WorldWideScience

Sample records for surface climate conditions

  1. Long-term climate change: the evolution of shield surface boundary conditions

    International Nuclear Information System (INIS)

    Peltier, W.R.

    2007-01-01

    The Earths surface during the Pleistocene epoch has been repeatedly subjected to glacial cycles that have markedly influenced both the landscape and surface boundary conditions that, in part, governed past evolution of deep-seated Shield groundwater flow domains. As part of the Deep Geologic Repository Technology Programme simulations of the last Laurentide glacial episode have been undertaken with the University of Toronto Glacial System Model (GSM). The purpose of these simulations is to yield constrained predictions of the magnitude and time rate of change of peri-glacial, glacial and boreal regimes that have perturbed Shield flow domains in the geologic past. A detailed model of long timescale climate change has been developed, which is able to make useful predictions of the process of continental glaciation and deglaciation that has occurred in the past due to the small changes in the effective intensity of the Sun at the location of the Earth caused by gravitational many body effects in Solar System evolution. Based upon the success of this model we are able to assert that we have demonstrated a basic understanding of why this process has continually recurred in the past on a timescale of approximately 100 000 years. Continuing work with the Glacial Systems Model and efforts to provide explicit linkage to numerical analyses of sub-surface hydrology are beginning to yield a new understanding of groundwater flow system evolution and response to glacial perturbations. In so doing this understanding is not only providing a reasoned basis on which to examine issues of geosphere stability as relevant to the safety of a hypothetical repository for used nuclear fuel in Shield terrain, but is also offering an improved basis for the integrated interpretation of multi-disciplinary geo-scientific data necessary for development of a descriptive geosphere model that is seen as fundamental to the repository Safety Case. (author)

  2. Natural emissions under future climate condition and their effects on surface ozone in the Yangtze River Delta region, China

    Science.gov (United States)

    Xie, Min; Shu, Lei; Wang, Ti-jian; Liu, Qian; Gao, Da; Li, Shu; Zhuang, Bing-liang; Han, Yong; Li, Meng-meng; Chen, Pu-long

    2017-02-01

    The natural emissions of ozone precursors (NOx and VOCs) are sensitive to climate. Future climate change can impact O3 concentrations by perturbing these emissions. To better estimate the variation of natural emissions under different climate conditions and understand its effect on surface O3, we model the present and the future air quality over the Yangtze River Delta (YRD) region by running different simulations with the aid of the WRF-CALGRID model system that contains a natural emission module. Firstly, we estimate the natural emissions at present and in IPCC A1B scenario. The results show that biogenic VOC emission and soil NOx emission over YRD in 2008 is 657 Gg C and 19.1 Gg N, respectively. According to climate change, these emissions in 2050 will increase by 25.5% and 11.5%, respectively. Secondly, the effects of future natural emissions and meteorology on surface O3 are investigated and compared. It is found that the variations in meteorological fields can significantly alter the spatial distribution of O3 over YRD, with the increases of 5-15 ppb in the north and the decreases of -5 to -15 ppb in the south. However, only approximately 20% of the surface O3 increases caused by climate change can be attributed to the natural emissions, with the highest increment up to 2.4 ppb. Finally, Ra (the ratio of impacts from NOx and VOCs on O3 formation) and H2O2/HNO3 (the ratio between the concentrations of H2O2 and HNO3) are applied to study the O3 sensitivity in YRD. The results show that the transition value of H2O2/HNO3 will turn from 0.3 to 0.5 in 2008 to 0.4-0.8 in 2050. O3 formation in the YRD region will be insensitive to VOCs under future climate condition, implying more NOx need to be cut down. Our findings can help us understand O3 variation trend and put forward the reasonable and effective pollution control policies in these famous polluted areas.

