found that the performance of 93 populations of 34 plant species worldwide - as measured by in situ population growth rate, its temporal variation and extinction risk - was not correlated with climate suitability. However, correlations of demographic processes underpinning population performance with climate suitability indicated both resistance and vulnerability pathways of population responses to climate: in less suitable climates, plants experienced greater retrogression (resistance pathway) and greater variability in some demographic rates (vulnerability pathway). While a range of demographic strategies occur within species' climatic niches, demographic strategies are more constrained in climates predicted to be less suitable. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.
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DEFF Research Database (Denmark)
Boegh, E.; Dellwik, Ebba; Hahmann, Andrea N.
2010-01-01
This paper discusses preliminary remote sensing (MODIS) based hydrological modelling results for the Danish island Sjælland (7330 km2) in relation to project objectives and methodologies of a new research project “Implementing Earth observation and advanced satellite based atmospheric sounders....... For this purpose, a) internal catchment processes will be studied using a Distributed Temperature Sensing (DTS) system, b) Earth observations will be used to upscale from field to regional scales, and c) at the largest scale, satellite based atmospheric sounders and meso-scale climate modelling will be used...
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Ing, Marsha
2013-01-01
Informally observing classrooms is one way that principals can help improve teaching and learning. This study describes the variability of principals' classroom observations across schools and identifies the conditions under which observations relate to the instructional climate in some schools and not others. Data for this study come from…
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Directory of Open Access Journals (Sweden)
B. Schneider
2008-04-01
Full Text Available Fully coupled climate carbon cycle models are sophisticated tools that are used to predict future climate change and its impact on the land and ocean carbon cycles. These models should be able to adequately represent natural variability, requiring model validation by observations. The present study focuses on the ocean carbon cycle component, in particular the spatial and temporal variability in net primary productivity (PP and export production (EP of particulate organic carbon (POC. Results from three coupled climate carbon cycle models (IPSL, MPIM, NCAR are compared with observation-based estimates derived from satellite measurements of ocean colour and results from inverse modelling (data assimilation. Satellite observations of ocean colour have shown that temporal variability of PP on the global scale is largely dominated by the permanently stratified, low-latitude ocean (Behrenfeld et al., 2006 with stronger stratification (higher sea surface temperature; SST being associated with negative PP anomalies. Results from all three coupled models confirm the role of the low-latitude, permanently stratified ocean for anomalies in globally integrated PP, but only one model (IPSL also reproduces the inverse relationship between stratification (SST and PP. An adequate representation of iron and macronutrient co-limitation of phytoplankton growth in the tropical ocean has shown to be the crucial mechanism determining the capability of the models to reproduce observed interactions between climate and PP.
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Towards multi-resolution global climate modeling with ECHAM6-FESOM. Part II: climate variability
Rackow, T.; Goessling, H. F.; Jung, T.; Sidorenko, D.; Semmler, T.; Barbi, D.; Handorf, D.
2018-04-01
This study forms part II of two papers describing ECHAM6-FESOM, a newly established global climate model with a unique multi-resolution sea ice-ocean component. While part I deals with the model description and the mean climate state, here we examine the internal climate variability of the model under constant present-day (1990) conditions. We (1) assess the internal variations in the model in terms of objective variability performance indices, (2) analyze variations in global mean surface temperature and put them in context to variations in the observed record, with particular emphasis on the recent warming slowdown, (3) analyze and validate the most common atmospheric and oceanic variability patterns, (4) diagnose the potential predictability of various climate indices, and (5) put the multi-resolution approach to the test by comparing two setups that differ only in oceanic resolution in the equatorial belt, where one ocean mesh keeps the coarse 1° resolution applied in the adjacent open-ocean regions and the other mesh is gradually refined to 0.25°. Objective variability performance indices show that, in the considered setups, ECHAM6-FESOM performs overall favourably compared to five well-established climate models. Internal variations of the global mean surface temperature in the model are consistent with observed fluctuations and suggest that the recent warming slowdown can be explained as a once-in-one-hundred-years event caused by internal climate variability; periods of strong cooling in the model (`hiatus' analogs) are mainly associated with ENSO-related variability and to a lesser degree also to PDO shifts, with the AMO playing a minor role. Common atmospheric and oceanic variability patterns are simulated largely consistent with their real counterparts. Typical deficits also found in other models at similar resolutions remain, in particular too weak non-seasonal variability of SSTs over large parts of the ocean and episodic periods of almost absent
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Historical Trends in Mean and Extreme Runoff and Streamflow Based on Observations and Climate Models
Directory of Open Access Journals (Sweden)
Behzad Asadieh
2016-05-01
Full Text Available To understand changes in global mean and extreme streamflow volumes over recent decades, we statistically analyzed runoff and streamflow simulated by the WBM-plus hydrological model using either observational-based meteorological inputs from WATCH Forcing Data (WFD, or bias-corrected inputs from five global climate models (GCMs provided by the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP. Results show that the bias-corrected GCM inputs yield very good agreement with the observation-based inputs in average magnitude of runoff and streamflow. On global average, the observation-based simulated mean runoff and streamflow both decreased about 1.3% from 1971 to 2001. However, GCM-based simulations yield increasing trends over that period, with an inter-model global average of 1% for mean runoff and 0.9% for mean streamflow. In the GCM-based simulations, relative changes in extreme runoff and extreme streamflow (annual maximum daily values and annual-maximum seven-day streamflow are slightly greater than those of mean runoff and streamflow, in terms of global and continental averages. Observation-based simulations show increasing trend in mean runoff and streamflow for about one-half of the land areas and decreasing trend for the other half. However, mean and extreme runoff and streamflow based on the GCMs show increasing trend for approximately two-thirds of the global land area and decreasing trend for the other one-third. Further work is needed to understand why GCM simulations appear to indicate trends in streamflow that are more positive than those suggested by climate observations, even where, as in ISI-MIP, bias correction has been applied so that their streamflow climatology is realistic.
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Multi-wheat-model ensemble responses to interannual climatic variability
DEFF Research Database (Denmark)
Ruane, A C; Hudson, N I; Asseng, S
2016-01-01
We compare 27 wheat models' yield responses to interannual climate variability, analyzed at locations in Argentina, Australia, India, and The Netherlands as part of the Agricultural Model Intercomparison and Improvement Project (AgMIP) Wheat Pilot. Each model simulated 1981–2010 grain yield, and ......-term warming, suggesting that additional processes differentiate climate change impacts from observed climate variability analogs and motivating continuing analysis and model development efforts.......We compare 27 wheat models' yield responses to interannual climate variability, analyzed at locations in Argentina, Australia, India, and The Netherlands as part of the Agricultural Model Intercomparison and Improvement Project (AgMIP) Wheat Pilot. Each model simulated 1981–2010 grain yield, and we...... evaluate results against the interannual variability of growing season temperature, precipitation, and solar radiation. The amount of information used for calibration has only a minor effect on most models' climate response, and even small multi-model ensembles prove beneficial. Wheat model clusters reveal...
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Lucas, S. E.
2017-12-01
The Climate Variability & Predictability (CVP) Program supports research aimed at providing process-level understanding of the climate system through observation, modeling, analysis, and field studies. This vital knowledge is needed to improve climate models and predictions so that scientists can better anticipate the impacts of future climate variability and change. To achieve its mission, the CVP Program supports research carried out at NOAA and other federal laboratories, NOAA Cooperative Institutes, and academic institutions. The Program also coordinates its sponsored projects with major national and international scientific bodies including the World Climate Research Programme (WCRP), the International and U.S. Climate Variability and Predictability (CLIVAR/US CLIVAR) Program, and the U.S. Global Change Research Program (USGCRP). The CVP program sits within NOAA's Climate Program Office (http://cpo.noaa.gov/CVP). In 2017, the CVP Program had a call for proposals focused on observing and understanding processes affecting the propagation of intraseasonal oscillations in the Maritime Continent region. This poster will present the recently funded CVP projects, the expected scientific outcomes, the geographic areas of their work in the Maritime Continent region, and the collaborations with the Office of Naval Research, Indonesian Agency for Meteorology, Climatology and Geophysics (BMKG), Japan Agency for Marine-Earth Science and Technology (JAMSTEC) and other partners.
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Alonso, E; Rubio, A; March, J C; Danet, A
2011-01-01
The aim of this study is to compare the emotional climate, quality of communication and performance indicators in a clinical management unit and two traditional hospital services. Quantitative study. questionnaire of 94 questions. 83 health professionals (63 responders) from the clinical management unit of breast pathology and the hospital services of medical oncology and radiation oncology. descriptive statistics, comparison of means, correlation and linear regression models. The clinical management unit reaches higher values compared with the hospital services about: performance indicators, emotional climate, internal communication and evaluation of the leadership. An important gap between existing and desired sources, channels, media and subjects of communication appear, in both clinical management unit and traditional services. The clinical management organization promotes better internal communication and interpersonal relations, leading to improved performance indicators. Copyright © 2011 SECA. Published by Elsevier Espana. All rights reserved.
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Climate change scenario data for the national parks
International Nuclear Information System (INIS)
Scott, D.
2003-01-01
This report presents daily scenario data obtained from monthly time scale climate change scenarios. The scenarios were applied to a stochastic weather generator, a statistical tool that simulates daily weather data for a range of climates at a particular location. The weather generators simulate weather that is statistically similar to observed climate data from climate stations. They can also generate daily scenario data for monthly time scales. This low cost computational method offers site-specific, multi-year climate change scenarios at a daily temporal level. The data is useful for situations that rely on climate thresholds such as forest fire season, drought conditions, or recreational season length. Data sets for temperature, precipitation and frost days was provided for 3 national parks for comparative evaluations. Daily scenarios for other parks can be derived using global climate model (GCM) output data through the Long Ashton Research Station (LARS) weather generator program. tabs
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Climate indices of Iran under climate change
alireza kochaki; mehdi nasiry; gholamali kamali
2009-01-01
Global warming will affect all climatic variables and particularly rainfall patterns. The purpose of present investigation was to predict climatic parameters of Iran under future climate change and to compare them with the present conditions. For this reason, UKMO General Circulation Model was used for the year 2025 and 2050. By running the model, minimum and maximum monthly temperature and also maximum monthly rainfall for the representative climate stations were calculated and finally the e...
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Gu, Yingxin; Wylie, B.K.
2010-01-01
This study identifies areas with ecosystem performance anomalies (EPA) within the Upper Colorado River Basin (UCRB) during 2005-2007 using satellite observations, climate data, and ecosystem models. The final EPA maps with 250-m spatial resolution were categorized as normal performance, underperformance, and overperformance (observed performance relative to weather-based predictions) at the 90% level of confidence. The EPA maps were validated using "percentage of bare soil" ground observations. The validation results at locations with comparable site potential showed that regions identified as persistently underperforming (overperforming) tended to have a higher (lower) percentage of bare soil, suggesting that our preliminary EPA maps are reliable and agree with ground-based observations. The 3-year (2005-2007) persistent EPA map from this study provides the first quantitative evaluation of ecosystem performance anomalies within the UCRB and will help the Bureau of Land Management (BLM) identify potentially degraded lands. Results from this study can be used as a prototype by BLM and other land managers for making optimal land management decisions. ?? 2010 by the authors.
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Decadal climate prediction with a refined anomaly initialisation approach
Volpi, Danila; Guemas, Virginie; Doblas-Reyes, Francisco J.; Hawkins, Ed; Nichols, Nancy K.
2017-03-01
In decadal prediction, the objective is to exploit both the sources of predictability from the external radiative forcings and from the internal variability to provide the best possible climate information for the next decade. Predicting the climate system internal variability relies on initialising the climate model from observational estimates. We present a refined method of anomaly initialisation (AI) applied to the ocean and sea ice components of the global climate forecast model EC-Earth, with the following key innovations: (1) the use of a weight applied to the observed anomalies, in order to avoid the risk of introducing anomalies recorded in the observed climate, whose amplitude does not fit in the range of the internal variability generated by the model; (2) the AI of the ocean density, instead of calculating it from the anomaly initialised state of temperature and salinity. An experiment initialised with this refined AI method has been compared with a full field and standard AI experiment. Results show that the use of such refinements enhances the surface temperature skill over part of the North and South Atlantic, part of the South Pacific and the Mediterranean Sea for the first forecast year. However, part of such improvement is lost in the following forecast years. For the tropical Pacific surface temperature, the full field initialised experiment performs the best. The prediction of the Arctic sea-ice volume is improved by the refined AI method for the first three forecast years and the skill of the Atlantic multidecadal oscillation is significantly increased compared to a non-initialised forecast, along the whole forecast time.
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Energy Technology Data Exchange (ETDEWEB)
Zoran, Maria; Savastru, Roxana; Savastru, Dan [National Institute of R& D for Optoelectronics, MG5 Bucharest-Magurele, 077125 Romania (Romania); Dida, Adrian [University Transylvania of Brasov, Brasov (Romania)
2016-03-25
Satellite Earth observation data in the visible and near-infrared (VNIR) wavelengths represent a useful source of information for forest systems monitoring through derived biogeophysical parameters (vegetation index, leaf area index, canopy cover, fraction of absorbed photosynthetically active radiation, chlorophyll content, net primary production, canopy water stress, etc.). Use of satellite remote sensing data to assess forest spatio-temporal changes due to climatic or anthropogenic stressors is an excellent example of the value of multispectral and multitemporal observations. Fusion technique was applied to time-series multispectral and multitemporal satellite imagery (NOAA AVHRR, MODIS Terra/Aqua, Landsat ETM and IKONOS satellite data) for periurban forest areas Cernica-Branesti, placed in the neighboring of Bucharest town, Romania, over 2002-2014 period.
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International Nuclear Information System (INIS)
Zoran, Maria; Savastru, Roxana; Savastru, Dan; Dida, Adrian
2016-01-01
Satellite Earth observation data in the visible and near-infrared (VNIR) wavelengths represent a useful source of information for forest systems monitoring through derived biogeophysical parameters (vegetation index, leaf area index, canopy cover, fraction of absorbed photosynthetically active radiation, chlorophyll content, net primary production, canopy water stress, etc.). Use of satellite remote sensing data to assess forest spatio-temporal changes due to climatic or anthropogenic stressors is an excellent example of the value of multispectral and multitemporal observations. Fusion technique was applied to time-series multispectral and multitemporal satellite imagery (NOAA AVHRR, MODIS Terra/Aqua, Landsat ETM and IKONOS satellite data) for periurban forest areas Cernica-Branesti, placed in the neighboring of Bucharest town, Romania, over 2002-2014 period.
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Studies of Day Care Center Climate and Its Effect on Children's Social and Emotional Behavior.
Ekholm, Bodil; Hedin, Anna
School climates at 12 day care centers in Sweden were compared to investigate effects of center climates on children's social and emotional behavior. Observations and interviews conducted at the day care centers revealed differences in center climates related to child-rearing patterns, patterns of interaction, the distribution of power, and in…
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Directory of Open Access Journals (Sweden)
Pierre Legagneux
2018-01-01
Full Text Available Scientists, policy makers, and journalists are three key, interconnected players involved in prioritizing and implementing solutions to mitigate the consequences of anthropogenic pressures on the environment. The way in which information is framed and expertise is communicated by the media is crucial for political decisions and for the integrated management of environmental issues. Here we present a comparative study of scientific literature and press articles addressing climate change and biodiversity. We extensively scrutinized the scientific literature, research funding, and press articles from the USA, Canada, and United Kingdom addressing climate change and biodiversity issues between 1991 and 2016. We found that media coverage of climate change was up to eight times higher compared to biodiversity. This discrepancy could not be explained by different scientific output between the two issues. Moreover, climate change media coverage was often related to specific events whereas no such indication of a connection was found in the case of biodiversity. An international communication strategy is urgently required to raise public awareness on biodiversity issues. We discussed several initiatives that scientists could undertake to better communicate major discoveries to the public and policy makers.
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Extreme weather and climate events with ecological relevance: a review.
Ummenhofer, Caroline C; Meehl, Gerald A
2017-06-19
Robust evidence exists that certain extreme weather and climate events, especially daily temperature and precipitation extremes, have changed in regard to intensity and frequency over recent decades. These changes have been linked to human-induced climate change, while the degree to which climate change impacts an individual extreme climate event (ECE) is more difficult to quantify. Rapid progress in event attribution has recently been made through improved understanding of observed and simulated climate variability, methods for event attribution and advances in numerical modelling. Attribution for extreme temperature events is stronger compared with other event types, notably those related to the hydrological cycle. Recent advances in the understanding of ECEs, both in observations and their representation in state-of-the-art climate models, open new opportunities for assessing their effect on human and natural systems. Improved spatial resolution in global climate models and advances in statistical and dynamical downscaling now provide climatic information at appropriate spatial and temporal scales. Together with the continued development of Earth System Models that simulate biogeochemical cycles and interactions with the biosphere at increasing complexity, these make it possible to develop a mechanistic understanding of how ECEs affect biological processes, ecosystem functioning and adaptation capabilities. Limitations in the observational network, both for physical climate system parameters and even more so for long-term ecological monitoring, have hampered progress in understanding bio-physical interactions across a range of scales. New opportunities for assessing how ECEs modulate ecosystem structure and functioning arise from better scientific understanding of ECEs coupled with technological advances in observing systems and instrumentation.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events
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Direct observations of ice seasonality reveal changes in climate over the past 320–570 years
Sharma, Sapna; Magnuson, John J.; Batt, Ryan D.; Winslow, Luke; Korhonen, Johanna; Yasuyuki Aono,
2016-01-01
Lake and river ice seasonality (dates of ice freeze and breakup) responds sensitively to climatic change and variability. We analyzed climate-related changes using direct human observations of ice freeze dates (1443–2014) for Lake Suwa, Japan, and of ice breakup dates (1693–2013) for Torne River, Finland. We found a rich array of changes in ice seasonality of two inland waters from geographically distant regions: namely a shift towards later ice formation for Suwa and earlier spring melt for Torne, increasing frequencies of years with warm extremes, changing inter-annual variability, waning of dominant inter-decadal quasi-periodic dynamics, and stronger correlations of ice seasonality with atmospheric CO2 concentration and air temperature after the start of the Industrial Revolution. Although local factors, including human population growth, land use change, and water management influence Suwa and Torne, the general patterns of ice seasonality are similar for both systems, suggesting that global processes including climate change and variability are driving the long-term changes in ice seasonality.
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Riebeek Kohl, H.; Chambers, L. H.; Murphy, T.
2016-12-01
For more that 20 years, the Global Learning and Observations to Benefit the Environment (GLOBE) Program has sought to increase environment literacy in students by involving them in the process of data collection and scientific research. In 2016, the program expanded to accept observations from citizen scientists of all ages through a relatively simple app. Called GLOBE Observer, the new program aims to help participants feel connected to a global community focused on advancing the scientific understanding of Earth system science while building climate literacy among participants and increasing valuable environmental data points to expand both student and scientific research. In October 2016, GLOBE Observer partnered with the Association of Science & Technology Centers (ASTC) in an international science experiment in which museums and patrons around the world collected cloud observations through GLOBE Observer to create a global cloud map in support of NASA satellite science. The experiment was an element of the International Science Center and Science Museum Day, an event planned in partnership with UNESCO and ASTC. Museums and science centers provided the climate context for the observations, while GLOBE Observer offered a uniform experience and a digital platform to build a connected global community. This talk will introduce GLOBE Observer and will present the results of the experiment, including evaluation feedback on gains in climate literacy through the event.
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Local climate change capacity : comparing four municipalities in the Dutch Twente region
van der Vegt, Arjen; Hoppe, Thomas; Stegmaier, Peter
2015-01-01
Climate change is seen as a key societal challenge to cities and regions. City governments design and implement policies to cope with climate change: on the one hand by mitigating greenhouse gas emissions and spurring low carbon transition; on the other hand by adapting to climate change, hence
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Directory of Open Access Journals (Sweden)
M. C. Demirel
2013-10-01
Full Text Available The impacts of climate change on the seasonality of low flows were analysed for 134 sub-catchments covering the River Rhine basin upstream of the Dutch-German border. Three seasonality indices for low flows were estimated, namely the seasonality ratio (SR, weighted mean occurrence day (WMOD and weighted persistence (WP. These indices are related to the discharge regime, timing and variability in timing of low flow events respectively. The three indices were estimated from: (1 observed low flows; (2 simulated low flows by the semi-distributed HBV model using observed climate as input; (3 simulated low flows using simulated inputs from seven combinations of General Circulation Models (GCMs and Regional Climate Models (RCMs for the current climate (1964–2007; (4 simulated low flows using simulated inputs from seven combinations of GCMs and RCMs for the future climate (2063–2098 including three different greenhouse gas emission scenarios. These four cases were compared to assess the effects of the hydrological model, forcing by different climate models and different emission scenarios on the three indices. Significant differences were found between cases 1 and 2. For instance, the HBV model is prone to overestimate SR and to underestimate WP and simulates very late WMODs compared to the estimated WMODs using observed discharges. Comparing the results of cases 2 and 3, the smallest difference was found for the SR index, whereas large differences were found for the WMOD and WP indices for the current climate. Finally, comparing the results of cases 3 and 4, we found that SR decreases substantially by 2063–2098 in all seven sub-basins of the River Rhine. The lower values of SR for the future climate indicate a shift from winter low flows (SR > 1 to summer low flows (SR < 1 in the two Alpine sub-basins. The WMODs of low flows tend to be earlier than for the current climate in all sub-basins except for the Middle Rhine and Lower Rhine sub
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Paleo-dust insights onto dust-climate interactions
Albani, S.; Mahowald, N. M.
2017-12-01
Mineral dust emissions are affected by changing climate conditions, and in turn dust impacts the atmospheric radiation budget, clouds and biogeochemical cycles. Climate and public health dust-related issues call for attention on the fate of the dust cycle in the future, and the representation of the dust cycle is now part of the strategy of the Paleoclimate Modelling Intercomparison Project phase 4 and the Coupled Model Intercomparison Project phase 6 (PMIP4-CMIP6). Since mineral aerosols are one of the most important natural aerosols, understanding past dust responses to climate in the paleoclimate will allow us to better understand mineral aerosol feedbacks with climate and biogeochemistry in the Anthropocene. Modern observations and paleoclimate records offer the possibility of multiple, complementary views on the global dust cycle, and allow to validate and/or constrain the numerical representation of dust in climate and Earth system models. We present our results from a set of simulations with the Community Earth System Model for different climate states, including present and past climates such as the pre-industrial, the mid-Holocene and the Last Glacial Maximum. A set of simulations including a prognostic dust cycle was thoroughly compared with a wide set of present day observations from different platforms and regions, in order to realistically constrain the magnitude of dust load, surface concentration, deposition, optical properties, and particle size distributions. The magnitude of emissions for past climate regimes was constrained based on compilations of paleodust mass accumulation rates and size distributions, as well as based on information on dust provenance. The comparison with a parallel set of simulations without dust allows estimating the impacts of dust on surface climate. We analyze impacts of dust on the mean and variability of surface temperature and precipitation in each climate state, as well as the impacts that changing dust emissions had
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Littell, J. S.; Poe, A.; van Pelt, T.
2015-12-01
Climate change is already affecting the Bering Sea and Aleutian Island region of Alaska. Past and present marine research across a broad spectrum of disciplines is shedding light on what sectors of the ecosystem and the human dimension will be most impacted. In a grassroots approach to extend existing research efforts, leveraging recently completed downscaled climate projections for the Bering Sea and Aleutian Islands region, we convened a team of 30 researchers-- with expertise ranging from anthropology to zooplankton to marine mammals-- to assess climate projections in the context of their expertise. This Aleutian-Bering Climate Vulnerability Assessment (ABCVA) began with researchers working in five teams to evaluate the vulnerabilities of key species and ecosystem services relative to projected changes in climate. Each team identified initial vulnerabilities for their focal species or services, and made recommendations for further research and information needs that would help managers and communities better understand the implications of the changing climate in this region. Those draft recommendations were shared during two focused, public sessions held within two hub communities for the Bering and Aleutian region: Unalaska and St. Paul. Qualitative insights about local concerns and observations relative to climate change were collected during these sessions, to be compared to the recommendations being made by the ABCVA team of researchers. Finally, we used a Structured Decision Making process to prioritize the recommendations of participating scientists, and integrate the insights shared during our community sessions. This work brought together residents, stakeholders, scientists, and natural resource managers to collaboratively identify priorities for addressing current and expected future impacts of climate change. Recommendations from this project will be incorporated into future research efforts of the Aleutian and Bering Sea Islands Landscape Conservation
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Rahman, Mohammad Atiqur; Yunsheng, Lou; Sultana, Nahid; Ongoma, Victor
2018-03-01
ET0 is an important hydro-meteorological phenomenon, which is influenced by changing climate like other climatic parameters. This study investigates the present and future trends of ET0 in Bangladesh using 39 years' historical and downscaled CMIP5 daily climatic data for the twenty-first century. Statistical Downscaling Model (SDSM) was used to downscale the climate data required to calculate ET0. Penman-Monteith formula was applied in ET0 calculation for both the historical and modelled data. To analyse ET0 trends and trend changing patterns, modified Mann-Kendall and Sequential Mann-Kendall tests were, respectively, done. Spatial variations of ET0 trends are presented by inverse distance weighting interpolation using ArcGIS 10.2.2. Results show that RCP8.5 (2061-2099) will experience the highest amount of ET0 totals in comparison to the historical and all other scenarios in the same time span of 39 years. Though significant positive trends were observed in the mid and last months of year from month-wise trend analysis of representative concentration pathways, significant negative trends were also found for some months using historical data in similar analysis. From long-term annual trend analysis, it was found that major part of the country represents decreasing trends using historical data, but increasing trends were observed for modelled data. Theil-Sen estimations of ET0 trends in the study depict a good consistency with the Mann-Kendall test results. The findings of the study would contribute in irrigation water management and planning of the country and also in furthering the climate change study using modelled data in the context of Bangladesh.
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Biotic and Biogeochemical Feedbacks to Climate Change
Torn, M. S.; Harte, J.
2002-12-01
Feedbacks to paleoclimate change are evident in ice core records showing correlations of temperature with carbon dioxide, nitrous oxide, and methane. Such feedbacks may be explained by plant and microbial responses to climate change, and are likely to occur under impending climate warming, as evidenced by results of ecosystem climate manipulation experiments and biometeorological observations along ecological and climate gradients. Ecosystems exert considerable influence on climate, by controlling the energy and water balance of the land surface as well as being sinks and sources of greenhouse gases. This presentation will focus on biotic and biogeochemical climate feedbacks on decadal to century time scales, emphasizing carbon storage and energy exchange. In addition to the direct effects of climate on decomposition rates and of climate and CO2 on plant productivity, climate change can alter species composition; because plant species differ in their surface properties, productivity, phenology, and chemistry, climate-induced changes in plant species composition can exert a large influence on the magnitude and sign of climate feedbacks. We discuss the effects of plant species on ecosystem carbon storage that result from characteristic differences in plant biomass and lifetime, allocation to roots vs. leaves, litter quality, microclimate for decomposition and the ultimate stabilization of soil organic matter. We compare the effect of species transitions on transpiration, albedo, and other surface properties, with the effect of elevated CO2 and warming on single species' surface exchange. Global change models and experiments that investigate the effect of climate only on existing vegetation may miss the biggest impacts of climate change on biogeochemical cycling and feedbacks. Quantification of feedbacks will require understanding how species composition and long-term soil processes will change under global warming. Although no single approach, be it experimental
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Simulation of climate variability and anthropogenic climate change
International Nuclear Information System (INIS)
Bengtsson, Lennart
1999-01-01
The climatic changes in the last century were discussed and focus was on the questions: 1) What are the causes of the rapid climate fluctuations and 2) Is the global warming, which is observed during the last century, caused by natural or anthropogenic effects. It is concluded that an understanding of climate based on the interpretation of observational data only is not feasible, unless supported by an adequate theoretical interpretation. The capabilities of climatic models were discussed and the importance of incorporating 1) calculations of the internal variability of the atmosphere when forced from an ocean with prescribed sea surface temperature as well as for a system consisting of an atmosphere and a mixed ocean of limited depth, 2) a fully coupled atmospheric and ocean model and finally, 3) a fully coupled system including transiently changing greenhouse gases and aerosols. A short summation of the results is presented. The pronounced warming during the last century is not reproduced under the assumption of constant forcing and pollution emissions have to be incorporated into the models in order to bring the simulated data in agreement with observations
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How Do Marine Pelagic Species Respond to Climate Change? Theories and Observations
Beaugrand, Grégory; Kirby, Richard R.
2018-01-01
In this review, we show how climate affects species, communities, and ecosystems, and why many responses from the species to the biome level originate from the interaction between the species’ ecological niche and changes in the environmental regime in both space and time. We describe a theory that allows us to understand and predict how marine species react to climate-induced changes in ecological conditions, how communities form and are reconfigured, and so how biodiversity is arranged and may respond to climate change. Our study shows that the responses of species to climate change are therefore intelligible—that is, they have a strong deterministic component and can be predicted.
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Informing climate-related decisions in complex river basins: A comparative assessment
Pulwarty, R. S.; Bark, R. H.; Maia, R.; Udall, B.
2010-12-01
Integrated water resources management provides an important governance framework to achieve climate-related adaptation measures across socio-economic, environmental and administrative systems. Adaptation includes technical changes that improve water use efficiency, early warning, demand management (e.g. through metering and pricing), and institutional changes that improve the tradability of water rights. Supply-side strategies generally involve increases in storage capacity, abstraction from watercourses, and water transfers. Incentives for improving water-use efficiency, hold considerable promise for water savings and the reallocation of water to highly valued uses. However, conflicts exist between processes and goals of water management and governance. These militate against the effectiveness of using scientific information to meet short-term needs in the context of reducing longer-term vulnerabilities such as for “increasing water supply while meeting environmental needs.” A complete analysis of the effects of climate change on human water uses would consider cross-sector interactions, including the impacts of transfers of the use of water from one sector to another. In this presentation we will review the challenges and lessons provided in water resources management in the context of a changing climate. Lessons are drawn from watersheds around the world including the Colorado, Columbia, Murray-Darling, Guadiana and others. We explore how watershed managers and researchers are attempting to address the risks associated with climatic change and potential surprises. In spite of numerous climate impacts studies the management of the cumulative impacts of extremes (droughts, floods etc.) remains reactive and crisis-driven. Most recommendations stay within the applied sciences realm of technological interventions and supply driven approaches. Clearly more is needed to inform an integrated watershed management approaches in which adaptive management functions as
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Energy Technology Data Exchange (ETDEWEB)
Leng, Guoyong; Tang, Qiuhong; Huang, Maoyi; Leung, Lai-Yung R.
2015-02-01
The Community Land Model 4.0 (CLM4) was used to investigate and compare the effects of climate change and irrigation on terrestrial water cycle. Three climate change scenarios and one irrigation scenario (IRRIG) were simulated in the North China Plain (NCP), which is one of the most vulnerable regions to climate change and human perturbations in China. The climate change scenarios consist of (1) HOT (i.e. temperature increase by 2oC); (2) HOTWET (same with HOT but with an increase of precipitation by 15%); (3) HOTDRY (same with HOT but with a decrease of precipitation by 15%). In the IRRIG scenario, the irrigation scheme was calibrated to simulate irrigation amounts that match the actual irrigation amounts and irrigation was divided between surface water and groundwater withdrawals based on census data. Our results show that the impacts of climate change were more widespread while those of irrigation were concentrated only over the agricultural regions. Specifically, the mean water table depth was simulated to decline persistently by over 1 m annually due to groundwater exploitation during the period of 1980-2000, while much smaller effects were induced by climate change. Although irrigation has comparable effects on surface fluxes and surface soil moisture as climate change, it has much greater effects on water table depth and groundwater storage. Moreover, irrigation has much larger effects on the top layer soil moisture whereas increase in precipitation associated with climate change exerts more influence on lower layer soil moisture. This study emphasizes the need to accurately account for irrigation impacts in adapting to climate change.
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Does the weather influence public opinion about climate change?
Donner, S. D.; McDaniel, J.
2010-12-01
Public opinion in North America about the science of anthropogenic climate change and the motivation for policy action has been variable over the past twenty years. The trends in public opinion over time have been attributed the general lack of pressing public concern about climate change to a range of political, economic and psychological factors. One driving force behind the variability in polling data from year to year may be the weather itself. The difference between what we “expect” - the climate - and what we “get” - the weather - can be a major source of confusion and obfuscation in the public discourse about climate change. For example, reaction to moderate global temperatures in 2007 and 2008 may have helped prompt the spread of a “global cooling” meme in the public and the news media. At the same time, a decrease in the belief in the science of climate change and the need for action has been noted in opinion polls. This study analyzes the relationship between public opinion about climate change and the weather in the U.S. since the mid-1980s using historical polling data from several major organizations (e.g. Gallup, Pew, Harris Interactive, ABC News), historical monthly air temperature (NCDC) and a survey of opinion articles from major U.S. newspapers (Washington Post, New York Times, Wall Street Journal, Houston Chronicle, USA Today). Seasonal and annual monthly temperature anomalies for the northeastern U.S and the continental U.S are compared with available national opinion data for three general categories of questions: i) Is the climate warming?, ii) Is the observed warming due to human activity?, and iii) Are you concerned about climate change? The variability in temperature and public opinion over time is also compared with the variability in the fraction of opinion articles in the newspapers (n ~ 7000) which express general agreement or disagreement with IPCC Summary for Policymakers consensus statements on climate change (“most of
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A new CM SAF Solar Surface Radiation Climate Data Set derived from Meteosat Satellite Observations
Trentmann, J.; Mueller, R. W.; Pfeifroth, U.; Träger-Chatterjee, C.; Cremer, R.
2014-12-01
The incoming surface solar radiation has been defined as an essential climate variable by GCOS. It is mandatory to monitor this part of the earth's energy balance, and thus gain insights on the state and variability of the climate system. In addition, data sets of the surface solar radiation have received increased attention over the recent years as an important source of information for the planning of solar energy applications. The EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF) is deriving surface solar radiation from geostationary and polar-orbiting satellite instruments. While CM SAF is focusing on the generation of high-quality long-term climate data records, also operationally data is provided in short time latency within 8 weeks. Here we present SARAH (Solar Surface Radiation Dataset - Heliosat), i.e. the new CM SAF Solar Surface Radiation data set based on Meteosat satellite observations. SARAH provides instantaneous, daily- and monthly-averaged data of the effective cloud albedo (CAL), the direct normalized solar radiation (DNI) and the solar irradiance (SIS) from 1983 to 2013 for the full view of the Meteosat satellite (i.e, Europe, Africa, parts of South America, and the Atlantic ocean). The data sets are generated with a high spatial resolution of 0.05 deg allowing for detailed regional studies, and are available in netcdf-format at no cost without restrictions at www.cmsaf.eu. We provide an overview of the data sets, including a validation against reference measurements from the BSRN and GEBA surface station networks.
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Climate-Induced Boreal Forest Change: Predictions versus Current Observations
Soja, Amber J.; Tchebakova, Nadezda M.; French, Nancy H. F.; Flannigan, Michael D.; Shugart, Herman H.; Stocks, Brian J.; Sukhinin, Anatoly I.; Parfenova, E. I.; Chapin, F. Stuart, III; Stackhouse, Paul W., Jr.
2007-01-01
For about three decades, there have been many predictions of the potential ecological response in boreal regions to the currently warmer conditions. In essence, a widespread, naturally occurring experiment has been conducted over time. In this paper, we describe previously modeled predictions of ecological change in boreal Alaska, Canada and Russia, and then we investigate potential evidence of current climate-induced change. For instance, ecological models have suggested that warming will induce the northern and upslope migration of the treeline and an alteration in the current mosaic structure of boreal forests. We present evidence of the migration of keystone ecosystems in the upland and lowland treeline of mountainous regions across southern Siberia. Ecological models have also predicted a moisture-stress-related dieback in white spruce trees in Alaska, and current investigations show that as temperatures increase, white spruce tree growth is declining. Additionally, it was suggested that increases in infestation and wildfire disturbance would be catalysts that precipitate the alteration of the current mosaic forest composition. In Siberia, five of the last seven years have resulted in extreme fire seasons, and extreme fire years have also been more frequent in both Alaska and Canada. In addition, Alaska has experienced extreme and geographically expansive multi-year outbreaks of the spruce beetle, which had been previously limited by the cold, moist environment. We suggest that there is substantial evidence throughout the circumboreal region to conclude that the biosphere within the boreal terrestrial environment has already responded to the transient effects of climate change. Additionally, temperature increases and warming-induced change are progressing faster than had been predicted in some regions, suggesting a potential non-linear rapid response to changes in climate, as opposed to the predicted slow linear response to climate change.
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Shantz, N. C.; Chang, R. Y.-W.; Slowik, J. G.; Vlasenko, A.; Abbatt, J. P. D.; Leaitch, W. R.
2010-01-01
Growth rates of water droplets were measured with a static diffusion cloud condensation chamber in May-June 2007 at a rural field site in Southern Ontario, Canada, 70 km north of Toronto. The observations include periods when the winds were from the south and the site was impacted by anthropogenic air from the U.S. and Southern Ontario as well as during a 5-day period of northerly wind flow when the aerosol was dominated by biogenic sources. The growth of droplets on anthropogenic size-selected particles centred at 0.1 μm diameter and composed of approximately 40% organic and 60% ammonium sulphate (AS) by mass, was delayed by on the order of 1 s compared to a pure AS aerosol. Simulations of the growth rate on monodisperse particles indicate that a lowering of the water mass accommodation coefficient from αc=1 to an average of αc=0.04 is needed (assuming an insoluble organic with hygroscopicity parameter, κorg, of zero). Simulations of the initial growth rate on polydisperse anthropogenic particles agree best with observations for αc=0.07. In contrast, the growth rate of droplets on size-selected aerosol of biogenic character, consisting of >80% organic, was similar to that of pure AS. Simulations of the predominantly biogenic polydisperse aerosol show agreement between the observations and simulations when κorg=0.2 (with upper and lower limits of 0.5 and 0.07, respectively) and αc=1. Inhibition of water uptake by the anthropogenic organic applied to an adiabatic cloud parcel model in the form of a constant low αc increases the number of droplets in a cloud compared to pure AS. If the αc is assumed to increase with increasing liquid water on the droplets, then the number of droplets decreases which could diminish the indirect climate forcing effect. The slightly lower κorg in the biogenic case decreases the number of droplets in a cloud compared to pure AS.
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Targeting climate diversity in conservation planning to build resilience to climate change
Heller, Nicole E.; Kreitler, Jason R.; Ackerly, David; Weiss, Stuart; Recinos, Amanda; Branciforte, Ryan; Flint, Lorraine E.; Flint, Alan L.; Micheli, Elisabeth
2015-01-01
Climate change is raising challenging concerns for systematic conservation planning. Are methods based on the current spatial patterns of biodiversity effective given long-term climate change? Some conservation scientists argue that planning should focus on protecting the abiotic diversity in the landscape, which drives patterns of biological diversity, rather than focusing on the distribution of focal species, which shift in response to climate change. Climate is one important abiotic driver of biodiversity patterns, as different climates host different biological communities and genetic pools. We propose conservation networks that capture the full range of climatic diversity in a region will improve the resilience of biotic communities to climate change compared to networks that do not. In this study we used historical and future hydro-climate projections from the high resolution Basin Characterization Model to explore the utility of directly targeting climatic diversity in planning. Using the spatial planning tool, Marxan, we designed conservation networks to capture the diversity of climate types, at the regional and sub-regional scale, and compared them to networks we designed to capture the diversity of vegetation types. By focusing on the Conservation Lands Network (CLN) of the San Francisco Bay Area as a real-world case study, we compared the potential resilience of networks by examining two factors: the range of climate space captured, and climatic stability to 18 future climates, reflecting different emission scenarios and global climate models. We found that the climate-based network planned at the sub-regional scale captured a greater range of climate space and showed higher climatic stability than the vegetation and regional based-networks. At the same time, differences among network scenarios are small relative to the variance in climate stability across global climate models. Across different projected futures, topographically heterogeneous areas
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Indicators of Arctic Sea Ice Bistability in Climate Model Simulations and Observations
2014-09-30
associated with the ice - albedo feedback and the seasonal melt and growth of sea ice , as well as horizontal climate variations on a global domain. (2...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Indicators of Arctic Sea Ice Bistability in Climate...possibility that the climate system supports multiple Arctic sea ice states that are relevant for the evolution of sea ice during the next several
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Landscape fires dominate terrestrial natural aerosol - climate feedbacks
Scott, C.; Arnold, S.; Monks, S. A.; Asmi, A.; Paasonen, P.; Spracklen, D. V.
2017-12-01
The terrestrial biosphere is an important source of natural aerosol including landscape fire emissions and secondary organic aerosol (SOA) formed from biogenic volatile organic compounds (BVOCs). Atmospheric aerosol alters the Earth's climate by absorbing and scattering radiation (direct radiative effect; DRE) and by perturbing the properties of clouds (aerosol indirect effect; AIE). Natural aerosol sources are strongly controlled by, and can influence, climate; giving rise to potential natural aerosol-climate feedbacks. Earth System Models (ESMs) include a description of some of these natural aerosol-climate feedbacks, predicting substantial changes in natural aerosol over the coming century with associated radiative perturbations. Despite this, the sensitivity of natural aerosols simulated by ESMs to changes in climate or emissions has not been robustly tested against observations. Here we combine long-term observations of aerosol number and a global aerosol microphysics model to assess terrestrial natural aerosol-climate feedbacks. We find a strong positive relationship between the summertime anomaly in observed concentration of particles greater than 100 nm diameter and the anomaly in local air temperature. This relationship is reproduced by the model and driven by variability in dynamics and meteorology, as well as natural sources of aerosol. We use an offline radiative transfer model to determine radiative effects due to changes in two natural aerosol sources: landscape fire and biogenic SOA. We find that interannual variability in the simulated global natural aerosol radiative effect (RE) is negatively related to the global temperature anomaly. The magnitude of global aerosol-climate feedback (sum of DRE and AIE) is estimated to be -0.15 Wm-2 K-1 for landscape fire aerosol and -0.06 Wm-2 K-1 for biogenic SOA. These feedbacks are comparable in magnitude, but opposite in sign to the snow albedo feedback, highlighting the need for natural aerosol feedbacks to
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Ecological forecasting under climatic data uncertainty: a case study in phenological modeling
International Nuclear Information System (INIS)
Cook, Benjamin I; Terando, Adam; Steiner, Allison
2010-01-01
Forecasting ecological responses to climate change represents a challenge to the ecological community because models are often site-specific and climate data are lacking at appropriate spatial and temporal resolutions. We use a case study approach to demonstrate uncertainties in ecological predictions related to the driving climatic input data. We use observational records, derived observational datasets (e.g. interpolated observations from local weather stations and gridded data products) and output from general circulation models (GCM) in conjunction with site based phenology models to estimate the first flowering date (FFD) for three woody flowering species. Using derived observations over the modern time period, we find that cold biases and temperature trends lead to biased FFD simulations for all three species. Observational datasets resolved at the daily time step result in better FFD predictions compared to simulations using monthly resolution. Simulations using output from an ensemble of GCM and regional climate models over modern and future time periods have large intra-ensemble spreads and tend to underestimate observed FFD trends for the modern period. These results indicate that certain forcing datasets may be missing key features needed to generate accurate hindcasts at the local scale (e.g. trends, temporal resolution), and that standard modeling techniques (e.g. downscaling, ensemble mean, etc) may not necessarily improve the prediction of the ecological response. Studies attempting to simulate local ecological processes under modern and future climate forcing therefore need to quantify and propagate the climate data uncertainties in their simulations.
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Watershed sensitivity and hydrologic response to high-resolution climate model
Troin, M.; Caya, D.
2012-12-01
Global climate models (GCMs) are fundamental research tools to assess climate change impacts on water resources. Regional climate models (RCMs) are complementary to GCMs. The added benefit of RCMs for hydrological applications is still not well understood because watersheds respond differently to RCM experiments. It is expected that the new generation of RCMs improve the representation of climate processes making it more attractive for impact studies. Given the cost of RCMs, it is ascertain to identify whether high-resolution RCMs allow offering more details than what is simulated in GCMs or RCMs with coarser resolution to address impacts on water resources. This study aims to assess the added value of RCM with emphasis on using high-resolution climate models. More specifically is how the hydrological cycle is represented when the resolution in climate models is increased (45 vs 200km; 15 vs 45km). We used simulations from the Canadian RCM (CRCM) driven by reanalyses integrated on high-resolution domains (45 and 15km) and CRCM driven by multiple members of two GCMs (the Canadian CGCM3; the German ECHAM5) with a horizontal resolution of 45 km. CRCM data and data from their host GCMs are compared to observation over 1971-2000. Precipitation and temperature from CRCM and GCMs' simulations are inputted into the hydrological SWAT model to simulate streamflow in watersheds for the historical period. The selected watersheds are two basins in Quebec (QC) and one basin in British Columbia (BC), Canada. CRCM-45km driven by GCMs performs well in representing precipitation but shows a cold bias of 3.3°C. Such bias in temperature is more significant for the BC basin (4.5°C) due to the Rocky Mountains. For the CRCM-45km/GCM combination (CGCM3 or ECHAM5), comparable skills in reproducing the observed climate are identified even though CGCM3 analyzed alone provides more accurate indication of climatology in the basins than ECHAM5. When we compared to GCMs results, CRCM-45km
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Europe adapts to climate change. Comparing National Adaptation Strategies in Europe
Swart, R.J.; Biesbroek, G.R.; Binnerup, S.; Carter, T.; Cowan, C.; Henrichs, T.; Loquen, S.; Mela, H.; Morecroft, M.; Reese, M.; Rey, D.
2009-01-01
Climate Change is happening. Even if global emission reductions and mitigation efforts over the next decades prove to be successful, a signifi cant amount of human-induced climate change has become inevitable. In addition to efforts to reduce greenhouse gas emissions, many EU countries are therefore
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Evans, Margaret E K; Hearn, David J; Hahn, William J; Spangle, Jennifer M; Venable, D Lawrence
2005-09-01
Evolutionary ecologists have long sought to understand the conditions under which perennial (iteroparous) versus annual (semelparous) plant life histories are favored. We evaluated the idea that aridity and variation in the length of droughts should favor the evolution of an annual life history, both by decreasing adult survival and by increasing the potential for high seedling survival via reduced plant cover. We calculated phylogenetically independent contrasts of climate with respect to life history in a clade of winter-establishing evening primroses (sections Anogra and Kleinia; Oenothera; Onagraceae), which includes seven annuals, 12 perennials, and two variable taxa. Climate variables were quantified from long-term records at weather stations near collection localities. To explicitly account for phylogenetic uncertainty, contrasts were calculated on a random sample of phylogenetic trees from the posterior distribution of a Bayesian analysis of DNA sequence data. Statements of association are based on comparing the per-tree mean contrast, which has a null expectation of zero, to a set of per-tree mean contrasts calculated on the same trees, after randomizing the climate data. As predicted, increased annual aridity, increased annual potential evapotranspiration, and decreased annual precipitation were associated with transitions to the annual habit, but these trends were not significantly different from the null pattern. Transitions to the annual habit were not significantly associated with increases in one measure of aridity in summer nor with increased summer drought, but they were associated with significantly increased maximum summer temperatures. In winter, increased aridity and decreased precipitation were significantly associated with transitions to the annual habit. Changes in life history were not significantly associated with changes in the coefficient of variation of precipitation, either on an annual or seasonal (summer vs. winter) basis. Though we
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Uncertainty in Land Cover observations and its impact on near surface climate
Georgievski, Goran; Hagemann, Stefan
2017-04-01
Land Cover (LC) and its bio-geo-physical feedbacks are important for the understanding of climate and its vulnerability to changes on the surface of the Earth. Recently ESA has published a new LC map derived by combining remotely sensed surface reflectance and ground-truth observations. For each grid-box at 300m resolution, an estimate of confidence is provided. This LC data set can be used in climate modelling to derive land surface boundary parameters for the respective Land Surface Model (LSM). However, the ESA LC classes are not directly suitable for LSMs, therefore they need to be converted into the model specific surface presentations. Due to different design and processes implemented in various climate models they might differ in the treatment of artificial, water bodies, ice, bare or vegetated surfaces. Nevertheless, usually vegetation distribution in models is presented by means of plant functional types (PFT), which is a classification system used to simplify vegetation representation and group different vegetation types according to their biophysical characteristics. The method of LC conversion into PFT is also called "cross-walking" (CW) procedure. The CW procedure is another source of uncertainty, since it depends on model design and processes implemented and resolved by LSMs. These two sources of uncertainty, (i) due to surface reflectance conversion into LC classes, (ii) due to CW procedure, have been studied by Hartley et al (2016) to investigate their impact on LSM state variables (albedo, evapotranspiration (ET) and primary productivity) by using three standalone LSMs. The present study is a follow up to that work and aims at quantifying the impact of these two uncertainties on climate simulations performed with the Max Planck Institute for Meteorology Earth System Model (MPI-ESM) using prescribed sea surface temperature and sea ice. The main focus is on the terrestrial water cycle, but the impacts on surface albedo, wind patterns, 2m temperatures
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Vines, Aleksander; Hamre, Torill; Lygre, Kjetil
2014-05-01
The GreenSeas project (Development of global plankton data base and model system for eco-climate early warning) aims to advance the knowledge and predictive capacities of how marine ecosystems will respond to global change. A main task has been to set up a data delivery and monitoring core service following the open and free data access policy implemented in the Global Monitoring for the Environment and Security (GMES) programme. A key feature of the system is its ability to compare data from different datasets, including an option to upload one's own netCDF files. The user can for example search in an in situ database for different variables (like temperature, salinity, different elements, light, specific plankton types or rate measurements) with different criteria (bounding box, date/time, depth, Longhurst region, cruise/transect) and compare the data with model data. The user can choose model data or Earth observation data from a list, or upload his/her own netCDF files to use in the comparison. The data can be visualized on a map, as graphs and plots (e.g. time series and property-property plots), or downloaded in various formats. The aim is to ensure open and free access to historical plankton data, new data (EO products and in situ measurements), model data (including estimates of simulation error) and biological, environmental and climatic indicators to a range of stakeholders, such as scientists, policy makers and environmental managers. We have implemented a web-based GIS(Geographical Information Systems) system and want to demonstrate the use of this. The tool is designed for a wide range of users: Novice users, who want a simple way to be able to get basic information about the current state of the marine planktonic ecosystem by utilizing predefined queries and comparisons with models. Intermediate level users who want to explore the database on their own and customize the prefedined setups. Advanced users who want to perform complex queries and
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Comparing climate and cost impacts of reference levels for reducing emissions from deforestation
Energy Technology Data Exchange (ETDEWEB)
Busch, Jonah [Center for Applied Biodiversity Science, Conservation International, 2011 Crystal Drive, Suite 500, Arlington, VA (United States); Strassburg, Bernardo [Center for Social and Economic Research on the Global Environment, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Cattaneo, Andrea [Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 02540-1644 (United States); Lubowski, Ruben [Environmental Defense Fund, 1875 Connecticut Avenue NW, Washington, DC (United States); Bruner, Aaron; Rice, Richard; Boltz, Frederick [Conservation International, 2011 Crystal Drive, Suite 500, Arlington, VA (United States); Creed, Anna; Ashton, Ralph, E-mail: jbusch@conservation.or [Terrestrial Carbon Group, 900 17th Street NW, Suite 700, Washington, DC (United States)
2009-10-15
The climate benefit and economic cost of an international mechanism for reducing emissions from deforestation and degradation (REDD) will depend on the design of reference levels for crediting emission reductions. We compare the impacts of six proposed reference level designs on emission reduction levels and on cost per emission reduction using a stylized partial equilibrium model (the open source impacts of REDD incentives spreadsheet; OSIRIS). The model explicitly incorporates national incentives to participate in an international REDD mechanism as well as international leakage of deforestation emissions. Our results show that a REDD mechanism can provide cost-efficient climate change mitigation benefits under a broad range of reference level designs. We find that the most effective reference level designs balance incentives to reduce historically high deforestation emissions with incentives to maintain historically low deforestation emissions. Estimates of emission reductions under REDD depend critically on the degree to which demand for tropical frontier agriculture generates leakage. This underscores the potential importance to REDD of complementary strategies to supply agricultural needs outside of the forest frontier.
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Comparing climate and cost impacts of reference levels for reducing emissions from deforestation
International Nuclear Information System (INIS)
Busch, Jonah; Strassburg, Bernardo; Cattaneo, Andrea; Lubowski, Ruben; Bruner, Aaron; Rice, Richard; Boltz, Frederick; Creed, Anna; Ashton, Ralph
2009-01-01
The climate benefit and economic cost of an international mechanism for reducing emissions from deforestation and degradation (REDD) will depend on the design of reference levels for crediting emission reductions. We compare the impacts of six proposed reference level designs on emission reduction levels and on cost per emission reduction using a stylized partial equilibrium model (the open source impacts of REDD incentives spreadsheet; OSIRIS). The model explicitly incorporates national incentives to participate in an international REDD mechanism as well as international leakage of deforestation emissions. Our results show that a REDD mechanism can provide cost-efficient climate change mitigation benefits under a broad range of reference level designs. We find that the most effective reference level designs balance incentives to reduce historically high deforestation emissions with incentives to maintain historically low deforestation emissions. Estimates of emission reductions under REDD depend critically on the degree to which demand for tropical frontier agriculture generates leakage. This underscores the potential importance to REDD of complementary strategies to supply agricultural needs outside of the forest frontier.
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Validation of CMIP5 multimodel ensembles through the smoothness of climate variables
Lee, Myoungji
2015-05-14
Smoothness is an important characteristic of a spatial process that measures local variability. If climate model outputs are realistic, then not only the values at each grid pixel but also the relative variation over nearby pixels should represent the true climate. We estimate the smoothness of long-term averages for land surface temperature anomalies in the Coupled Model Intercomparison Project Phase 5 (CMIP5), and compare them by climate regions and seasons. We also compare the estimated smoothness of the climate outputs in CMIP5 with those of reanalysis data. The estimation is done through the composite likelihood approach for locally self-similar processes. The composite likelihood that we consider is a product of conditional likelihoods of neighbouring observations. We find that the smoothness of the surface temperature anomalies in CMIP5 depends primarily on the modelling institution and on the climate region. The seasonal difference in the smoothness is generally small, except for some climate regions where the average temperature is extremely high or low.
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International Nuclear Information System (INIS)
Miller, C.; Bretherton, F.
1995-01-01
The assignment for Breakout Group A was to re-visit and expand upon the plenary session discussion on climate forcings and feedbacks and to develop a set of recommendations for each of the science disciplines or activities covered within this breakout category. Working guidelines for the group included identifying: (1) what has to be done; (2) why it has to be done, i.e. who is the customer? (3) the process for remedying deficiencies and, specifically, how to leverage the activities at operational centers; and (4) priorities (recognizing that it is premature to distinguish between major systems). The science ares addressed included: greenhouse gases (GHGs); radiation budget; water vapor; aerosols; clouds; precipitation; tropospheric ozone; and solar radiation. The role of climate satellites was also noted
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Model Interpretation of Climate Signals: Application to the Asian Monsoon Climate
Lau, William K. M.
2002-01-01
This is an invited review paper intended to be published as a Chapter in a book entitled "The Global Climate System: Patterns, Processes and Teleconnections" Cambridge University Press. The author begins with an introduction followed by a primer of climate models, including a description of various modeling strategies and methodologies used for climate diagnostics and predictability studies. Results from the CLIVAR Monsoon Model Intercomparison Project (MMIP) were used to illustrate the application of the strategies to modeling the Asian monsoon. It is shown that state-of-the art atmospheric GCMs have reasonable capability in simulating the seasonal mean large scale monsoon circulation, and response to El Nino. However, most models fail to capture the climatological as well as interannual anomalies of regional scale features of the Asian monsoon. These include in general over-estimating the intensity and/or misplacing the locations of the monsoon convection over the Bay of Bengal, and the zones of heavy rainfall near steep topography of the Indian subcontinent, Indonesia, and Indo-China and the Philippines. The intensity of convection in the equatorial Indian Ocean is generally weaker in models compared to observations. Most important, an endemic problem in all models is the weakness and the lack of definition of the Mei-yu rainbelt of the East Asia, in particular the part of the Mei-yu rainbelt over the East China Sea and southern Japan are under-represented. All models seem to possess certain amount of intraseasonal variability, but the monsoon transitions, such as the onset and breaks are less defined compared with the observed. Evidences are provided that a better simulation of the annual cycle and intraseasonal variability is a pre-requisite for better simulation and better prediction of interannual anomalies.
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Using ERA-Interim reanalysis for creating datasets of energy-relevant climate variables
Jones, Philip D.; Harpham, Colin; Troccoli, Alberto; Gschwind, Benoit; Ranchin, Thierry; Wald, Lucien; Goodess, Clare M.; Dorling, Stephen
2017-07-01
The construction of a bias-adjusted dataset of climate variables at the near surface using ERA-Interim reanalysis is presented. A number of different, variable-dependent, bias-adjustment approaches have been proposed. Here we modify the parameters of different distributions (depending on the variable), adjusting ERA-Interim based on gridded station or direct station observations. The variables are air temperature, dewpoint temperature, precipitation (daily only), solar radiation, wind speed, and relative humidity. These are available on either 3 or 6 h timescales over the period 1979-2016. The resulting bias-adjusted dataset is available through the Climate Data Store (CDS) of the Copernicus Climate Change Data Store (C3S) and can be accessed at present from climate.copernicus.eu" target="_blank">ftp://ecem.climate.copernicus.eu. The benefit of performing bias adjustment is demonstrated by comparing initial and bias-adjusted ERA-Interim data against gridded observational fields.
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Promise and Capability of NASA's Earth Observing System to Monitor Human-Induced Climate Variations
King, M. D.
2003-01-01
The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by which scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. The Moderate Resolution Imaging Spectroradiometer (MODIS), developed as part of the Earth Observing System (EOS) and launched on Terra in December 1999 and Aqua in May 2002, is designed to meet the scientific needs for satellite remote sensing of clouds, aerosols, water vapor, and land and ocean surface properties. This sensor and multi-platform observing system is especially well suited to observing detailed interdisciplinary components of the Earth s surface and atmosphere in and around urban environments, including aerosol optical properties, cloud optical and microphysical properties of both liquid water and ice clouds, land surface reflectance, fire occurrence, and many other properties that influence the urban environment and are influenced by them. In this presentation I will summarize the current capabilities of MODIS and other EOS sensors currently in orbit to study human-induced climate variations.
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van Huissteden, J.; Vandenberghe, J.; Pollard, D.
2003-01-01
A palaeotemperature reconstruction based on periglacial phenomena in Europe north of approximately 51 °N, is compared with high-resolution regional climate model simulations of the marine oxygen isotope Stage 3 (Stage 3) palaeoclimate. The experiments represent Stage 3 warm (interstadial), Stage 3
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Kirkby, Jasper
2007-01-01
Among the most puzzling questions in climate change is that of solar-climate variability, which has attracted the attention of scientists for more than two centuries. Until recently, even the existence of solar-climate variability has been controversialâperhaps because the observations had largely involved correlations between climate and the sunspot cycle that had persisted for only a few decades. Over the last few years, however, diverse reconstructions of past climate change have revealed clear associations with cosmic ray variations recorded in cosmogenic isotope archives, providing persuasive evidence for solar or cosmic ray forcing of the climate. However, despite the increasing evidence of its importance, solar-climate variability is likely to remain controversial until a physical mechanism is established. Although this remains a mystery, observations suggest that cloud cover may be influenced by cosmic rays, which are modulated by the solar wind and, on longer time scales, by the geomagnetic fiel...
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International Nuclear Information System (INIS)
Trenberth, K.; Angell, J.; Barry, R.; Bradley, R.; Diaz, H.; Elliott, W.; Etkins, R.; Folland, C.; Jenne, R.; Jones, P.; Karl, T.; Levitus, S.; Oort, A.; Parker, D.; Ropelewski, C.; Vinnikov, K.; Wigley, T.
1991-01-01
Topics of discussion include the following: the need for observations; issues in establishing global climate trends; climate variables such as surface air temperature over land, marine temperature, precipitation, circulation, upper air measurements, historical observations, subsurface ocean data, sea level, cryosphere, clouds, solar radiation, and aerosols; future considerations and recommendations which focuses on the establishment of a global benchmark climate monitoring network and data management
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International Nuclear Information System (INIS)
Trenberth, K.; Angell, J.; Barry, R.; Bradley, R.; Diaz, H.; Elliott, W.; Etkins, R.; Folland, C.; Jenne, R.; Jones, P.; Karl, T.; Levitus, S.; Oort, A.; Parker, D.; Ropelewski, C.; Vinnikov, K.; Wigley, T.
1990-01-01
Topics of discussion include the following: the need for observations; issues in establishing global climate trends; climate variables such as surface air temperature over land, marine temperature, precipitation, circulation, upper air measurements, historical observations, subsurface ocean data, sea level, cryosphere, clouds, solar radiation, and aerosols; future considerations and recommendations which focuses on the establishment of a global benchmark climate monitoring network and data management
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Li, Feng; Vikhliaev, Yury V.; Newman, Paul A.; Pawson, Steven; Perlwitz, Judith; Waugh, Darryn W.; Douglass, Anne R.
2016-01-01
Stratospheric ozone depletion plays a major role in driving climate change in the Southern Hemisphere. To date, many climate models prescribe the stratospheric ozone layer's evolution using monthly and zonally averaged ozone fields. However, the prescribed ozone underestimates Antarctic ozone depletion and lacks zonal asymmetries. In this study we investigate the impact of using interactive stratospheric chemistry instead of prescribed ozone on climate change simulations of the Antarctic and Southern Ocean. Two sets of 1960-2010 ensemble transient simulations are conducted with the coupled ocean version of the Goddard Earth Observing System Model, version 5: one with interactive stratospheric chemistry and the other with prescribed ozone derived from the same interactive simulations. The model's climatology is evaluated using observations and reanalysis. Comparison of the 1979-2010 climate trends between these two simulations reveals that interactive chemistry has important effects on climate change not only in the Antarctic stratosphere, troposphere, and surface, but also in the Southern Ocean and Antarctic sea ice. Interactive chemistry causes stronger Antarctic lower stratosphere cooling and circumpolar westerly acceleration during November-December-January. It enhances stratosphere-troposphere coupling and leads to significantly larger tropospheric and surface westerly changes. The significantly stronger surface wind stress trends cause larger increases of the Southern Ocean Meridional Overturning Circulation, leading to year-round stronger ocean warming near the surface and enhanced Antarctic sea ice decrease.
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Airborne geophysics for mesoscale observations of polar sea ice in a changing climate
Hendricks, S.; Haas, C.; Krumpen, T.; Eicken, H.; Mahoney, A. R.
2016-12-01
Sea ice thickness is an important geophysical parameter with a significant impact on various processes of the polar energy balance. It is classified as Essential Climate Variable (ECV), however the direct observations of the large ice-covered oceans are limited due to the harsh environmental conditions and logistical constraints. Sea-ice thickness retrieval by the means of satellite remote sensing is an active field of research, but current observational capabilities are not able to capture the small scale variability of sea ice thickness and its evolution in the presence of surface melt. We present an airborne observation system based on a towed electromagnetic induction sensor that delivers long range measurements of sea ice thickness for a wide range of sea ice conditions. The purpose-built sensor equipment can be utilized from helicopters and polar research aircraft in multi-role science missions. While airborne EM induction sounding is used in sea ice research for decades, the future challenge is the development of unmanned aerial vehicle (UAV) platform that meet the requirements for low-level EM sea ice surveys in terms of range and altitude of operations. The use of UAV's could enable repeated sea ice surveys during the the polar night, when manned operations are too dangerous and the observational data base is presently very sparse.
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Comparative study of different stochastic weather generators for long-term climate data simulation
Climate is one of the single most important factors affecting watershed ecosystems and water resources. The effect of climate variability and change has been studied extensively in some places; in many places, however, assessments are hampered by limited availability of long term continuous climate ...
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Explorative Observations of the Urban Climate System in the Rotterdam Metropolis
Jacobs, C. M.; van Hove, L. W.; Heusinkveld, B. G.; Steeneveld, G.; van Heerwaarden, C.; Elbers, J. A.
2009-12-01
Until recently, the Urban Heat Island (UHI) effect was thought to be relatively unimportant for Dutch conditions since The Netherlands are located in the mild Cfb climate, close to the sea. This view altered after the heat waves of 2003 and 2006 that caused an excess mortality between 1400 and 2200. The excess mortality was found in the cities in particular. Climate projections show that also in The Netherlands heat waves will likely become more frequent in the next decades, which may form an important threat to the livability in urban areas. However, information regarding UHI in Dutch cities is completely lacking, both from observational and model perspective, which hampers the design of suitable adaptation and heat mitigation strategies. In this study, an assessment of the intensity of UHI in the city of Rotterdam is made. The main aim is to assess whether or not heat stress already is or will be a critical issue in the Rotterdam area. Traverse measurements were performed in the city using two cargo bicycles as a mobile platform, equipped specifically for urban meteorology measurements. The cargo bicycles allow manoeuvring easily through the narrow streets in the city. They are equipped with a thermometer, a humidity sensor, a 2-dimensional sonic anemometer and a set of radiation sensors to measure solar radiation and infrared radiation exchange from six directions. The data are recorded at 1 Hz, and connected with concurrent GPS readings. The instruments are powered by a solar panel mounted on the baggage carrier. Measurements were performed along two previously determined routes through a number of characteristic urban districts, including an industrial area, an older residential area, a city park and the harbour area. The routes were photographed at fixed intervals from 50 cm above the ground with a fisheye lens pointing upwards. The observations were carried out during four 1-2h time intervals on 6 August 2009, a warm day with a maximum temperature of near 30
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Murdoch, P. S.
2007-12-01
The past 30 years of environmental research have shown that our world is not made up of discrete components acting independently, but rather of a mosaic of complex relations among air, land, water, living resources, and human activities. Recent warming of the climate is having a significant effect on the functioning of those systems. A national imperative is developing to quickly establish local, regional, and national systems for anticipating environmental degradation from a changing climate and developing cost-effective adaptation or mitigation strategies. In these circumstances, the debate over research versus monitoring becomes moot--there is a clear need for the integrated application of both across a range of temporal and spatial scales. A national framework that effectively addresses the multiple scales and complex multi-disciplinary processes of climate change is being assembled largely from existing programs through collaboration among Federal, State, local, and NGO organizations. The result will be an observation and research network capable of interpreting complex environmental changes at a range of spatial and temporal scales, but at less cost than if the network were funded as an independent initiative. A pilot implementation of the collaborative framework in the Delaware River Basin yielded multi-scale assessments of carbon storage and flux, and the effects of forest fragmentation and soil calcium depletion on ecosystem function. A prototype of a national climate-effects observation and research network linking research watersheds, regional surveys, remote sensing, and ecosystem modeling is being initiated in the Yukon River Basin where carbon flux associated with permafrost thaw could accelerate global warming.
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International Nuclear Information System (INIS)
Shine, Keith P.; Fuglestvedt, J.S.; Hailemariam, K.; Stuber, N.
2005-01-01
The Global Warming Potential (GWP) is used within the Kyoto Protocol to the United Nations Framework Convention on Climate Change as a metric for weighting the climatic impact of emissions of different greenhouse gases. The GWP has been subjected to many criticisms because of its formulation, but nevertheless it has retained some favour because of the simplicity of its design and application, and its transparency compared to proposed alternatives. Here, two new metrics are proposed, which are based on a simple analytical climate model. The first metric is called the Global Temperature Change Potential and represents the temperature change at a given time due to a pulse emission of a gas (GTPP); the second is similar but represents the effect of a sustained emission change (hence GTPS). Both GTPP and GTPS are presented as relative to the temperature change due to a similar emission change of a reference gas, here taken to be carbon dioxide. Both metrics are compared against an upwelling-diffusion energy balance model that resolves land and ocean and the hemispheres. The GTPP does not perform well, compared to the energy balance model, except for long-lived gases. By contrast, the GTPS is shown to perform well relative to the energy balance model, for gases with a wide variety of lifetimes. It is also shown that for time horizons in excess of about 100 years, the GTPS and GWP produce very similar results, indicating an alternative interpretation for the GWP. The GTPS retains the advantage of the GWP in terms of transparency, and the relatively small number of input parameters required for calculation. However, it has an enhanced relevance, as it is further down the cause-effect chain of the impacts of greenhouse gases emissions and has an unambiguous interpretation. It appears to be robust to key uncertainties and simplifications in its derivation and may be an attractive alternative to the GWP
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LES ARM Symbiotic Simulation and Observation (LASSO) Implementation Strategy
Energy Technology Data Exchange (ETDEWEB)
Gustafson Jr., WI [Pacific Northwest National Laboratory; Vogelmann, AM [Brookhaven National Laboratory
2015-09-01
This document illustrates the design of the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) workflow to provide a routine, high-resolution modeling capability to augment the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s high-density observations. LASSO will create a powerful new capability for furthering ARM’s mission to advance understanding of cloud, radiation, aerosol, and land-surface processes. The combined observational and modeling elements will enable a new level of scientific inquiry by connecting processes and context to observations and providing needed statistics for details that cannot be measured. The result will be improved process understanding that facilitates concomitant improvements in climate model parameterizations. The initial LASSO implementation will be for ARM’s Southern Great Plains site in Oklahoma and will focus on shallow convection, which is poorly simulated by climate models due in part to clouds’ typically small spatial scale compared to model grid spacing, and because the convection involves complicated interactions of microphysical and boundary layer processes.
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Satellite Observation Systems for Polar Climate Change Studies
Comiso, Josefino C.
2012-01-01
The key observational tools for detecting large scale changes of various parameters in the polar regions have been satellite sensors. The sensors include passive and active satellite systems in the visible, infrared and microwave frequencies. The monitoring started with Tiros and Nimbus research satellites series in the 1970s but during the period, not much data was stored digitally because of limitations and cost of the needed storage systems. Continuous global data came about starting with the launch of ocean color, passive microwave, and thermal infrared sensors on board Nimbus-7 and Synthetic Aperture Radar, Radar Altimeter and Scatterometer on board SeaSat satellite both launched in 1978. The Nimbus-7 lasted longer than expected and provided about 9 years of useful data while SeaSat quit working after 3 months but provided very useful data that became the baseline for follow-up systems with similar capabilities. Over the years, many new sensors were launched, some from Japan Aeronautics and Space Agency (JAXA), some from the European Space Agency (ESA) and more recently, from RuSSia, China, Korea, Canada and India. For polar studies, among the most useful sensors has been the passive microwave sensor which provides day/night and almost all weather observation of the surface. The sensor provide sea surface temperature, precipitation, wind, water vapor and sea ice concentration data that have been very useful in monitoring the climate of the region. More than 30 years of such data are now available, starting with the Scanning Multichannel Microwave Radiometer (SMMR) on board the Nimbus-7, the Special Scanning Microwave/Imager (SSM/I) on board a Defense Meteorological Satellite Program (DMSP) and the Advanced Microwave Scanning Radiometer on board the EOS/ Aqua satellite. The techniques that have been developed to derive geophysical parameters from data provided by these and other sensors and associated instrumental and algorithm errors and validation techniques
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Directory of Open Access Journals (Sweden)
O. H. Otterå
2009-11-01
Full Text Available The Bergen Climate Model (BCM is a fully-coupled atmosphere-ocean-sea-ice model that provides state-of-the-art computer simulations of the Earth's past, present, and future climate. Here, a pre-industrial multi-century simulation with an updated version of BCM is described and compared to observational data. The model is run without any form of flux adjustments and is stable for several centuries. The simulated climate reproduces the general large-scale circulation in the atmosphere reasonably well, except for a positive bias in the high latitude sea level pressure distribution. Also, by introducing an updated turbulence scheme in the atmosphere model a persistent cold bias has been eliminated. For the ocean part, the model drifts in sea surface temperatures and salinities are considerably reduced compared to earlier versions of BCM. Improved conservation properties in the ocean model have contributed to this. Furthermore, by choosing a reference pressure at 2000 m and including thermobaric effects in the ocean model, a more realistic meridional overturning circulation is simulated in the Atlantic Ocean. The simulated sea-ice extent in the Northern Hemisphere is in general agreement with observational data except for summer where the extent is somewhat underestimated. In the Southern Hemisphere, large negative biases are found in the simulated sea-ice extent. This is partly related to problems with the mixed layer parametrization, causing the mixed layer in the Southern Ocean to be too deep, which in turn makes it hard to maintain a realistic sea-ice cover here. However, despite some problematic issues, the pre-industrial control simulation presented here should still be appropriate for climate change studies requiring multi-century simulations.
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Haberlandt, Uwe; Wallner, Markus; Radtke, Imke
2013-04-01
Derived flood frequency analysis based on continuous hydrological modelling is very demanding regarding the required length and temporal resolution of precipitation input data. Often such flood predictions are obtained using long precipitation time series from stochastic approaches or from regional climate models as input. However, the calibration of the hydrological model is usually done using short time series of observed data. This inconsistent employment of different data types for calibration and application of a hydrological model increases its uncertainty. Here, it is proposed to calibrate a hydrological model directly on probability distributions of observed peak flows using model based rainfall in line with its later application. Two examples are given to illustrate the idea. The first one deals with classical derived flood frequency analysis using input data from an hourly stochastic rainfall model. The second one concerns a climate impact analysis using hourly precipitation from a regional climate model. The results show that: (I) the same type of precipitation input data should be used for calibration and application of the hydrological model, (II) a model calibrated on extreme conditions works quite well for average conditions but not vice versa, (III) the calibration of the hydrological model using regional climate model data works as an implicit bias correction method and (IV) the best performance for flood estimation is usually obtained when model based precipitation and observed probability distribution of peak flows are used for model calibration.
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Observations: Oceanic climate change and sea level
Digital Repository Service at National Institute of Oceanography (India)
Bindoff, N.L.; Willebrand, J.; Artale, V.; Cazenave, A; Gregory, J.; Gulev, S.; Hanawa, K.; LeQuere, C.; Levitus, S.; Nojiri, Y.; Shum, C.K.; Talley, L.D.; Unnikrishnan, A
change is 10.9 ± 3.1 × 10 22 J or 0.14 ± 0.04 W m –2 (data from Levitus et al., 2005a). All of these estimates are per unit area of Earth surface. Despite the fact that there are differences between these three ocean heat content estimates due... to the data used, quality control applied, instrumental biases, temporal and spatial averaging and analysis methods (Appendix 5.A.1), they are consistent with each other giving a high degree of confidence for their use in climate change studies. The global...
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Energy Technology Data Exchange (ETDEWEB)
NONE
2012-07-01
Precipitation and temperature from global (GCMs) and regional (RCMs) climate models are compared with reanalysis and observations over Scandinavia. Also projections for the next 50-100 years are considered. The climate development is visualised as moving averages (1920-2100). Box plots are used to illuminate how well GCM runs capture the observed seasonal cycle. Maps show the seasonal difference between results from control runs (RCM) and observations (E-OBS dataset) for the reference period 1981-2000. Plots illustrate the RCM-representation of seasonal temperature and precipitations cycle for five locations in Norway and Sweden: Oslo, Bergen, Trondheim, Tromsoe and Oestersund. The results show rather large differences between control runs and observations, demonstrating the need for bias correction of results from climate models. To get an indicator of which GC M-RCM-combination give the best representation of present climate over Scandinavia, a model ranking is provided. The performance measure used is the root-mean-square deviation of mean monthly and seasonal values. The data is compared both in an area-weighted spatial average of the whole domain as well as for the selected locations. The results indicate that the regional models RACMO2 and RCA show the smallest deviations from observed climate. Among the top ranking GCM-RCM combinations, most were driven by the global model ECHAM5 and some by a version of HadCM3. These two GCMs are also present among the worst performing GCM-RCM combinations indicating that selection of RCMs is crucial. (Author)
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Climate change and climate policy
International Nuclear Information System (INIS)
Alfsen, Knut H.; Kolshus, Hans H.; Torvanger, Asbjoern
2000-08-01
The climate issue is a great political and scientific challenge for several reasons: (1) There are many uncertain aspects of the climate problem, such as future emission of climate gases, the response of the climate system upon these gases, and the effects of climate changes. (2) It is probable, however, that anthropogenic emission of climate gases, deforestation etc. will cause noticeable climate changes in the future. This might be observed as increased frequency of extreme weather situations. This appears to be a greater threat than a gradual increase of temperature and precipitation. (3) Since the climate system is large and react only relatively slowly on changes in for instance the emission of climate gases, the climate problem can only be solved by means of long-term measures. (4) The climate changes may be irreversible. A rational short-term strategy is to ensure maximum flexibility, which can be done by ''slowing down'' (curtailing emissions) and by avoiding irreversible actions as much as possible. The long-term challenge is to develop an economically responsible alternative to the present fossil-based energy system that permits carbon-efficient technologies to compete on price with coal and unconventional oil and gas. Norway is in a special position by being a large exporter of fossil fuel and at the same time wanting to appear responsible in environmental matters. This combination may incur considerable expenses upon Norway and it is therefore important that environmental commitments like the Kyoto agreement can be honoured to the lowest possible cost. The costs can be minimized by: (1) minimizing the measure costs in Norway, (2) working to make the international quota price as low as possible, and (3) reducing the loss of petroleum income as much as possible. This report describes the earth's climate history, the forces behind climatic changes and what the prospects for the future look like. It also reviews what is being done to curtail the emission of
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Efficient climate policies under technology and climate uncertainty
International Nuclear Information System (INIS)
Held, Hermann; Kriegler, Elmar; Lessmann, Kai; Edenhofer, Ottmar
2009-01-01
This article explores efficient climate policies in terms of investment streams into fossil and renewable energy technologies. The investment decisions maximise social welfare while observing a probabilistic guardrail for global mean temperature rise under uncertain technology and climate parameters. Such a guardrail constitutes a chance constraint, and the resulting optimisation problem is an instance of chance constrained programming, not stochastic programming as often employed. Our analysis of a model of economic growth and endogenous technological change, MIND, suggests that stringent mitigation strategies cannot guarantee a very high probability of limiting warming to 2 o C since preindustrial time under current uncertainty about climate sensitivity and climate response time scale. Achieving the 2 o C temperature target with a probability P* of 75% requires drastic carbon dioxide emission cuts. This holds true even though we have assumed an aggressive mitigation policy on other greenhouse gases from, e.g., the agricultural sector. The emission cuts are deeper than estimated from a deterministic calculation with climate sensitivity fixed at the P* quantile of its marginal probability distribution (3.6 o C). We show that earlier and cumulatively larger investments into the renewable sector are triggered by including uncertainty in the technology and climate response time scale parameters. This comes at an additional GWP loss of 0.3%, resulting in a total loss of 0.8% GWP for observing the chance constraint. We obtained those results with a new numerical scheme to implement constrained welfare optimisation under uncertainty as a chance constrained programming problem in standard optimisation software such as GAMS. The scheme is able to incorporate multivariate non-factorial probability measures such as given by the joint distribution of climate sensitivity and response time. We demonstrate the scheme for the case of a four-dimensional parameter space capturing
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Evaluation of the applicability in the future climate of a statistical downscaling method in France
Dayon, G.; Boé, J.; Martin, E.
2013-12-01
The uncertainties in climate projections during the next decades generally remain large, with an important contribution of internal climate variability. To quantify and capture the impact of those uncertainties in impact projections, multi-model and multi-member approaches are essential. Statistical downscaling (SD) methods are computationally inexpensive allowing for large ensemble approaches. The main weakness of SD is that it relies on a stationarity hypothesis, namely that the statistical relation established in the present climate remains valid in the climate change context. In this study, the evaluation of SD methods developed for a future study of hydrological changes during the next decades over France is presented, focusing on precipitation. The SD methods are all based on the analogs method which is quite simple to set up and permits to easily test different combinations of predictors, the only changing parameter in the methods discussed in this presentation. The basic idea of the analogs method is that for a same large scale climatic state, the state of local variables will be identical. In a climate change context, the statistical relation established on past climate is assumed to remain valid in the future climate. In practice, this stationarity assumption is impossible to verify until the future climate is effectively observed. It is possible to evaluate the ability of SD methods to reproduce the interannual variability in the present climate, but this approach does not guarantee their validity in the future climate as the mechanisms that play in the interannual and climate change contexts may not be identical. Another common approach is to test whether a SD method is able to reproduce observed, as they may be partly caused by climate changes. The observed trends in precipitation are compared to those obtained by downscaling 4 different atmospheric reanalyses with analogs methods. The uncertainties in downscaled trends due to renalyses are very large
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Climate forcings and climate sensitivities diagnosed from atmospheric global circulation models
Energy Technology Data Exchange (ETDEWEB)
Anderson, Bruce T. [Boston University, Department of Geography and Environment, Boston, MA (United States); Knight, Jeff R.; Ringer, Mark A. [Met Office Hadley Centre, Exeter (United Kingdom); Deser, Clara; Phillips, Adam S. [National Center for Atmospheric Research, Boulder, CO (United States); Yoon, Jin-Ho [University of Maryland, Cooperative Institute for Climate and Satellites, Earth System Science Interdisciplinary Center, College Park, MD (United States); Cherchi, Annalisa [Centro Euro-Mediterraneo per i Cambiamenti Climatici, and Istituto Nazionale di Geofisica e Vulcanologia, Bologna (Italy)
2010-12-15
Understanding the historical and future response of the global climate system to anthropogenic emissions of radiatively active atmospheric constituents has become a timely and compelling concern. At present, however, there are uncertainties in: the total radiative forcing associated with changes in the chemical composition of the atmosphere; the effective forcing applied to the climate system resulting from a (temporary) reduction via ocean-heat uptake; and the strength of the climate feedbacks that subsequently modify this forcing. Here a set of analyses derived from atmospheric general circulation model simulations are used to estimate the effective and total radiative forcing of the observed climate system due to anthropogenic emissions over the last 50 years of the twentieth century. They are also used to estimate the sensitivity of the observed climate system to these emissions, as well as the expected change in global surface temperatures once the climate system returns to radiative equilibrium. Results indicate that estimates of the effective radiative forcing and total radiative forcing associated with historical anthropogenic emissions differ across models. In addition estimates of the historical sensitivity of the climate to these emissions differ across models. However, results suggest that the variations in climate sensitivity and total climate forcing are not independent, and that the two vary inversely with respect to one another. As such, expected equilibrium temperature changes, which are given by the product of the total radiative forcing and the climate sensitivity, are relatively constant between models, particularly in comparison to results in which the total radiative forcing is assumed constant. Implications of these results for projected future climate forcings and subsequent responses are also discussed. (orig.)
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Regional climate models downscaling in the Alpine area with multimodel superensemble
Directory of Open Access Journals (Sweden)
D. Cane
2013-05-01
Full Text Available The climatic scenarios show a strong signal of warming in the Alpine area already for the mid-XXI century. The climate simulations, however, even when obtained with regional climate models (RCMs, are affected by strong errors when compared with observations, due both to their difficulties in representing the complex orography of the Alps and to limitations in their physical parametrization. Therefore, the aim of this work is to reduce these model biases by using a specific post processing statistic technique, in order to obtain a more suitable projection of climate change scenarios in the Alpine area. For our purposes we used a selection of regional climate models (RCMs runs which were developed in the framework of the ENSEMBLES project. They were carefully chosen with the aim to maximise the variety of leading global climate models and of the RCMs themselves, calculated on the SRES scenario A1B. The reference observations for the greater Alpine area were extracted from the European dataset E-OBS (produced by the ENSEMBLES project, which have an available resolution of 25 km. For the study area of Piedmont daily temperature and precipitation observations (covering the period from 1957 to the present were carefully gridded on a 14 km grid over Piedmont region through the use of an optimal interpolation technique. Hence, we applied the multimodel superensemble technique to temperature fields, reducing the high biases of RCMs temperature field compared to observations in the control period. We also proposed the application of a brand new probabilistic multimodel superensemble dressing technique, already applied to weather forecast models successfully, to RCMS: the aim was to estimate precipitation fields, with careful description of precipitation probability density functions conditioned to the model outputs. This technique allowed for reducing the strong precipitation overestimation, arising from the use of RCMs, over the Alpine chain and to
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Regional climate models downscaling in the Alpine area with multimodel superensemble
Cane, D.; Barbarino, S.; Renier, L. A.; Ronchi, C.
2013-05-01
The climatic scenarios show a strong signal of warming in the Alpine area already for the mid-XXI century. The climate simulations, however, even when obtained with regional climate models (RCMs), are affected by strong errors when compared with observations, due both to their difficulties in representing the complex orography of the Alps and to limitations in their physical parametrization. Therefore, the aim of this work is to reduce these model biases by using a specific post processing statistic technique, in order to obtain a more suitable projection of climate change scenarios in the Alpine area. For our purposes we used a selection of regional climate models (RCMs) runs which were developed in the framework of the ENSEMBLES project. They were carefully chosen with the aim to maximise the variety of leading global climate models and of the RCMs themselves, calculated on the SRES scenario A1B. The reference observations for the greater Alpine area were extracted from the European dataset E-OBS (produced by the ENSEMBLES project), which have an available resolution of 25 km. For the study area of Piedmont daily temperature and precipitation observations (covering the period from 1957 to the present) were carefully gridded on a 14 km grid over Piedmont region through the use of an optimal interpolation technique. Hence, we applied the multimodel superensemble technique to temperature fields, reducing the high biases of RCMs temperature field compared to observations in the control period. We also proposed the application of a brand new probabilistic multimodel superensemble dressing technique, already applied to weather forecast models successfully, to RCMS: the aim was to estimate precipitation fields, with careful description of precipitation probability density functions conditioned to the model outputs. This technique allowed for reducing the strong precipitation overestimation, arising from the use of RCMs, over the Alpine chain and to reproduce well the
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Towards a Comparative Index of Seaport Climate-Risk: Development of Indicators from Open Data
McIntosh, R. D.; Becker, A.
2016-02-01
Seaports represent an example of coastal infrastructure that is at once critical to global trade, constrained to the land-sea interface, and exposed to weather and climate hazards. Seaports face impacts associated with projected changes in sea level, sedimentation, ocean chemistry, wave dynamics, temperature, precipitation, and storm frequency and intensity. Port decision-makers have the responsibility to enhance resilience against these impacts. At the multi-port (regional or national) scale, policy-makers must prioritize adaptation efforts to maximize the efficiency of limited physical and financial resources. Prioritization requires comparing across seaports, and comparison requires a standardized assessment method, but efforts to date have either been limited in scope to exposure-only assessments or limited in scale to evaluate one port in isolation from a system of ports. In order to better understand the distribution of risk across ports and to inform transportation resilience policy, we are developing a comparative assessment method to measure the relative climate-risk faced by a sample of ports. Our mixed-methods approach combines a quantitative, data-driven, indicator-based assessment with qualitative data collected via expert-elicitation. In this presentation, we identify and synthesize over 120 potential risk indicators from open data sources. Indicators represent exposure, sensitivity, and adaptive capacity for a pilot sample of 20 ports. Our exploratory data analysis, including Principal Component Analysis, uncovered sources of variance between individual ports and between indicators. Next steps include convening an expert panel representing the perspectives of multiple transportation system agencies to find consensus on a suite of robust indicators and metrics for maritime freight node climate risk assessment. The index will be refined based on expert feedback, the sample size expanded, and additional indicators sought from closed data sources
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The Cloud Project Climate Research with Accelerators
Kirkby, Jasper
2010-01-01
The current understanding of climate change in the in- dustrial age is that it is predominantly caused by anthro- pogenic greenhouse gases, with relatively small natural contributions due to solar irradiance and volcanoes. How- ever, palaeoclimatic reconstructions show that the climate has frequently varied on 100-year time scales during the Holocene (last 10 kyr) by amounts comparable to the present warming—and yet the mechanism is not under- stood. Estimated changes of solar irradiance on these time scales are too small to account for the climate observations. This raises the question of whether cosmic rays, which are modulated by the solar wind, may be directly affect- ing the climate, providing an effective indirect solar forcing mechanism. Indeed recent satellite observations—although disputed—suggest that cosmic rays may affect clouds un- der certain conditions. However, given the many sources of variability in the atmosphere and the lack of control of the cosmic ray flux, demonstrating overall ca...
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Younger, Jane L; Emmerson, Louise M; Miller, Karen J
2016-02-01
The Southern Ocean ecosystem is undergoing rapid physical and biological changes that are likely to have profound implications for higher-order predators. Here, we compare the long-term, historical responses of Southern Ocean predators to climate change. We examine palaeoecological evidence for changes in the abundance and distribution of seabirds and marine mammals, and place these into context with palaeoclimate records in order to identify key environmental drivers associated with population changes. Our synthesis revealed two key factors underlying Southern Ocean predator population changes; (i) the availability of ice-free ground for breeding and (ii) access to productive foraging grounds. The processes of glaciation and sea ice fluctuation were key; the distributions and abundances of elephant seals, snow petrels, gentoo, chinstrap and Adélie penguins all responded strongly to the emergence of new breeding habitat coincident with deglaciation and reductions in sea ice. Access to productive foraging grounds was another limiting factor, with snow petrels, king and emperor penguins all affected by reduced prey availability in the past. Several species were isolated in glacial refugia and there is evidence that refuge populations were supported by polynyas. While the underlying drivers of population change were similar across most Southern Ocean predators, the individual responses of species to environmental change varied because of species specific factors such as dispersal ability and environmental sensitivity. Such interspecific differences are likely to affect the future climate change responses of Southern Ocean marine predators and should be considered in conservation plans. Comparative palaeoecological studies are a valuable source of long-term data on species' responses to environmental change that can provide important insights into future climate change responses. This synthesis highlights the importance of protecting productive foraging grounds
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The observed sensitivity of the global hydrological cycle to changes in surface temperature
International Nuclear Information System (INIS)
Arkin, Phillip A; Janowiak, John; Smith, Thomas M; Sapiano, Mathew R P
2010-01-01
Climate models project large changes in global surface temperature in coming decades that are expected to be accompanied by significant changes in the global hydrological cycle. Validation of model simulations is essential to support their use in decision making, but observing the elements of the hydrological cycle is challenging, and model-independent global data sets exist only for precipitation. We compute the sensitivity of the global hydrological cycle to changes in surface temperature using available global precipitation data sets and compare the results against the sensitivities derived from model simulations of 20th century climate. The implications of the results for the global climate observing system are discussed.
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Energy Technology Data Exchange (ETDEWEB)
Jacob, Daniela; Goettel, Holger; Kotlarski, Sven; Lorenz, Philip; Sieck, Kevin [Max-Planck-Institut fuer Meteorologie (MPI-M), Hamburg (Germany)
2008-08-15
The regional climate scenarios were evaluated using the climate model REMO. The model calculations were actualized and compared with observed data. The validation of the modeling results was performed using data sets concerning the temporal behavior, the precipitation amounts in several altitudes and the analysis of the probability density function of the air temperature. The results of different climate scenarios are discussed for the mean monthly values of precipitation and temperature. The model allows the prediction of the temporal development and number of summer days and extremely hot days. The change of further indices due to the climatic change caused by increasing greenhouse gas emissions is discussed.