  3. A statistical adjustment approach for climate projections of snow conditions in mountain regions using energy balance land surface models

    Science.gov (United States)

    Verfaillie, Deborah; Déqué, Michel; Morin, Samuel; Lafaysse, Matthieu

    2017-04-01

    Projections of future climate change have been increasingly called for lately, as the reality of climate change has been gradually accepted and societies and governments have started to plan upcoming mitigation and adaptation policies. In mountain regions such as the Alps or the Pyrenees, where winter tourism and hydropower production are large contributors to the regional revenue, particular attention is brought to current and future snow availability. The question of the vulnerability of mountain ecosystems as well as the occurrence of climate-related hazards such as avalanches and debris-flows is also under consideration. In order to generate projections of snow conditions, however, downscaling global climate models (GCMs) by using regional climate models (RCMs) is not sufficient to capture the fine-scale processes and thresholds at play. In particular, the altitudinal resolution matters, since the phase of precipitation is mainly controlled by the temperature which is altitude-dependent. Simulations from GCMs and RCMs moreover suffer from biases compared to local observations, due to their rather coarse spatial and altitudinal resolution, and often provide outputs at too coarse time resolution to drive impact models. RCM simulations must therefore be adjusted using empirical-statistical downscaling and error correction methods, before they can be used to drive specific models such as energy balance land surface models. In this study, time series of hourly temperature, precipitation, wind speed, humidity, and short- and longwave radiation were generated over the Pyrenees and the French Alps for the period 1950-2100, by using a new approach (named ADAMONT for ADjustment of RCM outputs to MOuNTain regions) based on quantile mapping applied to daily data, followed by time disaggregation accounting for weather patterns selection. We first introduce a thorough evaluation of the method using using model runs from the ALADIN RCM driven by a global reanalysis over the

  4. Ideal climatic conditions for condensation of atmospheric moisture on the plants’ surface

    Directory of Open Access Journals (Sweden)

    Prokhorov Alexey

    2015-12-01

    A study of the diversity of the plant adaptation mechanisms that contribute to lowering the surface temperature and the absorption of condensate will allow us in the future to carry out introduction, genetic modification or selection of plants with the most visible effect of lowering the temperature and the least dependence on insolation.

  5. The Milankovitch theory and climate sensitivity. I - Equilibrium climate model solutions for the present surface conditions. II - Interaction between the Northern Hemisphere ice sheets and the climate system

    Science.gov (United States)

    Neeman, Binyamin U.; Ohring, George; Joseph, Joachim H.

    1988-01-01

    A seasonal climate model was developed to test the climate sensitivity and, in particular, the Milankovitch (1941) theory. Four climate model versions were implemented to investigate the range of uncertainty in the parameterizations of three basic feedback mechanisms: the ice albedo-temperature, the outgoing long-wave radiation-temperature, and the eddy transport-meridional temperature gradient. It was found that the differences between the simulation of the present climate by the four versions were generally small, especially for annually averaged results. The climate model was also used to study the effect of growing/shrinking of a continental ice sheet, bedrock sinking/uplifting, and sea level changes on the climate system, taking also into account the feedback effects on the climate of the building of the ice caps.

  6. Borehole temperatures, climate change and the pre-observational surface air temperature mean: allowance for hydraulic conditions

    Czech Academy of Sciences Publication Activity Database

    Bodri, L.; Čermák, Vladimír

    2005-01-01

    Roč. 45, č. 4 (2005), s. 265-276 ISSN 0921-8181 R&D Projects: GA AV ČR IAA3012005; GA ČR GA205/03/0998; GA AV ČR KSK3046108 Institutional research plan: CEZ:AV0Z3012916 Keywords : climate change * global warming * surface air temperature Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.223, year: 2005

  7. Investigation on the Temporal Surface Thermal Conditions for Thermal Comfort Researches Inside A Vehicle Cabin Under Summer Season Climate

    Directory of Open Access Journals (Sweden)

    Zhang Wencan

    2016-01-01

    Full Text Available With the proposes of improving occupant's thermal comfort and reducing the air conditioning power consumption, the present research carried out a comprehensive study on the surface thermal conductions and their influence parameters. A numerical model was built considering the transient conduction, convective and radiation heat transfer inside a vehicle cabin. For more accurate simulation of the radiation heat transfer behaviors, the radiation was considered into two spectral bands (short wave and long wave radiation, and the solar radiation was calculated by two solar fluxes (beam and diffuse solar radiation. An experiment was conducted to validate the numerical approach, showing a good agreement with the surface temperature. The surface thermal conditions were numerically simulated. The results show that the solar radiation is the most important factor in determining the internal surface thermal conditions. Effects of the window glass properties and the car body surface conditions were investigated. The numerical calculation results indicate that reducing the transitivity of window glass can effectively reduce the internal surface temperature. And the reflectivity of the vehicle cabin also has an important influence on the surface temperature, however, it's not so obvious as comparison to the window glass.