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Which climate change path are we following? Bad news from Scots pine.
Directory of Open Access Journals (Sweden)
Pierluigi Bombi
Full Text Available Current expectations on future climate derive from coordinated experiments, which compile many climate models for sampling the entire uncertainty related to emission scenarios, initial conditions, and modelling process. Quantifying this uncertainty is important for taking decisions that are robust under a wide range of possible future conditions. Nevertheless, if uncertainty is too large, it can prevent from planning specific and effective measures. For this reason, reducing the spectrum of the possible scenarios to a small number of one or a few models that actually represent the climate pathway influencing natural ecosystems would substantially increase our planning capacity. Here we adopt a multidisciplinary approach based on the comparison of observed and expected spatial patterns of response to climate change in order to identify which specific models, among those included in the CMIP5, catch the real climate variation driving the response of natural ecosystems. We used dendrochronological analyses for determining the geographic pattern of recent growth trends for three European species of trees. At the same time, we modelled the climatic niche for the same species and forecasted the suitability variation expected across Europe under each different GCM. Finally, we estimated how well each GCM explains the real response of ecosystems, by comparing the expected variation with the observed growth trends. Doing this, we identified four climatic models that are coherent with the observed trends. These models are close to the highest range limit of the climatic variations expected by the ensemble of the CMIP5 models, suggesting that current predictions of climate change impacts on ecosystems could be underestimated.
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Which climate change path are we following? Bad news from Scots pine.
Bombi, Pierluigi; D'Andrea, Ettore; Rezaie, Negar; Cammarano, Mario; Matteucci, Giorgio
2017-01-01
Current expectations on future climate derive from coordinated experiments, which compile many climate models for sampling the entire uncertainty related to emission scenarios, initial conditions, and modelling process. Quantifying this uncertainty is important for taking decisions that are robust under a wide range of possible future conditions. Nevertheless, if uncertainty is too large, it can prevent from planning specific and effective measures. For this reason, reducing the spectrum of the possible scenarios to a small number of one or a few models that actually represent the climate pathway influencing natural ecosystems would substantially increase our planning capacity. Here we adopt a multidisciplinary approach based on the comparison of observed and expected spatial patterns of response to climate change in order to identify which specific models, among those included in the CMIP5, catch the real climate variation driving the response of natural ecosystems. We used dendrochronological analyses for determining the geographic pattern of recent growth trends for three European species of trees. At the same time, we modelled the climatic niche for the same species and forecasted the suitability variation expected across Europe under each different GCM. Finally, we estimated how well each GCM explains the real response of ecosystems, by comparing the expected variation with the observed growth trends. Doing this, we identified four climatic models that are coherent with the observed trends. These models are close to the highest range limit of the climatic variations expected by the ensemble of the CMIP5 models, suggesting that current predictions of climate change impacts on ecosystems could be underestimated.
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Energy Technology Data Exchange (ETDEWEB)
Heimann, D.; Sept, V.
1998-12-01
Climatic changes in the Alpine region due to increasing greenhouse gas concentrations are assessed by using statistical-dynamical downscaling. The downscaling procedure is applied to two 30-year periods (1971-2000 and 2071-2100, summer months only) of the output of a transient coupled ocean/atmosphere climate scenario simulation. The downscaling results for the present-day climate are in sufficient agreement with observations. The estimated regional climate change during the next 100 years shows a general warming. The mean summer temperatures increase by about 3 to more than 5 Kelvin. The most intense climatic warming is predicted in the western parts of the Alps. The amount of summer precipitation decreases in most parts of central Europe by more than 20 percent. Only over the Adriatic area and parts of eastern central Europe an increase in precipitation is simulated. The results are compared with observed trends and results of regional climate change simulations of other authors. The observed trends and the majority of the simulated trends agree with our results. However, there are also climate change estimates which completely contradict with ours. (orig.) 29 refs.
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Energy Technology Data Exchange (ETDEWEB)
Eum, Hyung-Il; Laprise, Rene [University of Quebec at Montreal, ESCER (Etude et Simulation du Climat a l' Echelle Regionale), Montreal, QC (Canada); Gachon, Philippe [University of Quebec at Montreal, ESCER (Etude et Simulation du Climat a l' Echelle Regionale), Montreal, QC (Canada); Environment Canada, Adaptation and Impacts Research Section, Climate Research Division, Montreal, QC (Canada); Ouarda, Taha [University of Quebec, INRS-ETE (Institut National de la Recherche Scientifique, Centre Eau-Terre-Environnement), Quebec, QC (Canada)
2012-04-15
This study presents a combined weighting scheme which contains five attributes that reflect accuracy of climate data, i.e. short-term (daily), mid-term (annual), and long-term (decadal) timescales, as well as spatial pattern, and extreme values, as simulated from Regional Climate Models (RCMs) with respect to observed and regional reanalysis products. Southern areas of Quebec and Ontario provinces in Canada are used for the study area. Three series of simulation from two different versions of the Canadian RCM (CRCM4.1.1, and CRCM4.2.3) are employed over 23 years from 1979 to 2001, driven by both NCEP and ERA40 global reanalysis products. One series of regional reanalysis dataset (i.e. NARR) over North America is also used as reference for comparison and validation purpose, as well as gridded historical observed daily data of precipitation and temperatures, both series have been beforehand interpolated on the CRCM 45-km grid resolution. Monthly weighting factors are calculated and then combined into four seasons to reflect seasonal variability of climate data accuracy. In addition, this study generates weight averaged references (WARs) with different weighting factors and ensemble size as new reference climate data set. The simulation results indicate that the NARR is in general superior to the CRCM simulated precipitation values, but the CRCM4.1.1 provides the highest weighting factors during the winter season. For minimum and maximum temperature, both the CRCM4.1.1 and the NARR products provide the highest weighting factors, respectively. The NARR provides more accurate short- and mid-term climate data, but the two versions of the CRCM provide more precise long-term data, spatial pattern and extreme events. Or study confirms also that the global reanalysis data (i.e. NCEP vs. ERA40) used as boundary conditions in the CRCM runs has non-negligible effects on the accuracy of CRCM simulated precipitation and temperature values. In addition, this study demonstrates
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Walawender, Jakub; Kothe, Steffen; Trentmann, Jörg; Pfeifroth, Uwe; Cremer, Roswitha
2017-04-01
The purpose of this study is to create a 1 km2 gridded daily sunshine duration data record for Germany covering the period from 1983 to 2015 (33 years) based on satellite estimates of direct normalised surface solar radiation and in situ sunshine duration observations using a geostatistical approach. The CM SAF SARAH direct normalized irradiance (DNI) satellite climate data record and in situ observations of sunshine duration from 121 weather stations operated by DWD are used as input datasets. The selected period of 33 years is associated with the availability of satellite data. The number of ground stations is limited to 121 as there are only time series with less than 10% of missing observations over the selected period included to keep the long-term consistency of the output sunshine duration data record. In the first step, DNI data record is used to derive sunshine hours by applying WMO threshold of 120 W/m2 (SDU = DNI ≥ 120 W/m2) and weighting of sunny slots to correct the sunshine length between two instantaneous image data due to cloud movement. In the second step, linear regression between SDU and in situ sunshine duration is calculated to adjust the satellite product to the ground observations and the output regression coefficients are applied to create a regression grid. In the last step regression residuals are interpolated with ordinary kriging and added to the regression grid. A comprehensive accuracy assessment of the gridded sunshine duration data record is performed by calculating prediction errors (cross-validation routine). "R" is used for data processing. A short analysis of the spatial distribution and temporal variability of sunshine duration over Germany based on the created dataset will be presented. The gridded sunshine duration data are useful for applications in various climate-related studies, agriculture and solar energy potential calculations.
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Climate change in Australia: technical report 2007
International Nuclear Information System (INIS)
2007-01-01
The purpose of this report is to provide an up-to-date assessment of observed climate change over Australia, the likely causes, and projections of future changes to Australia's climate. It also provides information on how to apply the projections in impact studies and in risk assessments. The two main strategies for managing climate risk are mitigation (net reductions in greenhouse gas emissions) to slow climate change and adaptation to climate impacts that are unavoidable. A number of major advances have been made since the last report on climate change projections in Australia (CSIRO 2001) including: a much larger number of climate and ocean variables are projected (21 and 6 respectively); a much larger number (23) of climate models are used; the provision of probabilistic information on some of the projections, including the probability of exceeding the 10th, 50th and 90th percentiles; greater emphasis on projections from models that are better able to simulate observed Australian climate; a detailed assessment of observed changes in Australian climate and likely causes; and information on risk assessment, to provide guidance for using climate projections in impact studies
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Directory of Open Access Journals (Sweden)
Lauren V Weatherdon
2016-04-01
Full Text Available The Intergovernmental Panel on Climate Change (IPCC Fifth Assessment Report (AR5 states that climate change and ocean acidification are altering the oceans at a rate that is unprecedented compared with the recent past, leading to multifaceted impacts on marine ecosystems, associated goods and services, and human societies. AR5 underlined key uncertainties that remain regarding how synergistic changes in the ocean are likely to affect human systems, and how humans are likely to respond to these events. As climate change research has accelerated rapidly following AR5, an updated synthesis of available knowledge is necessary to identify emerging evidence, and to thereby better inform policy discussions. This paper reviews the literature to capture corroborating, conflicting, and novel findings published following the cut-off date for contribution to AR5. Specifically, we highlight key scientific developments on the impacts of climate-induced changes in the ocean on key socioeconomic sectors, including fisheries, aquaculture and tourism. New evidence continues to support a climate-induced redistribution of benefits and losses at multiple scales and across coastal and marine socio-ecological systems, partly resulting from species and ecosystem range shifts and changes in primary productivity. New efforts have been made to characterize and value ecosystem services in the context of climate change, with specific relevance to ecosystem-based adaptation. Recent studies have also explored synergistic interactions between climatic drivers, and have found strong variability between impacts on species at different life stages. Although climate change may improve conditions for some types of freshwater aquaculture, potentially providing alternative opportunities to adapt to impacts on wild capture fisheries, ocean acidification poses a risk to shellfish fisheries and aquaculture. The risk of increased prevalence of disease under warmer temperatures is
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Institutions for adaptation to climate change: comparing national adaptation strategies in Europe
Termeer, C.J.A.M.; Biesbroek, G.R.; Brink, van den M.A.
2012-01-01
In addition to reducing greenhouse gas emissions, societies worldwide have to cope with the potential impacts of climate change. The central question of this paper is to what extent our historically grown institutions enable actors to cope with the new challenges of climate adaptation. We present
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Regional model simulations of New Zealand climate
Renwick, James A.; Katzfey, Jack J.; Nguyen, Kim C.; McGregor, John L.
1998-03-01
Simulation of New Zealand climate is examined through the use of a regional climate model nested within the output of the Commonwealth Scientific and Industrial Research Organisation nine-level general circulation model (GCM). R21 resolution GCM output is used to drive a regional model run at 125 km grid spacing over the Australasian region. The 125 km run is used in turn to drive a simulation at 50 km resolution over New Zealand. Simulations with a full seasonal cycle are performed for 10 model years. The focus is on the quality of the simulation of present-day climate, but results of a doubled-CO2 run are discussed briefly. Spatial patterns of mean simulated precipitation and surface temperatures improve markedly as horizontal resolution is increased, through the better resolution of the country's orography. However, increased horizontal resolution leads to a positive bias in precipitation. At 50 km resolution, simulated frequency distributions of daily maximum/minimum temperatures are statistically similar to those of observations at many stations, while frequency distributions of daily precipitation appear to be statistically different to those of observations at most stations. Modeled daily precipitation variability at 125 km resolution is considerably less than observed, but is comparable to, or exceeds, observed variability at 50 km resolution. The sensitivity of the simulated climate to changes in the specification of the land surface is discussed briefly. Spatial patterns of the frequency of extreme temperatures and precipitation are generally well modeled. Under a doubling of CO2, the frequency of precipitation extremes changes only slightly at most locations, while air frosts become virtually unknown except at high-elevation sites.
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Observed soil temperature trends associated with climate change in the Tibetan Plateau, 1960-2014
Fang, Xuewei; Luo, Siqiong; Lyu, Shihua
2018-01-01
Soil temperature, an important indicator of climate change, has rarely explored due to scarce observations, especially in the Tibetan Plateau (TP) area. In this study, changes observed in five meteorological variables obtained from the TP between 1960 and 2014 were investigated using two non-parametric methods, the modified Mann-Kendall test and Sen's slope estimator method. Analysis of annual series from 1960 to 2014 has shown that surface (0 cm), shallow (5-20 cm), deep (40-320 cm) soil temperatures (ST), mean air temperature (AT), and precipitation (P) increased with rates of 0.47 °C/decade, 0.36 °C/decade, 0.36 °C/decade, 0.35 °C/decade, and 7.36 mm/decade, respectively, while maximum frozen soil depth (MFD) as well as snow cover depth (MSD) decreased with rates of 5.58 and 0.07 cm/decade. Trends were significant at 99 or 95% confidence level for the variables, with the exception of P and MSD. More impressive rate of the ST at each level than the AT indicates the clear response of soil to climate warming on a regional scale. Monthly changes observed in surface ST in the past decades were consistent with those of AT, indicating a central place of AT in the soil warming. In addition, with the exception of MFD, regional scale increasing trend of P as well as the decreasing MSD also shed light on the mechanisms driving soil trends. Significant negative-dominated correlation coefficients (α = 0.05) between ST and MSD indicate the decreasing MSD trends in TP were attributable to increasing ST, especially in surface layer. Owing to the frozen ground, the relationship between ST and P is complicated in the area. Higher P also induced higher ST, while the inhibition of freeze and thaw process on the ST in summer. With the increasing AT, P accompanied with the decreasing MFD, MSD should be the major factors induced the conspicuous soil warming of the TP in the past decades.
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Taminiau, Job
2010-01-01
The United States and the European Union address climate change in a fundamentally different manner. The US seems uninterested to address climate change from a federal level, but individual states within the US are definitely moving forward with climate c
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Simulating Climate Change in Ireland
Nolan, P.; Lynch, P.
2012-04-01
At the Meteorology & Climate Centre at University College Dublin, we are using the CLM-Community's COSMO-CLM Regional Climate Model (RCM) and the WRF RCM (developed at NCAR) to simulate the climate of Ireland at high spatial resolution. To address the issue of model uncertainty, a Multi-Model Ensemble (MME) approach is used. The ensemble method uses different RCMs, driven by several Global Climate Models (GCMs), to simulate climate change. Through the MME approach, the uncertainty in the RCM projections is quantified, enabling us to estimate the probability density function of predicted changes, and providing a measure of confidence in the predictions. The RCMs were validated by performing a 20-year simulation of the Irish climate (1981-2000), driven by ECMWF ERA-40 global re-analysis data, and comparing the output to observations. Results confirm that the output of the RCMs exhibit reasonable and realistic features as documented in the historical data record. Projections for the future Irish climate were generated by downscaling the Max Planck Institute's ECHAM5 GCM, the UK Met Office HadGEM2-ES GCM and the CGCM3.1 GCM from the Canadian Centre for Climate Modelling. Simulations were run for a reference period 1961-2000 and future period 2021-2060. The future climate was simulated using the A1B, A2, B1, RCP 4.5 & RCP 8.5 greenhouse gas emission scenarios. Results for the downscaled simulations show a substantial overall increase in precipitation and wind speed for the future winter months and a decrease during the summer months. The predicted annual change in temperature is approximately 1.1°C over Ireland. To date, all RCM projections are in general agreement, thus increasing our confidence in the robustness of the results.
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Public perception of climate change in the cold regions of Russia: an example of Yakutia
Directory of Open Access Journals (Sweden)
O. A. Anisimov
2017-01-01
Full Text Available The rate of climate change in the Russian cold regions is nearly twice larger than the global‑mean rate. Besides climate risks, such changes lead to new possibilities, which require scientifically based regional adaptation strategies. Climate could be viewed as an inexhaustible public resource that creates opportuni‑ ties for sustainable development. Long‑term trends show that climate as a resource is becoming more read‑ ily available in the cold regions, notwithstanding the general perception that globally climate change is one of the challenges of the 21st century. Adaptation strategies are required for balancing the risks and potential benefits resulting from the changing climate. Success of such strategies depends on the public perception of climate change. This study compares the observational data on climate and environmental changes with the results of the public survey conducted in Yakutia in the period 2012–2017. The survey involved nearly 2000 respondents in several cities and 2 villages (Ust‑Maja, Saskhulakh representing different economical, socio‑ logical, permafrost, vegetation, and climatic conditions. Results indicated that public perception of the climatic and environmental changes is not univocal, and depends on many factors. Low probability extreme events, such as unusual weather patterns or abrupt land‑ scape changes may have greater effect than the long‑term climate trends. Currently less than half of the pop‑ ulation in Yakutia consider climate change as an established fact, and are ready to take actions in this regard. Meanwhile, Yakutia is a region where observational records demonstrate the most pronounced changes in climatic regime compared to other Russian regions. The contrast between the actual changes and public per‑ ception of such changes has important implication for developing adaptation strategies. To be effective, such strategies should combine knowledge coming from instrumental‑ and
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Lereboullet, A.-L.; Beltrando, G.; Bardsley, D. K.
2012-04-01
The wine industry is very sensitive to extreme weather events, especially to temperatures above 35°C and drought. In a context of global climate change, Mediterranean climate regions are predicted to experience higher variability in rainfall and temperatures and an increased occurrence of extreme weather events. Some viticultural systems could be particularly at risk in those regions, considering their marginal position in the growth climatic range of Vitis vinifera, the long commercial lifespan of a vineyard, the high added-value of wine and the volatile nature of global markets. The wine industry, like other agricultural systems, is inserted in complex networks of climatic and non-climatic (other physical, economical, social and legislative) components, with constant feedbacks. We use a socio-ecosystem approach to analyse the adaptation of two Mediterranean viticultural systems to recent and future increase of extreme weather events. The present analysis focuses on two wine regions with a hot-summer Mediterranean climate (CSb type in the Köppen classification): Côtes-du-Roussillon in southern France and McLaren Vale in southern Australia. Using climate data from two synoptic weather stations, Perpignan (France) and Adelaide (Australia), with time series running from 1955 to 2010, we highlight changes in rainfall patterns and an increase in the number of days with Tx >35°c since the last three decades in both regions. Climate models (DRIAS project data for France and CSIRO Mk3.5 for Australia) project similar trends in the future. To date, very few projects have focused on an international comparison of the adaptive capacity of viticultural systems to climate change with a holistic approach. Here, the analysis of climate data was complemented by twenty in-depth semi-structured interviews with key actors of the two regional wine industries, in order to analyse adaptation strategies put in place regarding recent climate evolution. This mixed-methods approach
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Rooke, Anna C; Burness, Gary; Fox, Michael G
2017-02-01
Contemporary evolution of thermal physiology has the potential to help limit the physiological stress associated with rapidly changing thermal environments; however it is unclear if wild populations can respond quickly enough for such changes to be effective. We used native Canadian Pumpkinseed (Lepomis gibbosus) sunfish, and non-native Pumpkinseed introduced into the milder climate of Spain ~100 years ago, to assess genetic differences in thermal physiology in response to the warmer non-native climate. We compared temperature performance reaction norms of two Canadian and two Spanish Pumpkinseed populations born and raised within a common environment. We found that Canadian Pumpkinseed had higher routine metabolic rates when measured at seasonally high temperatures (15°C in winter, 30°C in summer), and that Spanish Pumpkinseed had higher critical thermal maxima when acclimated to 30°C in the summer. Growth rates were not significantly different among populations, however Canadian Pumpkinseed tended to have faster growth at the warmest temperatures measured (32°C). The observed differences in physiology among Canadian and Spanish populations at the warmest acclimation temperatures are consistent with the introduced populations being better suited to the warmer non-native climate than native populations. The observed differences could be the result of either founder effects, genetic drift, and/or contemporary adaptive evolution in the warmer non-native climate. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Paul, Carola; Weber, Michael; Knoke, Thomas
2017-06-01
Increasing land-use conflicts call for the development of land-use systems that reconcile agricultural production with the provisioning of multiple ecosystem services, including climate change mitigation. Agroforestry has been suggested as a global solution to increase land-use efficiency, while reducing environmental impacts and economic risks for farmers. Past research has often focused on comparing tree-crop combinations with agricultural monocultures, but agroforestry has seldom been systematically compared to other forms of land-use diversification, including a farm mosaic. This form of diversification mixes separate parcels of different land uses within the farm. The objective of this study was to develop a modelling approach to compare the performance of the agroforestry and farm mosaic diversification strategies, accounting for tree-crop interaction effects and economic and climate uncertainty. For this purpose, Modern Portfolio Theory and risk simulation were coupled with the process-based biophysical simulation model WaNuLCAS 4.0. For an example application, we used data from a field trial in Panama. The results show that the simulated agroforestry systems (Taungya, alley cropping and border planting) could outperform a farm mosaic approach in terms of cumulative production and return. Considering market and climate uncertainty, agroforestry showed an up to 21% higher economic return at the same risk level (i.e. standard deviation of economic returns). Farm compositions with large shares of land allocated to maize cultivation were also more severely affected by an increasing drought frequency in terms of both risks and returns. Our study demonstrates that agroforestry can be an economically efficient diversification strategy, but only if the design allows for economies of scope, beneficial interactions between trees and crops and higher income diversification compared to a farm mosaic. The modelling approach can make an important contribution to support
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Very high resolution regional climate model simulations over Greenland: Identifying added value
DEFF Research Database (Denmark)
Lucas-Picher, P.; Wulff-Nielsen, M.; Christensen, J.H.
2012-01-01
models. However, the bias between the simulations and the few available observations does not reduce with higher resolution. This is partly explained by the lack of observations in regions where the higher resolution is expected to improve the simulated climate. The RCM simulations show......This study presents two simulations of the climate over Greenland with the regional climate model (RCM) HIRHAM5 at 0.05° and 0.25° resolution driven at the lateral boundaries by the ERA-Interim reanalysis for the period 1989–2009. These simulations are validated against observations from...... that the temperature has increased the most in the northern part of Greenland and at lower elevations over the period 1989–2009. Higher resolution increases the relief variability in the model topography and causes the simulated precipitation to be larger on the coast and smaller over the main ice sheet compared...
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Directory of Open Access Journals (Sweden)
Peter Berg
2015-01-01
Full Text Available Lack of suitable observational data makes bias correction of high space and time resolution regional climate models (RCM problematic. We present a method to construct pseudo-observational precipitation data bymerging a large scale constrained RCMreanalysis downscaling simulation with coarse time and space resolution observations. The large scale constraint synchronizes the inner domain solution to the driving reanalysis model, such that the simulated weather is similar to observations on a monthly time scale. Monthly biases for each single month are corrected to the corresponding month of the observational data, and applied to the finer temporal resolution of the RCM. A low-pass filter is applied to the correction factors to retain the small spatial scale information of the RCM. The method is applied to a 12.5 km RCM simulation and proven successful in producing a reliable pseudo-observational data set. Furthermore, the constructed data set is applied as reference in a quantile mapping bias correction, and is proven skillful in retaining small scale information of the RCM, while still correcting the large scale spatial bias. The proposed method allows bias correction of high resolution model simulations without changing the fine scale spatial features, i.e., retaining the very information required by many impact models.
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Directory of Open Access Journals (Sweden)
Johann Mathias Housset
2016-10-01
Full Text Available Tree species responses to climate change will be greatly influenced by their evolutionary potential and their phenotypic plasticity. Investigating tree-rings responses to climate and population genetics at the regional scale is therefore crucial in assessing the tree behaviour to climate change. This study combined in situ dendroclimatology and population genetics over a latitudinal gradient and compared the variations between the two at the intra- and inter-population levels. This approach was applied on the northern marginal populations of Thuja occidentalis (eastern white-cedar in the Canadian boreal forest. We aimed first to assess the radial growth variability (response functional trait within populations across the gradient and to compare it with the genetic diversity (microsatellites. Second, we investigated the variability in the growth response to climate at the regional scale through the radial growth-climate relationships, and tested its correlation with environmental variables and population genetic structure. Model selection based on the Akaike Information Criteria revealed that the growth synchronicity between pairs of trees of a population covariates with both the genetic diversity of this population and the amount of precipitation (inverse correlation, although these variables only explained a small fraction of the observed variance. At the regional scale, variance partitioning and partial redundancy analysis indicate that the growth response to climate was greatly modulated by stand environmental variables, suggesting predominant plastic variations in growth-response to climate. Combining in situ dendroclimatology and population genetics is a promising way to investigate species’ response capacity to climate change in natural stands. We stress the need to control for local climate and site conditions effects on dendroclimatic response to climate to avoid misleading conclusions regarding the associations with genetic variables.
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Littlefield, Caitlin E; McRae, Brad H; Michalak, Julia L; Lawler, Joshua J; Carroll, Carlos
2017-12-01
Increasing connectivity is an important strategy for facilitating species range shifts and maintaining biodiversity in the face of climate change. To date, however, few researchers have included future climate projections in efforts to prioritize areas for increasing connectivity. We identified key areas likely to facilitate climate-induced species' movement across western North America. Using historical climate data sets and future climate projections, we mapped potential species' movement routes that link current climate conditions to analogous climate conditions in the future (i.e., future climate analogs) with a novel moving-window analysis based on electrical circuit theory. In addition to tracing shifting climates, the approach accounted for landscape permeability and empirically derived species' dispersal capabilities. We compared connectivity maps generated with our climate-change-informed approach with maps of connectivity based solely on the degree of human modification of the landscape. Including future climate projections in connectivity models substantially shifted and constrained priority areas for movement to a smaller proportion of the landscape than when climate projections were not considered. Potential movement, measured as current flow, decreased in all ecoregions when climate projections were included, particularly when dispersal was limited, which made climate analogs inaccessible. Many areas emerged as important for connectivity only when climate change was modeled in 2 time steps rather than in a single time step. Our results illustrate that movement routes needed to track changing climatic conditions may differ from those that connect present-day landscapes. Incorporating future climate projections into connectivity modeling is an important step toward facilitating successful species movement and population persistence in a changing climate. © 2017 Society for Conservation Biology.
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Mani, Muthukumara S.
2012-01-01
One of the strong messages that came out of the recent United Nations Climate Change conference in Durban was that the private sector has to play an important role if we are to globally move toward a low carbon, climate resilient -- or "climate compatible" -- future. However, private investment will only flow at the scale and pace necessary if it is supported by clear, credible, and long-t...
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Kuster, E.; Fox, G.
2016-12-01
Climate change is happening; scientists have already observed changes in sea level, increases in atmospheric carbon dioxide, and declining polar ice. The students of today are the leaders of tomorrow, and it is our duty to make sure they are well equipped and they understand the implications of climate change as part of their research and professional careers. Graduate students, in particular, are gaining valuable and necessary research, leadership, and critical thinking skills, but we need to ensure that they are receiving the appropriate climate education in their graduate training. Previous studies have primarily focused on capturing the K-12, college level, and general publics' knowledge of the climate system, concluding with recommendations on how to improve climate literacy in the classroom. While this is extremely important to study, very few studies have captured the current perception that graduate students hold regarding the amount of climate education being offered to them. This information is important to capture, as it can inform future curriculum development. We developed and distributed a nationwide survey (495 respondents) for graduate students to capture their perception on the level of climate system education being offered and their view on the importance of having climate education. We also investigated differences in the responses based on either geographic area or discipline. We compared how important graduate students felt it was to include climate education in their own discipline versus outside disciplines. The authors will discuss key findings from this ongoing research.
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Multi-Wheat-Model Ensemble Responses to Interannual Climate Variability
Ruane, Alex C.; Hudson, Nicholas I.; Asseng, Senthold; Camarrano, Davide; Ewert, Frank; Martre, Pierre; Boote, Kenneth J.; Thorburn, Peter J.; Aggarwal, Pramod K.; Angulo, Carlos
2016-01-01
We compare 27 wheat models' yield responses to interannual climate variability, analyzed at locations in Argentina, Australia, India, and The Netherlands as part of the Agricultural Model Intercomparison and Improvement Project (AgMIP) Wheat Pilot. Each model simulated 1981e2010 grain yield, and we evaluate results against the interannual variability of growing season temperature, precipitation, and solar radiation. The amount of information used for calibration has only a minor effect on most models' climate response, and even small multi-model ensembles prove beneficial. Wheat model clusters reveal common characteristics of yield response to climate; however models rarely share the same cluster at all four sites indicating substantial independence. Only a weak relationship (R2 0.24) was found between the models' sensitivities to interannual temperature variability and their response to long-termwarming, suggesting that additional processes differentiate climate change impacts from observed climate variability analogs and motivating continuing analysis and model development efforts.
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Validation and quantification of uncertainty in coupled climate models using network analysis
Energy Technology Data Exchange (ETDEWEB)
Bracco, Annalisa [Georgia Inst. of Technology, Atlanta, GA (United States)
2015-08-10
We developed a fast, robust and scalable methodology to examine, quantify, and visualize climate patterns and their relationships. It is based on a set of notions, algorithms and metrics used in the study of graphs, referred to as complex network analysis. This approach can be applied to explain known climate phenomena in terms of an underlying network structure and to uncover regional and global linkages in the climate system, while comparing general circulation models outputs with observations. The proposed method is based on a two-layer network representation, and is substantially new within the available network methodologies developed for climate studies. At the first layer, gridded climate data are used to identify ‘‘areas’’, i.e., geographical regions that are highly homogeneous in terms of the given climate variable. At the second layer, the identified areas are interconnected with links of varying strength, forming a global climate network. The robustness of the method (i.e. the ability to separate between topological distinct fields, while identifying correctly similarities) has been extensively tested. It has been proved that it provides a reliable, fast framework for comparing and ranking the ability of climate models of reproducing observed climate patterns and their connectivity. We further developed the methodology to account for lags in the connectivity between climate patterns and refined our area identification algorithm to account for autocorrelation in the data. The new methodology based on complex network analysis has been applied to state-of-the-art climate model simulations that participated to the last IPCC (International Panel for Climate Change) assessment to verify their performances, quantify uncertainties, and uncover changes in global linkages between past and future projections. Network properties of modeled sea surface temperature and rainfall over 1956–2005 have been constrained towards observations or reanalysis data sets
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Karrouk, M. S.
2017-12-01
Since the nineties of the last century, climatological research following a great scientific advance in the field of prediction, not the variability and evolution of the different climatic parameters was beginning to be clearer!But today, since the beginning of 2005, certainly due to oceanic thermal cumulations, and the shift of climatic zones towards poles in selective forms (more intense on the oceans present on the continents); Climatic events do not evolve according to the usual and expected rhythms: atmospheric circulation, precipitation, temperatures, seasonal phenomena, etc. These conditions are a spatiotemporal evolution and distribution, which characterize the new "global climate", by the new atmospheric regime imposing the Meridian Atmospheric Circulation (MAC), alternating the conditions of Freshness (humidity) and Heat (drought) along the year.In this new situation, Morocco, located in the climate transition zone, is fully affected by the "New Climate". Usually, the atmospheric response to major climatic events (ENSO) in this region such as "El Niño" was characterized by the establishment of the NAO positive index, stability and drought, due to dominance Zonal Atmospheric Circulation in winter. On the other hand, in the "La Niña" episode, the negative index of the NAO and the predominant Meridian Atmospheric Circulation and precipitation became abundant.Since the beginning of this century, qualified meteorological events of "exceptional !" causing floods have continued to occur in Morocco and elsewhere, with increasing recurrence, prompting us to wonder about the "new" mode of hydro-thermal function of the climate system that induces torrential rains, as well as its effect on environments and societies.The latest event is the flood disaster in October 2016 in the Laâyoune region of southern Morocco, which specializes in the unusual return of rain in a region considered dry and Saharan.Thanks to spatial observation and monitoring of meteorological
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Compton, Tanya J.; Rijkenberg, Micha J. A.; Drent, Jan; Piersma, Theunis
2007-01-01
The climate variability hypothesis proposes that in variable temperate climates poikilothermic animals have wide thermal tolerance windows, whereas in constant tropical climates they have small thermal tolerance windows. In this study we quantified and compared the upper and lower lethal thermal
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Kara, Fatih; Yucel, Ismail
2015-09-01
This study investigates the climate change impact on the changes of mean and extreme flows under current and future climate conditions in the Omerli Basin of Istanbul, Turkey. The 15 regional climate model output from the EU-ENSEMBLES project and a downscaling method based on local implications from geophysical variables were used for the comparative analyses. Automated calibration algorithm is used to optimize the parameters of Hydrologiska Byråns Vattenbalansavdel-ning (HBV) model for the study catchment using observed daily temperature and precipitation. The calibrated HBV model was implemented to simulate daily flows using precipitation and temperature data from climate models with and without downscaling method for reference (1960-1990) and scenario (2071-2100) periods. Flood indices were derived from daily flows, and their changes throughout the four seasons and year were evaluated by comparing their values derived from simulations corresponding to the current and future climate. All climate models strongly underestimate precipitation while downscaling improves their underestimation feature particularly for extreme events. Depending on precipitation input from climate models with and without downscaling the HBV also significantly underestimates daily mean and extreme flows through all seasons. However, this underestimation feature is importantly improved for all seasons especially for spring and winter through the use of downscaled inputs. Changes in extreme flows from reference to future increased for the winter and spring and decreased for the fall and summer seasons. These changes were more significant with downscaling inputs. With respect to current time, higher flow magnitudes for given return periods will be experienced in the future and hence, in the planning of the Omerli reservoir, the effective storage and water use should be sustained.
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Andrew K. Carlson,; William W. Taylor,; Hartikainen, Kelsey M.; Dana M. Infante,; Beard, Douglas; Lynch, Abigail
2017-01-01
Global climate change is predicted to increase air and stream temperatures and alter thermal habitat suitability for growth and survival of coldwater fishes, including brook charr (Salvelinus fontinalis), brown trout (Salmo trutta), and rainbow trout (Oncorhynchus mykiss). In a changing climate, accurate stream temperature modeling is increasingly important for sustainable salmonid management throughout the world. However, finite resource availability (e.g. funding, personnel) drives a tradeoff between thermal model accuracy and efficiency (i.e. cost-effective applicability at management-relevant spatial extents). Using different projected climate change scenarios, we compared the accuracy and efficiency of stream-specific and generalized (i.e. region-specific) temperature models for coldwater salmonids within and outside the State of Michigan, USA, a region with long-term stream temperature data and productive coldwater fisheries. Projected stream temperature warming between 2016 and 2056 ranged from 0.1 to 3.8 °C in groundwater-dominated streams and 0.2–6.8 °C in surface-runoff dominated systems in the State of Michigan. Despite their generally lower accuracy in predicting exact stream temperatures, generalized models accurately projected salmonid thermal habitat suitability in 82% of groundwater-dominated streams, including those with brook charr (80% accuracy), brown trout (89% accuracy), and rainbow trout (75% accuracy). In contrast, generalized models predicted thermal habitat suitability in runoff-dominated streams with much lower accuracy (54%). These results suggest that, amidst climate change and constraints in resource availability, generalized models are appropriate to forecast thermal conditions in groundwater-dominated streams within and outside Michigan and inform regional-level salmonid management strategies that are practical for coldwater fisheries managers, policy makers, and the public. We recommend fisheries professionals reserve resource
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Development of ALARO-Climate regional climate model for a very high resolution
Skalak, Petr; Farda, Ales; Brozkova, Radmila; Masek, Jan
2014-05-01
ALARO-Climate is a new regional climate model (RCM) derived from the ALADIN LAM model family. It is based on the numerical weather prediction model ALARO and developed at the Czech Hydrometeorological Institute. The model is expected to able to work in the so called "grey zone" physics (horizontal resolution of 4 - 7 km) and at the same time retain its ability to be operated in resolutions in between 20 and 50 km, which are typical for contemporary generation of regional climate models. Here we present the main results of the RCM ALARO-Climate model simulations in 25 and 6.25 km resolutions on the longer time-scale (1961-1990). The model was driven by the ERA-40 re-analyses and run on the integration domain of ~ 2500 x 2500 km size covering the central Europe. The simulated model climate was compared with the gridded observation of air temperature (mean, maximum, minimum) and precipitation from the E-OBS version dataset 8. Other simulated parameters (e.g., cloudiness, radiation or components of water cycle) were compared to the ERA-40 re-analyses. The validation of the first ERA-40 simulation in both, 25 km and 6.25 km resolutions, revealed significant cold biases in all seasons and overestimation of precipitation in the selected Central Europe target area (0° - 30° eastern longitude ; 40° - 60° northern latitude). The differences between these simulations were small and thus revealed a robustness of the model's physical parameterization on the resolution change. The series of 25 km resolution simulations with several model adaptations was carried out to study their effect on the simulated properties of climate variables and thus possibly identify a source of major errors in the simulated climate. The current investigation suggests the main reason for biases is related to the model physic. Acknowledgements: This study was performed within the frame of projects ALARO (project P209/11/2405 sponsored by the Czech Science Foundation) and CzechGlobe Centre (CZ.1
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Identifying misbehaving models using baseline climate variance
Schultz, Colin
2011-06-01
The majority of projections made using general circulation models (GCMs) are conducted to help tease out the effects on a region, or on the climate system as a whole, of changing climate dynamics. Sun et al., however, used model runs from 20 different coupled atmosphere-ocean GCMs to try to understand a different aspect of climate projections: how bias correction, model selection, and other statistical techniques might affect the estimated outcomes. As a case study, the authors focused on predicting the potential change in precipitation for the Murray-Darling Basin (MDB), a 1-million- square- kilometer area in southeastern Australia that suffered a recent decade of drought that left many wondering about the potential impacts of climate change on this important agricultural region. The authors first compared the precipitation predictions made by the models with 107 years of observations, and they then made bias corrections to adjust the model projections to have the same statistical properties as the observations. They found that while the spread of the projected values was reduced, the average precipitation projection for the end of the 21st century barely changed. Further, the authors determined that interannual variations in precipitation for the MDB could be explained by random chance, where the precipitation in a given year was independent of that in previous years.
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Climate Trends in the Arctic as Observed from Space
Comiso, Josefino C.; Hall, Dorothy K.
2014-01-01
The Arctic is a region in transformation. Warming in the region has been amplified, as expected from ice-albedo feedback effects, with the rate of warming observed to be approx. 0.60+/-0.07 C/decade in the Arctic (>64degN) compared to approx. 0.17 C/decade globally during the last three decades. This increase in surface temperature is manifested in all components of the cryosphere. In particular, the sea ice extent has been declining at the rate of approx. 3.8%/decade, whereas the perennial ice (represented by summer ice minimum) is declining at a much greater rate of approx.11.5%/decade. Spring snow cover has also been observed to be declining by -2.12%/decade for the period 1967-2012. The Greenland ice sheet has been losing mass at the rate of approx. 34.0Gt/year (sea level equivalence of 0.09 mm/year) during the period from 1992 to 2011, but for the period 2002-2011, a higher rate of mass loss of approx. 215 Gt/year has been observed. Also, the mass of glaciers worldwide declined at the rate of 226 Gt/year from 1971 to 2009 and 275 Gt/year from 1993 to 2009. Increases in permafrost temperature have also been measured in many parts of the Northern Hemisphere while a thickening of the active layer that overlies permafrost and a thinning of seasonally frozen ground has also been reported. To gain insight into these changes, comparative analysis with trends in clouds, albedo, and the Arctic Oscillation is also presented.
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DEFF Research Database (Denmark)
Almlund, Pernille
reports. This paper is based on a wonder of why the IPCC’s analysis and reports are not, to a higher degree, based on social science and human science. Are these scientific perspectives with many different approaches not important to this global political awareness of climate change? Especially now when...... all the IPCC’s assessment report have concluded that climate changes are human made and recently stated that 97 % of all climate researchers agree in that conclusion. Due to the theoretical work of Michel Callon, Lascoumes and Barthe (2011) and their ANT perspective, climate change can be observed...
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Climate Action Tracker Update. Climate Shuffle
Energy Technology Data Exchange (ETDEWEB)
Hoehne, N.; Fekete, H.; Vieweg, M.; Hare, B.; Schaeffer, M.; Rocha, M.; Larkin, J.; Guetschow, J.; Jeffery, L.
2011-11-15
The Climate Action Tracker (CAT) compares and assesses national and global action against a range of different climate targets across all relevant time frames, starting with an ongoing analysis of countries' current emission reduction pledges. National action on climate change mitigation appears to be joining the international climate negotiations in the new and ever popular 'climate shuffle' dance. It involves maximum effort and motion while staying in the same spot, or even, in some cases, going backwards. Recent emissions trends and estimates of the effects of those policies in place and proposed lead to a new estimate that warming is likely to approach 4C by 2100, significantly above the warming that would result from full implementation of the pledges (3.3C). The continuous global fossil-fuel intensive development of the past decade suggests that high warming levels of 4C are more plausible than assuming full implementation of current pledges. Evidence is ever increasing that existing and planned policies are not sufficient for countries to meet these pledges.
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Wilson, Laura E.; Chin, Karen
2014-01-01
The broad biogeographic distribution of Hesperornis fossils in Late Cretaceous Western Interior Seaway deposits has prompted questions about whether they endured polar winters or migrated between mid- and high latitudes. Here, we compare microstructures of hesperornithiform long bones from Kansas and the Arctic to investigate whether migration or Late Cretaceous polar climate affected bone growth. We also examine modern penguin bones to determine how migration and climate may influence bone growth in birds with known behaviours. Histological analysis of hesperornithiform samples reveals continuous bone deposition throughout the cortex, plus an outer circumferential layer in adults. No cyclic growth marks, zonation or differences in vasculature are apparent in the Hesperornis specimens. Comparatively, migratory Adélie and chinstrap penguin bones show no zonation or changes in microstructure, suggesting that migration is not necessarily recorded in avian bone microstructure. Non-migratory gentoos show evidence of rapid bone growth possibly associated with increased chick growth rates in high-latitude populations and large body size. The absence of histological evidence for migration in extinct Hesperornis and extant pygoscelid penguins may reflect that these birds reached skeletal maturity before migration or overwintering. This underscores the challenges of using bone microstructure to infer the effects of behaviour and climate on avian growth. PMID:26064560
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Russell, J. L.; Sarmiento, J. L.
2017-12-01
The Southern Ocean is central to the climate's response to increasing levels of atmospheric greenhouse gases as it ventilates a large fraction of the global ocean volume. Global coupled climate models and earth system models, however, vary widely in their simulations of the Southern Ocean and its role in, and response to, the ongoing anthropogenic forcing. Due to its complex water-mass structure and dynamics, Southern Ocean carbon and heat uptake depend on a combination of winds, eddies, mixing, buoyancy fluxes and topography. Understanding how the ocean carries heat and carbon into its interior and how the observed wind changes are affecting this uptake is essential to accurately projecting transient climate sensitivity. Observationally-based metrics are critical for discerning processes and mechanisms, and for validating and comparing climate models. As the community shifts toward Earth system models with explicit carbon simulations, more direct observations of important biogeochemical parameters, like those obtained from the biogeochemically-sensored floats that are part of the Southern Ocean Carbon and Climate Observations and Modeling project, are essential. One goal of future observing systems should be to create observationally-based benchmarks that will lead to reducing uncertainties in climate projections, and especially uncertainties related to oceanic heat and carbon uptake.
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Evaluation of high-resolution climate simulations for West Africa using COSMO-CLM
Dieng, Diarra; Smiatek, Gerhard; Bliefernicht, Jan; Laux, Patrick; Heinzeller, Dominikus; Kunstmann, Harald; Sarr, Abdoulaye; Thierno Gaye, Amadou
2017-04-01
The climate change modeling activities within the WASCAL program (West African Science Service Center on Climate Change and Adapted Land Use) concentrate on the provisioning of future climate change scenario data at high spatial and temporal resolution and quality in West Africa. Such information is highly required for impact studies in water resources and agriculture for the development of reliable climate change adaptation and mitigation strategies. In this study, we present a detailed evaluation of high simulation runs based on the regional climate model, COSMO model in CLimate Mode (COSMO-CLM). The model is applied over West Africa in a nested approach with two simulation domains at 0.44° and 0.11° resolution using reanalysis data from ERA-Interim (1979-2013). The models runs are compared to several state-of-the-art observational references (e.g., CRU, CHIRPS) including daily precipitation data provided by national meteorological services in West Africa. Special attention is paid to the reproduction of the dynamics of the West African Monsoon (WMA), its associated precipitation patterns and crucial agro-climatological indices such as the onset of the rainy season. In addition, first outcomes of the regional climate change simulations driven by MPI-ESM-LR are presented for a historical period (1980 to 2010) and two future periods (2020 to 2050, 2070 to 2100). The evaluation of the reanalysis runs shows that COSMO-CLM is able to reproduce the observed major climate characteristics including the West African Monsoon within the range of comparable RCM evaluations studies. However, substantial uncertainties remain, especially in the Sahel zone. The added value of the higher resolution of the nested run is reflected in a smaller bias in extreme precipitation statistics with respect to the reference data.