  8. Empirical methods for estimating future climatic conditions

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Applying the empirical approach permits the derivation of estimates of the future climate that are nearly independent of conclusions based on theoretical (model) estimates. This creates an opportunity to compare these results with those derived from the model simulations of the forthcoming changes in climate, thus increasing confidence in areas of agreement and focusing research attention on areas of disagreements. The premise underlying this approach for predicting anthropogenic climate change is based on associating the conditions of the climatic optimums of the Holocene, Eemian, and Pliocene with corresponding stages of the projected increase of mean global surface air temperature. Provided that certain assumptions are fulfilled in matching the value of the increased mean temperature for a certain epoch with the model-projected change in global mean temperature in the future, the empirical approach suggests that relationships leading to the regional variations in air temperature and other meteorological elements could be deduced and interpreted based on use of empirical data describing climatic conditions for past warm epochs. Considerable care must be taken, of course, in making use of these spatial relationships, especially in accounting for possible large-scale differences that might, in some cases, result from different factors contributing to past climate changes than future changes and, in other cases, might result from the possible influences of changes in orography and geography on regional climatic conditions over time

  9. Ocean climate and seal condition

    Directory of Open Access Journals (Sweden)

    Crocker Daniel E

    2005-03-01

    Full Text Available Abstract Background The condition of many marine mammals varies with fluctuations in productivity and food supply in the ocean basin where they forage. Prey is impacted by physical environmental variables such as cyclic warming trends. The weaning weight of northern elephant seal pups, Mirounga angustirostris, being closely linked to maternal condition, indirectly reflects prey availability and foraging success of pregnant females in deep waters of the northeastern Pacific. The aim of this study was to examine the effect of ocean climate on foraging success in this deep-diving marine mammal over the course of three decades, using cohort weaning weight as the principal metric of successful resource accrual. Results The mean annual weaning weight of pups declined from 1975 to the late 1990s, a period characterized by a large-scale, basin-wide warm decadal regime that included multiple strong or long-duration El Niños; and increased with a return to a cool decadal regime from about 1999 to 2004. Increased foraging effort and decreased mass gain of adult females, indicative of reduced foraging success and nutritional stress, were associated with high ocean temperatures. Conclusion Despite ranging widely and foraging deeply in cold waters beyond coastal thermoclines in the northeastern Pacific, elephant seals are impacted significantly by ocean thermal dynamics. Ocean warming redistributes prey decreasing foraging success of females, which in turn leads to lower weaning mass of pups. Annual fluctuations in weaning mass, in turn, reflect the foraging success of females during the year prior to giving birth and signals changes in ocean temperature cycles.

  10. 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)

  11. Climate conditions in bedded confinement buildings

    Science.gov (United States)

    Confinement buildings are utilized for finishing cattle to allow more efficient collection of animal waste and to buffer animals against adverse climatic conditions. Environmental data were obtained from a 29 m wide x 318 m long bedded confinement building with the long axis oriented east to west. T...

  12. Temporal and spatial variations in sand and dust storm events in East Asia from 2007 to 2016: Relationships with surface conditions and climate change.

    Science.gov (United States)

    An, Linchang; Che, Huizheng; Xue, Min; Zhang, Tianhang; Wang, Hong; Wang, Yaqiang; Zhou, Chunhong; Zhao, Hujia; Gui, Ke; Zheng, Yu; Sun, Tianze; Liang, Yuanxin; Sun, Enwei; Zhang, Hengde; Zhang, Xiaoye

    2018-08-15

    We analyzed the frequency and intensity of sand and dust storms (SDSs) in East Asia from 2007 to 2016 using observational data from ground stations, numerical modeling, and vegetation indices obtained from both satellite and reanalysis data. The relationships of SDSs with surface conditions and the synoptic circulation pattern were also analyzed. The statistical analyses demonstrated that the number and intensity of SDS events recorded in spring during 2007 to 2016 showed a decreasing trend. The total number of spring SDSs decreased from at least ten events per year before 2011 to less than ten events per year after 2011. The overall average annual variation of the surface dust concentration in the main dust source regions decreased 33.24μg/m 3 (-1.75%) annually. The variation in the temperatures near and below the ground surface and the amount of precipitation and soil moisture all favored an improvement in vegetation coverage, which reduced the intensity and frequency of SDSs. The strong winds accompanying the influx of cold air from high latitudes showed a decreasing trend, leading to a decrease in the number of SDSs and playing a key role in the decadal decrease of SDSs. The decrease in the intensity of the polar vortex during study period was closely related to the decrease in the intensity and frequency of SDSs. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Using petrographic techniques to evaluate the induced effects of NaCl, extreme climatic conditions, and traffic load on Spanish road surfaces

    Directory of Open Access Journals (Sweden)

    A. P. Pérez-Fortes

    2017-10-01

    Full Text Available The asphalt surface layer is the most exposed to weather and traffic conditions on roads, especially those subjected to winter maintenance. Therefore, a deep knowledge of the mechanisms which can damage this layer is necessary to improve its design, construction and long-term use. With this purpose, two types of asphalt mixtures used on roads from NW Spain were subjected to durability tests (freezing-thaw and thermal-stress with a saturated NaCl solution. After the durability tests, a wheel tracking test was performed on the samples, and the resultant material was analyzed by optical polarized light and fluorescence microscopy. This analysis showed that the binder-aggregate low adhesion was the main responsible of the asphalt mixture damage. This damage was concentrated in the aggregates because the binder acted as an impermeable wall. Consequently, the NaCl solution penetrated and degraded the aggregates quickly and strongly.

  14. Using petrographic techniques to evaluate the induced effects of NaCl, extreme climatic conditions, and traffic load on Spanish road surfaces

    International Nuclear Information System (INIS)

    Pérez-Fortes, A.F.; Varas-Muriel, M.J.; Castiñeiras, P.

    2017-01-01

    The asphalt surface layer is the most exposed to weather and traffic conditions on roads, especially those subjected to winter maintenance. Therefore, a deep knowledge of the mechanisms which can damage this layer is necessary to improve its design, construction and long-term use. With this purpose, two types of asphalt mixtures used on roads from NW Spain were subjected to durability tests (freezing-thaw and thermal-stress) with a saturated NaCl solution. After the durability tests, a wheel tracking test was performed on the samples, and the resultant material was analyzed by optical polarized light and fluorescence microscopy. This analysis showed that the binder-aggregate low adhesion was the main responsible of the asphalt mixture damage. This damage was concentrated in the aggregates because the binder acted as an impermeable wall. Consequently, the NaCl solution penetrated and degraded the aggregates quickly and strongly. [es

  15. Wind energy under cold climate conditions

    Energy Technology Data Exchange (ETDEWEB)

    Maribo Pedersen, B.

    1999-03-01

    There is an increasing interest in wind energy production under different climatic conditions, among them cold climate and icing conditions. More and more wind turbines are being installed in cold climates and even adapted technology has been developed for that environment. Various national activities are going on in at least Finland, Canada, Italy, Sweden, etc. and international collaboration has been carried out within the European Union's Non-nuclear energy programme. Wind turbine operation is affected by both the cold temperatures and the formation of ice on the blades and the supporting structure. Cold temperatures can be handled by material selections known in other technical fields but to prevent icing, new techniques have to be - and have been - developed. Icing affects the reliability of anemometers, which concerns both turbine control and resource estimation, and changes the aerodynamics of the blades, which eventually stops the turbine. In addition, occasional icing events can locally affect public safety. The development of applied technology has entered some different paths and different solutions are tried out. As the applications are entering a commercial phase, these is a request to gather the experiences and monitor the reliability in a form that can be utilised by developers, manufactureres, consultants and other tenderers. The Topical Experts Meeting will focus on site classification, operational experiences, modelling and mesurements of ice induced loads and safety aspects. (EHS)

  16. Climatic change due to land surface alterations

    Energy Technology Data Exchange (ETDEWEB)

    Franchito, S.H.; Rao, V.B.