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Ahmed, Kazi Farzan; Wang, Guiling; Silander, John; Wilson, Adam M.; Allen, Jenica M.; Horton, Radley; Anyah, Richard
2013-01-01
Statistical downscaling can be used to efficiently downscale a large number of General Circulation Model (GCM) outputs to a fine temporal and spatial scale. To facilitate regional impact assessments, this study statistically downscales (to 1/8deg spatial resolution) and corrects the bias of daily maximum and minimum temperature and daily precipitation data from six GCMs and four Regional Climate Models (RCMs) for the northeast United States (US) using the Statistical Downscaling and Bias Correction (SDBC) approach. Based on these downscaled data from multiple models, five extreme indices were analyzed for the future climate to quantify future changes of climate extremes. For a subset of models and indices, results based on raw and bias corrected model outputs for the present-day climate were compared with observations, which demonstrated that bias correction is important not only for GCM outputs, but also for RCM outputs. For future climate, bias correction led to a higher level of agreements among the models in predicting the magnitude and capturing the spatial pattern of the extreme climate indices. We found that the incorporation of dynamical downscaling as an intermediate step does not lead to considerable differences in the results of statistical downscaling for the study domain.
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The influence of inter-annually varying albedo on regional climate and drought
Meng, Xianhong
2013-05-05
Albedo plays an important role in land-atmosphere interactions and local climate. This study presents the impact on simulating regional climate, and the evolution of a drought, when using the default climatological albedo as is usually done in regional climate modelling, or using the actual observed albedo which is rarely done. Here, time-varying satellite derived albedo data is used to update the lower boundary condition of the Weather Research and Forecasting regional climate model in order to investigate the influence of observed albedo on regional climate simulations and also potential changes to land-atmosphere feedback over south-east Australia. During the study period from 2000 to 2008, observations show that albedo increased with an increasingly negative precipitation anomaly, though it lagged precipitation by several months. Compared to in-situ observations, using satellite observed albedo instead of the default climatological albedo provided an improvement in the simulated seasonal mean air temperature. In terms of precipitation, both simulations reproduced the drought that occurred from 2002 through 2006. Using the observed albedo produced a drier simulation overall. During the onset of the 2002 drought, albedo changes enhanced the precipitation reduction by 20 % on average, over locations where it was active. The area experiencing drought increased 6.3 % due to the albedo changes. Two mechanisms for albedo changes to impact land-atmosphere drought feedback are investigated. One accounts for the increased albedo, leading to reduced turbulent heat flux and an associated decrease of moist static energy density in the planetary boundary layer; the other considers that enhanced local radiative heating, due to the drought, favours a deeper planetary boundary layer, subsequently decreasing the moist static energy density through entrainment of the free atmosphere. Analysis shows that drought related large-scale changes in the regional climate favour a
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Climate Change and Algal Blooms =
Lin, Shengpan
Algal blooms are new emerging hazards that have had important social impacts in recent years. However, it was not very clear whether future climate change causing warming waters and stronger storm events would exacerbate the algal bloom problem. The goal of this dissertation was to evaluate the sensitivity of algal biomass to climate change in the continental United States. Long-term large-scale observations of algal biomass in inland lakes are challenging, but are necessary to relate climate change to algal blooms. To get observations at this scale, this dissertation applied machine-learning algorithms including boosted regression trees (BRT) in remote sensing of chlorophyll-a with Landsat TM/ETM+. The results show that the BRT algorithm improved model accuracy by 15%, compared to traditional linear regression. The remote sensing model explained 46% of the total variance of the ground-measured chlorophyll- a in the first National Lake Assessment conducted by the US Environmental Protection Agency. That accuracy was ecologically meaningful to study climate change impacts on algal blooms. Moreover, the BRT algorithm for chlorophyll- a would not have systematic bias that is introduced by sediments and colored dissolved organic matter, both of which might change concurrently with climate change and algal blooms. This dissertation shows that the existing atmospheric corrections for Landsat TM/ETM+ imagery might not be good enough to improve the remote sensing of chlorophyll-a in inland lakes. After deriving long-term algal biomass estimates from Landsat TM/ETM+, time series analysis was used to study the relations of climate change and algal biomass in four Missouri reservoirs. The results show that neither temperature nor precipitation was the only factor that controlled temporal variation of algal biomass. Different reservoirs, even different zones within the same reservoir, responded differently to temperature and precipitation changes. These findings were further
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Climate Stability: Pathway to understand abrupt glacial climate shifts
Zhang, X.; Knorr, G.; Barker, S.; Lohmann, G.
2017-12-01
Glacial climate is marked by abrupt, millennial-scale climate changes known as Dansgaard-Oeschger (DO) cycles that have been linked to variations in the Atlantic meridional overturning circulation (AMOC). The most pronounced stadial coolings, Heinrich Stadials (HSs), are associated with massive iceberg discharges to the North Atlantic. This motivates scientists to consider that the North Atlantic freshwater perturbations is a common trigger of the associated abrupt transitions between weak and strong AMOC states. However, recent studies suggest that the Heinrich ice-surging events are triggered by ocean subsurface warming associated with an AMOC slow-down. Furthermore, the duration of ice-rafting events does not systematically coincide with the beginning and end of the pronounced cold conditions during HSs. In this context, we show that both, changes in atmospheric CO2 and ice sheet configuration can provide important control on the stability of the AMOC, using a coupled atmosphere-ocean model. Our simulations reveal that gradual changes in Northern Hemisphere ice sheet height and atmospheric CO2 can act as a trigger of abrupt glacial/deglacial climate changes. The simulated global climate responses—including abrupt warming in the North Atlantic, a northward shift of the tropical rain belts, and Southern Hemisphere cooling related to the bipolar seesaw—are generally consistent with empirical evidence. We further find that under a delicate configuration of atmospheric CO2 and ice sheet height the AMOC can be characterized by a self-oscillation (resonance) feature (Hopf Bifucation) with a 1000-year cycle that is comparable with observed small DO events during the MIS 3. This provides an alternative explanation for millennial-scale DO variability during glacial periods.
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Roelofs, G.-J.; Brink, H. ten; Kiendler-Scharr, A.; Leeuw, G. de; Mensah, A.; Minikin, A.; Otjes, R.
2010-01-01
In May 2008, the measurement campaign IMPACT for observation of atmospheric aerosol and cloud properties was conducted in Cabauw, The Netherlands. With a nudged version of the coupled aerosol-climate model ECHAM5-HAM we simulate the size distribution and chemical composition of the aerosol and the
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Directory of Open Access Journals (Sweden)
M. Forkel
2017-12-01
Full Text Available Vegetation fires affect human infrastructures, ecosystems, global vegetation distribution, and atmospheric composition. However, the climatic, environmental, and socioeconomic factors that control global fire activity in vegetation are only poorly understood, and in various complexities and formulations are represented in global process-oriented vegetation-fire models. Data-driven model approaches such as machine learning algorithms have successfully been used to identify and better understand controlling factors for fire activity. However, such machine learning models cannot be easily adapted or even implemented within process-oriented global vegetation-fire models. To overcome this gap between machine learning-based approaches and process-oriented global fire models, we introduce a new flexible data-driven fire modelling approach here (Satellite Observations to predict FIre Activity, SOFIA approach version 1. SOFIA models can use several predictor variables and functional relationships to estimate burned area that can be easily adapted with more complex process-oriented vegetation-fire models. We created an ensemble of SOFIA models to test the importance of several predictor variables. SOFIA models result in the highest performance in predicting burned area if they account for a direct restriction of fire activity under wet conditions and if they include a land cover-dependent restriction or allowance of fire activity by vegetation density and biomass. The use of vegetation optical depth data from microwave satellite observations, a proxy for vegetation biomass and water content, reaches higher model performance than commonly used vegetation variables from optical sensors. We further analyse spatial patterns of the sensitivity between anthropogenic, climate, and vegetation predictor variables and burned area. We finally discuss how multiple observational datasets on climate, hydrological, vegetation, and socioeconomic variables together with
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Forkel, Matthias; Dorigo, Wouter; Lasslop, Gitta; Teubner, Irene; Chuvieco, Emilio; Thonicke, Kirsten
2017-12-01
Vegetation fires affect human infrastructures, ecosystems, global vegetation distribution, and atmospheric composition. However, the climatic, environmental, and socioeconomic factors that control global fire activity in vegetation are only poorly understood, and in various complexities and formulations are represented in global process-oriented vegetation-fire models. Data-driven model approaches such as machine learning algorithms have successfully been used to identify and better understand controlling factors for fire activity. However, such machine learning models cannot be easily adapted or even implemented within process-oriented global vegetation-fire models. To overcome this gap between machine learning-based approaches and process-oriented global fire models, we introduce a new flexible data-driven fire modelling approach here (Satellite Observations to predict FIre Activity, SOFIA approach version 1). SOFIA models can use several predictor variables and functional relationships to estimate burned area that can be easily adapted with more complex process-oriented vegetation-fire models. We created an ensemble of SOFIA models to test the importance of several predictor variables. SOFIA models result in the highest performance in predicting burned area if they account for a direct restriction of fire activity under wet conditions and if they include a land cover-dependent restriction or allowance of fire activity by vegetation density and biomass. The use of vegetation optical depth data from microwave satellite observations, a proxy for vegetation biomass and water content, reaches higher model performance than commonly used vegetation variables from optical sensors. We further analyse spatial patterns of the sensitivity between anthropogenic, climate, and vegetation predictor variables and burned area. We finally discuss how multiple observational datasets on climate, hydrological, vegetation, and socioeconomic variables together with data
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Monitoring Top-of-Atmosphere Radiative Energy Imbalance for Climate Prediction
Lin, Bing; Chambers, Lin H.; Stackhouse, Paul W., Jr.; Minnis, Patrick
2009-01-01
Large climate feedback uncertainties limit the prediction accuracy of the Earth s future climate with an increased CO2 atmosphere. One potential to reduce the feedback uncertainties using satellite observations of top-of-atmosphere (TOA) radiative energy imbalance is explored. Instead of solving the initial condition problem in previous energy balance analysis, current study focuses on the boundary condition problem with further considerations on climate system memory and deep ocean heat transport, which is more applicable for the climate. Along with surface temperature measurements of the present climate, the climate feedbacks are obtained based on the constraints of the TOA radiation imbalance. Comparing to the feedback factor of 3.3 W/sq m/K of the neutral climate system, the estimated feedback factor for the current climate system ranges from -1.3 to -1.0 W/sq m/K with an uncertainty of +/-0.26 W/sq m/K. That is, a positive climate feedback is found because of the measured TOA net radiative heating (0.85 W/sq m) to the climate system. The uncertainty is caused by the uncertainties in the climate memory length. The estimated time constant of the climate is large (70 to approx. 120 years), implying that the climate is not in an equilibrium state under the increasing CO2 forcing in the last century.
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Energy Technology Data Exchange (ETDEWEB)
Fortelius, C; Holopainen, E; Kaurola, J; Ruosteenoja, K; Raeisaenen, J [Helsinki Univ. (Finland). Dept. of Meteorology
1997-12-31
In recent years the modelling of interannual climate variability has been studied, the atmospheric energy and water cycles, and climate simulations with the ECHAM3 model. In addition, the climate simulations of several models have been compared with special emphasis in the area of northern Europe
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Energy Technology Data Exchange (ETDEWEB)
Fortelius, C.; Holopainen, E.; Kaurola, J.; Ruosteenoja, K.; Raeisaenen, J. [Helsinki Univ. (Finland). Dept. of Meteorology
1996-12-31
In recent years the modelling of interannual climate variability has been studied, the atmospheric energy and water cycles, and climate simulations with the ECHAM3 model. In addition, the climate simulations of several models have been compared with special emphasis in the area of northern Europe
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Directory of Open Access Journals (Sweden)
Asma Foughali
2015-07-01
Full Text Available This work aims to evaluate the performance of a hydrological balance model in a watershed located in northern Tunisia (wadi Sejnane, 378 km2 in present climate conditions using input variables provided by four regional climate models. A modified version (MBBH of the lumped and single layer surface model BBH (Bucket with Bottom Hole model, in which pedo-transfer parameters estimated using watershed physiographic characteristics are introduced is adopted to simulate the water balance components. Only two parameters representing respectively the water retention capacity of the soil and the vegetation resistance to evapotranspiration are calibrated using rainfall-runoff data. The evaluation criterions for the MBBH model calibration are: relative bias, mean square error and the ratio of mean actual evapotranspiration to mean potential evapotranspiration. Daily air temperature, rainfall and runoff observations are available from 1960 to 1984. The period 1960–1971 is selected for calibration while the period 1972–1984 is chosen for validation. Air temperature and precipitation series are provided by four regional climate models (DMI, ARP, SMH and ICT from the European program ENSEMBLES, forced by two global climate models (GCM: ECHAM and ARPEGE. The regional climate model outputs (precipitation and air temperature are compared to the observations in terms of statistical distribution. The analysis was performed at the seasonal scale for precipitation. We found out that RCM precipitation must be corrected before being introduced as MBBH inputs. Thus, a non-parametric quantile-quantile bias correction method together with a dry day correction is employed. Finally, simulated runoff generated using corrected precipitation from the regional climate model SMH is found the most acceptable by comparison with runoff simulated using observed precipitation data, to reproduce the temporal variability of mean monthly runoff. The SMH model is the most accurate to
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On the nature of the solar influence on climate and its contribution to climate change
Vieira, L. A.; da Silva, L. A.; Guarnieri, F.; Echer, E.; Dal Lago, A.; Wrasse, C. M.; Schuch, N.
2007-05-01
The influence of solar magnetic variability on the lower atmospheric regions has been observed on different atmospheric parameters in different time scales, but a plausible mechanism to explain these observations remains unclear. It is also indistinguishable whether or not the variability on the solar-terrestrial coupling drives the present climate change. New observations suggested that the existence of a geomagnetic signal in climate data would support a direct link between solar variability and their effects on climate. Usoskin and colleagues compared 1000-year reconstructions of sunspot numbers and cosmic ray flux, derived from cosmogenic isotope dates, with air temperature history in the Northern hemisphere. They observed higher temperatures during periods of intense solar activity. In addition, they report that three different statistical tests consistently indicate that the long-term trends in the temperature correlate better with cosmic rays than with sunspot numbers. Vieira and Da Silva observed that the clouds effects on the radiative flux in the atmosphere in the southern Pacific are related to the intensity of the geomagnetic field. They have also observed a cosmic rays modulation of the variability of the long wavelength radiative flux in the atmosphere. More recently, Vieira and colleagues reported that a correlation between increasing sea-level pressure in the tropical Pacific, and decreasing magnetic field intensity is observed. This indicates that the physical processes in the magnetosphere, ionosphere and upper atmosphere are mapped downward to the Earth's surface. It was suggested that that the coupling mechanism may be linked to the ozone depletion in the lower mesosphere, and in the upper stratosphere of the auroral region, and/or the southern hemisphere magnetic anomaly region. The depletion is caused by high energy protons produced during solar proton events (SPEs) released during large solar storms. Variations in solar irradiance, and ozone
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Bonsal, Barrie R.; Prowse, Terry D.; Pietroniro, Alain
2003-12-01
Climate change is projected to significantly affect future hydrologic processes over many regions of the world. This is of particular importance for alpine systems that provide critical water supplies to lower-elevation regions. The western cordillera of Canada is a prime example where changes to temperature and precipitation could have profound hydro-climatic impacts not only for the cordillera itself, but also for downstream river systems and the drought-prone Canadian Prairies. At present, impact researchers primarily rely on global climate models (GCMs) for future climate projections. The main objective of this study is to assess several GCMs in their ability to simulate the magnitude and spatial variability of current (1961-90) temperature and precipitation over the western cordillera of Canada. In addition, several gridded data sets of observed climate for the study region are evaluated.Results reveal a close correspondence among the four gridded data sets of observed climate, particularly for temperature. There is, however, considerable variability regarding the various GCM simulations of this observed climate. The British, Canadian, German, Australian, and US GFDL models are superior at simulating the magnitude and spatial variability of mean temperature. The Japanese GCM is of intermediate ability, and the US NCAR model is least representative of temperature in this region. Nearly all the models substantially overestimate the magnitude of total precipitation, both annually and on a seasonal basis. An exception involves the British (Hadley) model, which best represents the observed magnitude and spatial variability of precipitation. This study improves our understanding regarding the accuracy of GCM climate simulations over the western cordillera of Canada. The findings may assist in producing more reliable future scenarios of hydro-climatic conditions over various regions of the country. Copyright
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The Copernicus programme and its Climate Change Service (C3S): a European answer to Climate Change
Pinty, Bernard; Thepaut, Jean-Noel; Dee, Dick
2016-07-01
In November 2014, The European Centre for Medium-range Weather Forecasts (ECMWF) signed an agreement with the European Commission to deliver two of the Copernicus Earth Observation Programme Services on the Commission's behalf. The ECMWF delivered services - the Copernicus Climate Change Service (C3S) and Atmosphere Monitoring Service (CAMS) - will bring a consistent standard to how we measure and predict atmospheric conditions and climate change. They will maximise the potential of past, current and future earth observations - ground, ocean, airborne, satellite - and analyse these to monitor and predict atmospheric conditions and in the future, climate change. With the wealth of free and open data that the services provide, they will help business users to assess the impact of their business decisions and make informed choices, delivering a more energy efficient and climate aware economy. These sound investment decisions now will not only stimulate growth in the short term, but reduce the impact of climate change on the economy and society in the future. C3S is in its proof of concept phase and through its climate data store will provide global and regional climate data reanalyses; multi-model seasonal forecasts; customisable visual data to enable examination of wide range of scenarios and model the impact of changes; access to all the underlying data, including climate data records from various satellite and in-situ observations. In addition, C3S will provide key indicators on climate change drivers (such as carbon dioxide) and impacts (such as reducing glaciers). The aim of these indicators will be to support European adaptation and mitigation policies in a number of economic sectors. The presentation will provide an overview of this newly created Service, its various components and activities, and a roadmap towards achieving a fully operational European Climate Service at the horizon 2019-2020. It will focus on the requirements for quality-assured Observation
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Climate: some aspects of sceptical criticism; Climat: quelques elements de critique sceptique
Energy Technology Data Exchange (ETDEWEB)
Muller, Ch.
2008-07-01
The author discusses some reasons to be sceptical about the media-supported idea of an actual climate change, and more particularly about the critical role assigned to carbon dioxide in global warming, about the ability to make the distinction between natural and man-induced climate variations, about the quality of models and simulations, about the knowledge on climate physics, about the interpretation of the recently observed warming (since 1997)
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Quantifying and Comparing Effects of Climate Engineering Methods on the Earth System
Sonntag, Sebastian; Ferrer González, Miriam; Ilyina, Tatiana; Kracher, Daniela; Nabel, Julia E. M. S.; Niemeier, Ulrike; Pongratz, Julia; Reick, Christian H.; Schmidt, Hauke
2018-02-01
To contribute to a quantitative comparison of climate engineering (CE) methods, we assess atmosphere-, ocean-, and land-based CE measures with respect to Earth system effects consistently within one comprehensive model. We use the Max Planck Institute Earth System Model (MPI-ESM) with prognostic carbon cycle to compare solar radiation management (SRM) by stratospheric sulfur injection and two carbon dioxide removal methods: afforestation and ocean alkalinization. The CE model experiments are designed to offset the effect of fossil-fuel burning on global mean surface air temperature under the RCP8.5 scenario to follow or get closer to the RCP4.5 scenario. Our results show the importance of feedbacks in the CE effects. For example, as a response to SRM the land carbon uptake is enhanced by 92 Gt by the year 2100 compared to the reference RCP8.5 scenario due to reduced soil respiration thus reducing atmospheric CO2. Furthermore, we show that normalizations allow for a better comparability of different CE methods. For example, we find that due to compensating processes such as biogeophysical effects of afforestation more carbon needs to be removed from the atmosphere by afforestation than by alkalinization to reach the same global warming reduction. Overall, we illustrate how different CE methods affect the components of the Earth system; we identify challenges arising in a CE comparison, and thereby contribute to developing a framework for a comparative assessment of CE.
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"Climate change" and vulnerability analysis: poor will become poorer
Ozer, Pierre
2013-01-01
The recent Intergovernmental Panel on Climate Change’s Fifth Assessment Report (IPCC-AR5) considers new evidence of climate change based on many independent scientific analyses from observations of the climate system, paleoclimate archives, theoretical studies of climate processes and simulations using climate models. “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warme...
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Hellstrom, R. A.; Fernandez, A.; Mark, B. G.; Covert, J. M.
2016-12-01
Peru is facing imminent water resource issues as glaciers retreat and demand increases, yet limited observations and model resolution hamper understanding of hydrometerological processes on local to regional scales. Much of current global and regional climate studies neglect the meteorological forcing of lapse rates (LRs) and valley and slope wind dynamics on critical components of the Peruvian Andes' water-cycle, and herein we emphasize the wet season. In 2004 and 2005 we installed an autonomous sensor network (ASN) within the glacierized Llanganuco Valley, Cordillera Blanca (9°S), consisting of discrete, cost-effective, automatic temperature loggers located along the valley axis and anchored by two automatic weather stations. Comparisons of these embedded hydrometeorological measurements from the ASN and climate modeling by dynamical downscaling using the Weather Research and Forecasting model (WRF) elucidate distinct diurnal and seasonal characteristics of the mountain wind regime and LRs. Wind, temperature, humidity, and cloud simulations suggest that thermally driven up-valley and slope winds converging with easterly flow aloft enhance late afternoon and evening cloud development which helps explain nocturnal wet season precipitation maxima measured by the ASN. Furthermore, the extreme diurnal variability of along-valley-axis LR, and valley wind detected from ground observations and confirmed by dynamical downscaling demonstrate the importance of realistic scale parameterizations of the atmospheric boundary layer to improve regional climate model projections in mountainous regions. We are currently considering to use intermediate climate models such as ICAR to reduce computing cost and we continue to maintain the ASN in the Cordillera Blanca.
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On The Impact of Climate Change to Agricultural Productivity in East Java
Kuswanto, Heri; Salamah, Mutiah; Mumpuni Retnaningsih, Sri; Dwi Prastyo, Dedy
2018-03-01
Many researches showed that climate change has significant impact on agricultural sector, which threats the food security especially in developing countries. It has been observed also that the climate change increases the intensity of extreme events. This research investigated the impact climate to the agricultural productivity in East Java, as one of the main rice producers in Indonesia. Standard regression as well as panel regression models have been performed in order to find the best model which is able to describe the climate change impact. The analysis found that the fixed effect model of panel regression outperforms the others showing that climate change had negatively impacted the rice productivity in East Java. The effect in Malang and Pasuruan were almost the same, while the impact in Sumenep was the least one compared to other districts.
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Lens on Climate Change: Making Climate Meaningful through Student-Produced Videos
Gold, Anne U.; Oonk, David J.; Smith, Lesley; Boykoff, Maxwell T.; Osnes, Beth; Sullivan, Susan B.
2015-01-01
Learning about climate change is tangible when it addresses impacts that can be observed close to home. In this program, sixty-four diverse middle and high school students produced videos about locally relevant climate change topics. Graduate and undergraduate students provided mentorship. The program engaged students in research and learning…
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Gosling, S. N.; Taylor, R. G.; Arnell, N. W.; Todd, M. C.
2011-01-01
We present a comparative analysis of projected impacts of climate change on river runoff from two types of distributed hydrological model, a global hydrological model (GHM) and catchment-scale hydrological models (CHM). Analyses are conducted for six catchments that are global in coverage and feature strong contrasts in spatial scale as well as climatic and developmental conditions. These include the Liard (Canada), Mekong (SE Asia), Okavango (SW Africa), Rio Grande (Brazil), Xiangxi (China) and Harper's Brook (UK). A single GHM (Mac-PDM.09) is applied to all catchments whilst different CHMs are applied for each catchment. The CHMs include SLURP v. 12.2 (Liard), SLURP v. 12.7 (Mekong), Pitman (Okavango), MGB-IPH (Rio Grande), AV-SWAT-X 2005 (Xiangxi) and Cat-PDM (Harper's Brook). The CHMs typically simulate water resource impacts based on a more explicit representation of catchment water resources than that available from the GHM and the CHMs include river routing, whereas the GHM does not. Simulations of mean annual runoff, mean monthly runoff and high (Q5) and low (Q95) monthly runoff under baseline (1961-1990) and climate change scenarios are presented. We compare the simulated runoff response of each hydrological model to (1) prescribed increases in global-mean air temperature of 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 °C relative to baseline from the UKMO HadCM3 Global Climate Model (GCM) to explore response to different amounts of climate forcing, and (2) a prescribed increase in global-mean air temperature of 2.0 °C relative to baseline for seven GCMs to explore response to climate model structural uncertainty. We find that the differences in projected changes of mean annual runoff between the two types of hydrological model can be substantial for a given GCM (e.g. an absolute GHM-CHM difference in mean annual runoff percentage change for UKMO HadCM3 2 °C warming of up to 25%), and they are generally larger for indicators of high and low monthly runoff. However
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Directory of Open Access Journals (Sweden)
S. N. Gosling
2011-01-01
Full Text Available We present a comparative analysis of projected impacts of climate change on river runoff from two types of distributed hydrological model, a global hydrological model (GHM and catchment-scale hydrological models (CHM. Analyses are conducted for six catchments that are global in coverage and feature strong contrasts in spatial scale as well as climatic and developmental conditions. These include the Liard (Canada, Mekong (SE Asia, Okavango (SW Africa, Rio Grande (Brazil, Xiangxi (China and Harper's Brook (UK. A single GHM (Mac-PDM.09 is applied to all catchments whilst different CHMs are applied for each catchment. The CHMs include SLURP v. 12.2 (Liard, SLURP v. 12.7 (Mekong, Pitman (Okavango, MGB-IPH (Rio Grande, AV-SWAT-X 2005 (Xiangxi and Cat-PDM (Harper's Brook. The CHMs typically simulate water resource impacts based on a more explicit representation of catchment water resources than that available from the GHM and the CHMs include river routing, whereas the GHM does not. Simulations of mean annual runoff, mean monthly runoff and high (Q5 and low (Q95 monthly runoff under baseline (1961–1990 and climate change scenarios are presented. We compare the simulated runoff response of each hydrological model to (1 prescribed increases in global-mean air temperature of 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 °C relative to baseline from the UKMO HadCM3 Global Climate Model (GCM to explore response to different amounts of climate forcing, and (2 a prescribed increase in global-mean air temperature of 2.0 °C relative to baseline for seven GCMs to explore response to climate model structural uncertainty.
We find that the differences in projected changes of mean annual runoff between the two types of hydrological model can be substantial for a given GCM (e.g. an absolute GHM-CHM difference in mean annual runoff percentage change for UKMO HadCM3 2 °C warming of up to 25%, and they are generally larger for indicators of high and low monthly runoff -
Todd, James; Legler, David; Piotrowicz, Stephen; Raymond, Megan; Smith, Emily; Tedesco, Kathy; Thurston, Sidney
2017-04-01
The Ocean Observing and Monitoring Division (OOMD, formerly the Climate Observation Division) of the National Oceanic and Atmospheric Administration (NOAA) Climate Program Office provides long-term, high-quality global observations, climate information and products for researchers, forecasters, assessments and other users of environmental information. In this context, OOMD-supported activities serve a foundational role in an enterprise that aims to advance 1) scientific understanding, 2) monitoring and prediction of climate and 3) understanding of potential impacts to enable a climate resilient society. Leveraging approximately 50% of the Global Ocean Observing System, OOMD employs an internationally-coordinated, multi-institution global strategy that brings together data from multiple platforms including surface drifting buoys, Argo profiling floats, flux/transport moorings (RAMA, PIRATA, OceanSITES), GLOSS tide gauges, SOOP-XBT and SOOP-CO2, ocean gliders and repeat hydrographic sections (GO-SHIP). OOMD also engages in outreach, education and capacity development activities to deliver training on the social-economic applications of ocean data. This presentation will highlight recent activities and plans for 2017 and beyond.
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International Nuclear Information System (INIS)
Duplessy, J.C.; Pons, A.; Fantechi, R.
1991-01-01
The present volume contains the lessons delivered at the course held in Arles, France, on the subject Climate and Global Change: natural variability of the geosphere and biosphere systems, biogeochemical cycles and their perturbation by human activities, monitoring and forecasting global changes (satellite observations, modelling,...). Short presentations of students' own research activities are also proposed (climatic fluctuation in the Mediterranean area, climate/vegetation relations, etc.)
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GLOBAL CLIMATE MODEL:A COMPREHENSIVE TOOL IN CLIMATE CHANGE IMPACT STUDIES
Directory of Open Access Journals (Sweden)
Dharmaveer Singh
2015-01-01
Full Text Available There is growing concern, how and to what extent future changes in climate will affect human society and natural environments. Continuous emissions of Green House Gasses (GHGs at or above current rates will cause further warming. This, in turn, may modify global climate system during 21st century that very likely would have larger impacts than those observed during 20th century. At present, Global Climate Models (GCMs are only the most reliable tools available for studying behaviour of the climate system. This paper presents a comprehensive review of GCMs including their development and applications in climate change impacts studies. Following a discussion of the limitations of GCMs at regional and local scales, different approaches of downscaling are discussed in detail.
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Sensitivity of the Regional Climate in the Middle East and North Africa to Volcanic Perturbations
Dogar, Muhammad Mubashar; Stenchikov, Georgiy L.; Osipov, Sergey; Wyman, Bruce; Zhao, Ming
2017-01-01
The Middle East and North Africa (MENA) regional climate appears to be extremely sensitive to volcanic eruptions. Winter cooling after the 1991 Pinatubo eruption far exceeded the mean hemispheric temperature anomaly, even causing snowfall in Israel. To better understand MENA climate variability, the climate responses to the El Chichón and Pinatubo volcanic eruptions are analyzed using observations, NOAA/NCEP Climate Forecast System Reanalysis, and output from the Geophysical Fluid Dynamics Laboratory's High-Resolution Atmospheric Model (HiRAM). A multiple regression analysis both for the observations and the model output is performed on seasonal summer and winter composites to separate out the contributions from climate trends, El Niño Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian summer monsoon and volcanic aerosols. Strong regional temperature and precipitation responses over the MENA region are found in both winter and summer. The model and the observations both show that a positive NAO amplifies the MENA volcanic winter cooling. In boreal summer, the patterns of changing temperature and precipitation suggest a weakening and southward shift of the Intertropical Convergence Zone, caused by volcanic surface cooling and weakening of the Indian and West African monsoons. The model captures the main features of the climate response; however, it underestimates the total cooling, especially in winter, and exhibits a different spatial pattern of the NAO climate response in MENA compared to the observations. The conducted analysis sheds light on the internal mechanisms of MENA climate variability and helps to selectively diagnose the model deficiencies.
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Sensitivity of the Regional Climate in the Middle East and North Africa to Volcanic Perturbations
Dogar, Muhammad Mubashar
2017-07-27
The Middle East and North Africa (MENA) regional climate appears to be extremely sensitive to volcanic eruptions. Winter cooling after the 1991 Pinatubo eruption far exceeded the mean hemispheric temperature anomaly, even causing snowfall in Israel. To better understand MENA climate variability, the climate responses to the El Chichón and Pinatubo volcanic eruptions are analyzed using observations, NOAA/NCEP Climate Forecast System Reanalysis, and output from the Geophysical Fluid Dynamics Laboratory\\'s High-Resolution Atmospheric Model (HiRAM). A multiple regression analysis both for the observations and the model output is performed on seasonal summer and winter composites to separate out the contributions from climate trends, El Niño Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian summer monsoon and volcanic aerosols. Strong regional temperature and precipitation responses over the MENA region are found in both winter and summer. The model and the observations both show that a positive NAO amplifies the MENA volcanic winter cooling. In boreal summer, the patterns of changing temperature and precipitation suggest a weakening and southward shift of the Intertropical Convergence Zone, caused by volcanic surface cooling and weakening of the Indian and West African monsoons. The model captures the main features of the climate response; however, it underestimates the total cooling, especially in winter, and exhibits a different spatial pattern of the NAO climate response in MENA compared to the observations. The conducted analysis sheds light on the internal mechanisms of MENA climate variability and helps to selectively diagnose the model deficiencies.
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Sensitivity of the regional climate in the Middle East and North Africa to volcanic perturbations
Dogar, Muhammad Mubashar; Stenchikov, Georgiy; Osipov, Sergey; Wyman, Bruce; Zhao, Ming
2017-08-01
The Middle East and North Africa (MENA) regional climate appears to be extremely sensitive to volcanic eruptions. Winter cooling after the 1991 Pinatubo eruption far exceeded the mean hemispheric temperature anomaly, even causing snowfall in Israel. To better understand MENA climate variability, the climate responses to the El Chichón and Pinatubo volcanic eruptions are analyzed using observations, NOAA/National Centers for Environmental Prediction Climate Forecast System Reanalysis, and output from the Geophysical Fluid Dynamics Laboratory's High-Resolution Atmospheric Model. A multiple regression analysis both for the observations and the model output is performed on seasonal summer and winter composites to separate out the contributions from climate trends, El Niño-Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian summer monsoon, and volcanic aerosols. Strong regional temperature and precipitation responses over the MENA region are found in both winter and summer. The model and the observations both show that a positive NAO amplifies the MENA volcanic winter cooling. In boreal summer, the patterns of changing temperature and precipitation suggest a weakening and southward shift of the Intertropical Convergence Zone, caused by volcanic surface cooling and weakening of the Indian and West African monsoons. The model captures the main features of the climate response; however, it underestimates the total cooling, especially in winter, and exhibits a different spatial pattern of the NAO climate response in MENA compared to the observations. The conducted analysis sheds light on the internal mechanisms of MENA climate variability and helps to selectively diagnose the model deficiencies.
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Energy Technology Data Exchange (ETDEWEB)
Wall, Casey J. [Department of Atmospheric Sciences, University of Washington, Seattle, Washington; Hartmann, Dennis L. [Department of Atmospheric Sciences, University of Washington, Seattle, Washington; Ma, Po-Lun [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington
2017-12-01
Instantaneous, coincident, footprint-level satellite observations of cloud properties and radiation taken during austral summer over the Southern Ocean are used to study relationships between clouds and large-scale meteorology. Cloud properties are very sensitive to the strength of vertical motion in the middle-troposphere, and low-cloud properties are sensitive to estimated inversion strength, low-level temperature advection, and sea surface temperature. These relationships are quantified. An index for the meteorological anomalies associated with midlatitude cyclones is presented, and it is used to reveal the sensitivity of clouds to the meteorology within the warm- and cold-sector of cyclones. The observed relationships between clouds and meteorology are compared to those in the Community Atmosphere Model version 5 (CAM5) using satellite simulators. Low-clouds simulated by CAM5 are too few, too bright, and contain too much ice, and low-clouds located in the cold-sector of cyclones are too sensitive to variations in the meteorology. The latter two biases are dramatically reduced when CAM5 is coupled with an updated boundary layer parameterization know as Cloud Layers Unified by Binormals (CLUBB). More generally, this study demonstrates that examining the instantaneous timescale is a powerful approach to understanding the physical processes that control clouds and how they are represented in climate models. Such an evaluation goes beyond the cloud climatology and exposes model bias under various meteorological conditions.
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Dedicated Low Latitude Diurnal CO2 Frost Observation Campaigns by the Mars Climate Sounder
Piqueux, S.; Kass, D. M.; Kleinboehl, A.; Hayne, P. O.; Heavens, N. G.; McCleese, D. J.; Schofield, J. T.; Shirley, J. H.
2017-12-01
In December 2016 (Ls≈280, MY33) and July 2017 (Ls≈30, MY34), the Mars Climate Sounder (MCS) onboard the Mars Reconnaissance Orbiter (MRO) conducted two distinct observation campaigns. The first one aimed at 1) confirming the presence of low latitude diurnal CO2 frost on Mars, and 2) refining the estimated mass of carbon dioxide condensed at the surface, whereas the second campaign was designed to 3) search for temporally and spatially varying spectral characteristics indicative of frost properties (i.e., crystal size, contamination, etc.) and relationship to the regolith. To meet these goals, MCS acquired thermal infrared observations of the surface and atmosphere at variable local times (≈1.70-3.80 h Local True Solar Time) and in the 10°-50°N latitude band where very low thermal inertia material (frost distribution and spectral properties. In addition, pre-frost deposition surface cooling rates are found to be consistent with those predicted by numerical models (i.e., 1-2K per hour). Finally, we observe buffered surface temperatures near the local frost point, indicating a surface emissivity ≈1. (i.e., optically thin frost layers, or dust contaminated frost, or slab-like ice) and no discernable frost metamorphism. We will present a detailed analysis of these new and unique observations, and elaborate on the potential relationship between the regolith and this recurring frost cycle.
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Climate Change Accuracy: Requirements and Economic Value
Wielicki, B. A.; Cooke, R.; Mlynczak, M. G.; Lukashin, C.; Thome, K. J.; Baize, R. R.
2014-12-01
Higher than normal accuracy is required to rigorously observe decadal climate change. But what level is needed? How can this be quantified? This presentation will summarize a new more rigorous and quantitative approach to determining the required accuracy for climate change observations (Wielicki et al., 2013, BAMS). Most current global satellite observations cannot meet this accuracy level. A proposed new satellite mission to resolve this challenge is CLARREO (Climate Absolute Radiance and Refractivity Observatory). CLARREO is designed to achieve advances of a factor of 10 for reflected solar spectra and a factor of 3 to 5 for thermal infrared spectra (Wielicki et al., Oct. 2013 BAMS). The CLARREO spectrometers are designed to serve as SI traceable benchmarks for the Global Satellite Intercalibration System (GSICS) and to greatly improve the utility of a wide range of LEO and GEO infrared and reflected solar passive satellite sensors for climate change observations (e.g. CERES, MODIS, VIIIRS, CrIS, IASI, Landsat, SPOT, etc). Providing more accurate decadal change trends can in turn lead to more rapid narrowing of key climate science uncertainties such as cloud feedback and climate sensitivity. A study has been carried out to quantify the economic benefits of such an advance as part of a rigorous and complete climate observing system. The study concludes that the economic value is $12 Trillion U.S. dollars in Net Present Value for a nominal discount rate of 3% (Cooke et al. 2013, J. Env. Sys. Dec.). A brief summary of these two studies and their implications for the future of climate science will be presented.
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Dunning, C.; Black, E.; Allan, R. P.
2017-12-01
The seasonality of rainfall over Africa plays a key role in determining socio-economic impacts for agricultural stakeholders, influences energy supply from hydropower, affects the length of the malaria transmission season and impacts surface water supplies. Hence, failure or delays of these rains can lead to significant socio-economic impacts. Diagnosing and interpreting interannual variability and long-term trends in seasonality, and analysing the physical driving mechanisms, requires a robust definition of African precipitation seasonality, applicable to both observational datasets and model simulations. Here we present a methodology for objectively determining the onset and cessation of multiple wet seasons across the whole of Africa. Compatibility with known physical drivers of African rainfall, consistency with indigenous methods, and generally strong agreement between satellite-based rainfall data sets confirm that the method is capturing the correct seasonal progression of African rainfall. Application of this method to observational datasets reveals that over East Africa cessation of the short rains is 5 days earlier in La Nina years, and the failure of the rains and subsequent humanitarian disaster is associated with shorter as well as weaker rainy seasons over this region. The method is used to examine the representation of the seasonality of African precipitation in CMIP5 model simulations. Overall, atmosphere-only and fully coupled CMIP5 historical simulations represent essential aspects of the seasonal cycle; patterns of seasonal progression of the rainy season are captured, for the most part mean model onset/ cessation dates agree with mean observational dates to within 18 days. However, unlike the atmosphere-only simulations, the coupled simulations do not capture the biannual regime over the southern West African coastline, linked to errors in Gulf of Guinea Sea Surface Temperature. Application to both observational and climate model datasets, and
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Matte, Dominic; Thériault, Julie M.; Laprise, René
2018-05-01
Winter weather events with temperatures near 0°C are often associated with freezing rain. They can have major impacts on the society by causing power outages and disruptions to the transportation networks. Despite the catastrophic consequences of freezing rain, very few studies have investigated how their occurrences could evolve under climate change. This study aims to investigate the change of freezing rain and ice pellets over southern Québec using regional climate modeling at high resolution. The fifth-generation Canadian Regional Climate Model with climate scenario RCP 8.5 at 0.11° grid mesh was used. The precipitation types such as freezing rain, ice pellets or their combination are diagnosed using five methods (Cantin and Bachand, Bourgouin, Ramer, Czys and, Baldwin). The occurrences of the diagnosed precipitation types for the recent past (1980-2009) are found to be comparable to observations. The projections for the future scenario (2070-2099) suggested a general decrease in the occurrences of mixed precipitation over southern Québec from October to April. This is mainly due to a decrease in long-duration events (≥6 h ). Overall, this study contributes to better understand how the distribution of freezing rain and ice pellets might change in the future using high-resolution regional climate model.
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Climate Model Diagnostic Analyzer
Lee, Seungwon; Pan, Lei; Zhai, Chengxing; Tang, Benyang; Kubar, Terry; Zhang, Zia; Wang, Wei
2015-01-01
The comprehensive and innovative evaluation of climate models with newly available global observations is critically needed for the improvement of climate model current-state representation and future-state predictability. A climate model diagnostic evaluation process requires physics-based multi-variable analyses that typically involve large-volume and heterogeneous datasets, making them both computation- and data-intensive. With an exploratory nature of climate data analyses and an explosive growth of datasets and service tools, scientists are struggling to keep track of their datasets, tools, and execution/study history, let alone sharing them with others. In response, we have developed a cloud-enabled, provenance-supported, web-service system called Climate Model Diagnostic Analyzer (CMDA). CMDA enables the physics-based, multivariable model performance evaluations and diagnoses through the comprehensive and synergistic use of multiple observational data, reanalysis data, and model outputs. At the same time, CMDA provides a crowd-sourcing space where scientists can organize their work efficiently and share their work with others. CMDA is empowered by many current state-of-the-art software packages in web service, provenance, and semantic search.
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Testing the Value of Information of Climate Change Indicators that use Earth Observations
Kenney, M. A.
2012-12-01
Indicators are usually thought of as measurements or calculations that represent important features of the status, trend, or performance of a system of interest (e.g. the economy, agriculture, air quality). They are often used for the most practical of reasons - one cannot measure everything important about systems of interest, so there is a practical need to identify major features that can be reported periodically and used to guide both research and decisions (National Research Council (NRC). 2000. Ecological Indicators for the Nation. National Academy Press. Washington, DC). The use of indicators to track the status and trends of many features of environmental or economic performance, quality of life, and a host of other social concerns is embedded in the fabric of our everyday lives. Businesses, governments, and consumers regularly use the common economic indices - e.g. the unemployment index or consumer price index - as guides for decision-making on investments and hiring. There is an analogous demand for indicators of environmental conditions and performance - everything from agricultural yields to air and water quality to weather and climate - that are currently less publicly visible than the common economic indicators, but that can have critically important uses in such areas as natural resource management, improvement of environmental quality, emergency planning, and infrastructure development. A number of these environmental indicators, be it physical or ecological, use a range of data sources including earth observations. Despite the extensive development and use of indicators, there is little testing of these indicators to assure that they indeed provide the assumed positive information benefit. This is particularly concerning because if these indicators are systematically misunderstood by the intended audience or a sub-group of that audience, such individuals could make decisions that are consistent with their incorrect understanding of the indicator
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Energy Technology Data Exchange (ETDEWEB)
Beverly Law; David Turner; Warren Cohen; Mathias Goeckede
2008-05-22
The goal is to quantify and explain the carbon (C) budget for Oregon and N. California. The research compares "bottom -up" and "top-down" methods, and develops prototype analytical systems for regional analysis of the carbon balance that are potentially applicable to other continental regions, and that can be used to explore climate, disturbance and land-use effects on the carbon cycle. Objectives are: 1) Improve, test and apply a bottom up approach that synthesizes a spatially nested hierarchy of observations (multispectral remote sensing, inventories, flux and extensive sites), and the Biome-BGC model to quantify the C balance across the region; 2) Improve, test and apply a top down approach for regional and global C flux modeling that uses a model-data fusion scheme (MODIS products, AmeriFlux, atmospheric CO2 concentration network), and a boundary layer model to estimate net ecosystem production (NEP) across the region and partition it among GPP, R(a) and R(h). 3) Provide critical understanding of the controls on regional C balance (how NEP and carbon stocks are influenced by disturbance from fire and management, land use, and interannual climate variation). The key science questions are, "What are the magnitudes and distributions of C sources and sinks on seasonal to decadal time scales, and what processes are controlling their dynamics? What are regional spatial and temporal variations of C sources and sinks? What are the errors and uncertainties in the data products and results (i.e., in situ observations, remote sensing, models)?
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Energy Technology Data Exchange (ETDEWEB)
Lindzen, Richard [M.I.T.
2011-11-09
Warming observed thus far is entirely consistent with low climate sensitivity. However, the result is ambiguous because the sources of climate change are numerous and poorly specified. Model predictions of substantial warming aredependent on positive feedbacks associated with upper level water vapor and clouds, but models are notably inadequate in dealing with clouds and the impacts of clouds and water vapor are intimately intertwined. Various approaches to measuring sensitivity based on the physics of the feedbacks will be described. The results thus far point to negative feedbacks. Problems with these approaches as well as problems with the concept of climate sensitivity will be described.