    1992-01-01

    A primitive equations global zonally averaged climate model is developed. The model includes biofeedback mechanisms. For the Northern Hemisphere the parameterization of biofeedback mechanisms is similar to that used by Gutman et al. For the Southern Hemisphere new parameterizations are derived. The model simulates reasonably well the mean annual zonally averaged climate and geobotanic zones. Deforestation, desertification, and irrigation experiments are performed. In the case of deforestation and desertification there is a reduction in the surface net radiation, evaporation, and precipitation and an increase in the surface temperature. In the case of irrigation experiment opposite changes occurred. In all the cases considered the changes in evapotranspiration overcome the effect of surface albedo modification. In all the experiments changes are smaller in the Southern Hemisphere.

  17. Heating of roads. Heat consumption and heat output as a function of climate, construction, demands on surface conditions and principle of heat supply. Uppvaermning av vaegar

    Energy Technology Data Exchange (ETDEWEB)

    Magnusson, R

    1977-01-01

    In this work analytical formulas for calculation of temperatures in a heated roadbed are given. The heat flux from a heated surface has been studied. The methods for snowclearence on different types of roads have been investigated. The construction work has been studied. The analytical formulas have been evaluated by comparison between calculated temperatures and temperatures measured in field and laboratory. The heat transfer coefficients in those formulas have been developed empirically by tests in laboratory and field. Surfaces with different types of traffic are divided into three classes according to the demands for snow removal. The construction work has been divided into cost elements. This has given a basis for calculating the economic effects of alternative designs. By this work has been developed a method useful on one hand for calculation of the optimum principle of regulation of the supply of heat and on the other hand for the design of the heat installations in the road.

  18. Automatically Maintain Climatic Conditions inside Agricultural Greenhouses

    Directory of Open Access Journals (Sweden)

    Ali Jasim Ramadhan

    2016-11-01

    Full Text Available In this work, a novel system is designed to remote monitor / automatic control of the temperature, humidity and soil moisture of the agricultural greenhouses. In the proposed system, the author used the mentioned sensors for monitoring the climatic conditions of the agricultural greenhouses; and the system makes a controlling process to fix the required parameters for plant growth by running / stopping the fan, air exchanger and irrigation devices when any changes happened in these parameters. The presented system is based on XBee protocol in the implemented wireless sensor star topology network (WSN to monitor the agricultural greenhouses in real time, and used the GSM and Internet technologies to monitor the agricultural greenhouses from anywhere.

  19. Conditions for mould growth on typical interior surfaces

    DEFF Research Database (Denmark)

    Møller, Eva B.; Andersen, Birgitte; Rode, Carsten

    2017-01-01

    Prediction of the risk for mould growth is an important parameter for the analysis and design of the hygrothermal performance of building constructions. However, in practice the mould growth does not always follow the predicted behavior described by the mould growth models. This is often explained...... by uncertainty in the real conditions of exposure. In this study, laboratory experiments were designed to determine mould growth at controlled transient climate compared to growth at constant climate. The experiment included three building materials with four different surface treatments. The samples were...

  20. Relationship between climate conditions and nosocomial infection ...

    African Journals Online (AJOL)

    EB

    Conclusion: To decrease NIRs and improve health care quality, it is necessary to strengthen the control of ... level, etc.) and environmental factors (climatic ... those in developing countries the wards are generally ... Therefore, effects of ambient.

  1. Do downscaled general circulation models reliably simulate historical climatic conditions?

    Science.gov (United States)

    Bock, Andrew R.; Hay, Lauren E.; McCabe, Gregory J.; Markstrom, Steven L.; Atkinson, R. Dwight