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Gomes, Sandra; Deus, Ricardo; Nogueira, Miguel; Viterbo, Pedro; Miranda, Miguel; Antunes, Sílvia; Silva, Alvaro; Miranda, Pedro
2016-04-01
The Portuguese Local Warming Website (http://portaldoclima.pt) has been developed in order to support the society in Portugal in preparing for the adaptation to the ongoing and future effects of climate change. The climate portal provides systematic and easy access to authoritative scientific data ready to be used by a vast and diverse user community from different public and private sectors, key players and decision makers, but also to high school students, contributing to the increase in knowledge and awareness on climate change topics. A comprehensive set of regional climate variables and indicators are computed, explained and graphically presented. Variables and indicators were built in agreement with identified needs after consultation of the relevant social partners from different sectors, including agriculture, water resources, health, environment and energy and also in direct cooperation with the Portuguese National Strategy for Climate Change Adaptation (ENAAC) group. The visual interface allows the user to dynamically interact, explore, quickly analyze and compare, but also to download and import the data and graphics. The climate variables and indicators are computed from state-of-the-art regional climate model (RCM) simulations (e.g., CORDEX project), at high space-temporal detail, allowing to push the limits of the projections down to local administrative regions (NUTS3) and monthly or seasonal periods, promoting local adaptation strategies. The portal provides both historical data (observed and modelled for the 1971-2000 period) and future climate projections for different scenarios (modelled for the 2011-2100 period). A large effort was undertaken in order to quantify the impacts of the risk of extreme events, such as heavy rain and flooding, droughts, heat and cold waves, and fires. Furthermore the different climate scenarios and the ensemble of RCM models, with high temporal (daily) and spatial (~11km) detail, is taken advantage in order to
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Gregson, Kim D; Erath, Stephen A; Pettit, Gregory S; Tu, Kelly M
2016-12-01
Associations linking parenting emotional climate and quality of parental social coaching with young adolescents' receptivity to parental social coaching were examined (N = 80). Parenting emotional climate was assessed with adolescent-reported parental warmth and hostility. Quality of parental social coaching (i.e., prosocial advice, benign framing) was assessed via parent-report and behavioral observations during a parent-adolescent discussion about negative peer evaluation. An adolescent receptivity latent variable score was derived from observations of adolescents' behavior during the discussion, change in adolescents' peer response plan following the discussion, and adolescent-reported tendency to seek social advice from the parent. Parenting climate moderated associations between coaching and receptivity: Higher quality coaching was associated with greater receptivity in the context of a more positive climate. Analyses suggested a stronger association between coaching and receptivity among younger compared to older adolescents. © 2015 The Authors. Journal of Research on Adolescence © 2015 Society for Research on Adolescence.
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Terzi, Stefano; Torresan, Silvia; Schneiderbauer, Stefan
2017-04-01
Keywords: Climate change, mountain regions, multi-risk assessment, climate change adaptation. Climate change has already led to a wide range of impacts on the environment, the economy and society. Adaptation actions are needed to cope with the impacts that have already occurred (e.g. storms, glaciers melting, floods, droughts) and to prepare for future scenarios of climate change. Mountain environment is particularly vulnerable to the climate changes due to its exposure to recent climate warming (e.g. water regime changes, thawing of permafrost) and due to the high degree of specialization of both natural and human systems (e.g. alpine species, valley population density, tourism-based economy). As a consequence, the mountain local governments are encouraged to undertake territorial governance policies to climate change, considering multi-risks and opportunities for the mountain economy and identifying the best portfolio of adaptation strategies. This study aims to provide a literature review of available qualitative and quantitative tools, methodological guidelines and best practices to conduct multi-risk assessments in the mountain environment within the context of climate change. We analyzed multi-risk modelling and assessment methods applied in alpine regions (e.g. event trees, Bayesian Networks, Agent Based Models) in order to identify key concepts (exposure, resilience, vulnerability, risk, adaptive capacity), climatic drivers, cause-effect relationships and socio-ecological systems to be integrated in a comprehensive framework. The main outcomes of the review, including a comparison of existing techniques based on different criteria (e.g. scale of analysis, targeted questions, level of complexity) and a snapshot of the developed multi-risk framework for climate change adaptation will be here presented and discussed.
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The ESA climate change initiative: Satellite data records for essential climate variables
DEFF Research Database (Denmark)
Hollmann, R.; Merchant, C.J.; Saunders, R.
2013-01-01
The European Space Agency (ESA) has launched the Climate Change Initiative (CCI) to provide satellite-based climate data records (CDRs) that meet the challenging requirements of the climate community. The aim is to realize the full potential of the long-term Earth observation (EO) archives...... that both ESA and third parties have established. This includes aspects of producing a CDR, which involve data acquisition, calibration, algorithm development, validation, maintenance, and provision of the data to the climate research community. The CCI is consistent with several international efforts...... targeting the generation of satellite derived climate data records. One focus of the CCI is to provide products for climate modelers who increasingly use satellite data to initialize, constrain, and validate models on a wide range of space and time scales....
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Ice core melt features in relation to Antarctic coastal climate
Kaczmarska, M.; Isaksson, E.; Karlöf, L.; Brandt, O.; Winther, J.G.; van de Wal, R.S.W.; van den Broeke, M.R.; Johnsen, S.J.
2006-01-01
Measurement of light intensity transmission was carried out on an ice core S100 from coastal Dronning Maud Land (DML). Ice lenses were observed in digital pictures of the core and recorded as peaks in the light transmittance record. The frequency of ice layer occurrence was compared with climate
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Macroweather Predictions and Climate Projections using Scaling and Historical Observations
Hébert, R.; Lovejoy, S.; Del Rio Amador, L.
2017-12-01
There are two fundamental time scales that are pertinent to decadal forecasts and multidecadal projections. The first is the lifetime of planetary scale structures, about 10 days (equal to the deterministic predictability limit), and the second is - in the anthropocene - the scale at which the forced anthropogenic variability exceeds the internal variability (around 16 - 18 years). These two time scales define three regimes of variability: weather, macroweather and climate that are respectively characterized by increasing, decreasing and then increasing varibility with scale.We discuss how macroweather temperature variability can be skilfully predicted to its theoretical stochastic predictability limits by exploiting its long-range memory with the Stochastic Seasonal and Interannual Prediction System (StocSIPS). At multi-decadal timescales, the temperature response to forcing is approximately linear and this can be exploited to make projections with a Green's function, or Climate Response Function (CRF). To make the problem tractable, we exploit the temporal scaling symmetry and restrict our attention to global mean forcing and temperature response using a scaling CRF characterized by the scaling exponent H and an inner scale of linearity τ. An aerosol linear scaling factor α and a non-linear volcanic damping exponent ν were introduced to account for the large uncertainty in these forcings. We estimate the model and forcing parameters by Bayesian inference using historical data and these allow us to analytically calculate a median (and likely 66% range) for the transient climate response, and for the equilibrium climate sensitivity: 1.6K ([1.5,1.8]K) and 2.4K ([1.9,3.4]K) respectively. Aerosol forcing typically has large uncertainty and we find a modern (2005) forcing very likely range (90%) of [-1.0, -0.3] Wm-2 with median at -0.7 Wm-2. Projecting to 2100, we find that to keep the warming below 1.5 K, future emissions must undergo cuts similar to Representative
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Winker, David M.
1999-01-01
Current uncertainties in the effects of clouds and aerosols on the Earth radiation budget limit our understanding of the climate system and the potential for global climate change. Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations - Climatologie Etendue des Nuages et des Aerosols (PICASSO-CENA) is a recently approved satellite mission within NASA's Earth System Science Pathfinder (ESSP) program which will address these uncertainties with a unique suite of active and passive instruments. The Lidar In-space Technology Experiment (LITE) demonstrated the potential benefits of space lidar for studies of clouds and aerosols. PICASSO-CENA builds on this experience with a payload consisting of a two-wavelength polarization-sensitive lidar, an oxygen A-band spectrometer (ABS), an imaging infrared radiometer (IIR), and a wide field camera (WFC). Data from these instruments will be used to measure the vertical distributions of aerosols and clouds in the atmosphere, as well as optical and physical properties of aerosols and clouds which influence the Earth radiation budget. PICASSO-CENA will be flown in formation with the PM satellite of the NASA Earth Observing System (EOS) to provide a comprehensive suite of coincident measurements of atmospheric state, aerosol and cloud optical properties, and radiative fluxes. The mission will address critical uncertainties iin the direct radiative forcing of aerosols and clouds as well as aerosol influences on cloud radiative properties and cloud-climate radiation feedbacks. PICASSO-CENA is planned for a three year mission, with a launch in early 2003. PICASSO-CENA is being developed within the framework of a collaboration between NASA and CNES.
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Complexity in Climate Change Manipulation Experiments
DEFF Research Database (Denmark)
Kreyling, Juergen; Beier, Claus
2014-01-01
Climate change goes beyond gradual changes in mean conditions. It involves increased variability in climatic drivers and increased frequency and intensity of extreme events. Climate manipulation experiments are one major tool to explore the ecological impacts of climate change. Until now...... variability in temperature are ecologically important. Embracing complexity in future climate change experiments in general is therefore crucial......., precipitation experiments have dealt with temporal variability or extreme events, such as drought, resulting in a multitude of approaches and scenarios with limited comparability among studies. Temperature manipulations have mainly been focused only on warming, resulting in better comparability among studies...
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CIRUN: Climate Information Responding to User Needs
Busalacchi, A. J.
2009-12-01
The Earth System will experience real climate change over the next 50 years, exceeding the scope of natural climate variability. A paramount question facing society is how to adapt to this certainty of climate variability and change. In response, OSTP and NOAA are considering how comprehensive climate services would best inform decisions about adaptation. Similarly, NASA is considering the optimal configuration of the next generation of Earth, environmental, and climate observations to be deployed over the coming 10-20 years. Moreover, much of the added-value information for specific climate-related decisions will be provided by private, academic and non-governmental organizations. In this context, over the past several years the University of Maryland has established the CIRUN (Climate Information: Responding to User Needs) initiative to identify the nature of national needs for climate information and services from a decision support perspective. To date, CIRUN has brought together decisionmakers in a number of sectors to help understand their perspectives on climate with the goal of improving the usefulness of climate information, observations and prediction products to specific user communities. CIRUN began with a major workshop in October 2007 that convened 430 participants in agriculture, parks and recreation, terrestrial ecosystems, insurance/investment, energy, national security, state/local/municipal, water, human health, commerce and manufacturing, transportation, and coastal/marine sectors. Plenary speakers such as Norman Augustine, R. James Woolsey, James Mahoney, and former Senator Joseph Tydings, breakout panel sessions, and participants provided input based on the following: - How would you characterize the exposure or vulnerability to climate variability or change impacting your organization? - Does climate variability and/or change currently factor into your organization's objectives or operations? - Are any of your existing plans being affected by
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Climate Trends and Impacts in China
Chris Sall
2013-01-01
This discussion paper summarizes observed and projected trends in extreme weather events, present-day climate variability, and future climate change and their impacts on China's different regions. Findings are presented from China's national assessment report on climate change (2007) and second national assessment report on climate change (2011) as well as other studies by Chinese and inte...
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Giant planet population synthesis: comparing theory with observations
International Nuclear Information System (INIS)
Benz, W; Mordasini, C; Alibert, Y; Naef, D
2008-01-01
The characteristics of the now over 250 known extra-solar giant planets begin to provide a database with which current planet formation theories can be put to the test. To do this, we synthesize the expected planet population based on the core-accretion scenario by sampling initial conditions in a Monte Carlo fashion. We then apply appropriate observational detection biases and compare the resulting population with the one actually detected. Quantitative statistical tests allow us to determine how well the models are reproducing the observed samples. The model can be applied to compute the expected planet population detectable with different techniques (radial velocity measurements, transits, gravitational lensing, etc) or orbiting stars of different masses. In the latter case, we show that forming Jupiter-mass planets orbiting M dwarfs within the lifetime of proto-planetary disks is indeed possible. However, the models predict that with decreasing stellar mass, the ratio of Jupiter- to Neptune-mass planets will sharply decrease
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Giant planet population synthesis: comparing theory with observations
Benz, W.; Mordasini, C.; Alibert, Y.; Naef, D.
2008-08-01
The characteristics of the now over 250 known extra-solar giant planets begin to provide a database with which current planet formation theories can be put to the test. To do this, we synthesize the expected planet population based on the core-accretion scenario by sampling initial conditions in a Monte Carlo fashion. We then apply appropriate observational detection biases and compare the resulting population with the one actually detected. Quantitative statistical tests allow us to determine how well the models are reproducing the observed samples. The model can be applied to compute the expected planet population detectable with different techniques (radial velocity measurements, transits, gravitational lensing, etc) or orbiting stars of different masses. In the latter case, we show that forming Jupiter-mass planets orbiting M dwarfs within the lifetime of proto-planetary disks is indeed possible. However, the models predict that with decreasing stellar mass, the ratio of Jupiter- to Neptune-mass planets will sharply decrease.
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Flanagan, S.; Hurtt, G. C.; Fisk, J. P.; Rourke, O.
2012-12-01
A robust understanding of the sensitivity of the pattern, structure, and dynamics of ecosystems to climate, climate variability, and climate change is needed to predict ecosystem responses to current and projected climate change. We present results of a study designed to first quantify the sensitivity of ecosystems to climate through the use of climate and ecosystem data, and then use the results to test the sensitivity of the climate data in a state-of the art ecosystem model. A database of available ecosystem characteristics such as mean canopy height, above ground biomass, and basal area was constructed from sources like the National Biomass and Carbon Dataset (NBCD). The ecosystem characteristics were then paired by latitude and longitude with the corresponding climate characteristics temperature, precipitation, photosynthetically active radiation (PAR) and dew point that were retrieved from the North American Regional Reanalysis (NARR). The average yearly and seasonal means of the climate data, and their associated maximum and minimum values, over the 1979-2010 time frame provided by NARR were constructed and paired with the ecosystem data. The compiled results provide natural patterns of vegetation structure and distribution with regard to climate data. An advanced ecosystem model, the Ecosystem Demography model (ED), was then modified to allow yearly alterations to its mechanistic climate lookup table and used to predict the sensitivities of ecosystem pattern, structure, and dynamics to climate data. The combined ecosystem structure and climate data results were compared to ED's output to check the validity of the model. After verification, climate change scenarios such as those used in the last IPCC were run and future forest structure changes due to climate sensitivities were identified. The results of this study can be used to both quantify and test key relationships for next generation models. The sensitivity of ecosystem characteristics to climate data
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Climate trends in the Arctic as observed from space.
Comiso, Josefino C; Hall, Dorothy K
2014-05-01
The Arctic is a region in transformation. Warming in the region has been amplified, as expected from ice-albedo feedback effects, with the rate of warming observed to be ∼0.60 ± 0.07°C/decade in the Arctic (>64°N) compared to ∼0.17°C/decade globally during the last three decades. This increase in surface temperature is manifested in all components of the cryosphere. In particular, the sea ice extent has been declining at the rate of ∼3.8%/decade, whereas the perennial ice (represented by summer ice minimum) is declining at a much greater rate of ∼11.5%/decade. Spring snow cover has also been observed to be declining by -2.12%/decade for the period 1967-2012. The Greenland ice sheet has been losing mass at the rate of ∼34.0 Gt/year (sea level equivalence of 0.09 mm/year) during the period from 1992 to 2011, but for the period 2002-2011, a higher rate of mass loss of ∼215 Gt/year has been observed. Also, the mass of glaciers worldwide declined at the rate of 226 Gt/year from 1971 to 2009 and 275 Gt/year from 1993 to 2009. Increases in permafrost temperature have also been measured in many parts of the Northern Hemisphere while a thickening of the active layer that overlies permafrost and a thinning of seasonally frozen ground has also been reported. To gain insight into these changes, comparative analysis with trends in clouds, albedo, and the Arctic Oscillation is also presented. How to cite this article: WIREs Clim Change 2014, 5:389�409. doi: 10.1002/wcc.277.
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Treeline dynamics with climate change at Central Nepal Himalaya
Gaire, N. P.; Koirala, M.; Bhuju, D. R.; Borgaonkar, H. P.
2013-10-01
Global climate change has multidimensional impacts with several biological fingerprints, and treeline shifting in tandem with climate change is a widely observed phenomenon in various parts of the world. In Nepal several impacts of climate change on physical environments have been observed. However, studies on the biological impacts are lacking. This dendrochronological study was carried out at the treeline ecotone (3750-4003 m a.s.l.) in the Kalchuman Lake (Kal Tal) area of the Manaslu Conservation Area in central Nepal Himalaya with the aim to study the dynamic impact of climate change at the treeline. The study provides an insight into regeneration and treeline dynamics over the past 200 yr. Two belt transect plots (size: 20 m wide, >250 m long) were laid covering forest line, treeline as well as tree species Abies spectabilis and Betula utilis was done and their tree-cores were collected. Stand character and age distribution revealed an occurrence of more matured B. utilis (max. age 198 yr old) compared to A. spectabilis (max. age 160 yr). A. spectabilis contained an overwhelmingly high population (89%) of younger plants (plant density as well as upward shifting in the studied treeline ecotones was observed. Thus, two species presented species-specific responses to climate change and much wider differences anticipated in their population status as climate continues to cha spectabilis correlated negatively with the mean monthly temperature of May-August of the current year and with September of the previous year. The regeneration of A. spectabilis, on the other hand, was positively related with May-August precipitation and January-April temperature of the current year. The reconstructed average summer temperature (May-August) using tree ring data revealed alternate period of cool and warm period with warming in the 2nd half of the 20th century. Further palynological and geochronological studies of sediments of the Kalchuman Lake would advance our understanding
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Detection and Attribution of Anthropogenic Climate Change Impacts
Rosenzweig, Cynthia; Neofotis, Peter
2013-01-01
Human-influenced climate change is an observed phenomenon affecting physical and biological systems across the globe. The majority of observed impacts are related to temperature changes and are located in the northern high- and midlatitudes. However, new evidence is emerging that demonstrates that impacts are related to precipitation changes as well as temperature, and that climate change is impacting systems and sectors beyond the Northern Hemisphere. In this paper, we highlight some of this new evidence-focusing on regions and sectors that the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4) noted as under-represented-in the context of observed climate change impacts, direct and indirect drivers of change (including carbon dioxide itself), and methods of detection. We also present methods and studies attributing observed impacts to anthropogenic forcing. We argue that the expansion of methods of detection (in terms of a broader array of climate variables and data sources, inclusion of the major modes of climate variability, and incorporation of other drivers of change) is key to discerning the climate sensitivities of sectors and systems in regions where the impacts of climate change currently remain elusive. Attributing such changes to human forcing of the climate system, where possible, is important for development of effective mitigation and adaptation. Current challenges in documenting adaptation and the role of indigenous knowledge in detection and attribution are described.
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New use of global warming potentials to compare cumulative and short-lived climate pollutants
Allen, Myles R.; Fuglestvedt, Jan S.; Shine, Keith P.; Reisinger, Andy; Pierrehumbert, Raymond T.; Forster, Piers M.
2016-08-01
Parties to the United Nations Framework Convention on Climate Change (UNFCCC) have requested guidance on common greenhouse gas metrics in accounting for Nationally determined contributions (NDCs) to emission reductions. Metric choice can affect the relative emphasis placed on reductions of `cumulative climate pollutants' such as carbon dioxide versus `short-lived climate pollutants' (SLCPs), including methane and black carbon. Here we show that the widely used 100-year global warming potential (GWP100) effectively measures the relative impact of both cumulative pollutants and SLCPs on realized warming 20-40 years after the time of emission. If the overall goal of climate policy is to limit peak warming, GWP100 therefore overstates the importance of current SLCP emissions unless stringent and immediate reductions of all climate pollutants result in temperatures nearing their peak soon after mid-century, which may be necessary to limit warming to ``well below 2 °C'' (ref. ). The GWP100 can be used to approximately equate a one-off pulse emission of a cumulative pollutant and an indefinitely sustained change in the rate of emission of an SLCP. The climate implications of traditional CO2-equivalent targets are ambiguous unless contributions from cumulative pollutants and SLCPs are specified separately.
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Probability for Weather and Climate
Smith, L. A.
2013-12-01
decision making versus advance science, are noted. It is argued that, just as no point forecast is complete without an estimate of its accuracy, no model-based probability forecast is complete without an estimate of its own irrelevance. The same nonlinearities that made the electronic computer so valuable links the selection and assimilation of observations, the formation of ensembles, the evolution of models, the casting of model simulations back into observables, and the presentation of this information to those who use it to take action or to advance science. Timescales of interest exceed the lifetime of a climate model and the career of a climate scientist, disarming the trichotomy that lead to swift advances in weather forecasting. Providing credible, informative climate services is a more difficult task. In this context, the value of comparing the forecasts of simulation models not only with each other but also with the performance of simple empirical models, whenever possible, is stressed. The credibility of meteorology is based on its ability to forecast and explain the weather. The credibility of climatology will always be based on flimsier stuff. Solid insights of climate science may be obscured if the severe limits on our ability to see the details of the future even probabilistically are not communicated clearly.
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The Copernicus Climate Change Service (C3S): Open Access to a Climate Data Store
Thepaut, Jean-Noel; Dee, Dick
2016-04-01
In November 2014, The European Centre for Medium-range Weather Forecasts (ECMWF) signed an agreement with the European Commission to deliver two of the Copernicus Earth Observation Programme Services on the Commission's behalf. The ECMWF delivered services - the Copernicus Climate Change Service (C3S) and Atmosphere Monitoring Service (CAMS) - will bring a consistent standard to how we monitor and predict atmospheric conditions and climate change. They will maximise the potential of past, current and future earth observations - ground, ocean, airborne, satellite - and analyse these to monitor and predict atmospheric conditions and in the future, climate change. With the wealth of free and open data that the services provide, they will help business users to assess the impact of their business decisions and make informed choices, delivering a more energy efficient and climate aware economy. These sound investment decisions now will not only stimulate growth in the short term, but reduce the impact of climate change on the economy and society in the future. C3S is in its proof of concept phase and through its Climate Data Store will provide • global and regional climate data reanalyses; • multi-model seasonal forecasts; • customisable visual data to enable examination of wide range of scenarios and model the impact of changes; • access to all the underlying data, including climate data records from various satellite and in-situ observations. In addition, C3S will provide key indicators on climate change drivers (such as carbon dioxide) and impacts (such as reducing glaciers). The aim of these indicators will be to support European adaptation and mitigation policies in a number of economic sectors. At the heart of the Service is the provision of open access to a one stop shop (the Climate Data Store) of climate data and modelling, analysing more than 20 Essential Climate Variables to build a global picture of our past, present and future climate and developing
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Climatic growing conditions of Jatropha curcas L.
Energy Technology Data Exchange (ETDEWEB)
Maes, W.H.; Achten, W.M.J.; Muys, B. [Katholieke Universiteit Leuven, Division Forest, Nature and Landscape, Celestijnenlaan 200 E Box 2411, BE-3001 Leuven (Belgium); Trabucco, A. [Katholieke Universiteit Leuven, Division Forest, Nature and Landscape, Celestijnenlaan 200 E Box 2411, BE-3001 Leuven (Belgium); International Water Management Institute (IWMI), P.O. Box 2075, Colombo (Sri Lanka)
2009-10-15
The massive investment in new jatropha plantations worldwide is not sufficiently based on a profound scientific knowledge of its ecology. In this article, we define the climatic conditions in its area of natural distribution by combining the locations of herbarium specimens with corresponding climatic information, and compare these conditions with those in 83 jatropha plantations worldwide. Most specimens (87%) were found in tropical savannah and monsoon climates (A{sub m}, A{sub w}) and in temperate climates without dry season and with hot summer (C{sub fa}), while very few were found in semi-arid (B{sub S}) and none in arid climates (B{sub W}). Ninety-five percent of the specimens grew in areas with a mean annual rainfall above 944 mm year{sup -1} and an average minimum temperature of the coldest month (T{sub min}) above 10.5 C. The mean annual temperature range was 19.3-27.2 C. The climatic conditions at the plantations were different from those of the natural distribution specimens for all studied climatic variables, except average maximum temperature in the warmest month. Roughly 40% of the plantations were situated in regions with a drier climate than in 95% of the area of the herbarium specimens, and 28% of the plantations were situated in areas with T{sub min} below 10.5 C. The observed precipitation preferences indicate that jatropha is not common in regions with arid and semi-arid climates. Plantations in arid and semi-arid areas hold the risk of low productivity or irrigation requirement. Plantations in regions with frost risk hold the risk of damage due to frost. (author)
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Müller, M. F.; Thompson, S. E.
2015-09-01
The prediction of flow duration curves (FDCs) in ungauged basins remains an important task for hydrologists given the practical relevance of FDCs for water management and infrastructure design. Predicting FDCs in ungauged basins typically requires spatial interpolation of statistical or model parameters. This task is complicated if climate becomes non-stationary, as the prediction challenge now also requires extrapolation through time. In this context, process-based models for FDCs that mechanistically link the streamflow distribution to climate and landscape factors may have an advantage over purely statistical methods to predict FDCs. This study compares a stochastic (process-based) and statistical method for FDC prediction in both stationary and non-stationary contexts, using Nepal as a case study. Under contemporary conditions, both models perform well in predicting FDCs, with Nash-Sutcliffe coefficients above 0.80 in 75 % of the tested catchments. The main drives of uncertainty differ between the models: parameter interpolation was the main source of error for the statistical model, while violations of the assumptions of the process-based model represented the main source of its error. The process-based approach performed better than the statistical approach in numerical simulations with non-stationary climate drivers. The predictions of the statistical method under non-stationary rainfall conditions were poor if (i) local runoff coefficients were not accurately determined from the gauge network, or (ii) streamflow variability was strongly affected by changes in rainfall. A Monte Carlo analysis shows that the streamflow regimes in catchments characterized by a strong wet-season runoff and a rapid, strongly non-linear hydrologic response are particularly sensitive to changes in rainfall statistics. In these cases, process-based prediction approaches are strongly favored over statistical models.
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Bassett, Richard; Cai, Xiaoming; Chapman, Lee; Heaviside, Clare; Thornes, John E.
2017-10-01
Weather and climate networks traditionally follow rigorous siting guidelines, with individual stations located away from frost hollows, trees or urban areas. However, the diverse nature of the UK landscape suggests that the feasibility of siting stations that are truly representative of regional climate and free from distorting local effects is increasingly difficult. Whilst the urban heat island is a well-studied phenomenon and usually accounted for, the effect of warm urban air advected downwind is rarely considered, particularly at rural stations adjacent to urban areas. Until recently, urban heat advection (UHA) was viewed as an urban boundary-layer process through the formation of an urban plume that rises above the surface as it is advected. However, these dynamic UHA effects are shown to also have an impact on surface observations. Results show a significant difference in temperatures anomalies (p careful interpretation of long-term temperature data taken near small urban areas.
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Four Sectors of Industry in USA and Europe compared. Business Strategies and Climate Change
International Nuclear Information System (INIS)
Van der Woerd, F.; De Wit, K.; Vellinga, P.; Kolk, A.; Levy, D.
2000-01-01
Private companies will play a critical role in implementation of successful climate policies. However, until now little is known about triggers to develop corporate climate strategies. In a USA-Europe co-operation, researchers have investigated emerging climate strategies in the oil, automobile, chemical and bank and insurance industries. A focal question was whether strategies of EU based corporations differ systematically from USA based corporations. Results show rather sectorial specific developments. In most sectors, i.e. oil, automobile and banks, European corporations generally tend to have more advanced climate policies than their USA counterparts, but this does not apply to chemical companies. In the automobile industry, USA and Europe show convergent strategies. In the other sectors, convergence is not clearly visible
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Steen, Valerie; Sofaer, Helen R; Skagen, Susan K; Ray, Andrea J; Noon, Barry R
2017-11-01
Species distribution models (SDMs) are commonly used to assess potential climate change impacts on biodiversity, but several critical methodological decisions are often made arbitrarily. We compare variability arising from these decisions to the uncertainty in future climate change itself. We also test whether certain choices offer improved skill for extrapolating to a changed climate and whether internal cross-validation skill indicates extrapolative skill. We compared projected vulnerability for 29 wetland-dependent bird species breeding in the climatically dynamic Prairie Pothole Region, USA. For each species we built 1,080 SDMs to represent a unique combination of: future climate, class of climate covariates, collinearity level, and thresholding procedure. We examined the variation in projected vulnerability attributed to each uncertainty source. To assess extrapolation skill under a changed climate, we compared model predictions with observations from historic drought years. Uncertainty in projected vulnerability was substantial, and the largest source was that of future climate change. Large uncertainty was also attributed to climate covariate class with hydrological covariates projecting half the range loss of bioclimatic covariates or other summaries of temperature and precipitation. We found that choices based on performance in cross-validation improved skill in extrapolation. Qualitative rankings were also highly uncertain. Given uncertainty in projected vulnerability and resulting uncertainty in rankings used for conservation prioritization, a number of considerations appear critical for using bioclimatic SDMs to inform climate change mitigation strategies. Our results emphasize explicitly selecting climate summaries that most closely represent processes likely to underlie ecological response to climate change. For example, hydrological covariates projected substantially reduced vulnerability, highlighting the importance of considering whether water
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Hall Sharon K; Nicklas Theresa A; Cross Matthew B; Papaioannou Maria A; Power Thomas G; Hughes Sheryl O; Shewchuk Richard M
2011-01-01
Abstract Background A number of studies conducted with ethnically diverse, low-income samples have found that parents with indulgent feeding styles had children with a higher weight status. Indulgent parents are those who are responsive to their child's emotional states but have problems setting appropriate boundaries with their child. Because the processes through which styles impact child weight are poorly understood, the aim of this study was to observe differences in the emotional climate...
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Estimation of the global climate effect of brown carbon
Zhang, A.; Wang, Y.; Zhang, Y.; Weber, R. J.; Song, Y.
2017-12-01
Carbonaceous aerosols significantly affect global radiative forcing and climate through absorption and scattering of sunlight. Black carbon (BC) and brown carbon (BrC) are light-absorbing carbonaceous aerosols. The global distribution and climate effect of BrC is uncertain. A recent study suggests that BrC absorption is comparable to BC in the upper troposphere over biomass burning region and that the resulting heating tends to stabilize the atmosphere. Yet current climate models do not include proper treatments of BrC. In this study, we derived a BrC global biomass burning emission inventory from Global Fire Emissions Database 4 (GFED4) and developed a BrC module in the Community Atmosphere Model version 5 (CAM5) of Community Earth System Model (CESM) model. The model simulations compared well to BrC observations of the Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) and Deep Convective Clouds and Chemistry Project (DC-3) campaigns and includes BrC bleaching. Model results suggested that BrC in the upper troposphere due to convective transport is as important an absorber as BC globally. Upper tropospheric BrC radiative forcing is particularly significant over the tropics, affecting the atmosphere stability and Hadley circulation.
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An intercomparison of regional climate model data for hydrological impact studies in Denmark
DEFF Research Database (Denmark)
Van Roosmalen, Lieke Petronella G; Christensen, Jens Hesselbjerg; Butts, Michael
2010-01-01
The use of high-resolution regional climate models (RCM) to examine the hydrological impacts of climate change has grown significantly in recent years due to the improved representation of the local climate. However, the application is not straightforward because most RCMs are subject to consider......The use of high-resolution regional climate models (RCM) to examine the hydrological impacts of climate change has grown significantly in recent years due to the improved representation of the local climate. However, the application is not straightforward because most RCMs are subject...... to considerable systematic errors. In this study, projected climate change data from the RCM HIRHAM4 are used to generate climate scenario time series of precipitation, temperature, and reference evapotranspiration for the period 2071-2100 for hydrological impact assessments in Denmark. RCM output for the present......-day period (1961-1990) are compared to an observational data set, with precipitation corrected for undercatch and wetting losses, to quantify systematic model errors. A delta change method is applied to cope with these biases. A question arises as to how variable the climate change signals are...
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Singh, G.; McElroy, C. T.; Vaziri, Z.; Barton, D.; Blair, G.; Grandmont, F. J.
2017-12-01
The fifth assessment report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) states that the warming of zonal mean surface temperature at higher latitudes exceeds the global average temperature change. This poses a great problem as the warming leads to the thawing of the permafrost in the Arctic region that acts as an envelope to trap greenhouse gases such as carbon dioxide and methane. Therefore, there is an urgent need to develop scientific instruments that can be flown in space over the Arctic to provide atmospheric information to quantify the evolution and transport of these gases. The Laboratory for Atmospheric Remote Sounding from Space (LARSS) at York University is developing an imaging Fourier transform spectrometer (IFTS) for climate observations by atmospheric sounding. The spectrometer has two individual channels, one centred at 1650 nm to measure the atmospheric column of carbon dioxide and methane, and another centred at 762 nm to measure the temperature-pressure profile by making measurements of the O2A band. A Commercial-Off-The-Shelf (COTS) modulator has been purchased from ABB Inc. of Quebec City. Interferometers are widely used in many scientific laboratories to measure concentrations of different constituents in a given sample. The performance of these instruments is highly dependent on environmental effects and various properties of the input beam such as coherence, polarity, etc. Thus, the use of such instruments to measure atmospheric concentration is complicated and challenging. The immediate goal of this project is to develop an IFTS system which can measure backscattered radiation in a laboratory environment and develop design elements that will make it operable in the space environment. Progress on the project and information concerning some of the issues listed above will be discussed. The developments which flow from this research project will support efforts by Environment and Climate Change Canada, the Canadian Space
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Merlis, Timothy M.; Held, Isaac M.; Stenchikov, Georgiy L.; Zeng, Fanrong; Horowitz, Larry W.
2014-01-01
Coupled climate model simulations of volcanic eruptions and abrupt changes in CO2 concentration are compared in multiple realizations of the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.1 (GFDL CM2.1). The change in global-mean surface temperature (GMST) is analyzed to determine whether a fast component of the climate sensitivity of relevance to the transient climate response (TCR; defined with the 1%yr-1 CO2-increase scenario) can be estimated from shorter-time-scale climate changes. The fast component of the climate sensitivity estimated from the response of the climate model to volcanic forcing is similar to that of the simulations forced by abrupt CO2 changes but is 5%-15% smaller than the TCR. In addition, the partition between the top-of-atmosphere radiative restoring and ocean heat uptake is similar across radiative forcing agents. The possible asymmetry between warming and cooling climate perturbations, which may affect the utility of volcanic eruptions for estimating the TCR, is assessed by comparing simulations of abrupt CO2 doubling to abrupt CO2 halving. There is slightly less (~5%) GMST change in 0.5 × CO2 simulations than in 2 × CO2 simulations on the short (~10 yr) time scales relevant to the fast component of the volcanic signal. However, inferring the TCR from volcanic eruptions is more sensitive to uncertainties from internal climate variability and the estimation procedure. The response of the GMST to volcanic eruptions is similar in GFDL CM2.1 and GFDL Climate Model, version 3 (CM3), even though the latter has a higher TCR associated with a multidecadal time scale in its response. This is consistent with the expectation that the fast component of the climate sensitivity inferred from volcanic eruptions is a lower bound for the TCR.
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Merlis, Timothy M.
2014-10-01
Coupled climate model simulations of volcanic eruptions and abrupt changes in CO2 concentration are compared in multiple realizations of the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.1 (GFDL CM2.1). The change in global-mean surface temperature (GMST) is analyzed to determine whether a fast component of the climate sensitivity of relevance to the transient climate response (TCR; defined with the 1%yr-1 CO2-increase scenario) can be estimated from shorter-time-scale climate changes. The fast component of the climate sensitivity estimated from the response of the climate model to volcanic forcing is similar to that of the simulations forced by abrupt CO2 changes but is 5%-15% smaller than the TCR. In addition, the partition between the top-of-atmosphere radiative restoring and ocean heat uptake is similar across radiative forcing agents. The possible asymmetry between warming and cooling climate perturbations, which may affect the utility of volcanic eruptions for estimating the TCR, is assessed by comparing simulations of abrupt CO2 doubling to abrupt CO2 halving. There is slightly less (~5%) GMST change in 0.5 × CO2 simulations than in 2 × CO2 simulations on the short (~10 yr) time scales relevant to the fast component of the volcanic signal. However, inferring the TCR from volcanic eruptions is more sensitive to uncertainties from internal climate variability and the estimation procedure. The response of the GMST to volcanic eruptions is similar in GFDL CM2.1 and GFDL Climate Model, version 3 (CM3), even though the latter has a higher TCR associated with a multidecadal time scale in its response. This is consistent with the expectation that the fast component of the climate sensitivity inferred from volcanic eruptions is a lower bound for the TCR.
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Climate News Across Media Platforms
DEFF Research Database (Denmark)
Eskjær, Mikkel Fugl
2015-01-01
In a changing media landscape marked by technological, institutional and cultural convergence, comparative and cross-media content analysis represents a valuable analytical tool in mapping the diverse channels of climate change communication. This paper presents a comparative study of climate...... quantitative and qualitative content analysis the paper documents and explores the extent and character of climate change news across different media platforms. The study aims at contributing to the on-going assessment of how news media are addressing climate change at a time when old and new media...... change news on five different media platforms: newspapers, television, radio, web-news and mobile news. It investigates the themes and actors represented in public climate change communication as well as the diverse possibilities of participating in public debates and information sharing. By combining...
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Climate change and climate policy; Klimaendringer og klimapolitikk
Energy Technology Data Exchange (ETDEWEB)
Alfsen, Knut H.; Kolshus, Hans H.; Torvanger, Asbjoern
2000-08-01
The climate issue is a great political and scientific challenge for several reasons: (1) There are many uncertain aspects of the climate problem, such as future emission of climate gases, the response of the climate system upon these gases, and the effects of climate changes. (2) It is probable, however, that anthropogenic emission of climate gases, deforestation etc. will cause noticeable climate changes in the future. This might be observed as increased frequency of extreme weather situations. This appears to be a greater threat than a gradual increase of temperature and precipitation. (3) Since the climate system is large and react only relatively slowly on changes in for instance the emission of climate gases, the climate problem can only be solved by means of long-term measures. (4) The climate changes may be irreversible. A rational short-term strategy is to ensure maximum flexibility, which can be done by ''slowing down'' (curtailing emissions) and by avoiding irreversible actions as much as possible. The long-term challenge is to develop an economically responsible alternative to the present fossil-based energy system that permits carbon-efficient technologies to compete on price with coal and unconventional oil and gas. Norway is in a special position by being a large exporter of fossil fuel and at the same time wanting to appear responsible in environmental matters. This combination may incur considerable expenses upon Norway and it is therefore important that environmental commitments like the Kyoto agreement can be honoured to the lowest possible cost. The costs can be minimized by: (1) minimizing the measure costs in Norway, (2) working to make the international quota price as low as possible, and (3) reducing the loss of petroleum income as much as possible. This report describes the earth's climate history, the forces behind climatic changes and what the prospects for the future look like. It also reviews what is being done
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Guo, Jianping; Zhao, Junfang; Xu, Yanhong; Chu, Zheng; Mu, Jia; Zhao, Qian
Quantitatively evaluating the effects of adjusting cropping systems on the utilization efficiency of climatic resources under climate change is an important task for assessing food security in China. To understand these effects, we used daily climate variables obtained from the regional climate model RegCM3 from 1981 to 2100 under the A1B scenario and crop observations from 53 agro-meteorological experimental stations from 1981 to 2010 in Northeast China. Three one-grade zones of cropping systems were divided by heat, water, topography and crop-type, including the semi-arid areas of the northeast and northwest (III), the one crop area of warm-cool plants in semi-humid plain or hilly regions of the northeast (IV), and the two crop area in irrigated farmland in the Huanghuaihai Plain (VI). An agro-ecological zone model was used to calculate climatic potential productivities. The effects of adjusting cropping systems on climate resource utilization in Northeast China under the A1B scenario were assessed. The results indicated that from 1981 to 2100 in the III, IV and VI areas, the planting boundaries of different cropping systems in Northeast China obviously shifted toward the north and the east based on comprehensively considering the heat and precipitation resources. However, due to high temperature stress, the climatic potential productivity of spring maize was reduced in the future. Therefore, adjusting the cropping system is an effective way to improve the climatic potential productivity and climate resource utilization. Replacing the one crop in one year model (spring maize) by the two crops in one year model (winter wheat and summer maize) significantly increased the total climatic potential productivity and average utilization efficiencies. During the periods of 2011-2040, 2041-2070 and 2071-2100, the average total climatic potential productivities of winter wheat and summer maize increased by 9.36%, 11.88% and 12.13% compared to that of spring maize
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Climate change and its effect on world food
International Nuclear Information System (INIS)
Roberts, W.O.
1974-01-01
In February of 1972 earth-orbiting artificial satellites revealed the existence of a greatly increased area of the snow and ice cover of the north polar cap as compared to all previous years of space age observations. Some scientists believe that this may have presaged the onset of the dramatic climate anomalies of 1972 that brought far-reaching adversities to the world's peoples. Moreover, there is mounting evidence that the bad climate of 1972 may be the forerunner of a long series of less favorable agricultural crop years that lie ahead for most world societies. Thus widespread food shortages threaten just at the same time that world populations are growing to new highs. Indeed, less favorable climate may be the new global norm. The Earth may have entered a new 'little ice age'. Perhaps this future period will not be so extreme as that around 1700 AD, but it seems likely, at least, to be a cooler period resembling the hemispheric climatic regimes of the period from 1880-1920. (author)
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International Nuclear Information System (INIS)
Piazza, Marie; Page, Christian; Sanchez-Gomez, Emilia; Terray, Laurent; Deque, Michel
2013-01-01
Mountain regions are highly vulnerable to climate change and are likely to be among the areas most impacted by global warming. But climate projections for the end of the 21. century are developed with general circulation models of climate, which do not present a sufficient horizontal resolution to accurately evaluate the impacts of warming on these regions. Several techniques are then used to perform a spatial down-scaling (on the order of 10 km). There are two categories of down-scaling methods: dynamical methods that require significant computational resources for the achievement of regional climate simulations at high resolution, and statistical methods that require few resources but an observation dataset over a long period and of good quality. In this study, climate simulations of the global atmospheric model ARPEGE projections over France are down-scaled according to a dynamical method, performed with the ALADIN-Climate regional model, and a statistical method performed with the software DSClim developed at CERFACS. The two down-scaling methods are presented and the results on the climate of the French mountains are evaluated for the current climate. Both methods give similar results for average snowfall. However extreme events of total precipitation (droughts, intense precipitation events) are largely underestimated by the statistical method. Then, the results of both methods are compared for two future climate projections, according to the greenhouse gas emissions scenario A1B of IPCC. The two methods agree on fewer frost days, a significant decrease in the amounts of solid precipitation and an average increase in the percentage of dry days of more than 10%. The results obtained on Corsica are more heterogeneous but they are questionable because the reduced spatial domain is probably not very relevant regarding statistical sampling. (authors)
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Spatial scale separation in regional climate modelling
Energy Technology Data Exchange (ETDEWEB)
Feser, F.
2005-07-01
In this thesis the concept of scale separation is introduced as a tool for first improving regional climate model simulations and, secondly, to explicitly detect and describe the added value obtained by regional modelling. The basic idea behind this is that global and regional climate models have their best performance at different spatial scales. Therefore the regional model should not alter the global model's results at large scales. The for this purpose designed concept of nudging of large scales controls the large scales within the regional model domain and keeps them close to the global forcing model whereby the regional scales are left unchanged. For ensemble simulations nudging of large scales strongly reduces the divergence of the different simulations compared to the standard approach ensemble that occasionally shows large differences for the individual realisations. For climate hindcasts this method leads to results which are on average closer to observed states than the standard approach. Also the analysis of the regional climate model simulation can be improved by separating the results into different spatial domains. This was done by developing and applying digital filters that perform the scale separation effectively without great computational effort. The separation of the results into different spatial scales simplifies model validation and process studies. The search for 'added value' can be conducted on the spatial scales the regional climate model was designed for giving clearer results than by analysing unfiltered meteorological fields. To examine the skill of the different simulations pattern correlation coefficients were calculated between the global reanalyses, the regional climate model simulation and, as a reference, of an operational regional weather analysis. The regional climate model simulation driven with large-scale constraints achieved a high increase in similarity to the operational analyses for medium-scale 2 meter
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Quantitative approaches in climate change ecology
DEFF Research Database (Denmark)
Brown, Christopher J.; Schoeman, David S.; Sydeman, William J.
2011-01-01
Contemporary impacts of anthropogenic climate change on ecosystems are increasingly being recognized. Documenting the extent of these impacts requires quantitative tools for analyses of ecological observations to distinguish climate impacts in noisy data and to understand interactions between...... climate variability and other drivers of change. To assist the development of reliable statistical approaches, we review the marine climate change literature and provide suggestions for quantitative approaches in climate change ecology. We compiled 267 peer‐reviewed articles that examined relationships...
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ARM Cloud Radar Simulator Package for Global Climate Models Value-Added Product
Energy Technology Data Exchange (ETDEWEB)
Zhang, Yuying [North Carolina State Univ., Raleigh, NC (United States); Xie, Shaocheng [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2017-05-01
It has been challenging to directly compare U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility ground-based cloud radar measurements with climate model output because of limitations or features of the observing processes and the spatial gap between model and the single-point measurements. To facilitate the use of ARM radar data in numerical models, an ARM cloud radar simulator was developed to converts model data into pseudo-ARM cloud radar observations that mimic the instrument view of a narrow atmospheric column (as compared to a large global climate model [GCM] grid-cell), thus allowing meaningful comparison between model output and ARM cloud observations. The ARM cloud radar simulator value-added product (VAP) was developed based on the CloudSat simulator contained in the community satellite simulator package, the Cloud Feedback Model Intercomparison Project (CFMIP) Observation Simulator Package (COSP) (Bodas-Salcedo et al., 2011), which has been widely used in climate model evaluation with satellite data (Klein et al., 2013, Zhang et al., 2010). The essential part of the CloudSat simulator is the QuickBeam radar simulator that is used to produce CloudSat-like radar reflectivity, but is capable of simulating reflectivity for other radars (Marchand et al., 2009; Haynes et al., 2007). Adapting QuickBeam to the ARM cloud radar simulator within COSP required two primary changes: one was to set the frequency to 35 GHz for the ARM Ka-band cloud radar, as opposed to 94 GHz used for the CloudSat W-band radar, and the second was to invert the view from the ground to space so as to attenuate the beam correctly. In addition, the ARM cloud radar simulator uses a finer vertical resolution (100 m compared to 500 m for CloudSat) to resolve the more detailed structure of clouds captured by the ARM radars. The ARM simulator has been developed following the COSP workflow (Figure 1) and using the capabilities available in COSP
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The impacts of past climate change on terrestrial and aquatic ecosystems
International Nuclear Information System (INIS)
Bradshaw, R.H.W.; Anderson, N.J.