    2018-01-01

    The accuracy of statistically downscaled (SD) general circulation model (GCM) simulations of monthly surface climate for historical conditions (1950–2005) was assessed for the conterminous United States (CONUS). The SD monthly precipitation (PPT) and temperature (TAVE) from 95 GCMs from phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5) were used as inputs to a monthly water balance model (MWBM). Distributions of MWBM input (PPT and TAVE) and output [runoff (RUN)] variables derived from gridded station data (GSD) and historical SD climate were compared using the Kolmogorov–Smirnov (KS) test For all three variables considered, the KS test results showed that variables simulated using CMIP5 generally are more reliable than those derived from CMIP3, likely due to improvements in PPT simulations. At most locations across the CONUS, the largest differences between GSD and SD PPT and RUN occurred in the lowest part of the distributions (i.e., low-flow RUN and low-magnitude PPT). Results indicate that for the majority of the CONUS, there are downscaled GCMs that can reliably simulate historical climatic conditions. But, in some geographic locations, none of the SD GCMs replicated historical conditions for two of the three variables (PPT and RUN) based on the KS test, with a significance level of 0.05. In these locations, improved GCM simulations of PPT are needed to more reliably estimate components of the hydrologic cycle. Simple metrics and statistical tests, such as those described here, can provide an initial set of criteria to help simplify GCM selection.

  2. Projection of climatic suitability for Aedes albopictus Skuse (Culicidae) in Europe under climate change conditions

    Science.gov (United States)

    Fischer, Dominik; Thomas, Stephanie Margarete; Niemitz, Franziska; Reineking, Björn; Beierkuhnlein, Carl

    2011-07-01

    During the last decades the disease vector Aedes albopictus ( Ae. albopictus) has rapidly spread around the globe. The spread of this species raises serious public health concerns. Here, we model the present distribution and the future climatic suitability of Europe for this vector in the face of climate change. In order to achieve the most realistic current prediction and future projection, we compare the performance of four different modelling approaches, differentiated by the selection of climate variables (based on expert knowledge vs. statistical criteria) and by the geographical range of presence records (native range vs. global range). First, models of the native and global range were built with MaxEnt and were either based on (1) statistically selected climatic input variables or (2) input variables selected with expert knowledge from the literature. Native models show high model performance (AUC: 0.91-0.94) for the native range, but do not predict the European distribution well (AUC: 0.70-0.72). Models based on the global distribution of the species, however, were able to identify all regions where Ae. albopictus is currently established, including Europe (AUC: 0.89-0.91). In a second step, the modelled bioclimatic envelope of the global range was projected to future climatic conditions in Europe using two emission scenarios implemented in the regional climate model COSMO-CLM for three time periods 2011-2040, 2041-2070, and 2071-2100. For both global-driven models, the results indicate that climatically suitable areas for the establishment of Ae. albopictus will increase in western and central Europe already in 2011-2040 and with a temporal delay in eastern Europe. On the other hand, a decline in climatically suitable areas in southern Europe is pronounced in the Expert knowledge based model. Our projections appear unaffected by non-analogue climate, as this is not detected by Multivariate Environmental Similarity Surface analysis. The generated risk maps

  3. Relationship between climate conditions and nosocomial infection ...

    African Journals Online (AJOL)

    Background: Nosocomial infections constitute a global health problem. Objective: To explore the relationship between nosocomial infection rates (NIRs) and climatic factors including temperature and relative humidity in Guangzhou area of China. Methods: 30892 patients in our hospital in 2009 were investigated for ...

  4. Community responses to extreme climatic conditions

    Directory of Open Access Journals (Sweden)

    Frédéric JIGUET, Lluis BROTONS, Vincent DEVICTOR

    2011-06-01

    Full Text Available Species assemblages and natural communities are increasingly impacted by changes in the frequency and severity of extreme climatic events. Here we propose a brief overview of expected and demonstrated direct and indirect impacts of extreme events on animal communities. We show that differential impacts on basic biological parameters of individual species can lead to strong changes in community composition and structure with the potential to considerably modify the functional traits of the community. Sudden disequilibria have even been shown to induce irreversible shifts in marine ecosystems, while cascade effects on various taxonomic groups have been highlighted in Mediterranean forests. Indirect effects of extreme climatic events are expected when event-induced habitat changes (e.g. soil stability, vegetation composition, water flows altered by droughts, floods or hurricanes have differential consequences on species assembled within the communities. Moreover, in increasing the amplitude of trophic mismatches, extreme events are likely to turn many systems into ecological traps under climate change. Finally, we propose a focus on the potential impacts of an extreme heat wave on local assemblages as an empirical case study, analysing monitoring data on breeding birds collected in France. In this example, we show that despite specific populations were differently affected by local temperature anomalies, communities seem to be unaffected by a sudden heat wave. These results suggest that communities are tracking climate change at the highest possible rate [Current Zoology 57 (3: 406–413, 2011].