2001-01-01
The last two million years of global history have been dominated by the impacts of rapid climate change. This influence is not immediately obvious to most biologists whose observations rarely extend beyond a period of a few years, but becomes apparent when interpreting long-term data sets whether they be population studies or palaeoecological data. It is appropriate therefore to consider how terrestrial and aquatic ecosystems have responded to climate change during the Quaternary when speculating about response to future climatic developments. In this chapter we discuss and illustrate the complex interactions between climate and anthropogenic influence on terrestrial and aquatic ecosystems during the Holocene. Climate influences ecosystems both directly (e.g. physiological responses or lake thermal stratification) and indirectly (e.g. via fire frequency or catchment hydrology). Lake sediments can be used to study both past climatic change directly and the effects of past climatic variability. In this chapter we present summary examples of the influence of past climate change on terrestrial and aquatic ecosystems as well showing how lake sediment records can provide proxy records of past climate change. The geological record from the last 18 000 years documents large changes in terrestrial and aquatic ecosystems that are primarily driven by climatic change, but are modified by internal ecosystem processes. These changes are comparable in magnitude and rapidity to those predicted for the near future. Species at their distributional limits are particularly sensitive to climate change and contractions of range can be sudden in response to extreme climatic events such as the storm of December 1999 that damaged Picea trees far more than tree species that lay within their natural range limits. Palaeoecological records provide compelling evidence for direct climate forcing of aquatic and terrestrial ecosystems but importantly also permit comparative analyses of impacts
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Pérez Lancellotti, Gino; Ziede Bize, Marcela
2017-10-01
This article proposes to make a comparative bioclimatic analysis from 1990 to 2014 of the main square of Antofagasta, a coastal desert city in Chile, which was remodelled in 1995, and shows how the redesigning of green areas affects the microclimatic conditions and thermal comfort of the urban space. Ex ante measurements dating 1990 were compared with ex post results from 2014. Data were obtained in both cases in the month of September at different times of a day and in different climate conditions. The variables studied were: land surface temperature, humidity, wind speed, amount of light and square use frequency inside the square and in surrounding streets. The temperatures are not statistically different during the years 1990 and 2014 for the city of Antofagasta. The main layout of the square has not changed, and inside the square it is similar for both periods, but new species were introduced and bigger trees with shadow projection were cut down. The square had a micro-climate role in 2014 as well as in 1990. The highest frequency zone with an important surface lost it is comfort thermic condition with an increase of 1°C. Other smaller zones with less relevance for users gained in cooling with a 0.5°C reduction. The new design has been detrimental to the intensity of its micro climatic regulatory function affecting the thermic comfort of the square’s internal spaces, especially those formerly protected by shadow, which mitigate a high solar radiation. The study results suggest that bio-climatic analysis of public open spaces is a key component for the design of future projects as a heat mitigating tool in the context of climate change. Research question is: How does the redesign of the square impact a cool urban island and the thermic comfort of users? Significant differences between data in situ collected in 1990 and 2014. Thermal comfort was negatively affected by the redesign in the square. The square is still a cool island but with less strength.
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Directory of Open Access Journals (Sweden)
P. A. Troch
2013-06-01
Full Text Available Budyko (1974 postulated that long-term catchment water balance is controlled to first order by the available water and energy. This leads to the interesting question of how do landscape characteristics (soils, geology, vegetation and climate properties (precipitation, potential evaporation, number of wet and dry days interact at the catchment scale to produce such a simple and predictable outcome of hydrological partitioning? Here we use a physically-based hydrologic model separately parameterized in 12 US catchments across a climate gradient to decouple the impact of climate and landscape properties to gain insight into the role of climate-vegetation-soil interactions in long-term hydrologic partitioning. The 12 catchment models (with different paramterizations are subjected to the 12 different climate forcings, resulting in 144 10 yr model simulations. The results are analyzed per catchment (one catchment model subjected to 12 climates and per climate (one climate filtered by 12 different model parameterization, and compared to water balance predictions based on Budyko's hypothesis (E/P = ϕ (Ep/P; E: evaporation, P: precipitation, Ep: potential evaporation. We find significant anti-correlation between average deviations of the evaporation index (E/P computed per catchment vs. per climate, compared to that predicted by Budyko. Catchments that on average produce more E/P have developed in climates that on average produce less E/P, when compared to Budyko's prediction. Water and energy seasonality could not explain these observations, confirming previous results reported by Potter et al. (2005. Next, we analyze which model (i.e., landscape filter characteristics explain the catchment's tendency to produce more or less E/P. We find that the time scale that controls subsurface storage release explains the observed trend. This time scale combines several geomorphologic and hydraulic soil properties. Catchments with relatively longer
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Possible climate change over Eurasia under different emission scenarios
Sokolov, A. P.; Monier, E.; Gao, X.
2012-12-01
In an attempt to evaluate possible climate change over EURASIA, we analyze results of six AMIP type simulations with CAM version 3 (CAM3) at 2x2.5 degree resolution. CAM3 is driven by time series of sea surface temperatures (SSTs) and sea ice obtained by running the MIT IGSM2.3, which consists of a 3D ocean GCM coupled to a zonally-averaged atmospheric climate-chemistry model. In addition to changes in SSTs, CAM3 is forced by changes in greenhouse gases and ozone concentrations, sulfate aerosol forcing and black carbon loading calculated by the IGSM2.3. An essential feature of the IGSM is the possibility to vary its climate sensitivity (using a cloud adjustment technique) and the strength of the aerosol forcing. For consistency, new modules were developed in CAM3 to modify its climate sensitivity and aerosol forcing to match those used in the simulations with the IGSM2.3. The simulations presented in this paper were carried out for two emission scenarios, a "Business as usual" scenario and a 660 ppm of CO2-EQ stabilization, which are similar to the RCP8.5 and RCP4.5 scenarios, respectively. Values of climate sensitivity used in the simulations within the IGSM-CAM framework are median and the bounds of the 90% probability interval of the probability distribution obtained by comparing the 20th century climate simulated by different versions of the IGSM with observations. The associated strength of the aerosol forcing was chosen to ensure a good agreement with the observed climate change over the 20th century. Because the concentration of sulfate aerosol significantly decreases over the 21st century in both emissions scenarios, climate changes obtained in these simulations provide a good approximation for the median, and the 5th and 95th percentiles of the probability distribution of 21st century climate change.
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Gerald E. Rehfeldt; Barry C. Jaquish; Cuauhtemoc Saenz-Romero; Dennis G. Joyce; Laura P. Leites; J. Bradley St Clair; Javier Lopez-Upton
2014-01-01
Impacts of climate change on the climatic niche of the sub-specific varieties of Pinus ponderosa and Pseudotsuga menziesii and on the adaptedness of their populations are considered from the viewpoint of reforestation. In using climate projections from an ensemble of 17 general circulation models targeting the decade surrounding 2060, our analyses suggest that a...
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Linking models of human behaviour and climate alters projected climate change
Beckage, Brian; Gross, Louis J.; Lacasse, Katherine; Carr, Eric; Metcalf, Sara S.; Winter, Jonathan M.; Howe, Peter D.; Fefferman, Nina; Franck, Travis; Zia, Asim; Kinzig, Ann; Hoffman, Forrest M.
2018-01-01
Although not considered in climate models, perceived risk stemming from extreme climate events may induce behavioural changes that alter greenhouse gas emissions. Here, we link the C-ROADS climate model to a social model of behavioural change to examine how interactions between perceived risk and emissions behaviour influence projected climate change. Our coupled climate and social model resulted in a global temperature change ranging from 3.4-6.2 °C by 2100 compared with 4.9 °C for the C-ROADS model alone, and led to behavioural uncertainty that was of a similar magnitude to physical uncertainty (2.8 °C versus 3.5 °C). Model components with the largest influence on temperature were the functional form of response to extreme events, interaction of perceived behavioural control with perceived social norms, and behaviours leading to sustained emissions reductions. Our results suggest that policies emphasizing the appropriate attribution of extreme events to climate change and infrastructural mitigation may reduce climate change the most.
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International Nuclear Information System (INIS)
Willett, Katharine M; Thorne, Peter W; Jones, Philip D; Gillett, Nathan P
2010-01-01
Observed changes in the HadCRUH global land surface specific humidity and CRUTEM3 surface temperature from 1973 to 1999 are compared to CMIP3 archive climate model simulations with 20th Century forcings. Observed humidity increases are proportionately largest in the Northern Hemisphere, especially in winter. At the largest spatio-temporal scales moistening is close to the Clausius-Clapeyron scaling of the saturated specific humidity (∼7% K -1 ). At smaller scales in water-limited regions, changes in specific humidity are strongly inversely correlated with total changes in temperature. Conversely, in some regions increases are faster than implied by the Clausius-Clapeyron relation. The range of climate model specific humidity seasonal climatology and variance encompasses the observations. The models also reproduce the magnitude of observed interannual variance over all large regions. Observed and modelled trends and temperature-humidity relationships are comparable except for the extratropical Southern Hemisphere where observations exhibit no trend but models exhibit moistening. This may arise from: long-term biases remaining in the observations; the relative paucity of observational coverage; or common model errors. The overall degree of consistency of anthropogenically forced models with the observations is further evidence for anthropogenic influence on the climate of the late 20th century.
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Situating Urgenda v the Netherlands within comparative climate change litigation
Roy, Suryapratim; Woerdman, Edwin
2016-01-01
This article situates the judgement of The Hague District Court in Urgenda Foundation v the Kingdom of the Netherlands within the life of global climate change litigation. To do so, the paper concentrates on the legal particulars of Dutch law, elements of ‘diffused’ jurisprudence from other
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Climate change with Korea as the center
International Nuclear Information System (INIS)
Kim, Yeon Ok
1998-04-01
This book deals with climate change with Korea as the center, which is divided into ten chapters. It explain climate change by human life. The contents of this book are climate change, climate before human period, great ice age of prehistoric period, prehistoric times of last glacial era, climate change in historical era, change during observation time for 100 years, warming period, global environment period, the cause of climate change and climate and human. It has reference and an index.
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Andriuzzi, W S; Adams, B J; Barrett, J E; Virginia, R A; Wall, D H
2018-02-01
Long-term observations of ecological communities are necessary for generating and testing predictions of ecosystem responses to climate change. We investigated temporal trends and spatial patterns of soil fauna along similar environmental gradients in three sites of the McMurdo Dry Valleys, Antarctica, spanning two distinct climatic phases: a decadal cooling trend from the early 1990s through the austral summer of February 2001, followed by a shift to the current trend of warming summers and more frequent discrete warming events. After February 2001, we observed a decline in the dominant species (the nematode Scottnema lindsayae) and increased abundance and expanded distribution of less common taxa (rotifers, tardigrades, and other nematode species). Such diverging responses have resulted in slightly greater evenness and spatial homogeneity of taxa. However, total abundance of soil fauna appears to be declining, as positive trends of the less common species so far have not compensated for the declining numbers of the dominant species. Interannual variation in the proportion of juveniles in the dominant species was consistent across sites, whereas trends in abundance varied more. Structural equation modeling supports the hypothesis that the observed biological trends arose from dissimilar responses by dominant and less common species to pulses of water availability resulting from enhanced ice melt. No direct effects of mean summer temperature were found, but there is evidence of indirect effects via its weak but significant positive relationship with soil moisture. Our findings show that combining an understanding of species responses to environmental change with long-term observations in the field can provide a context for validating and refining predictions of ecological trends in the abundance and diversity of soil fauna. © 2018 by the Ecological Society of America.
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International Nuclear Information System (INIS)
Shine, Keith P.; Fuglestvedt, Jan S.; Stuber, Nicola
2003-01-01
The global warming potential (GWP) is used within the Kyoto Protocol to the United Nations Framework Convention on Climate Change as a metric for weighting the climate impact of emissions of different greenhouse gases. The GQP has been subject at many criticism because of its formulation but nevertheless it has retained some favour because of the simplicity of this design and application and its transparency compared to proposed alternatives. Here a new metric which we call the Global Temperature Change Potential (GTP) is proposed which is based on a simple analytical climate model that represents the temperature change as a given time due to either a pulse emission of a gas or a sustained emission change relative to a similar emission change of carbon dioxide. The GTP for a pulse emission illustrates that the GWP does not represent well the relative temperature response; however, the GWP is shown to be very close to the GTP for a sustained emission change for time horizons of 100 years or more. The new metric retains the advantage of the GWP in terms of transparency and the relatively small number of input parameters required for calculation. However, it has an enhanced relevance as it is further down the cause-effect chain of the impacts of greenhouse gases emissions. The GTP for a sustained emission appears to be robust to a number of uncertainties and simplifications in its derivation and may be an attractive alternative to the GWP. (Author)
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Detecting anthropogenic climate change with an optimal fingerprint method
International Nuclear Information System (INIS)
Hegerl, G.C.; Storch, H. von; Hasselmann, K.; Santer, B.D.; Jones, P.D.
1994-01-01
We propose a general fingerprint strategy to detect anthropogenic climate change and present application to near surface temperature trends. An expected time-space-variable pattern of anthropogenic climate change (the 'signal') is identified through application of an appropriate optimally matched space-time filter (the 'fingerprint') to the observations. The signal and the fingerprint are represented in a space with sufficient observed and simulated data. The signal pattern is derived from a model-generated prediction of anthropogenic climate change. Application of the fingerprint filter to the data yields a scalar detection variable. The statistically optimal fingerprint is obtained by weighting the model-predicted pattern towards low-noise directions. A combination of model output and observations is used to estimate the noise characteristics of the detection variable, arising from the natural variability of climate in the absence of external forcing. We test then the null hypothesis that the observed climate change is part of natural climate variability. We conclude that a statistically significant externally induced warming has been observed, with the caveat of a possibly inadequate estimate of the internal climate variability. In order to attribute this warming uniquely to anthropogenic greenhouse gas forcing, more information on the climate's response to other forcing mechanisms (e.g. changes in solar radiation, volcanic or anthropogenic aerosols) and their interaction is needed. (orig./KW)
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Contribution of human and climate change impacts to changes in streamflow of Canada.
Tan, Xuezhi; Gan, Thian Yew
2015-12-04
Climate change exerts great influence on streamflow by changing precipitation, temperature, snowpack and potential evapotranspiration (PET), while human activities in a watershed can directly alter the runoff production and indirectly through affecting climatic variables. However, to separate contribution of anthropogenic and natural drivers to observed changes in streamflow is non-trivial. Here we estimated the direct influence of human activities and climate change effect to changes of the mean annual streamflow (MAS) of 96 Canadian watersheds based on the elasticity of streamflow in relation to precipitation, PET and human impacts such as land use and cover change. Elasticities of streamflow for each watershed are analytically derived using the Budyko Framework. We found that climate change generally caused an increase in MAS, while human impacts generally a decrease in MAS and such impact tends to become more severe with time, even though there are exceptions. Higher proportions of human contribution, compared to that of climate change contribution, resulted in generally decreased streamflow of Canada observed in recent decades. Furthermore, if without contributions from retreating glaciers to streamflow, human impact would have resulted in a more severe decrease in Canadian streamflow.
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Asplund, Therese
2016-07-01
While previous research into understandings of climate change has usually examined general public perceptions, this study offers an audience-specific departure point. This article analyses how Swedish farmers perceive climate change and how they jointly shape their understandings. The agricultural sector is of special interest because it both contributes to and is directly affected by climate change. Through focus group discussions with Swedish farmers, this study finds that (1) farmers relate to and understand climate change through their own experiences, (2) climate change is understood either as a natural process subject to little or no human influence or as anthropogenic and (3) various communication tools contribute to the formation of natural and anthropogenic climate change frames. The article ends by discussing frame resonance and frame clash in public understanding of climate change and by comparing potential similarities and differences in how various segments of the public make sense of climate change. © The Author(s) 2014.
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Energy Technology Data Exchange (ETDEWEB)
Meineri, Eric
2012-02-15
Aims and background: Species range shift is among the most well-documented responses to climate change. As a result, a growing number of studies model species climatic niches to predict how species ranges may displace in space and time (SDM studies). These studies are criticised because they do not include reproduction in their predictions. Other studies use empirical data to assess climatic control on reproductive life-stages. However, the climatic niche of reproductive life-stages may not determine the climatic niche of species, limiting the ability of both types of studies to assess the effect of climate change. In this synthesis, I compare the results of a SDM study (Paper I) with the results of two empirical studies focussing on flowering performance (Paper II) and seedling emergence (Paper III). The research focuses on the leading and rear altitudinal edges of lowland and alpine species ranges, respectively, as those are the two delimiting fronts that are expected to be specifically vulnerable to climate change. Reproduction response to climate is a complex process because it involves several sub-stages that can be affected by climate in several ways. Therefore, the results included in this synthesis integrate several direct and size-dependent climatic effects on flowering performance and report on the importance of both the climate conditions occurring at the recruitment sites and those experienced by the source populations for seedling emergence. Study area and species: This thesis makes use of the sub-alpine and alpine landscapes of western Norway to investigate climatic control on species occurrence and reproduction. This study area was chosen because it includes the leading altitudinal edge of lowland species ranges and the rear altitudinal edge of alpine species ranges. The research uses Viola biflora (alpine), Viola palustris (lowland), Veronica alpina (alpine), and Veronica officinalis (lowland) as study cases because these species are common in the
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Lee, Jung-Seok; Carabali, Mabel; Lim, Jacqueline K; Herrera, Victor M; Park, Il-Yeon; Villar, Luis; Farlow, Andrew
2017-07-10
Dengue has been prevalent in Colombia with high risk of outbreaks in various locations. While the prediction of dengue epidemics will bring significant benefits to the society, accurate forecasts have been a challenge. Given competing health demands in Colombia, it is critical to consider the effective use of the limited healthcare resources by identifying high risk areas for dengue fever. The Climate Risk Factor (CRF) index was constructed based upon temperature, precipitation, and humidity. Considering the conditions necessary for vector survival and transmission behavior, elevation and population density were taken into account. An Early Warning Signal (EWS) model was developed by estimating the elasticity of the climate risk factor function to detect dengue epidemics. The climate risk factor index was further estimated at the smaller geographical unit (5 km by 5 km resolution) to identify populations at high risk. From January 2007 to December 2015, the Early Warning Signal model successfully detected 75% of the total number of outbreaks 1 ~ 5 months ahead of time, 12.5% in the same month, and missed 12.5% of all outbreaks. The climate risk factors showed that populations at high risk are concentrated in the Western part of Colombia where more suitable climate conditions for vector mosquitoes and the high population level were observed compared to the East. This study concludes that it is possible to detect dengue outbreaks ahead of time and identify populations at high risk for various disease prevention activities based upon observed climate and non-climate information. The study outcomes can be used to minimize potential societal losses by prioritizing limited healthcare services and resources, as well as by conducting vector control activities prior to experiencing epidemics.
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Mapping climate change in European temperature distributions
International Nuclear Information System (INIS)
Stainforth, David A; Chapman, Sandra C; Watkins, Nicholas W
2013-01-01
Climate change poses challenges for decision makers across society, not just in preparing for the climate of the future but even when planning for the climate of the present day. When making climate sensitive decisions, policy makers and adaptation planners would benefit from information on local scales and for user-specific quantiles (e.g. the hottest/coldest 5% of days) and thresholds (e.g. days above 28 ° C), not just mean changes. Here, we translate observations of weather into observations of climate change, providing maps of the changing shape of climatic temperature distributions across Europe since 1950. The provision of such information from observations is valuable to support decisions designed to be robust in today’s climate, while also providing data against which climate forecasting methods can be judged and interpreted. The general statement that the hottest summer days are warming faster than the coolest is made decision relevant by exposing how the regions of greatest warming are quantile and threshold dependent. In a band from Northern France to Denmark, where the response is greatest, the hottest days in the temperature distribution have seen changes of at least 2 ° C, over four times the global mean change over the same period. In winter the coldest nights are warming fastest, particularly in Scandinavia. (letter)
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Communities under climate change
DEFF Research Database (Denmark)
Nogues, David Bravo; Rahbek, Carsten
2011-01-01
The distribution of species on Earth and the interactions among them are tightly linked to historical and contemporary climate, so that global climate change will transform the world in which we live. Biological models can now credibly link recent decadal trends in field data to climate change......, but predicting future impacts on biological communities is a major challenge. Attempts to move beyond general macroecological predictions of climate change impact on one hand, and observations from specific, local-scale cases, small-scale experiments, or studies of a few species on the other, raise a plethora...... of unanswered questions. On page 1124 of this issue, Harley (1) reports results that cast new light on how biodiversity, across different trophic levels, responds to climate change....
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Secular trends and climate drift in coupled ocean-atmosphere general circulation models
Covey, Curt; Gleckler, Peter J.; Phillips, Thomas J.; Bader, David C.
2006-02-01
Coupled ocean-atmosphere general circulation models (coupled GCMs) with interactive sea ice are the primary tool for investigating possible future global warming and numerous other issues in climate science. A long-standing problem with such models is that when different components of the physical climate system are linked together, the simulated climate can drift away from observation unless constrained by ad hoc adjustments to interface fluxes. However, 11 modern coupled GCMs, including three that do not employ flux adjustments, behave much better in this respect than the older generation of models. Surface temperature trends in control run simulations (with external climate forcing such as solar brightness and atmospheric carbon dioxide held constant) are small compared with observed trends, which include 20th century climate change due to both anthropogenic and natural factors. Sea ice changes in the models are dominated by interannual variations. Deep ocean temperature and salinity trends are small enough for model control runs to extend over 1000 simulated years or more, but trends in some regions, most notably the Arctic, differ substantially among the models and may be problematic. Methods used to initialize coupled GCMs can mitigate climate drift but cannot eliminate it. Lengthy "spin-ups" of models, made possible by increasing computer power, are one reason for the improvements this paper documents.
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Lin, W.; Xie, S.; Jackson, R. C.; Endo, S.; Vogelmann, A. M.; Collis, S. M.; Golaz, J. C.
2017-12-01
Climate models are known to have difficulty in simulating tropical diurnal convections that exhibit distinct characteristics over land and open ocean. While the causes are rooted in deficiencies in convective parameterization in general, lack of representations of mesoscale dynamics in terms of land-sea breeze, convective organization, and propagation of convection-induced gravity waves also play critical roles. In this study, the problem is investigated at the process-level with the U.S. Department of Energy Accelerated Climate Modeling for Energy (ACME) model in short-term hindcast mode using the Cloud Associated Parameterization Testbed (CAPT) framework. Convective-scale radar retrievals and observation-driven convection-permitting simulations for the Tropical Warm Pool-International Cloud Experiment (TWP-ICE) cases are used to guide the analysis of the underlying processes. The emphasis will be on linking deficiencies in representation of detailed process elements to the model biases in diurnal convective properties and their contrast among inland, coastal and open ocean conditions.
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Achieving Climate Change Absolute Accuracy in Orbit
Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.;
2013-01-01
The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high absolute radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high absolute accuracy will be verified and traceable on orbit to Système Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for determining the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.
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Monthly Total Precipitation Observation for Climate Prediction Center (CPC)Forecast Divisions
National Oceanic and Atmospheric Administration, Department of Commerce — This ASCII dataset contains monthly total precipitation for 102 Forecast Divisions within the conterminous U.S. It is derived from the monthly NCDC climate division...
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Monthly Mean Temperature Observation for Climate Prediction Center (CPC) Forecast Divisions
National Oceanic and Atmospheric Administration, Department of Commerce — This ASCII dataset contains monthly mean temperatures for 102 Forecast Divisions within the conterminous U.S. and is derived from the monthly NCDC climate division...
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Moisan, John R.
2009-01-01
Ocean phytoplankton supply about half of the oxygen that humans utilize to sustain life. In this lecture, we will explore how phytoplankton plays a critical role in modulating the Earth's climate. These tiny organisms are the base of the Ocean's food web. They can modulate the rate at which solar heat is absorbed by the ocean, either through direct absorption or through production of highly scattering cellular coverings. They take up and help sequester carbon dioxide, a key greenhouse gas that modulated the Earth's climate. They are the source of cloud nucleation gases that are key to cloud formation/processes. They are also able to modify the nutrient budgets of the ocean through active uptake of inert atmospheric nitrogen. Climate variations have a pronounced impact on phytoplankton dynamics. Long term variations in the climate have been studied through geological interpretations on its influence on phytoplankton populations. The presentation will focus on presenting the numerous linkages that have been observed between climate and phytoplankton and further discuss how present climate change scenarios are likely to impact phytoplankton populations as well as present findings from several studies that have tried to understand how the climate might react to the feedbacks from these numerous climate-phytop|ankton linkages.
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Energy Technology Data Exchange (ETDEWEB)
Hattermann, F. F.; Krysanova, V.; Gosling, S. N.; Dankers, R.; Daggupati, P.; Donnelly, C.; Flörke, M.; Huang, S.; Motovilov, Y.; Buda, S.; Yang, T.; Müller, C.; Leng, G.; Tang, Q.; Portmann, F. T.; Hagemann, S.; Gerten, D.; Wada, Y.; Masaki, Y.; Alemayehu, T.; Satoh, Y.; Samaniego, L.
2017-01-04
Ideally, the results from models operating at different scales should agree in trend direction and magnitude of impacts under climate change. However, this implies that the sensitivity of impact models designed for either scale to climate variability and change is comparable. In this study, we compare hydrological changes simulated by 9 global and 9 regional hydrological models (HM) for 11 large river basins in all continents under reference and scenario conditions. The foci are on model validation runs, sensitivity of annual discharge to climate variability in the reference period, and sensitivity of the long-term average monthly seasonal dynamics to climate change. One major result is that the global models, mostly not calibrated against observations, often show a considerable bias in mean monthly discharge, whereas regional models show a much better reproduction of reference conditions. However, the sensitivity of two HM ensembles to climate variability is in general similar. The simulated climate change impacts in terms of long-term average monthly dynamics evaluated for HM ensemble medians and spreads show that the medians are to a certain extent comparable in some cases with distinct differences in others, and the spreads related to global models are mostly notably larger. Summarizing, this implies that global HMs are useful tools when looking at large-scale impacts of climate change and variability, but whenever impacts for a specific river basin or region are of interest, e.g. for complex water management applications, the regional-scale models validated against observed discharge should be used.
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Gampe, D.; Ludwig, R.
2017-12-01
Regional Climate Models (RCMs) that downscale General Circulation Models (GCMs) are the primary tool to project future climate and serve as input to many impact models to assess the related changes and impacts under such climate conditions. Such RCMs are made available through the Coordinated Regional climate Downscaling Experiment (CORDEX). The ensemble of models provides a range of possible future climate changes around the ensemble mean climate change signal. The model outputs however are prone to biases compared to regional observations. A bias correction of these deviations is a crucial step in the impact modelling chain to allow the reproduction of historic conditions of i.e. river discharge. However, the detection and quantification of model biases are highly dependent on the selected regional reference data set. Additionally, in practice due to computational constraints it is usually not feasible to consider the entire ensembles of climate simulations with all members as input for impact models which provide information to support decision-making. Although more and more studies focus on model selection based on the preservation of the climate model spread, a selection based on validity, i.e. the representation of the historic conditions is still a widely applied approach. In this study, several available reference data sets for precipitation are selected to detect the model bias for the reference period 1989 - 2008 over the alpine catchment of the Adige River located in Northern Italy. The reference data sets originate from various sources, such as station data or reanalysis. These data sets are remapped to the common RCM grid at 0.11° resolution and several indicators, such as dry and wet spells, extreme precipitation and general climatology, are calculate to evaluate the capability of the RCMs to produce the historical conditions. The resulting RCM spread is compared against the spread of the reference data set to determine the related uncertainties and
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Hernes, Helga; Dalfelt, Arne; Berntsen, Terje; Holtsmark, Bjart; Næss, Lars Otto; Selrod, Rolf; Aaheim, H. Asbjørn
1995-01-01
1. General observations Africa south of the Sahara is probably the most vulnerable region when it comes to the impact and consequences of climate changes. Yet the African continent runs a serious risk of being marginalized in the global dialogue on climate issues. Africa contributes little to the global emissions of CO2, and other greenhouse gases. The major focus of the Framework Convention on Climate Change is on abatement and mitigation of emissions rather than adaptation to the con...
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Combining satellite derived phenology with climate data for climate change impact assessment
Ivits, E.; Cherlet, M.; Tóth, G.; Sommer, S.; Mehl, W.; Vogt, J.; Micale, F.
2012-05-01
The projected influence of climate change on the timing and volume of phytomass production is expected to affect a number of ecosystem services. In order to develop coherent and locally effective adaptation and mitigation strategies, spatially explicit information on the observed changes is needed. Long-term variations of the vegetative growing season in different environmental zones of Europe for 1982-2006 have been derived by analysing time series of GIMMS NDVI data. The associations of phenologically homogenous spatial clusters to time series of temperature and precipitation data were evaluated. North-east Europe showed a trend to an earlier and longer growing season, particularly in the northern Baltic areas. Despite the earlier greening up large areas of Europe exhibited rather stable season length indicating the shift of the entire growing season to an earlier period. The northern Mediterranean displayed a growing season shift towards later dates while some agglomerations of earlier and shorter growing season were also seen. The correlation of phenological time series with climate data shows a cause-and-effect relationship over the semi natural areas consistent with results in literature. Managed ecosystems however appear to have heterogeneous change pattern with less or no correlation to climatic trends. Over these areas climatic trends seemed to overlap in a complex manner with more pronounced effects of local biophysical conditions and/or land management practices. Our results underline the importance of satellite derived phenological observations to explain local nonconformities to climatic trends for climate change impact assessment.
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Variability and changes in selected climate elements in Madrid and Alicante in the period 2000-2014
Directory of Open Access Journals (Sweden)
Cielecka Katarzyna
2015-10-01
Full Text Available The aim of this study is to compare climatic conditions between the interior of the Iberian Peninsula and the southeastern coast of Spain. The article analyzes selected elements of climate over the last 15 years (2000-2014. Synoptic data from airport meteorological stations in Madrid Barajas and Alicante Elche were used. Attention was focused on annual air temperature, relative humidity and precipitation. The mean climatic conditions over the period 2000-2014 were compared with those over the 1961-1990 period which is recommended by WMO as climate normal and with data for the 1971-2000 coming from ‘Climate Atlas’ of Spanish meteorologists group AEMET. Two of climate elements discussed were characterized by significant changes. The annual air temperature was higher by about 0.2°C in Alicante and 0.9°C in Madrid in the period 2000-2014 compared to the 1961-1990. The current winters were colder than in years 1961-1990 at both stations. Gradual decrease in annual precipitation totals was observed at both stations. In 1961-1990 the annual average precipitation in Madrid amounted to 414 mm, while in Alicante it was 356 mm. However, in the recent years of 2000-2014 these totals were lower compared to 1961-1990 reaching 364.1 mm in the central part of Spain and 245.7 mm on the south-western coast.
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Haustein, Karsten; Otto, Friederike; Uhe, Peter; Allen, Myles; Cullen, Heidi
2015-04-01
Extreme weather detection and attribution analysis has emerged as a core theme in climate science over the last decade or so. By using a combination of observational data and climate models it is possible to identify the role of climate change in certain types of extreme weather events such as sea level rise and its contribution to storm surges, extreme heat events and droughts or heavy rainfall and flood events. These analyses are usually carried out after an extreme event has occurred when reanalysis and observational data become available. The Climate Central WWA project will exploit the increasing forecast skill of seasonal forecast prediction systems such as the UK MetOffice GloSea5 (Global seasonal forecasting system) ensemble forecasting method. This way, the current weather can be fed into climate models to simulate large ensembles of possible weather scenarios before an event has fully emerged yet. This effort runs along parallel and intersecting tracks of science and communications that involve research, message development and testing, staged socialization of attribution science with key audiences, and dissemination. The method we employ uses a very large ensemble of simulations of regional climate models to run two different analyses: one to represent the current climate as it was observed, and one to represent the same events in the world that might have been without human-induced climate change. For the weather "as observed" experiment, the atmospheric model uses observed sea surface temperature (SST) data from GloSea5 (currently) and present-day atmospheric gas concentrations to simulate weather events that are possible given the observed climate conditions. The weather in the "world that might have been" experiments is obtained by removing the anthropogenic forcing from the observed SSTs, thereby simulating a counterfactual world without human activity. The anthropogenic forcing is obtained by comparing the CMIP5 historical and natural simulations
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Modelling coffee leaf rust risk in Colombia with climate reanalysis data.
Bebber, Daniel P; Castillo, Ángela Delgado; Gurr, Sarah J
2016-12-05
Many fungal plant diseases are strongly controlled by weather, and global climate change is thus likely to have affected fungal pathogen distributions and impacts. Modelling the response of plant diseases to climate change is hampered by the difficulty of estimating pathogen-relevant microclimatic variables from standard meteorological data. The availability of increasingly sophisticated high-resolution climate reanalyses may help overcome this challenge. We illustrate the use of climate reanalyses by testing the hypothesis that climate change increased the likelihood of the 2008-2011 outbreak of Coffee Leaf Rust (CLR, Hemileia vastatrix) in Colombia. We develop a model of germination and infection risk, and drive this model using estimates of leaf wetness duration and canopy temperature from the Japanese 55-Year Reanalysis (JRA-55). We model germination and infection as Weibull functions with different temperature optima, based upon existing experimental data. We find no evidence for an overall trend in disease risk in coffee-growing regions of Colombia from 1990 to 2015, therefore, we reject the climate change hypothesis. There was a significant elevation in predicted CLR infection risk from 2008 to 2011 compared with other years. JRA-55 data suggest a decrease in canopy surface water after 2008, which may have helped terminate the outbreak. The spatial resolution and accuracy of climate reanalyses are continually improving, increasing their utility for biological modelling. Confronting disease models with data requires not only accurate climate data, but also disease observations at high spatio-temporal resolution. Investment in monitoring, storage and accessibility of plant disease observation data are needed to match the quality of the climate data now available.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'. © 2016 The Authors.
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Ground Water and Climate Change
Taylor, Richard G.; Scanlon, Bridget; Doell, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike;
2013-01-01
As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.
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Assessment of the climate in the Netherlands 2008
International Nuclear Information System (INIS)
Kattenberg, A.
2008-07-01
An overview is provided of the state of the climate in the Netherlands over the last years. The first chapter pays attention to the weather of the last years and striking events are discussed, such as storms, strikingly hot periods or local flooding due to abundant raining. The events are put in the context of the Dutch climate over a much longer period of time. The research results that are described in Chapter 2 and 3 provide insight in the possible causes of the striking weather events. The observed heating of the Netherlands is compared to observations in surrounding countries and to model calculations. Abundant coastal rains in summer are addressed in more detail as well as dry periods. Chapter four addresses air quality research by addressing the connection between warming and the ozone content in the atmosphere. The end of the report provides information on ranges of temperatures and meteorological language use. [mk] [nl
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Sea Surface Temperature Climate Data Record for the North Sea and Baltic Sea
DEFF Research Database (Denmark)
Høyer, Jacob L.; Karagali, Ioanna
2016-01-01
A 30-yr climate data record (CDR) of sea surface temperature (SST) has been produced with daily gap-free analysis fields for the North Sea and the Baltic Sea region from 1982 to 2012 by combining the Pathfinder AVHRR satellite data record with the Along-Track Scanning Radiometer (ATSR) Reprocessing...... for Climate (ARC) dataset and with in situ observations. A dynamical bias correction scheme adjusts the Pathfinder observations toward the ARC and in situ observations. Largest Pathfinder-ARC differences are found in the summer months, when the Pathfinder observations are up to 0.4 °C colder than the ARC...... observations on average. Validation against independent in situ observations shows a very stable performance of the data record, with a mean difference of -0.06 °C compared to moored buoys and a 0.46 °C standard deviation of the differences. The mean annual biases of the SST CDR are small for all years...
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An overview of European efforts in generating climate data records
Su, Z.; Timmermans, W.J.; Zeng, Y.; Schulz, J.; John, V.O.; Roebeling, R.A.; Poli, P.; Tan, D.; Kaspar, F.; Kaiser-Weiss, A.; Swinnen, E.; Tote, C.; Gregow, H.; Manninen, T.; Riihela, A.; Calvet, J.C.; Ma, Yaoming; Wen, Jun
2018-01-01
The Coordinating Earth Observation Data Validation for Reanalysis for Climate Services project (CORE-CLIMAX) aimed to substantiate how Copernicus observations and products can contribute to climate change analyses. CORE-CLIMAX assessed the European capability to provide climate data records (CDRs)
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The cross-country implications of alternative climate policies
International Nuclear Information System (INIS)
Li, Aijun; Du, Nan; Wei, Qian
2014-01-01
Because of worldwide growing concerns about global climate change, great interest has been expressed in the potential of alternative climate policies to reduce global carbon emissions. In this paper, we compare cross-country implications of alternative climate policies, including unilateral and multilateral climate policies. Our main findings are as follows. Firstly, there are large differences in cross-country effects of alternative unilateral climate policies, when the same given carbon emission reductions are achieved in each abating country respectively. Meanwhile, cross-border externalities undermine efficiency of unilateral climate policies. Secondly, there are significant differences in cross-country implications of alternative multilateral climate policies, when the same global emission reductions are allocated in several different ways among abating countries. Thirdly, it is difficult to reach a stable global climate treaty, since any abating country has the incentive to argue for small carbon emission reductions. Finally, multilateral climate policies can reduce the negative impacts of cross-border externalities, but cannot cure all cross-border externalities. Looking ahead, it will be a great policy challenge for the world to reduce carbon emissions in a cost-effective way. - highlights: • We compare impacts of unilateral climate policies across countries. • We compare effects of alternative multilateral climate policies. • We explore whether cross-border externalities disappear under multilateral climate policies
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Nicholls, R. J.; Suckall, N.; Mensah, A.; Mondal, S.; Dey, S.; Hazra, S.
2015-12-01
In low and middle-income countries, many deltaic communities directly depend on the natural environment for income and well-being. Current environmental concerns that threaten deltaic communities, such as increasing salinity, sedimentation, erosion and subsidence are likely to be exacerbated by climate change and variability, for example sea-level rise, increased storminess and rising temperatures. Such changes, along with other social and environmental stressors, mean that communities must adapt. This paper outlines findings of a systematic review of the peer-reviewed and grey literature that examines observed adaptations in three deltas of differing sizes in various geographical contexts: the Ganges-Meghna-Brahmaputra in India and Bangladesh, the Mahanadi in India, and the Volta in Ghana. It compares and contrasts various elements of observed adaptations, including who is driving the adaptation, the beneficiaries, barriers to participation and evidence for maladaptation. The predominant drivers of adaptation vary from government (at state level in India and national level in Bangladesh) and NGOs (in Ghana). Autonomous adaptations are not widely reported in the literature from any of the deltas. In all three deltas there is a focus on supporting adaptation in farming rather than fishing; despite the fact that fisheries contribute to local food security as well as national economies. Lack of access to financial, natural, physical and human capital are common barriers to adaptation in all three deltas. Additionally the Indian literature in particular highlights the lack of coordination between different government departments, coupled with an excessively top-down (state-driven) approach to adaptation. Maladaptation is most commonly reported in the literature from Bangladesh, for example, loss of employment of inland fishermen in embanked areas. The paper concludes by highlighting some of the implications of these findings for adaptation policy in deltas.
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Greenhouse gas observations from space: The GHG-CCI project of ESA's Climate Change Initiative
Buchwitz, Michael; Noël, Stefan; Bergamaschi, Peter; Boesch, Hartmut; Bovensmann, Heinrich; Notholt, Justus; Schneising, Oliver; Hasekamp, Otto; Reuter, Maximilian; Parker, Robert; Dils, Bart; Chevallier, Frederic; Zehner, Claus; Burrows, John
2012-07-01
The GHG-CCI project (http://www.esa-ghg-cci.org) is one of several projects of ESA's Climate Change Initiative (CCI), which will deliver various Essential Climate Variables (ECVs). The goal of GHG-CCI is to deliver global satellite-derived data sets of the two most important anthropogenic greenhouse gases (GHGs) carbon dioxide (CO2) and methane (CH4) suitable to obtain information on regional CO2 and CH4 surface sources and sinks as needed for better climate prediction. The GHG-CCI core ECV data products are column-averaged mole fractions of CO2 and CH4, XCO2 and XCH4, retrieved from SCIAMACHY on ENVISAT and TANSO on GOSAT. Other satellite instruments will be used to provide constraints in upper layers such as IASI, MIPAS, and ACE-FTS. Which of the advanced algorithms, which are under development, will be the best for a given data product still needs to be determined. For each of the 4 GHG-CCI core data products - XCO2 and XCH4 from SCIAMACHY and GOSAT - several algorithms are being further developed and the corresponding data products are inter-compared to identify which data product is the most appropriate. This includes comparisons with corresponding data products generated elsewhere, most notably with the operational data products of GOSAT generated at NIES and the NASA/ACOS GOSAT XCO2 product. This activity, the so-called "Round Robin exercise", will be performed in the first two years of this project. At the end of the 2 year Round Robin phase (end of August 2012) a decision will be made which of the algorithms performs best. The selected algorithms will be used to generate the first version of the ECV GHG. In the last six months of this 3 year project the resulting data products will be validated and made available to all interested users. In the presentation and overview about this project will be given focussing on the latest results.
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Van Den Broucke, Sam; Luyssaert, Sebastiaan; Davin, Edouard L.; Janssens, Ivan; Van Lipzig, Nicole
2015-01-01
In this study, we present a new methodology for evaluating the biogeophysical impact of land use change (LUC) in regional climate models. For this, we use observational data from paired eddy covariance flux towers in Europe, representing a LUC from forest to open land (deforestation). Two model
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Williamson, Fiona; Allan, Rob; Switzer, Adam D.; Chan, Johnny C. L.; Wasson, Robert James; D'Arrigo, Rosanne; Gartner, Richard
2015-12-01
The value of historic observational weather data for reconstructing long-term climate patterns and the detailed analysis of extreme weather events has long been recognized (Le Roy Ladurie, 1972; Lamb, 1977). In some regions however, observational data has not been kept regularly over time, or its preservation and archiving has not been considered a priority by governmental agencies. This has been a particular problem in Southeast Asia where there has been no systematic country-by-country method of keeping or preserving such data, the keeping of data only reaches back a few decades, or where instability has threatened the survival of historic records. As a result, past observational data are fragmentary, scattered, or even absent altogether. The further we go back in time, the more obvious the gaps. Observational data can be complimented however by historical documentary or proxy records of extreme events such as floods, droughts and other climatic anomalies. This review article highlights recent initiatives in sourcing, recovering, and preserving historical weather data and the potential for integrating the same with proxy (and other) records. In so doing, it focuses on regional initiatives for data research and recovery - particularly the work of the international Atmospheric Circulation Reconstructions over the Earth's (ACRE) Southeast Asian regional arm (ACRE SEA) - and the latter's role in bringing together disparate, but interrelated, projects working within this region. The overarching goal of the ACRE SEA initiative is to connect regional efforts and to build capacity within Southeast Asian institutions, agencies and National Meteorological and Hydrological Services (NMHS) to improve and extend historical instrumental, documentary and proxy databases of Southeast Asian hydroclimate, in order to contribute to the generation of high-quality, high-resolution historical hydroclimatic reconstructions (reanalyses) and, to build linkages with humanities researchers
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Fazel, Nasim; Torabi Haghighi, Ali; Kløve, Bjørn
2017-11-01
The natural flow regime of rivers has been strongly altered world-wide, resulting in ecosystem degradation and lakes drying up, especially in arid and semi-arid regions. Determining whether this is due mainly to climate change or to water withdrawal for direct human use (e.g. irrigation) is difficult, particularly for saline lake basins where hydrology data are scarce. In this study, we developed an approach for assessing climate and land use change impacts based on river flow records for headwater and lowland reaches of rivers, using the case of Lake Urmia basin, in north-westen Iran. Flow regimes at upstream and downstream stations were studied before and after major dam construction and irrigation projects. Data from 57 stations were used to establish five different time intervals representing 10 different land use development periods (scenarios) for upstream (not impacted) and downstream (impacted) systems. An existing river impact (RI) index was used to assess changes in three main characteristics of flow (magnitude, timing and, intra-annual variability). The results showed that irrigation was by far the main driving force for river flow regime changes in the lake basin. All stations close to the lake and on adjacent plains showed significantly higher impacts of land use change than headwaters. As headwaters are relatively unaffected by agriculture, the non-significant changes observed in headwater flow regimes indicate a minor effect of climate change on river flows in the region. The benefit of the method developed is clear interpretation of results based on river flow records, which is useful in communicating land use and climate change information to decision makers and lake restoration planners.
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Designing ecological climate change impact assessments to reflect key climatic drivers.
Sofaer, Helen R; Barsugli, Joseph J; Jarnevich, Catherine S; Abatzoglou, John T; Talbert, Marian K; Miller, Brian W; Morisette, Jeffrey T
2017-07-01
Identifying the climatic drivers of an ecological system is a key step in assessing its vulnerability to climate change. The climatic dimensions to which a species or system is most sensitive - such as means or extremes - can guide methodological decisions for projections of ecological impacts and vulnerabilities. However, scientific workflows for combining climate projections with ecological models have received little explicit attention. We review Global Climate Model (GCM) performance along different dimensions of change and compare frameworks for integrating GCM output into ecological models. In systems sensitive to climatological means, it is straightforward to base ecological impact assessments on mean projected changes from several GCMs. Ecological systems sensitive to climatic extremes may benefit from what we term the 'model space' approach: a comparison of ecological projections based on simulated climate from historical and future time periods. This approach leverages the experimental framework used in climate modeling, in which historical climate simulations serve as controls for future projections. Moreover, it can capture projected changes in the intensity and frequency of climatic extremes, rather than assuming that future means will determine future extremes. Given the recent emphasis on the ecological impacts of climatic extremes, the strategies we describe will be applicable across species and systems. We also highlight practical considerations for the selection of climate models and data products, emphasizing that the spatial resolution of the climate change signal is generally coarser than the grid cell size of downscaled climate model output. Our review illustrates how an understanding of how climate model outputs are derived and downscaled can improve the selection and application of climatic data used in ecological modeling. © 2017 John Wiley & Sons Ltd.
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International Nuclear Information System (INIS)
Phylipsen, D.; Price, L.; Worrell, E.; Blok, K.
1999-01-01
In light of the commitments accepted within the Framework Convention on Climate Change there is an increasing need for useful information on energy consumption and energy efficiency. Governments can use this information in designing policies to reduce greenhouse gas emissions and prioritizing energy savings options. International comparison of energy efficiency can provide a benchmark against which a country's performance can be measured and policies can be evaluated. A methodology for international comparisons of industrial energy efficiency was developed by the International Network on Energy Demand analysis in the Industrial Sector. In this paper this methodology is used to analyze the energy efficiency of two energy-intensive industries in major developing countries. Energy consumption trends are shown for the steel and cement industry and an analysis is made of technologies used. In light of the Byrd-Hagel resolution, which states that the US will not ratify any climate treaty unless it also mandates commitments to limit greenhouse gas emissions for developing countries, the energy efficiency in the two sectors is compared to that of the US. The analysis shows that in the iron and steel sector South Korea and Brazil are more energy-efficient than the US, while Mexico has achieved a comparable energy efficiency level in recent years. For cement, South Korea, Brazil and Mexico are the most efficient countries analyzed. In recent years, China, and especially, India appear to have achieved energy efficiency levels, more or less comparable to that of the US. In light of data constraints, however, further analysis is required
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Parametric decadal climate forecast recalibration (DeFoReSt 1.0
Directory of Open Access Journals (Sweden)
A. Pasternack
2018-01-01
Full Text Available Near-term climate predictions such as decadal climate forecasts are increasingly being used to guide adaptation measures. For near-term probabilistic predictions to be useful, systematic errors of the forecasting systems have to be corrected. While methods for the calibration of probabilistic forecasts are readily available, these have to be adapted to the specifics of decadal climate forecasts including the long time horizon of decadal climate forecasts, lead-time-dependent systematic errors (drift and the errors in the representation of long-term changes and variability. These features are compounded by small ensemble sizes to describe forecast uncertainty and a relatively short period for which typically pairs of reforecasts and observations are available to estimate calibration parameters. We introduce the Decadal Climate Forecast Recalibration Strategy (DeFoReSt, a parametric approach to recalibrate decadal ensemble forecasts that takes the above specifics into account. DeFoReSt optimizes forecast quality as measured by the continuous ranked probability score (CRPS. Using a toy model to generate synthetic forecast observation pairs, we demonstrate the positive effect on forecast quality in situations with pronounced and limited predictability. Finally, we apply DeFoReSt to decadal surface temperature forecasts from the MiKlip prototype system and find consistent, and sometimes considerable, improvements in forecast quality compared with a simple calibration of the lead-time-dependent systematic errors.
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Parametric decadal climate forecast recalibration (DeFoReSt 1.0)
Pasternack, Alexander; Bhend, Jonas; Liniger, Mark A.; Rust, Henning W.; Müller, Wolfgang A.; Ulbrich, Uwe
2018-01-01
Near-term climate predictions such as decadal climate forecasts are increasingly being used to guide adaptation measures. For near-term probabilistic predictions to be useful, systematic errors of the forecasting systems have to be corrected. While methods for the calibration of probabilistic forecasts are readily available, these have to be adapted to the specifics of decadal climate forecasts including the long time horizon of decadal climate forecasts, lead-time-dependent systematic errors (drift) and the errors in the representation of long-term changes and variability. These features are compounded by small ensemble sizes to describe forecast uncertainty and a relatively short period for which typically pairs of reforecasts and observations are available to estimate calibration parameters. We introduce the Decadal Climate Forecast Recalibration Strategy (DeFoReSt), a parametric approach to recalibrate decadal ensemble forecasts that takes the above specifics into account. DeFoReSt optimizes forecast quality as measured by the continuous ranked probability score (CRPS). Using a toy model to generate synthetic forecast observation pairs, we demonstrate the positive effect on forecast quality in situations with pronounced and limited predictability. Finally, we apply DeFoReSt to decadal surface temperature forecasts from the MiKlip prototype system and find consistent, and sometimes considerable, improvements in forecast quality compared with a simple calibration of the lead-time-dependent systematic errors.
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Individual survival curves comparing subjective and observed mortality risks.
Bissonnette, Luc; Hurd, Michael D; Michaud, Pierre-Carl
2017-12-01
We compare individual survival curves constructed from objective (actual mortality) and elicited subjective information (probability of survival to a given target age). We develop a methodology to estimate jointly subjective and objective individual survival curves accounting for rounding on subjective reports of perceived survival. We make use of the long follow-up period in the Health and Retirement Study and the high quality of mortality data to estimate individual survival curves that feature both observed and unobserved heterogeneity. This allows us to compare objective and subjective estimates of remaining life expectancy for various groups and compare welfare effects of objective and subjective mortality risk using the life cycle model of consumption. We find that subjective and objective hazards are not the same. The median welfare loss from misperceptions of mortality risk when annuities are not available is 7% of current wealth at age 65 whereas more than 25% of respondents have losses larger than 60% of wealth. When annuities are available and exogenously given, the welfare loss is substantially lower. Copyright © 2017 John Wiley & Sons, Ltd.
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Directory of Open Access Journals (Sweden)
M. Trail
2013-09-01
Full Text Available Climate change can exacerbate future regional air pollution events by making conditions more favorable to form high levels of ozone. In this study, we use spectral nudging with the Weather Research and Forecasting (WRF model to downscale NASA earth system GISS modelE2 results during the years 2006 to 2010 and 2048 to 2052 over the contiguous United States in order to compare the resulting meteorological fields from the air quality perspective during the four seasons of five-year historic and future climatological periods. GISS results are used as initial and boundary conditions by the WRF regional climate model (RCM to produce hourly meteorological fields. The downscaling technique and choice of physics parameterizations used are evaluated by comparing them with in situ observations. This study investigates changes of similar regional climate conditions down to a 12 km by 12 km resolution, as well as the effect of evolving climate conditions on the air quality at major US cities. The high-resolution simulations produce somewhat different results than the coarse-resolution simulations in some regions. Also, through the analysis of the meteorological variables that most strongly influence air quality, we find consistent changes in regional climate that would enhance ozone levels in four regions of the US during fall (western US, Texas, northeastern, and southeastern US, one region during summer (Texas, and one region where changes potentially would lead to better air quality during spring (Northeast. Changes in regional climate that would enhance ozone levels are increased temperatures and stagnation along with decreased precipitation and ventilation. We also find that daily peak temperatures tend to increase in most major cities in the US, which would increase the risk of health problems associated with heat stress. Future work will address a more comprehensive assessment of emissions and chemistry involved in the formation and removal of air
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Changing Climate and Overgrazing Are Decimating Mongolian Steppes
Liu, Yi Y.; Evans, Jason P.; McCabe, Matthew; de Jeu, Richard A. M.; van Dijk, Albert I. J. M.; Dolman, Albertus J.; Saizen, Izuru
2013-01-01
Satellite observations identify the Mongolian steppes as a hotspot of global biomass reduction, the extent of which is comparable with tropical rainforest deforestation. To conserve or restore these grasslands, the relative contributions of climate and human activities to degradation need to be understood. Here we use a recently developed 21-year (1988-2008) record of satellite based vegetation optical depth (VOD, a proxy for vegetation water content and aboveground biomass), to show that nearly all steppe grasslands in Mongolia experienced significant decreases in VOD. Approximately 60% of the VOD declines can be directly explained by variations in rainfall and surface temperature. After removing these climate induced influences, a significant decreasing trend still persists in the VOD residuals across regions of Mongolia. Correlations in spatial patterns and temporal trends suggest that a marked increase in goat density with associated grazing pressures and wild fires are the most likely non-climatic factors behind grassland degradation. © 2013 Liu et al.
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Changing climate and overgrazing are decimating Mongolian steppes.
Directory of Open Access Journals (Sweden)
Yi Y Liu
Full Text Available Satellite observations identify the Mongolian steppes as a hotspot of global biomass reduction, the extent of which is comparable with tropical rainforest deforestation. To conserve or restore these grasslands, the relative contributions of climate and human activities to degradation need to be understood. Here we use a recently developed 21-year (1988-2008 record of satellite based vegetation optical depth (VOD, a proxy for vegetation water content and aboveground biomass, to show that nearly all steppe grasslands in Mongolia experienced significant decreases in VOD. Approximately 60% of the VOD declines can be directly explained by variations in rainfall and surface temperature. After removing these climate induced influences, a significant decreasing trend still persists in the VOD residuals across regions of Mongolia. Correlations in spatial patterns and temporal trends suggest that a marked increase in goat density with associated grazing pressures and wild fires are the most likely non-climatic factors behind grassland degradation.
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Changing Climate and Overgrazing Are Decimating Mongolian Steppes
Liu, Yi Y.
2013-02-25
Satellite observations identify the Mongolian steppes as a hotspot of global biomass reduction, the extent of which is comparable with tropical rainforest deforestation. To conserve or restore these grasslands, the relative contributions of climate and human activities to degradation need to be understood. Here we use a recently developed 21-year (1988-2008) record of satellite based vegetation optical depth (VOD, a proxy for vegetation water content and aboveground biomass), to show that nearly all steppe grasslands in Mongolia experienced significant decreases in VOD. Approximately 60% of the VOD declines can be directly explained by variations in rainfall and surface temperature. After removing these climate induced influences, a significant decreasing trend still persists in the VOD residuals across regions of Mongolia. Correlations in spatial patterns and temporal trends suggest that a marked increase in goat density with associated grazing pressures and wild fires are the most likely non-climatic factors behind grassland degradation. © 2013 Liu et al.
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Simulating the Current Water Cycle with the NASA Ames Mars Global Climate Model
Kahre, M. A.; Haberle, R. M.; Hollingsworth, J. L.; Brecht, A. S.; Urata, R. A.; Montmessin, F.
2017-12-01
The water cycle is a critical component of the current Mars climate system, and it is now widely recognized that water ice clouds significantly affect the nature of the simulated water cycle. Two processes are key to implementing clouds in a Mars global climate model (GCM): the microphysical processes of formation and dissipation, and their radiative effects on atmospheric heating/cooling rates. Together, these processes alter the thermal structure, change the atmospheric dynamics, and regulate inter-hemispheric transport. We have made considerable progress using the NASA Ames Mars GCM to simulate the current-day water cycle with radiatively active clouds. Cloud fields from our baseline simulation are in generally good agreement with observations. The predicted seasonal extent and peak IR optical depths are consistent MGS/TES observations. Additionally, the thermal response to the clouds in the aphelion cloud belt (ACB) is generally consistent with observations and other climate model predictions. Notably, there is a distinct gap in the predicted clouds over the North Residual Cap (NRC) during local summer, but the clouds reappear in this simulation over the NRC earlier than the observations indicate. Polar clouds are predicted near the seasonal CO2 ice caps, but the column thicknesses of these clouds are generally too thick compared to observations. Our baseline simulation is dry compared to MGS/TES-observed water vapor abundances, particularly in the tropics and subtropics. These areas of disagreement appear to be a consistent with other current water cycle GCMs. Future avenues of investigation will target improving our understanding of what controls the vertical extent of clouds and the apparent seasonal evolution of cloud particle sizes within the ACB.
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Directory of Open Access Journals (Sweden)
Ian D. Lloyd
2011-11-01
Full Text Available This paper examines the ability of recent versions of the Geophysical Fluid Dynamics Laboratory Operational Hurricane Forecast Model (GHM to reproduce the observed relationship between hurricane intensity and hurricane-induced Sea Surface Temperature (SST cooling. The analysis was performed by taking a Lagrangian composite of all hurricanes in the North Atlantic from 1998–2009 in observations and 2005–2009 for the GHM. A marked improvement in the intensity-SST relationship for the GHM compared to observations was found between the years 2005 and 2006–2009 due to the introduction of warm-core eddies, a representation of the loop current, and changes to the drag coefficient parameterization for bulk turbulent flux computation. A Conceptual Hurricane Intensity Model illustrates the essential steady-state characteristics of the intensity-SST relationship and is explained by two coupled equations for the atmosphere and ocean. The conceptual model qualitatively matches observations and the 2006–2009 period in the GHM, and presents supporting evidence for the conclusion that weaker upper oceanic thermal stratification in the Gulf of Mexico, caused by the introduction of the loop current and warm core eddies, is crucial to explaining the observed SST-intensity pattern. The diagnostics proposed by the conceptual model offer an independent set of metrics for comparing operational hurricane forecast models to observations.
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International Nuclear Information System (INIS)
Jaramillo T, Jose Hernan
2001-01-01
Because the movement of the solar system is periodic, it might think that the climate is periodic also. However we have not the whole information in order to establish if it is periodic and which would be that period. The systematic observation of the climate only began in 1850. For this reason the climate prediction is not very believable. In the probably near future, we will be able to establish the weather with some reasonable inaccuracy. The present work studies the seasonal factors of the climate and it how interacts in its. These factors are: the sun, the atmosphere, the oceans, the water cycle, the clouds, ice sheets and snow and the earth surface. This work we will give an idea why the climate changes and the inaccuracy in the weather prediction
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Song, Chunqiao; Ke, Linghong; Huang, Bo; Richards, Keith S.
2015-01-01
The southeast Tibetan Plateau (SETP) includes the majority of monsoonal temperate glaciers in High Mountain Asia (HMA), which is an important source of water for the upper reaches of several large Asian river systems. Climatic change and variability has substantial impacts on cryosphere and hydrological processes in the SETP. The Gravity Recovery and Climate Experiment (GRACE) gravimetry observations between 2003 and 2009 suggest that there was an average mass loss rate of - 5.99 ± 2.78 Gigatonnes (Gt)/yr in this region. Meanwhile, the hydrological data by model calculations from the GLDAS/Noah and CPC are used to estimate terrestrial water storage (TWS) changes with a slight negative trend of about - 0.3 Gt/yr. The recent studies (Kääb et al., 2012; Gardner et al., 2013) reported the thinning rates of mountain glaciers in HMA based on the satellite laser altimetry, and an approximate estimation of the glacier mass budget in the SETP was 4.69 ± 2.03 Gt/yr during 2003-2009. This estimate accounted for a large proportion ( 78.3%) of the difference between the GRACE TWS and model-calculated TWS changes. To better understand the cause of sharp mass loss existing in the SETP, the correlations between key climatic variables (precipitation and temperature) and the GRACE TWS changes are examined at different timescales between 2003 and 2011. The results show that precipitation is the leading factors of abrupt, seasonal and multi-year undulating signals of GRACE TWS anomaly time series, but with weak correlations with the inter-annual trend and annual mass budget of GRACE TWS. In contrast, the annual mean temperature is tightly associated with the annual net mass budget (r = 0.81, p < 0.01), which indirectly suggests that the GRACE-observed mass loss in the SETP may be highly related to glacial processes.
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Climate Change Impacts on Future Wave Climate around the UK
Directory of Open Access Journals (Sweden)
William G. Bennett
2016-11-01
Full Text Available Understanding the changes in future storm wave climate is crucial for coastal managers and planners to make informed decisions required for sustainable coastal management and for the renewable energy industry. To investigate potential future changes to storm climate around the UK, global wave model outputs of two time slice experiments were analysed with 1979–2009 representing present conditions and 2075–2100 representing the future climate. Three WaveNet buoy sites around the United Kingdom, which represent diverse site conditions and have long datasets, were chosen for this study. A storm event definition (Dissanayake et al., 2015 was used to separate meteorologically-independent storm events from wave data, which in turn allowed storm wave characteristics to be analysed. Model outputs were validated through a comparison of the modelled storm data with observed storm data for overlapping periods. Although no consistent trends across all future clusters were observed, there were no significant increases in storm wave height, storm count or storm power in the future, at least according to the global wave projection results provided by the chosen model.
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Stavrakou, Trissevgeni; Müller, Jean-François; Bauwens, Maite; De Smedt, Isabelle; Van Roozendael, Michel
2017-04-01
Biogenic hydrocarbon emissions (BVOC) respond to temperature, photosynthetically active radiation, leaf area index, as well as to factors like leaf age, soil moisture, and ambient CO2 concentrations. Isoprene is the principal contributor to BVOC emissions and accounts for about half of the estimated total emissions on the global scale, whereas monoterpenes are also significant over boreal ecosystems. Due to their large emissions, their major role in the tropospheric ozone formation and contribution to secondary organic aerosols, BVOCs are highly relevant to both air quality and climate. Their oxidation in the atmosphere leads to the formation of formaldehyde (HCHO) at high yields. Satellite observations of HCHO abundances can therefore inform us on the spatial and temporal variability of the underlying sources and on their emission trends. The main objective of this study is to investigate the interannual variability and trends of observed HCHO columns during the growing season, when BVOC emissions are dominant, and interpret them in terms of BVOC emission flux variability. To this aim, we use the MEGAN-MOHYCAN model driven by the ECMWF ERA-interim meteorology to calculate bottom-up BVOC fluxes on the global scale (Müller et al. 2008, Stavrakou et al. 2014) over 2003-2015, and satellite HCHO observations from SCIAMACHY (2003-2011) and OMI (2005-2015) instruments (De Smedt et al. 2008, 2015). We focus on mid- and high-latitude regions of the Northern Hemisphere in summertime, as well as tropical regions taking care to exclude biomass burning events which also lead to HCHO column enhancements. We find generally a very strong temporal correlation (>0.7) between the simulated BVOC emissions and the observed HCHO columns over temperate and boreal ecosystems. Positive BVOC emission trends associated to warming climate are found in almost all regions and are well corroborated by the observations. Furthermore, using OMI HCHO observations over 2005-2015 as constraints in
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Energy Technology Data Exchange (ETDEWEB)
Osborn, Timothy J.; Briffa, Keith R. [University of East Anglia, Climatic Research Unit, School of Environmental Sciences, Norwich (United Kingdom); Raper, Sarah C.B. [University of East Anglia, Climatic Research Unit, School of Environmental Sciences, Norwich (United Kingdom); Manchester Metropolitan University, Dalton Research Institute, Manchester (United Kingdom)
2006-08-15
An intercomparison of eight climate simulations, each driven with estimated natural and anthropogenic forcings for the last millennium, indicates that the so-called ''Erik'' simulation of the ECHO-G coupled ocean-atmosphere climate model exhibits atypical behaviour. The ECHO-G simulation has a much stronger cooling trend from 1000 to 1700 and a higher rate of warming since 1800 than the other simulations, with the result that the overall amplitude of millennial-scale temperature variations in the ECHO-G simulation is much greater than in the other models. The MAGICC (Model for the Assessment of Greenhouse-gas-Induced Climate Change) simple climate model is used to investigate possible causes of this atypical behaviour. It is shown that disequilibrium in the initial conditions probably contributes spuriously to the cooling trend in the early centuries of the simulation, and that the omission of tropospheric sulphate aerosol forcing is the likely explanation for the anomalously large recent warming. The simple climate model results are used to adjust the ECHO-G Erik simulation to mitigate these effects, which brings the simulation into better agreement with the other seven models considered here and greatly reduces the overall range of temperature variations during the last millennium simulated by ECHO-G. Smaller inter-model differences remain which can probably be explained by a combination of the particular forcing histories and model sensitivities of each experiment. These have not been investigated here, though we have diagnosed the effective climate sensitivity of ECHO-G to be 2.39{+-}0.11 K for a doubling of CO{sub 2}. (orig.)
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Updating beliefs and combining evidence in adaptive forest management under climate change
DEFF Research Database (Denmark)
Yousefpour, Rasoul; Temperli, Christian; Bugmann, Harald
2013-01-01
We study climate uncertainty and how managers' beliefs about climate change develop and influence their decisions. We develop an approach for updating knowledge and beliefs based on the observation of forest and climate variables and illustrate its application for the adaptive management of an even...... variables may influence a decision maker's beliefs about climate development and thereby management decisions. While forest managers may be inclined to rely on observed forest variables to infer climate change and impacts, we found that observation of climate state, e.g. temperature or precipitation...... on when managers switch to forward-looking management schemes. Thus, robust climate adaptation policies may depend crucially on a better understanding of what factors influence managers' belief in climate change....
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Exploring climate regimes for differentiation of commitments to achieve the EU climate target
Elzen den MGJ; Berk MM; Lucas P; Eickhout B; Vuuren van DP; KMD
2003-01-01
This report explores the implications of various international climate regimes for differentiating post-Kyoto (after 2012) commitments compatible with the EU long-term climate objective to limit global-mean temperature increase to less than 2 degrees Celsius compared to pre-industrial levels. Five
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Modeling climatic effects of anthropogenic CO2 emissions: Unknowns and uncertainties
Soon, W.; Baliunas, S.; Idso, S.; Kondratyev, K. Ya.; Posmentier, E. S.
2001-12-01
A likelihood of disastrous global environmental consequences has been surmised as a result of projected increases in anthropogenic greenhouse gas emissions. These estimates are based on computer climate modeling, a branch of science still in its infancy despite recent, substantial strides in knowledge. Because the expected anthropogenic climate forcings are relatively small compared to other background and forcing factors (internal and external), the credibility of the modeled global and regional responses rests on the validity of the models. We focus on this important question of climate model validation. Specifically, we review common deficiencies in general circulation model calculations of atmospheric temperature, surface temperature, precipitation and their spatial and temporal variability. These deficiencies arise from complex problems associated with parameterization of multiply-interacting climate components, forcings and feedbacks, involving especially clouds and oceans. We also review examples of expected climatic impacts from anthropogenic CO2 forcing. Given the host of uncertainties and unknowns in the difficult but important task of climate modeling, the unique attribution of observed current climate change to increased atmospheric CO2 concentration, including the relatively well-observed latest 20 years, is not possible. We further conclude that the incautious use of GCMs to make future climate projections from incomplete or unknown forcing scenarios is antithetical to the intrinsically heuristic value of models. Such uncritical application of climate models has led to the commonly-held but erroneous impression that modeling has proven or substantiated the hypothesis that CO2 added to the air has caused or will cause significant global warming. An assessment of the positive skills of GCMs and their use in suggesting a discernible human influence on global climate can be found in the joint World Meteorological Organisation and United Nations
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Sensitivity of simulated maize crop yields to regional climate in the Southwestern United States
Kim, S.; Myoung, B.; Stack, D.; Kim, J.; Hatzopoulos, N.; Kafatos, M.
2013-12-01
The sensitivity of maize yield to the regional climate in the Southwestern United States (SW US) has been investigated by using a crop-yield simulation model (APSIM) in conjunction with meteorological forcings (daily minimum and maximum temperature, precipitation, and radiation) from the North American Regional Reanalysis (NARR) dataset. The primary focus of this study is to look at the effects of interannual variations of atmospheric components on the crop productivity in the SW US over the 21-year period (1991 to 2011). First of all, characteristics and performance of APSIM was examined by comparing simulated maize yields with observed yields from United States Department of Agriculture (USDA) and the leaf-area index (LAI) from MODIS satellite data. Comparisons of the simulated maize yield with the available observations show that the crop model can reasonably reproduce observed maize yields. Sensitivity tests were performed to assess the relative contribution of each climate driver to regional crop yield. Sensitivity experiments show that potential crop production responds nonlinearly to climate drivers and the yield sensitivity varied among geographical locations depending on their mean climates. Lastly, a detailed analysis of both the spatial and temporal variations of each climate driver in the regions where maize is actually grown in three states (CA, AZ, and NV) in the SW US was performed.
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Projected climate change futures for Southern Africa
CSIR Research Space (South Africa)
Tadross, M
2017-10-01
Full Text Available of the Council for Scientific and Industrial Research (CSIR) in South Africa. In these experiments, a variable-resolution atmospheric global circulation model, CCAM, was applied as a regional climate model (RCM) to simulate both present-day and future climate... climate projection Observed climate RCM Climate forcing Climate simulation Statistical downscaling Dynamical downscaling 22 | Second Edition There are four pathways – RCP2.6, RCP4.5, RCP6.0 and RCP8.5. RCP 2.6 describes a scenario of very low...
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Köberl, Judith; Prettenthaler, Franz; Bird, David Neil
2016-02-01
Tourism represents an important source of income and employment in many Mediterranean regions, including the island of Sardinia (Italy) and the Cap Bon peninsula (Tunisia). Climate change may however impact tourism in both regions, for example, by altering the regions' climatic suitability for common tourism types or affecting water availability. This paper assesses the potential impacts of climate change on tourism in the case study regions of Sardinia and Cap Bon. Direct impacts are studied in a quantitative way by applying a range of climate scenario data on the empirically estimated relationship between climatic conditions and tourism demand, using two different approaches. Results indicate a potential for climate-induced tourism revenue gains especially in the shoulder seasons during spring and autumn, but also a threat of climate-induced revenue losses in the summer months due to increased heat stress. Annual direct net impacts are nevertheless suggested to be (slightly) positive in both case study regions. Significant climate-induced reductions in total available water may however somewhat counteract the positive direct impacts of climate change by putting additional water costs on the tourism industry. Copyright © 2015 Elsevier B.V. All rights reserved.
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Fire in Mediterranean climate ecosystems: a comparative overview
Keeley, Jon E.
2012-01-01
Four regions of the world share a similar climate and structurally similar plant communities with the Mediterranean Basin. These five areas, known collectively as "mediterranean-type climate (MTC) regions", are dominated by evergreen sclerophyllous-leaved shrublands, semi-deciduous scrub, and woodlands, all of which are prone to widespread crown fires. Summer droughts produce an annual fire hazard that contributes to a highly predictable fire regime. Fire has been an important factor driving the convergence of these systems and is reflected in plant traits such as lignotubers in resprouting shrubs and delayed reproduction that restricts recruitment to a postfire pulse of seedlings. On fertile soils where postfire resprouting is very rapid, opportunities for postfire seedling recruitment are limited and thus these woody taxa have not opted for delaying reproduction. Such fire-independent recruitment is widespread in the floras of MTC regions of the Mediterranean Basin and California and postfire seeding tends to dominate at the more arid end of the gradient. Due to very different geological histories in South Africa and Western Australia, substrates are nutrient poor and thus postfire resprouters do not pose a similar competitive challenge to seedlings and thus postfire seeding is very widespread in these floras. Although circumstantial evidence suggests that the MTC region of Chile had fire-prone landscapes in the Tertiary, these were lost with the late Miocene completion of the Andean uplift, which now blocks summer lightning storms from moving into the region. Today these five regions pose a significant fire management challenge due to the annual fire hazard and metropolitan centers juxtaposed with highly flammable vegetation. This challenge varies across the five MTC landscapes as a function of differences in regional fuel loads and population density.
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Earth as Humans’ Habitat: Global Climate Change and the Health of Populations
Directory of Open Access Journals (Sweden)
Anthony J McMichael
2014-01-01
Full Text Available Human-induced climate change, with such rapid and continuing global-scale warming, is historically unprecedented and signifies that human pressures on Earth’s life-supporting natural systems now exceed the planet’s bio-geo-capacity. The risks from climate change to health and survival in populations are diverse, as are the social and political ramifications. Although attributing observed health changes in a population to the recent climatic change is difficult, a coherent pattern of climate- and weather-associated changes is now evident in many regions of the world. The risks impinge unevenly, especially on poorer and vulnerable regions, and are amplified by pre-existing high rates of climate-sensitive diseases and conditions. If, as now appears likely, the world warms by 3-5oC by 2100, the health consequences, directly and via massive social and economic disruption, will be severe. The health sector has an important message to convey, comparing the health risks and benefits of enlightened action to avert climate change and to achieve sustainable ways of living versus the self-interested or complacent inaction.
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Earth as humans’ habitat: global climate change and the health of populations
McMichael, Anthony J
2014-01-01
Human-induced climate change, with such rapid and continuing global-scale warming, is historically unprecedented and signifies that human pressures on Earth’s life-supporting natural systems now exceed the planet’s bio-geo-capacity. The risks from climate change to health and survival in populations are diverse, as are the social and political ramifications. Although attributing observed health changes in a population to the recent climatic change is difficult, a coherent pattern of climate- and weather-associated changes is now evident in many regions of the world. The risks impinge unevenly, especially on poorer and vulnerable regions, and are amplified by pre-existing high rates of climate-sensitive diseases and conditions. If, as now appears likely, the world warms by 3-5oC by 2100, the health consequences, directly and via massive social and economic disruption, will be severe. The health sector has an important message to convey, comparing the health risks and benefits of enlightened action to avert climate change and to achieve sustainable ways of living versus the self-interested or complacent inaction. PMID:24596901
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Erosion of lizard diversity by climate change and altered thermal niches.
Sinervo, Barry; Méndez-de-la-Cruz, Fausto; Miles, Donald B; Heulin, Benoit; Bastiaans, Elizabeth; Villagrán-Santa Cruz, Maricela; Lara-Resendiz, Rafael; Martínez-Méndez, Norberto; Calderón-Espinosa, Martha Lucía; Meza-Lázaro, Rubi Nelsi; Gadsden, Héctor; Avila, Luciano Javier; Morando, Mariana; De la Riva, Ignacio J; Victoriano Sepulveda, Pedro; Rocha, Carlos Frederico Duarte; Ibargüengoytía, Nora; Aguilar Puntriano, César; Massot, Manuel; Lepetz, Virginie; Oksanen, Tuula A; Chapple, David G; Bauer, Aaron M; Branch, William R; Clobert, Jean; Sites, Jack W
2010-05-14
It is predicted that climate change will cause species extinctions and distributional shifts in coming decades, but data to validate these predictions are relatively scarce. Here, we compare recent and historical surveys for 48 Mexican lizard species at 200 sites. Since 1975, 12% of local populations have gone extinct. We verified physiological models of extinction risk with observed local extinctions and extended projections worldwide. Since 1975, we estimate that 4% of local populations have gone extinct worldwide, but by 2080 local extinctions are projected to reach 39% worldwide, and species extinctions may reach 20%. Global extinction projections were validated with local extinctions observed from 1975 to 2009 for regional biotas on four other continents, suggesting that lizards have already crossed a threshold for extinctions caused by climate change.
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Climate evolution on the terrestrial planets
International Nuclear Information System (INIS)
Kasting, J.F.; Toon, O.B.
1989-01-01
The present comparative evaluation of the long-term evolution of the Venus, earth, and Mars climates suggests that the earth's climate has remained temperate over most of its history despite a secular solar luminosity increase in virtue of a negative-feedback cycle based on atmospheric CO 2 levels and climate. The examination of planetary climate histories suggests that an earth-sized planet should be able to maintain liquid water on its surface at orbital distances in the 0.9-1.5 AU range, comparable to the orbit of Mars; this, in turn, implies that there may be many other habitable planets within the Galaxy
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International Nuclear Information System (INIS)
Kandel, R.
1998-01-01
The climate is a fundamental aspect of our environment. It determines the life possibilities on our planet. The author takes stock of actual questions such: the greenhouse effect, the hole of the ozone layer, the deforestation of tropical forests, the warming of the planet, 'El Nino', by initiating us into climatology, this science that just have known a true technological revolution: climate modeling, paleoclimatology rise, development of observations by satellites. (N.C.)
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Climate Certainties and Uncertainties
International Nuclear Information System (INIS)
Morel, Pierre
2012-01-01
In issue 380 of Futuribles in December 2011, Antonin Pottier analysed in detail the workings of what is today termed 'climate scepticism' - namely the propensity of certain individuals to contest the reality of climate change on the basis of pseudo-scientific arguments. He emphasized particularly that what fuels the debate on climate change is, largely, the degree of uncertainty inherent in the consequences to be anticipated from observation of the facts, not the description of the facts itself. In his view, the main aim of climate sceptics is to block the political measures for combating climate change. However, since they do not admit to this political posture, they choose instead to deny the scientific reality. This month, Futuribles complements this socio-psychological analysis of climate-sceptical discourse with an - in this case, wholly scientific - analysis of what we know (or do not know) about climate change on our planet. Pierre Morel gives a detailed account of the state of our knowledge in the climate field and what we are able to predict in the medium/long-term. After reminding us of the influence of atmospheric meteorological processes on the climate, he specifies the extent of global warming observed since 1850 and the main origin of that warming, as revealed by the current state of knowledge: the increase in the concentration of greenhouse gases. He then describes the changes in meteorological regimes (showing also the limits of climate simulation models), the modifications of hydrological regimes, and also the prospects for rises in sea levels. He also specifies the mechanisms that may potentially amplify all these phenomena and the climate disasters that might ensue. Lastly, he shows what are the scientific data that cannot be disregarded, the consequences of which are now inescapable (melting of the ice-caps, rises in sea level etc.), the only remaining uncertainty in this connection being the date at which these things will happen. 'In this
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Lurton, Thibaut; Jégou, Fabrice; Berthet, Gwenaël; Renard, Jean-Baptiste; Clarisse, Lieven; Schmidt, Anja; Brogniez, Colette; Roberts, Tjarda J.
2018-03-01
Volcanic eruptions impact climate through the injection of sulfur dioxide (SO2), which is oxidized to form sulfuric acid aerosol particles that can enhance the stratospheric aerosol optical depth (SAOD). Besides large-magnitude eruptions, moderate-magnitude eruptions such as Kasatochi in 2008 and Sarychev Peak in 2009 can have a significant impact on stratospheric aerosol and hence climate. However, uncertainties remain in quantifying the atmospheric and climatic impacts of the 2009 Sarychev Peak eruption due to limitations in previous model representations of volcanic aerosol microphysics and particle size, whilst biases have been identified in satellite estimates of post-eruption SAOD. In addition, the 2009 Sarychev Peak eruption co-injected hydrogen chloride (HCl) alongside SO2, whose potential stratospheric chemistry impacts have not been investigated to date. We present a study of the stratospheric SO2-particle-HCl processing and impacts following Sarychev Peak eruption, using the Community Earth System Model version 1.0 (CESM1) Whole Atmosphere Community Climate Model (WACCM) - Community Aerosol and Radiation Model for Atmospheres (CARMA) sectional aerosol microphysics model (with no a priori assumption on particle size). The Sarychev Peak 2009 eruption injected 0.9 Tg of SO2 into the upper troposphere and lower stratosphere (UTLS), enhancing the aerosol load in the Northern Hemisphere. The post-eruption evolution of the volcanic SO2 in space and time are well reproduced by the model when compared to Infrared Atmospheric Sounding Interferometer (IASI) satellite data. Co-injection of 27 Gg HCl causes a lengthening of the SO2 lifetime and a slight delay in the formation of aerosols, and acts to enhance the destruction of stratospheric ozone and mono-nitrogen oxides (NOx) compared to the simulation with volcanic SO2 only. We therefore highlight the need to account for volcanic halogen chemistry when simulating the impact of eruptions such as Sarychev on
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Accounting for multiple climate components when estimating climate change exposure and velocity
Nadeau, Christopher P.; Fuller, Angela K.
2015-01-01
The effect of anthropogenic climate change on organisms will likely be related to climate change exposure and velocity at local and regional scales. However, common methods to estimate climate change exposure and velocity ignore important components of climate that are known to affect the ecology and evolution of organisms.We develop a novel index of climate change (climate overlap) that simultaneously estimates changes in the means, variation and correlation between multiple weather variables. Specifically, we estimate the overlap between multivariate normal probability distributions representing historical and current or projected future climates. We provide methods for estimating the statistical significance of climate overlap values and methods to estimate velocity using climate overlap.We show that climates have changed significantly across 80% of the continental United States in the last 32 years and that much of this change is due to changes in the variation and correlation between weather variables (two statistics that are rarely incorporated into climate change studies). We also show that projected future temperatures are predicted to be locally novel (using climate overlap compared to 1·4 km yr−1 when estimated using traditional methods.Our results suggest that accounting for changes in the means, variation and correlation between multiple weather variables can dramatically affect estimates of climate change exposure and velocity. These climate components are known to affect the ecology and evolution of organisms, but are ignored by most measures of climate change. We conclude with a set of future directions and recommend future work to determine which measures of climate change exposure and velocity are most related to biological responses to climate change.
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Climate change in China and China’s policies and actions for addressing climate change
Directory of Open Access Journals (Sweden)
Luo Y.
2010-12-01
Full Text Available Since the first assessment report (FAR of Inter-Governmental Panel on Climate Change (IPCC in 1990, the international scientific community has made substantial progresses in climate change sciences. Changes in components of climate system, including the atmosphere, oceans and cryosphere, indicate that global warming is unequivocal. Instrumental records demonstrate that the global mean temperature has a significant increasing trend during the 20th century and in the latest 50 years the warming become faster. In the meantime, the global sea level has a strong increasing trend, as well as the snow coverage of Northern Hemisphere showed an obvious downward trend. Moreover, the global warming plays a key role in significantly affecting the climate system and social-economy on both global and regional scales, such as sea level rise, melting of mountain glaciers and ice sheets, desertification, deforestation, increase of weather extremes (typhoon, hurricane and rainstorm and so on. The state of the art understanding of IPCC Fourth Assessment Report (AR4 was most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in the concentrations of anthropogenic greenhouse gases. Climate change issues, as a grave challenge to the sustainable development of the human society, have received ever greater attention from the international community. Deeply cognizant of the complexity and extensive influence of these issues and fully aware of the arduousness and urgency of the task of addressing climate change, the Chinese government is determined to address climate change in the process of pursuing sustainable development. The facts of climate change in China and its impacts, and China’s policies and actions for addressing climate change are introduced in this paper.
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Quantitative Comparison of the Variability in Observed and Simulated Shortwave Reflectance
Roberts, Yolanda, L.; Pilewskie, P.; Kindel, B. C.; Feldman, D. R.; Collins, W. D.
2013-01-01
The Climate Absolute Radiance and Refractivity Observatory (CLARREO) is a climate observation system that has been designed to monitor the Earth's climate with unprecedented absolute radiometric accuracy and SI traceability. Climate Observation System Simulation Experiments (OSSEs) have been generated to simulate CLARREO hyperspectral shortwave imager measurements to help define the measurement characteristics needed for CLARREO to achieve its objectives. To evaluate how well the OSSE-simulated reflectance spectra reproduce the Earth s climate variability at the beginning of the 21st century, we compared the variability of the OSSE reflectance spectra to that of the reflectance spectra measured by the Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY). Principal component analysis (PCA) is a multivariate decomposition technique used to represent and study the variability of hyperspectral radiation measurements. Using PCA, between 99.7%and 99.9%of the total variance the OSSE and SCIAMACHY data sets can be explained by subspaces defined by six principal components (PCs). To quantify how much information is shared between the simulated and observed data sets, we spectrally decomposed the intersection of the two data set subspaces. The results from four cases in 2004 showed that the two data sets share eight (January and October) and seven (April and July) dimensions, which correspond to about 99.9% of the total SCIAMACHY variance for each month. The spectral nature of these shared spaces, understood by examining the transformed eigenvectors calculated from the subspace intersections, exhibit similar physical characteristics to the original PCs calculated from each data set, such as water vapor absorption, vegetation reflectance, and cloud reflectance.
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International Nuclear Information System (INIS)
Bernier, Jean-Claude; Brasseur, Guy; Brechet, Yves; Candel, Sebastien; Cazenave, Anny; Courtillot, Vincent; Fontecave, Marc; Garnier, Emmanuel; Goebel, Philippe; Legrand, Jack; Legrand, Michel; Le Treut, Herve; Mauberger, Pascal; Dinh-Audouin, Minh-Thu; Olivier, Daniele; Rigny, Paul; Bigot, Bernard
2016-01-01
In its first part, this collective publication addresses the decennial and centuries-old variations of climate: perspectives and implications of climate change for the 21. century, questions remaining about the understanding of climate change from its sources to its modelling, extreme climate variations and societies during the last millennium. The contributions of the second part outline how chemistry is a tool to study climate change: ice chemistry as an archive of our past environment, observations and predictions on sea level rise, relationship between atmosphere chemistry and climate. The third set of contributions discusses the transformation of the energy system for a cleaner atmosphere and the management of the climate risk: the chemical processing of CO_2, actions of chemical companies to support the struggle against climate change, relationship between barrel price and renewable energies, relationship between grid complexity and green energy. The last part outlines the role chemistry can have to be able to do without fossil fuels: chemistry in front of challenges of transformation of the energy system, the use of micro-algae, the use of hydrogen as a vector of energy transition
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The effect of climate policy on the impacts of climate change on river flows in the UK
Arnell, Nigel W.; Charlton, Matthew B.; Lowe, Jason A.
2014-03-01
This paper compares the effects of two indicative climate mitigation policies on river flows in six catchments in the UK with two scenarios representing un-mitigated emissions. It considers the consequences of uncertainty in both the pattern of catchment climate change as represented by different climate models and hydrological model parameterisation on the effects of mitigation policy. Mitigation policy has little effect on estimated flow magnitudes in 2030. By 2050 a mitigation policy which achieves a 2 °C temperature rise target reduces impacts on low flows by 20-25% compared to a business-as-usual emissions scenario which increases temperatures by 4 °C by the end of the 21st century, but this is small compared to the range in impacts between different climate model scenarios. However, the analysis also demonstrates that an early peak in emissions would reduce impacts by 40-60% by 2080 (compared with the 4 °C pathway), easing the adaptation challenge over the long term, and can delay by several decades the impacts that would be experienced from around 2050 in the absence of policy. The estimated proportion of impacts avoided varies between climate model patterns and, to a lesser extent, hydrological model parameterisations, due to variations in the projected shape of the relationship between climate forcing and hydrological response.
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Boyte, Stephen P.; Wylie, Bruce K.; Major, Donald J.
2016-01-01
Cheatgrass (Bromus tectorum L.) is a highly invasive species in the Northern Great Basin that helps decrease fire return intervals. Fire fragments the shrub steppe and reduces its capacity to provide forage for livestock and wildlife and habitat critical to sagebrush obligates. Of particular interest is the greater sage grouse (Centrocercus urophasianus), an obligate whose populations have declined so severely due, in part, to increases in cheatgrass and fires that it was considered for inclusion as an endangered species. Remote sensing technologies and satellite archives help scientists monitor terrestrial vegetation globally, including cheatgrass in the Northern Great Basin. Along with geospatial analysis and advanced spatial modeling, these data and technologies can identify areas susceptible to increased cheatgrass cover and compare these with greater sage grouse priority areas for conservation (PAC). Future climate models forecast a warmer and wetter climate for the Northern Great Basin, which likely will force changing cheatgrass dynamics. Therefore, we examine potential climate-caused changes to cheatgrass. Our results indicate that future cheatgrass percent cover will remain stable over more than 80% of the study area when compared with recent estimates, and higher overall cheatgrass cover will occur with slightly more spatial variability. The land area projected to increase or decrease in cheatgrass cover equals 18% and 1%, respectively, making an increase in fire disturbances in greater sage grouse habitat likely. Relative susceptibility measures, created by integrating cheatgrass percent cover and temporal standard deviation datasets, show that potential increases in future cheatgrass cover match future projections. This discovery indicates that some greater sage grouse PACs for conservation could be at heightened risk of fire disturbance. Multiple factors will affect future cheatgrass cover including changes in precipitation timing and totals and
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THE STELLAR MASS COMPONENTS OF GALAXIES: COMPARING SEMI-ANALYTICAL MODELS WITH OBSERVATION
International Nuclear Information System (INIS)
Liu Lei; Yang Xiaohu; Mo, H. J.; Van den Bosch, Frank C.; Springel, Volker
2010-01-01
We compare the stellar masses of central and satellite galaxies predicted by three independent semi-analytical models (SAMs) with observational results obtained from a large galaxy group catalog constructed from the Sloan Digital Sky Survey. In particular, we compare the stellar mass functions of centrals and satellites, the relation between total stellar mass and halo mass, and the conditional stellar mass functions, Φ(M * |M h ), which specify the average number of galaxies of stellar mass M * that reside in a halo of mass M h . The SAMs only predict the correct stellar masses of central galaxies within a limited mass range and all models fail to reproduce the sharp decline of stellar mass with decreasing halo mass observed at the low mass end. In addition, all models over-predict the number of satellite galaxies by roughly a factor of 2. The predicted stellar mass in satellite galaxies can be made to match the data by assuming that a significant fraction of satellite galaxies are tidally stripped and disrupted, giving rise to a population of intra-cluster stars (ICS) in their host halos. However, the amount of ICS thus predicted is too large compared to observation. This suggests that current galaxy formation models still have serious problems in modeling star formation in low-mass halos.