  5. Climate change impact on shallow groundwater conditions in Hungary: Conclusions from a regional modelling study

    Science.gov (United States)

    Kovács, Attila; Marton, Annamária; Tóth, György; Szöcs, Teodóra

    2016-04-01

    A quantitative methodology has been developed for the calculation of groundwater table based on measured and simulated climate parameters. The aim of the study was to develop a toolset which can be used for the calculation of shallow groundwater conditions for various climate scenarios. This was done with the goal of facilitating the assessment of climate impact and vulnerability of shallow groundwater resources. The simulated groundwater table distributions are representative of groundwater conditions at the regional scale. The introduced methodology is valid for modelling purposes at various scales and thus represents a versatile tool for the assessment of climate vulnerability of shallow groundwater bodies. The calculation modules include the following: 1. A toolset to calculate climate zonation from climate parameter grids, 2. Delineation of recharge zones (Hydrological Response Units, HRUs) based on geology, landuse and slope conditions, 3. Calculation of percolation (recharge) rates using 1D analytical hydrological models, 4. Simulation of the groundwater table using numerical groundwater flow models. The applied methodology provides a quantitative link between climate conditions and shallow groundwater conditions, and thus can be used for assessing climate impacts. The climate data source applied in our calculation comprised interpolated daily climate data of the Central European CARPATCLIM database. Climate zones were determined making use of the Thorntwaite climate zonation scheme. Recharge zones (HRUs) were determined based on surface geology, landuse and slope conditions. The HELP hydrological model was used for the calculation of 1D water balance for hydrological response units. The MODFLOW numerical groundwater modelling code was used for the calculation of the water table. The developed methodology was demonstrated through the simulation of regional groundwater table using spatially averaged climate data and hydrogeological properties for various time

  6. Climate conditions in Sweden in a 100,000-year time perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kjellstroem, Erik; Strandberg, Gustav (Rossby Centre, SMHI, Norrkoeping (Sweden)); Brandefelt, Jenny (Dept. of Mechanics, Royal Inst. of Technology, Stockholm (Sweden)); Naeslund, Jens-Ove (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Smith, Ben (Dept of Physical Geography and Ecosystems Analysis, Lund Univ., Lund (Sweden)); Wohlfarth, Barbara (Dept. of Geology and Geochemistry, Stockholm Univ., Stockholm (Sweden))

    2009-04-15

    This report presents results from a project devoted to describing the climatic extremes within which the climate in Fennoscandia may vary over a 100,000 year time span. Based on forcing conditions which have yielded extreme conditions during the last glacial-interglacial cycle, as well as possible future conditions following continued anthropogenic emissions, projections of climate conditions have been made with climate models. Three different periods have been studied; i) a stadial within Marine Isotope Stage 3 (MIS 3) during the last glacial cycle, representing a cold period with a relatively small ice sheet covering parts of Fennoscandia, ii) the Last Glacial Maximum (LGM), with an extensive ice sheet covering large parts of northern Europe and iii) a possible future period in a climate warmer than today. The future case is characterised by high greenhouse gas concentrations in the atmosphere and a complete loss of the Greenland ice sheet. The climate modelling involved the use of a global climate model (GCM) for producing boundary conditions that were used by a regional climate model (RCM). The regional model produced detailed information on climate variables like near-surface air temperature and precipitation over Europe. These climate variables were subsequently used to force a vegetation model that produced a vegetation cover over Europe, consistent with the simulated regional climate. In a final step, the new vegetation cover from the vegetation model was used in the regional climate model to produce the final regional climate. For the studied periods, data on relevant climate parameters have been extracted from the regional model for the Forsmark and Oskarshamn areas on the Swedish east coast and the Olkiluoto region on the west coast of Finland. Due to computational constraints, the modelling efforts include only one forcing scenario per time period. As there is a large degree of uncertainty in the choice of an appropriate forcing scenario, we perform