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Decadel climate prediction: challenges and opportunities
International Nuclear Information System (INIS)
Hurrell, J W
2008-01-01
The scientific understanding of climate change is now sufficiently clear to show that climate change from global warming is already upon us, and the rate of change as projected exceeds anything seen in nature in the past 10,000 years. Uncertainties remain, however, especially regarding how climate will change at regional and local scales where the signal of natural variability is large. Addressing many of these uncertainties will require a movement toward high resolution climate system predictions, with a blurring of the distinction between shorter-term predictions and longer-term climate projections. The key is the realization that climate system predictions, regardless of timescale, will require initialization of coupled general circulation models with best estimates of the current observed state of the atmosphere, oceans, cryosphere, and land surface. Formidable challenges exist: for instance, what is the best method of initialization given imperfect observations and systematic errors in models? What effect does initialization have on climate predictions? What predictions should be attempted, and how would they be verified? Despite such challenges, the unrealized predictability that resides in slowly evolving phenomena, such as ocean current systems, is of paramount importance for society to plan and adapt for the next few decades. Moreover, initialized climate predictions will require stronger collaboration with shared knowledge, infrastructure and technical capabilities among those in the weather and climate prediction communities. The potential benefits include improved understanding and predictions on all time scales
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Merchant, C. J.; Hulley, G. C.
2013-12-01
There are many datasets describing the evolution of global sea surface temperature (SST) over recent decades -- so why make another one? Answer: to provide observations of SST that have particular qualities relevant to climate applications: independence, accuracy and stability. This has been done within the European Space Agency (ESA) Climate Change Initative (CCI) project on SST. Independence refers to the fact that the new SST CCI dataset is not derived from or tuned to in situ observations. This matters for climate because the in situ observing network used to assess marine climate change (1) was not designed to monitor small changes over decadal timescales, and (2) has evolved significantly in its technology and mix of types of observation, even during the past 40 years. The potential for significant artefacts in our picture of global ocean surface warming is clear. Only by having an independent record can we confirm (or refute) that the work done to remove biases/trend artefacts in in-situ datasets has been successful. Accuracy is the degree to which SSTs are unbiased. For climate applications, a common accuracy target is 0.1 K for all regions of the ocean. Stability is the degree to which the bias, if any, in a dataset is constant over time. Long-term instability introduces trend artefacts. To observe trends of the magnitude of 'global warming', SST datasets need to be stable to <5 mK/year. The SST CCI project has produced a satellite-based dataset that addresses these characteristics relevant to climate applications. Satellite radiances (brightness temperatures) have been harmonised exploiting periods of overlapping observations between sensors. Less well-characterised sensors have had their calibration tuned to that of better characterised sensors (at radiance level). Non-conventional retrieval methods (optimal estimation) have been employed to reduce regional biases to the 0.1 K level, a target violated in most satellite SST datasets. Models for
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Multivariate geostatistical application for climate characterization of Minas Gerais State, Brazil
de Carvalho, Luiz G.; de Carvalho Alves, Marcelo; de Oliveira, Marcelo S.; Vianello, Rubens L.; Sediyama, Gilberto C.; de Carvalho, Luis M. T.
2010-11-01
The objective of the present study was to assess for Minas Gerais the cokriging methodology, in order to characterize the spatial variability of Thornthwaite annual moisture index, annual rainfall, and average annual air temperature, based on geographical coordinates, altitude, latitude, and longitude. The climatic element data referred to 39 INMET climatic stations located in the state of Minas Gerais and in nearby areas and the covariables altitude, latitude, and longitude to the SRTM digital elevation model. Spatial dependence of data was observed through spherical cross semivariograms and cross covariance models. Box-Cox and log transformation were applied to the positive variables. In these situations, kriged predictions were back-transformed and returned to the same scale as the original data. Trend was removed using global polynomial interpolation. Universal simple cokriging best characterized the climate variables without tendentiousness and with high accuracy and precision when compared to simple cokriging. Considering the satisfactory implementation of universal simple cokriging for the monitoring of climatic elements, this methodology presents enormous potential for the characterization of climate change impact in Minas Gerais state.
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Houet, Thomas; Pigeon, Grégoire
2011-01-01
Facing the concern of the population to its environment and to climatic change, city planners are now considering the urban climate in their choices of planning. The use of climatic maps, such Urban Climate Zone‑UCZ, is adapted for this kind of application. The objective of this paper is to demonstrate that the UCZ classification, integrated in the World Meteorological Organization guidelines, first can be automatically determined for sample areas and second is meaningful according to climatic variables. The analysis presented is applied on Toulouse urban area (France). Results show first that UCZ differentiate according to air and surface temperature. It has been possible to determine the membership of sample areas to an UCZ using landscape descriptors automatically computed with GIS and remote sensed data. It also emphasizes that climate behavior and magnitude of UCZ may vary from winter to summer. Finally we discuss the influence of climate data and scale of observation on UCZ mapping and climate characterization. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Arctic ecosystem responses to a warming climate
DEFF Research Database (Denmark)
Mortensen, Lars O.
sheet, loss of multiannual sea-ice and significant advances in snowmelt days. The biotic components of the arctic ecosystem have also been affected by the rapid changes in climate, for instance resulting in the collapse of the collared lemming cycle, advances in spring flowering and changes in the intra...... biotic interactions. Hence, through the use of up-to-date multivariate statistical tools, this Ph.D. study has been concerned with analyzing how the observed rapid climate changes are affecting the arctic ecosystems. The primary tool has been the implementation of structural equation modeling (SEM) which....... Additionally, the study demonstrated that climate effects had distinct direct and indirect effects on different trophic levels, indicating cascading effects of climate through the trophic system. Results suggest that the Arctic is being significantly affected by the observed climate changes and depending...
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The Global Climate Dashboard: a Software Interface to Stream Comprehensive Climate Data
Gardiner, N.; Phillips, M.; NOAA Climate Portal Dashboard
2011-12-01
The Global Climate Dashboard is an integral component of NOAA's web portal to climate data, services, and value-added content for decision-makers, teachers, and the science-attentive public (www.clmate.gov). The dashboard provides a rapid view of observational data that demonstrate climate change and variability, as well as outputs from the Climate Model Intercomparison Project version 3, which was built to support the Intergovernmental Panel on Climate Change fourth assessment. The data shown in the dashboard therefore span a range of climate science disciplines with applications that serve audiences with diverse needs. The dashboard is designed with reusable software components that allow it to be implemented incrementally on a wide range of platforms including desktops, tablet devices, and mobile phones. The underlying software components support live streaming of data and provide a way of encapsulating graph sytles and other presentation details into a device-independent standard format that results in a common visual look and feel across all platforms. Here we describe the pedagogical objectives, technical implementation, and the deployment of the dashboard through climate.gov and partner web sites and describe plans to develop a mobile application using the same framework.
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A regional climate simulation over the Iberian Peninsula for the last millennium
Directory of Open Access Journals (Sweden)
J. J. Gómez-Navarro
2011-04-01
Full Text Available A high-resolution (30 km regional paleoclimate simulation of the last millennium over the Iberian Peninsula (IP is presented. The simulation was performed with a climate version of the mesoscale model MM5 driven by the global model ECHO-G. Both models were driven by the same reconstructions of several external forcing factors. The high spatial resolution of the regional model allows climatologists to realistically simulate many aspects of the climate in the IP, as compared to an observational data set in the reference period 1961–1990. Although the spatial-averaged values developed by the regional model are tightly driven by the boundary conditions, it is capable to develop a different realisation of the past climate at regional scales, especially in the high-frequency domain and for precipitation. This has to be considered when comparing the results of climate simulations versus proxy reconstructions. A preliminary comparison of the simulation results with reconstructions of temperature and precipitation over the IP shows good agreement in the warming trends in the last century of the simulation, although there are large disagreements in key periods such as the precipitation anomalies in the Maunder Minimum.
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Evolution of extreme temperature events in short term climate projection for Iberian Peninsula.
Rodriguez, Alfredo; Tarquis, Ana M.; Sanchez, Enrique; Dosio, Alessandro; Ruiz-Ramos, Margarita
2014-05-01
Extreme events of maximum and minimum temperatures are a main hazard for agricultural production in Iberian Peninsula. For this purpose, in this study we analyze projections of their evolution that could be valid for the next decade, represented in this study by the 30-year period 2004-2034 (target period). For this purpose two kinds of data were used in this study: 1) observations from the station network of AEMET (Spanish National Meteorological Agency) for five Spanish locations, and 2) simulated data at a resolution of 50 ×50 km horizontal grid derived from the outputs of twelve Regional Climate Models (RCMs) taken from project ENSEMBLES (van der Linden and Mitchell, 2009), with a bias correction (Dosio and Paruolo, 2011; Dosio et al., 2012) regarding the observational dataset Spain02 (Herrera et al., 2012). To validate the simulated climate, the available period of observations was compared to a baseline period (1964-1994) of simulated climate for all locations. Then, to analyze the changes for the present/very next future, probability of extreme temperature events for 2004-2034 were compared to that of the baseline period. Although only minor changes are expected, small variations in variability may have a significant impact in crop performance. The objective of the work is to evaluate the utility of these short term projections for potential users, as for instance insurance companies. References Dosio A. and Paruolo P., 2011. Bias correction of the ENSEMBLES high-resolution climate change projections for use by impact models: Evaluation on the present climate. Journal of Geophysical Research, VOL. 116,D16106, doi:10.1029/2011JD015934 Dosio A., Paruolo P. and Rojas R., 2012. Bias correction of the ENSEMBLES high resolution climate change projections for use by impact models: Analysis of the climate change signal. Journal of Geophysical Research,Volume 117, D17, doi: 0.1029/2012JD017968 Herrera et. al. (2012) Development and Analysis of a 50 year high
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Modeling key processes causing climate change and variability
Energy Technology Data Exchange (ETDEWEB)
Henriksson, S.
2013-09-01
Greenhouse gas warming, internal climate variability and aerosol climate effects are studied and the importance to understand these key processes and being able to separate their influence on the climate is discussed. Aerosol-climate model ECHAM5-HAM and the COSMOS millennium model consisting of atmospheric, ocean and carbon cycle and land-use models are applied and results compared to measurements. Topics at focus are climate sensitivity, quasiperiodic variability with a period of 50-80 years and variability at other timescales, climate effects due to aerosols over India and climate effects of northern hemisphere mid- and high-latitude volcanic eruptions. The main findings of this work are (1) pointing out the remaining challenges in reducing climate sensitivity uncertainty from observational evidence, (2) estimates for the amplitude of a 50-80 year quasiperiodic oscillation in global mean temperature ranging from 0.03 K to 0.17 K and for its phase progression as well as the synchronising effect of external forcing, (3) identifying a power law shape S(f) {proportional_to} f-{alpha} for the spectrum of global mean temperature with {alpha} {approx} 0.8 between multidecadal and El Nino timescales with a smaller exponent in modelled climate without external forcing, (4) separating aerosol properties and climate effects in India by season and location (5) the more efficient dispersion of secondary sulfate aerosols than primary carbonaceous aerosols in the simulations, (6) an increase in monsoon rainfall in northern India due to aerosol light absorption and a probably larger decrease due to aerosol dimming effects and (7) an estimate of mean maximum cooling of 0.19 K due to larger northern hemisphere mid- and high-latitude volcanic eruptions. The results could be applied or useful in better isolating the human-caused climate change signal, in studying the processes further and in more detail, in decadal climate prediction, in model evaluation and in emission policy
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Homogenised Australian climate datasets used for climate change monitoring
International Nuclear Information System (INIS)
Trewin, Blair; Jones, David; Collins; Dean; Jovanovic, Branislava; Braganza, Karl
2007-01-01
Full text: The Australian Bureau of Meteorology has developed a number of datasets for use in climate change monitoring. These datasets typically cover 50-200 stations distributed as evenly as possible over the Australian continent, and have been subject to detailed quality control and homogenisation.The time period over which data are available for each element is largely determined by the availability of data in digital form. Whilst nearly all Australian monthly and daily precipitation data have been digitised, a significant quantity of pre-1957 data (for temperature and evaporation) or pre-1987 data (for some other elements) remains to be digitised, and is not currently available for use in the climate change monitoring datasets. In the case of temperature and evaporation, the start date of the datasets is also determined by major changes in instruments or observing practices for which no adjustment is feasible at the present time. The datasets currently available cover: Monthly and daily precipitation (most stations commence 1915 or earlier, with many extending back to the late 19th century, and a few to the mid-19th century); Annual temperature (commences 1910); Daily temperature (commences 1910, with limited station coverage pre-1957); Twice-daily dewpoint/relative humidity (commences 1957); Monthly pan evaporation (commences 1970); Cloud amount (commences 1957) (Jovanovic etal. 2007). As well as the station-based datasets listed above, an additional dataset being developed for use in climate change monitoring (and other applications) covers tropical cyclones in the Australian region. This is described in more detail in Trewin (2007). The datasets already developed are used in analyses of observed climate change, which are available through the Australian Bureau of Meteorology website (http://www.bom.gov.au/silo/products/cli_chg/). They are also used as a basis for routine climate monitoring, and in the datasets used for the development of seasonal
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da Silva, Felipe das Neves Roque; Alves, José Luis Drummond; Cataldi, Marcio
2018-03-01
This paper aims to validate inflow simulations concerning the present-day climate at Água Vermelha Hydroelectric Plant (AVHP—located on the Grande River Basin) based on the Soil Moisture Accounting Procedure (SMAP) hydrological model. In order to provide rainfall data to the SMAP model, the RegCM regional climate model was also used working with boundary conditions from the MIROC model. Initially, present-day climate simulation performed by RegCM model was analyzed. It was found that, in terms of rainfall, the model was able to simulate the main patterns observed over South America. A bias correction technique was also used and it was essential to reduce mistakes related to rainfall simulation. Comparison between rainfall simulations from RegCM and MIROC showed improvements when the dynamical downscaling was performed. Then, SMAP, a rainfall-runoff hydrological model, was used to simulate inflows at Água Vermelha Hydroelectric Plant. After calibration with observed rainfall, SMAP simulations were evaluated in two different periods from the one used in calibration. During calibration, SMAP captures the inflow variability observed at AVHP. During validation periods, the hydrological model obtained better results and statistics with observed rainfall. However, in spite of some discrepancies, the use of simulated rainfall without bias correction captured the interannual flow variability. However, the use of bias removal in the simulated rainfall performed by RegCM brought significant improvements to the simulation of natural inflows performed by SMAP. Not only the curve of simulated inflow became more similar to the observed inflow, but also the statistics improved their values. Improvements were also noticed in the inflow simulation when the rainfall was provided by the regional climate model compared to the global model. In general, results obtained so far prove that there was an added value in rainfall when regional climate model was compared to global climate
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Fornace, K. L.; Galy, V.; Hughen, K. A.
2014-12-01
The application of compound-specific radiocarbon dating to molecular biomarkers has allowed for tracking of specific organic carbon pools as they move through the environment, providing insight into complex processes within the global carbon cycle. Here we use this technique to investigate links between glacial-interglacial climate change and terrestrial organic carbon cycling in the catchments of Cariaco Basin and Lake Titicaca, two tropical South American sites with well-characterized climate histories since the last glacial period. By comparing radiocarbon ages of terrestrial biomarkers (leaf wax compounds) with deposition ages in late glacial and Holocene sediments, we are able to gauge the storage time of these compounds in the catchments in soils, floodplains, etc. before transport to marine or lacustrine sediments. We are also able to probe the effects of temperature and hydrologic change individually by taking advantage of opposite hydrologic trends at the two sites: while both were colder during the last glacial period, precipitation at Titicaca decreased from the last glacial period to the Holocene, but the late glacial was marked by drier conditions at Cariaco. Preliminary data from both sites show a wide range of apparent ages of long-chain n-fatty acids (within error of 0 to >10,000 years older than sediment), with the majority showing ages on the order of several millennia at time of deposition and age generally increasing with chain length. While late glacial leaf waxes appear to be older relative to sediment than those deposited in the Holocene at both sites, at Cariaco we find a ~2-3 times larger glacial-interglacial age difference than at Titicaca. We hypothesize that at Titicaca the competing influences of wetter and colder conditions during the last glacial period, which respectively tend to increase and decrease the rate of organic carbon turnover on land, served to minimize the contrast between glacial and interglacial leaf wax storage time
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An empirical perspective for understanding climate change impacts in Switzerland
Henne, Paul; Bigalke, Moritz; Büntgen, Ulf; Colombaroli, Daniele; Conedera, Marco; Feller, Urs; Frank, David; Fuhrer, Jürg; Grosjean, Martin; Heiri, Oliver; Luterbacher, Jürg; Mestrot, Adrien; Rigling, Andreas; Rössler, Ole; Rohr, Christian; Rutishauser, This; Schwikowski, Margit; Stampfli, Andreas; Szidat, Sönke; Theurillat, Jean-Paul; Weingartner, Rolf; Wilcke, Wolfgan; Tinner, Willy
2018-01-01
Planning for the future requires a detailed understanding of how climate change affects a wide range of systems at spatial scales that are relevant to humans. Understanding of climate change impacts can be gained from observational and reconstruction approaches and from numerical models that apply existing knowledge to climate change scenarios. Although modeling approaches are prominent in climate change assessments, observations and reconstructions provide insights that cannot be derived from simulations alone, especially at local to regional scales where climate adaptation policies are implemented. Here, we review the wealth of understanding that emerged from observations and reconstructions of ongoing and past climate change impacts in Switzerland, with wider applicability in Europe. We draw examples from hydrological, alpine, forest, and agricultural systems, which are of paramount societal importance, and are projected to undergo important changes by the end of this century. For each system, we review existing model-based projections, present what is known from observations, and discuss how empirical evidence may help improve future projections. A particular focus is given to better understanding thresholds, tipping points and feedbacks that may operate on different time scales. Observational approaches provide the grounding in evidence that is needed to develop local to regional climate adaptation strategies. Our review demonstrates that observational approaches should ideally have a synergistic relationship with modeling in identifying inconsistencies in projections as well as avenues for improvement. They are critical for uncovering unexpected relationships between climate and agricultural, natural, and hydrological systems that will be important to society in the future.
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National Oceanic and Atmospheric Administration, Department of Commerce — The Global Hourly Summaries are simple indicators of observational normals which include climatic data summarizations and frequency distributions. These typically...
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Some comments on reconstructing the historical climate of California, USA
International Nuclear Information System (INIS)
Mock, C.J.
2006-01-01
This paper describes some examples of historical climate reconstruction pertaining to California, USA, focusing mostly on winter climate given the expected strongest teleconnection signals for this season. Climatic data consist of early instrumental data from the US Army Surgeon General at military forts, observers of the Smithsonian Institution, the Signal Service, and some private observers. Documentary (non-instrumental) data were also used in assessing extreme events. Original daily records of these data were carefully assessed for discontinuities from examining diurnal temperature ranges and daily precipitation amounts. The climatic reconstructions conducted were as follows: 1) winter precipitation time series for selected locations since 1850, particularly for Sacramento and San Francisco, 2) winter temperature time series for selected locations since 1850, and 3) analyses of an extreme flooding event in January 1862 and a landfalling tropical cyclone of September 1939. Results indicate distinctive wetter winters for central and northern California in the late nineteenth century, and some of these wetter years correspond to well-known very strong El Ni no events. Connections to weaker El Nino and La Nina events, however, are not clearly evident. The flood of January 1862 is considered unprecedented when compared to other floods of the last 130 years. The reconstruction of a landfalling tropical cyclone for September 1939 near Los Angeles suggests its intensity at just below hurricane strength
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Priestley, Kory J.; Smith, George L.
2010-01-01
The goal of the Clouds and the Earth s Radiant Energy System (CERES) project is to provide a long-term record of radiation budget at the top-of-atmosphere (TOA), within the atmosphere, and at the surface with consistent cloud and aerosol properties at climate accuracy. CERES consists of an integrated instrument-algorithm validation science team that provides development of higher-level products (Levels 1-3) and investigations. It involves a high level of data fusion, merging inputs from 25 unique input data sources to produce 18 CERES data products. Over 90% of the CERES data product volume involves two or more instruments. Continuation of the Earth Radiation Budget (ERB) Climate Data Record (CDR) has been identified as critical in the 2007 NRC Decadal Survey, the Global Climate Observing System WCRP report, and in an assessment titled Impacts of NPOESS Nunn-McCurdy Certification on Joint NASA-NOAA Climate Goals . Five CERES instruments have flown on three different spacecraft: TRMM, EOS-Terra and EOS-Aqua. In response, NASA, NOAA and NPOESS have agreed to fly the existing CERES Flight Model (FM-5) on the NPP spacecraft in 2011 and to procure an additional CERES Sensor with modest upgrades for flight on the JPSS C1 spacecraft in 2014, followed by a CERES follow-on sensor for flight in 2018. CERES is a scanning broadband radiometer that measures filtered radiance in the SW (0.3-5 m), total (TOT) (0.3-200 m) and WN (8-12 m) regions. Pre-launch calibration is performed on each Flight Model to meet accuracy requirements of 1% for SW and 0.5% for outgoing LW observations. Ground to flight or in-flight changes are monitored using protocols employing onboard and vicarious calibration sources. Studies of flight data show that SW response can change dramatically due to optical contamination. with greatest impact in blue-to UV radiance, where tungsten lamps are largely devoid of output. While science goals remain unchanged for ERB Climate Data Record, it is now understood
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Klaus, D.; Dethloff, K.; Dorn, W.; Rinke, A.; Wu, D. L.
2016-05-01
Cloud observations from the CloudSat and CALIPSO satellites helped to explain the reduced total cloud cover (Ctot) in the atmospheric regional climate model HIRHAM5 with modified cloud physics. Arctic climate conditions are found to be better reproduced with (1) a more efficient Bergeron-Findeisen process and (2) a more generalized subgrid-scale variability of total water content. As a result, the annual cycle of Ctot is improved over sea ice, associated with an almost 14% smaller area average than in the control simulation. The modified cloud scheme reduces the Ctot bias with respect to the satellite observations. Except for autumn, the cloud reduction over sea ice improves low-level temperature profiles compared to drifting station data. The HIRHAM5 sensitivity study highlights the need for improving accuracy of low-level (<700 m) cloud observations, as these clouds exert a strong impact on the near-surface climate.
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Eye tracking and climate change: How is climate literacy information processed?
Williams, C. C.; McNeal, K. S.
2011-12-01
The population of the Southeastern United States is perceived to be resistant to information regarding global climate change. The Climate Literacy Partnership in the Southeast (CLiPSE) project was formed to provide a resource for climate science information. As part of this project, we are evaluating the way that education materials influence the interpretation of climate change related information. At Mississippi State University, a study is being conducted examining how individuals from the Southeastern United States process climate change information and whether or not the interaction with such information impacts the interpretation of subsequent climate change related information. By observing the patterns both before and after an educational intervention, we are able to evaluate the effectiveness of the climate change information on an individual's interpretation of related information. Participants in this study view figures describing various types of climate change related information (CO2 emissions, sea levels, etc.) while their eye movements are tracked to determine a baseline for the way that they process this type of graphical data. Specifically, we are examining time spent viewing and number of fixations on critical portions of the figures prior to exposure to an educational document on climate change. Following the baseline period, we provide participants with portions of a computerized version of Climate Literacy: The Essential Principles of Climate Sciences that the participants read at their own pace while their eye movements are monitored. Participants are told that they will be given a test on the material after reading the resource. After reading the excerpt, participants are presented with a new set of climate change related figures to interpret (with eye tracking) along with a series of questions regarding information contained in the resource. We plan to evaluate changes that occur in the way that climate change related information is
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BinMag: Widget for comparing stellar observed with theoretical spectra
Kochukhov, O.
2018-05-01
BinMag examines theoretical stellar spectra computed with Synth/SynthMag/Synmast/Synth3/SME spectrum synthesis codes and compare them to observations. An IDL widget program, BinMag applies radial velocity shift and broadening to the theoretical spectra to account for the effects of stellar rotation, radial-tangential macroturbulence, instrumental smearing. The code can also simulate spectra of spectroscopic binary stars by appropriate coaddition of two synthetic spectra. Additionally, BinMag can be used to measure equivalent width, fit line profile shapes with analytical functions, and to automatically determine radial velocity and broadening parameters. BinMag interfaces with the Synth3 (ascl:1212.010) and SME (ascl:1202.013) codes, allowing the user to determine chemical abundances and stellar atmospheric parameters from the observed spectra.
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Institute of Scientific and Technical Information of China (English)
WANG Shuang-Jing; CAO Long; LI Na
2014-01-01
Based on simulations using the University of Victoria’s Earth System Climate Model, we analyzed the responses of the ocean carbon cycle to increasing atmospheric CO2 levels and climate change from 1800 to 2500 following the RCP 8.5 scenario and its extension. Compared to simulations without climate change, the simulation with a climate sensitivity of 3.0 K shows that in 2100, due to increased atmospheric CO2 concentrations, the simulated sea surface temperature increases by 2.7 K, the intensity of the North Atlantic deep water formation reduces by4.5 Sv, and the oceanic uptake of anthropogenic CO2 decreases by 0.8 Pg C. Climate change is also found to have a large effect on the North Atlantic’s ocean column inventory of anthropogenic CO2. Between the years 1800 and 2500, compared with the simulation with no climate change, the simulation with climate change causes a reduction in the total anthropogenic CO2 column inventory over the entire ocean and in North Atlantic by 23.1% and 32.0%, respectively. A set of simulations with climate sensitivity variations from 0.5 K to 4.5 K show that with greater climate sensitivity climate change would have a greater effect in reducing the ocean’s ability to absorb CO2 from the atmosphere.
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Patterns in household-level engagement with climate change in Indonesia
Bohensky, Erin L.; Smajgl, Alex; Brewer, Tom
2013-04-01
Understanding how individuals engage with climate change is critical for developing successful climate adaptation policies. Indonesia ranks among the world's top CO2 emitters, affirming its relevance to the global climate change policy arena, yet the dynamics of climate change engagement in Indonesia may differ from developed countries from which much research on this issue derives. We surveyed 6,310 households in two Indonesian regions to investigate patterns in four steps of engagement: observation, risk perception, reactive action (in response to present climate change) and proactive action (in anticipation of future climate change). We show that 89.5% of households exhibited a pattern whereby taking each of these steps in sequence implied taking all steps that precede it. Exceptions occurred in urban areas, where households were more likely to take action without having observed climate change or perceiving risks. In rural areas, households were more likely to observe climate change without taking action. These variations suggest a potentially nonlinear relationship between steps of engagement. We distinguish three types of household requiring adaptation support, and stress that Indonesian climate policy should shift emphasis from raising awareness to identifying broader institutional structures and processes to facilitate household engagement.
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International Nuclear Information System (INIS)
2006-03-01
The New Zealand Government is committed to playing its part in the global response to climate change. This Fourth National Communication provides a snapshot of New Zealand's progress with implementing the United Nations Framework Convention on Climate Change (UNFCCC). This document covers the period from the submission of the Third National Communication in January 2002 through to the end of December 2005. This document also contains New Zealand's Report on the Global Climate Observing System and the Report on Demonstrable Progress under the Kyoto Protocol. New Zealand's response to climate change has evolved substantially since the Third National Communication was submitted. On 19 December 2002, New Zealand became the 101st nation to ratify the Kyoto Protocol. In 2002, the New Zealand Parliament passed the Climate Change Response Act. This Act established a New Zealand climate change registry and corresponding institutional arrangements in accordance with Kyoto Protocol requirements. Other achievements are detailed throughout this Fourth National Communication. When the Government introduced its climate change policy package in 2002, it anticipated there would be three reviews of the package not later than 2005, 2007 and 2010. The reviews would be necessary to monitor progress with emissions reductions, assess the effectiveness of policies, and confirm that New Zealand was positioned to meet its commitments. The first of these reviews was commissioned by the Government in mid-2005 and completed by November 2005. The review concluded that some elements of the Government's 2002 climate change policy package should be modified to better position New Zealand to respond to the longer-term challenges of climate change. A key outcome of the policy review was the announcement by the newly elected Government in December 2005 that the previously announced carbon tax would not proceed. In addition, a suite of future work programmes would be required to inform Government
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Robertson, A. W.; Ceccato, P.
2015-12-01
In order to fill the gaps existing in climate and public health, agriculture, natural disasters knowledge and practices, the International Research Institute for Climate and Society (IRI) has developed a Curriculum for Best Practices in Climate Information. This Curriculum builds on the experience of 10 years courses on 'Climate Information' and captures lessons and experiences from different tailored trainings that have been implemented in many countries in Africa, Asia and Latin America. In this presentation, we will provide examples of training activities we have developed to bring remote sensing products to monitor climatic and environmental information into decision processes that benefited users such as the World Health Organization, Ministries of Health, Ministries of Agriculture, Universities, Research Centers such as CIFOR and FIOCRUZ. The framework developed by IRI to provide capacity building is based on the IDEAS framework: Innovation (research) Around climate impacts, evaluation of interventions, and the value of climate information in reducing risks and maximizing opportunities Demonstration E.g. in-country GFCS projects in Tanzania and Malawi - or El Nino work in Ethiopia Education Academic and professional training efforts Advocacy This might focus on communication of variability and change? We are WHO collaborating center so are engaged through RBM/Global Malaria Programme Service ENACTS and Data library key to this. Country data better quality than NASA as incorporates all relevant station data and NASA products. This presentation will demonstrate how the IDEAS framework has been implemented and lessons learned.
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Schwab, Markus J.; Brauer, Achim; Błaszkiewicz, Mirosław; Raab, Thomas; Wilmking, Martin
2015-04-01
Understanding causes and effects of present-day climate change on landscapes and the human habitat faces two main challenges, (i) too short time series of instrumental observation that do not cover the full range of variability since mechanisms of climate change and landscape evolution work on different time scales, which often not susceptible to human perception, and, (ii) distinct regional differences due to the location with respect to oceanic/continental climatic influences, the geological underground, and the history and intensity of anthropogenic land-use. Both challenges are central for the ICLEA research strategy and demand a high degree of interdisciplinary. In particular, the need to link observations and measurements of ongoing changes with information from the past taken from natural archives requires joint work of scientists with very different time perspectives. On the one hand, scientists that work at geological time scales of thousands and more years and, on the other hand, those observing and investigating recent processes at short time scales. The GFZ, Greifswald University and the Brandenburg University of Technology together with their partner the Polish Academy of Sciences strive for focusing their research capacities and expertise in ICLEA. ICLEA offers young researchers an interdisciplinary and structured education and promote their early independence through coaching and mentoring. Postdoctoral rotation positions at the ICLEA partner institutions ensure mobility of young researchers and promote dissemination of information and expertise between disciplines. Training, Research and Analytical workshops between research partners of the ICLEA virtual institute are another important measure to qualify young researchers. The long-term mission of the Virtual Institute is to provide a substantiated data basis for sustained environmental maintenance based on a profound process understanding at all relevant time scales. Aim is to explore processes of
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Climate indices of Iran under climate change
Directory of Open Access Journals (Sweden)
alireza kochaki
2009-06-01
Full Text Available Global warming will affect all climatic variables and particularly rainfall patterns. The purpose of present investigation was to predict climatic parameters of Iran under future climate change and to compare them with the present conditions. For this reason, UKMO General Circulation Model was used for the year 2025 and 2050. By running the model, minimum and maximum monthly temperature and also maximum monthly rainfall for the representative climate stations were calculated and finally the effects of climate change on these variables based on pre-determined scenarios was evaluated. The results showed that averaged over all stations, mean temperature increase for spring in the year 2025 and 2050 will be 3.1 and 3.9, for summer 3.8 and 4.7, for autumn 2.3 and 3 and for winter 2.0 and 2.4 ºC, respectively. This increase will be more pronounced from North to the South and from East to the West parts of the country. Mean decrease in autumn rainfall for the target years of 2025 and 2050 will be 8 and 11 percent, respectively. This decrease is negligible for summer months. Length of dry season for the years 2025 and 2050 will be increased, respectively up to 214 and 223 days due to combined effects of increased temperature and decreased rainfall.
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Energy Technology Data Exchange (ETDEWEB)
Fenge, T.
2001-12-31
Marked climate change has been forecast for regions in high latitudes by global climate models presented by the Intergovernmental Panel on Climate Change. Observations and reports of significant alterations to the natural environment of Canada's north have been reported by Inuit and other indigenous peoples using their traditional ecological knowledge as a reference. Global climate change appears to be the cause for the changes noted. Many aspects of climate change need to be addressed, such as research, outreach, impacts, adaptations and international negotiations. Based on the strong partnership that had been developed between the Inuit and four federal agencies, three territorial governments and four indigenous people's organizations in support of the Northern Contaminants Program, Inuit are now seeking a partnership with the federal government to address the issues mentioned above concerning climate change. refs., 1 tab.
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Gross, John E.; Tercek, Michael; Guay, Kevin; Chang, Tony; Talbert, Marian; Rodman, Ann; Thoma, David; Jantz, Patrick; Morisette, Jeffrey T.
2016-01-01
Most of the western United States is experiencing the effects of rapid and directional climate change (Garfin et al. 2013). These effects, along with forecasts of profound changes in the future, provide strong motivation for resource managers to learn about and prepare for future changes. Climate adaptation plans are based on an understanding of historic climate variation and their effects on ecosystems and on forecasts of future climate trends. Frameworks for climate adaptation thus universally identify the importance of a summary of historical, current, and projected climates (Glick, Stein, and Edelson 2011; Cross et al. 2013; Stein et al. 2014). Trends in physical climate variables are usually the basis for evaluating the exposure component in vulnerability assessments. Thus, this chapter focuses on step 2 of the Climate-Smart Conservation framework (chap. 2): vulnerability assessment. We present analyses of historical and current observations of temperature, precipitation, and other key climate measurements to provide context and a baseline for interpreting the ecological impacts of projected climate changes.
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Climate Change, Politics and Religion: Australian Churchgoers’ Beliefs about Climate Change
Directory of Open Access Journals (Sweden)
Miriam Pepper
2016-05-01
Full Text Available A growing literature has sought to understand the relationships between religion, politics and views about climate change and climate change policy in the United States. However, little comparative research has been conducted in other countries. This study draws on data from the 2011 Australian National Church Life Survey to examine the beliefs of Australian churchgoers from some 20 denominations about climate change—whether or not it is real and whether it is caused by humans—and political factors that explain variation in these beliefs. Pentecostals, Baptist and Churches of Christ churchgoers, and people from the smallest Protestant denominations were less likely than other churchgoers to believe in anthropogenic climate change, and voting and hierarchical and individualistic views about society predicted beliefs. There was some evidence that these views function differently in relation to climate change beliefs depending on churchgoers’ degree of opposition to gay rights. These findings are of interest not only for the sake of international comparisons, but also in a context where Australia plays a role in international climate change politics that is disproportionate to its small population.
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Twenty first century climate change as simulated by European climate models
International Nuclear Information System (INIS)
Cubasch, Ulrich
2007-01-01
Full text: Climate change simulation results for seven European state-of-the-art climate models, participating in the European research project ENSEMBLES (ENSEMBLE-based Predictions of Climate Changes and their Impacts), will be presented. Models from Norway, France, Germany, Denmark, and Great Britain, representing a sub-ensemble of the models contributing to the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), are included. Climate simulations are conducted with all the models for present-day climate and for future climate under the SRES A1B, A2, and B1 scenarios. The design of the simulations follows the guidelines of the IPCC AR4. The 21st century projections are compared to the corresponding present-day simulations. The ensemble mean global mean near surface temperature rise for the year 2099 compared to the 1961-1990 period amounts to 3.2Kforthe A1B scenario, to 4.1 K for the A2 scenario, and to 2.1 K for the B1 scenario. The spatial patterns of temperature change are robust among the contributing models with the largest temperature increase over the Arctic in boreal winter, stronger warming overland than over ocean, and little warming over the southern oceans. The ensemble mean globally averaged precipitation increases for the three scenarios (5.6%, 5.7%, and 3.8% for scenarios A1B, A2, and B1, respectively). The precipitation signals of the different models display a larger spread than the temperature signals. In general, precipitation increases in the Intertropical Convergence Zone and the mid- to high latitudes (most pronounced during the hemispheric winter) and decreases in the subtropics. Sea-level pressure decreases over the polar regions in all models and all scenarios, which is mainly compensated by a pressure increase in the subtropical highs. These changes imply an intensification of the Southern and Northern Annular Modes
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Möller, Jens; Heinrich, Hartmut
2017-04-01
As a consequence of climate change atmospheric and oceanographic extremes and their potential impacts on coastal regions are of growing concern for governmental authorities responsible for the transportation infrastructure. Highest risks for shipping as well as for rail and road traffic originate from combined effects of extremes of storm surges and heavy rainfall which sometimes lead to insufficient dewatering of inland waterways. The German Ministry of Transport and digital Infrastructure therefore has tasked its Network of Experts to investigate the possible evolutions of extreme threats for low lands and especially for Kiel Canal, which is an important shortcut for shipping between the North and Baltic Seas. In this study we present results of a comparison of an Extreme Value Analysis (EVA) carried out on gauge observations and values derived from a coupled Regional Ocean-Atmosphere Climate Model (MPI-OM). High water levels at the coasts of the North and Baltic Seas are one of the most important hazards which increase the risk of flooding of the low-lying land and prevents such areas from an adequate dewatering. In this study changes in the intensity (magnitude of the extremes) and duration of extreme water levels (above a selected threshold) are investigated for several gauge stations with data partly reaching back to 1843. Different methods are used for the extreme value statistics, (1) a stationary general Pareto distribution (GPD) model as well as (2) an instationary statistical model for better reproduction of the impact of climate change. Most gauge stations show an increase of the mean water level of about 1-2 mm/year, with a stronger increase of the highest water levels and a decrease (or lower increase) of the lowest water levels. Also, the duration of possible dewatering time intervals for the Kiel-Canal was analysed. The results for the historical gauge station observations are compared to the statistics of modelled water levels from the coupled
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Is climate change intensifying the drying-trend in the Caribbean?
Herrera, D. A.; Ault, T.; Fasullo, J.; Carrillo, C. M.
2017-12-01
Since 1950, the Caribbean (11ºN-25ºN; 85ºW-60ºW) has seen a significant drying trend characterized by several recent droughts, some of them contemporaneous with El Niño events. Moreover, the most recent drought from 2013 to 2016 was both the most severe and widespread event since at least 1950, and was associated with high temperatures, likely driven in part by climate change. This work examines the role of increased evaporative demand resulting from warmer temperatures on the drying trend observed in the Caribbean since 1950, using observations and model simulations. Large-scale dynamics associated with drought are also analyzed using sea surface temperature, geopotential height, wind, and precipitation anomalies, as well as radiative fluxes anomalies. Furthermore, land surface model soil moisture and high-resolution self-calibrated Palmer Drought Severity Index (scPDSI) datasets are used to quantify drought severity at local scales. The anthropogenic contribution to drought severity is estimated as the difference between the scPDSI calculated using linearly-detrended temperatures, and the scPDSI computed with the observed trend, with unadjusted precipitation, net radiation, and wind speed. Soil moisture anomalies driven by climate change are derived by comparing a large ensemble of forced simulations against a pre-industrial control. The resulting analysis indicates that anthropogenic forcing has intensified the drying trend in the Caribbean by -0.4 scPDSI-units over 60 years, and has increased the dry-land area by 10%. These findings are consistent with observed potential evapotranspiration (PET) anomalies, which are 30% higher than PET-anomalies estimated using detrended temperatures. These results suggest that climate change is already increasing the risk of drought in the Caribbean by enhancing the atmospheric demand of moisture through temperature, and provide insights into the role of climate change in future drought risk in the region.
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Directory of Open Access Journals (Sweden)
Marieke van der Maaten-Theunissen
2013-05-01
Full Text Available We analyzed inter-annual variations in ring width and maximumwood density of Norway spruce (Picea abies (L. Karst. at different altitudes in Baden-Württemberg, southwestern Germany, to determine the climate response of these parameters under contrasting climate conditions. In addition, we compared maximum, average and minimum wood density between sites. Bootstrapped correlation coefficients of ring width and maximum wood density with monthly temperature and precipitation, revealed a different climate sensitivity of both parameters. Ring width showed strong correlations with climate variables in the previous year and in the first half of the growingseason. Further, a negative relationship with summer temperature was observed at the low-altitude sites. Maximum wood density correlated best with temperature during the growing season, whereby strongest correlations were found between September temperature and maximum wood density at the high-altitude sites. Observed differences in maximum, average and minimum wood density are suggested to relate to the local climate; with lower temperature and higher water availability having a negative effect on wood density.
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Directory of Open Access Journals (Sweden)
Marieke van der Maaten-Theunissen
2013-07-01
Full Text Available We analyzed inter-annual variations in ring width and maximum wood density of Norway spruce (Picea abies (L. Karst. at different altitudes in Baden-Württemberg, southwestern Germany, to determine the climate response of these parameters under contrasting climate conditions. In addition, we compared maximum, average and minimum wood density between sites. Bootstrapped correlation coefficients of ring width and maximum wood density with monthly temperature and precipitation, revealed a different climate sensitivity of both parameters. Ring width showed strong correlations with climate variables in the previous year and in the first half of the growing season. Further, a negative relationship with summer temperature was observed at the low-altitude sites. Maximum wood density correlated best with temperature during the growing season, whereby strongest correlations were found between September temperature and maximum wood density at the high-altitude sites. Observed differences in maximum, average and minimum wood density are suggested to relate to the local climate; with lower temperatures and higher water availability having a negative effect on wood density.
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Constraining the models' response of tropical low clouds to SST forcings using CALIPSO observations
Cesana, G.; Del Genio, A. D.; Ackerman, A. S.; Brient, F.; Fridlind, A. M.; Kelley, M.; Elsaesser, G.
2017-12-01
Low-cloud response to a warmer climate is still pointed out as being the largest source of uncertainty in the last generation of climate models. To date there is no consensus among the models on whether the tropical low cloudiness would increase or decrease in a warmer climate. In addition, it has been shown that - depending on their climate sensitivity - the models either predict deeper or shallower low clouds. Recently, several relationships between inter-model characteristics of the present-day climate and future climate changes have been highlighted. These so-called emergent constraints aim to target relevant model improvements and to constrain models' projections based on current climate observations. Here we propose to use - for the first time - 10 years of CALIPSO cloud statistics to assess the ability of the models to represent the vertical structure of tropical low clouds for abnormally warm SST. We use a simulator approach to compare observations and simulations and focus on the low-layered clouds (i.e. z fraction. Vertically, the clouds deepen namely by decreasing the cloud fraction in the lowest levels and increasing it around the top of the boundary-layer. This feature is coincident with an increase of the high-level cloud fraction (z > 6.5km). Although the models' spread is large, the multi-model mean captures the observed variations but with a smaller amplitude. We then employ the GISS model to investigate how changes in cloud parameterizations affect the response of low clouds to warmer SSTs on the one hand; and how they affect the variations of the model's cloud profiles with respect to environmental parameters on the other hand. Finally, we use CALIPSO observations to constrain the model by determining i) what set of parameters allows reproducing the observed relationships and ii) what are the consequences on the cloud feedbacks. These results point toward process-oriented constraints of low-cloud responses to surface warming and environmental
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Use of RCM simulations to assess the impact of climate change on wind energy availability
DEFF Research Database (Denmark)
Pryor, S.C.; Barthelmie, Rebecca Jane
2004-01-01
There is considerable interest in the potential impact of climate change on the feasibility and predictability of renewable energy sources including wind energy. This report presents an application and evaluation of physical (dynamical) downscaling toolsfor examining the impact of climate change...... on near-surface flow and hence wind energy density across northern Europe. It is shown that: - Simulated wind fields using the Rossby Centre coupled Regional Climate Model (RCM) (RCAO) during the control period(1961-1990) exhibit reasonable and realistic features as documented in in situ observations...... and reanalysis data products. - The differences between near-surface wind speed and direction calculated for the control run (January 1, 1961 – December 30, 1990)based on boundary conditions derived from two Global Climate Models (GCM): HadAM3H and ECHAM4/OPYC3 are comparable to changes in the climate change...
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Evaluation of global climate models for Indian monsoon climatology
International Nuclear Information System (INIS)
Kodra, Evan; Ganguly, Auroop R; Ghosh, Subimal
2012-01-01
The viability of global climate models for forecasting the Indian monsoon is explored. Evaluation and intercomparison of model skills are employed to assess the reliability of individual models and to guide model selection strategies. Two dominant and unique patterns of Indian monsoon climatology are trends in maximum temperature and periodicity in total rainfall observed after 30 yr averaging over India. An examination of seven models and their ensembles reveals that no single model or model selection strategy outperforms the rest. The single-best model for the periodicity of Indian monsoon rainfall is the only model that captures a low-frequency natural climate oscillator thought to dictate the periodicity. The trend in maximum temperature, which most models are thought to handle relatively better, is best captured through a multimodel average compared to individual models. The results suggest a need to carefully evaluate individual models and model combinations, in addition to physical drivers where possible, for regional projections from global climate models. (letter)
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Nuclear Renaissance in an Era of Anthropogenic Climate Change
International Nuclear Information System (INIS)
Bird, John
2008-01-01
This paper substantiates the anthropogenic origin of climate change, demonstrates the resulting consequences, and thereby establishes the need for a nuclear renaissance over the next thirty years. First, the mechanisms behind the natural cycles in global warming, specifically, cycles of precession and eccentricity in Earth's orbit, as measured in ice cores, are compared to the mechanisms of anthropogenic warming, revealing the scientific basis for the observed correlation between carbon dioxide and temperature. Second, the resulting climate change is exemplified by key results from experiments performed by the author in the Arctic and at the South Geographic Pole, and the author's experience of Switzerland's costliest natural catastrophe - the flash flood of 2005. Third, although facing barriers such as research and development requirements, political will and public acceptance, the potential for nuclear power to triple to 1,000 GWe by 2050 would mitigate climate change by holding carbon dioxide concentration below 500 ppm, thereby challenging the younger nuclear generation to contribute to the most important issue facing humanity. (authors)