  7. Climate conditions in Sweden in a 100,000-year time perspective

    International Nuclear Information System (INIS)

    Kjellstroem, Erik; Strandberg, Gustav; Brandefelt, Jenny; Naeslund, Jens-Ove; Smith, Ben; Wohlfarth, Barbara

    2009-04-01

    This report presents results from a project devoted to describing the climatic extremes within which the climate in Fennoscandia may vary over a 100,000 year time span. Based on forcing conditions which have yielded extreme conditions during the last glacial-interglacial cycle, as well as possible future conditions following continued anthropogenic emissions, projections of climate conditions have been made with climate models. Three different periods have been studied; i) a stadial within Marine Isotope Stage 3 (MIS 3) during the last glacial cycle, representing a cold period with a relatively small ice sheet covering parts of Fennoscandia, ii) the Last Glacial Maximum (LGM), with an extensive ice sheet covering large parts of northern Europe and iii) a possible future period in a climate warmer than today. The future case is characterised by high greenhouse gas concentrations in the atmosphere and a complete loss of the Greenland ice sheet. The climate modelling involved the use of a global climate model (GCM) for producing boundary conditions that were used by a regional climate model (RCM). The regional model produced detailed information on climate variables like near-surface air temperature and precipitation over Europe. These climate variables were subsequently used to force a vegetation model that produced a vegetation cover over Europe, consistent with the simulated regional climate. In a final step, the new vegetation cover from the vegetation model was used in the regional climate model to produce the final regional climate. For the studied periods, data on relevant climate parameters have been extracted from the regional model for the Forsmark and Oskarshamn areas on the Swedish east coast and the Olkiluoto region on the west coast of Finland. Due to computational constraints, the modelling efforts include only one forcing scenario per time period. As there is a large degree of uncertainty in the choice of an appropriate forcing scenario, we perform

  8. Georgian climate change under global warming conditions

    Directory of Open Access Journals (Sweden)

    Mariam Elizbarashvili

    2017-03-01

    Full Text Available Georgian Climate change has been considered comprehensively, taking into account World Meteorological Organization recommendations and recent observation data. On the basis of mean temperature and precipitation decadal trend geo-information maps for 1936–2012 years period, Georgian territory zoning has been carried out and for each areas climate indices main trends have been studied, that best characterize climate change - cold and hot days, tropical nights, vegetation period duration, diurnal maximum precipitation, maximum five-day total precipitation, precipitation intensity simple index, precipitation days number of at least 10 mm, 20 mm and 50 mm, rainy and rainless periods duration. Trends of temperature indices are statistically significant. On the Black Sea coastline and Colchis lowland at high confidence level cold and hot days and tropical nights number changes are statistically significant. On eastern Georgia plains at high level of statistical significance, the change of all considered temperature indices has been fixed except for the number of hot days. In mountainous areas only hot day number increasing is significant. Trends of most moisture indices are statistically insignificant. While keeping Georgian climate change current trends, precipitation amount on the Black Sea coastline and Colchis lowland, as well as in some parts of Western Caucasus to the end of the century will increase by 50% and amounts to 3000 and 6000 mm, respectively this will strengthen humidity of those areas. Besides increasing of rainy period duration may constitute the risk for flooding and high waters. On eastern Georgia plains, in particular Kvemo Kartli, annual precipitation amount will decrease by 50% or more, and will be only 150–200 mm and the precipitation daily maximum will decrease by about 20 mm and be only 10–15 mm, which of course will increase the intensity of desertification of steppe and semi-desert landscapes.

  9. Agroclimatic conditions in Europe under climate change

    Czech Academy of Sciences Publication Activity Database

    Trnka, Miroslav; Olesen, J. E.; Kersebaum, K. C.; Skjelvag, A. O.; Eitzinger, J.; Seguin, B.; Peltonen-Sainio, P.; Rotter, R.; Iglesias, A.; Orlandini, S.; Dubrovský, Martin; Hlavinka, P.; Balek, J.; Eckersten, H.; Cloppet, E.; Calanca, P.; Vucetic, V.; Nejedlík, P.; Kumar, S.; Lalic, B.; Mestre, A.; Rossi, F.; Kozyra, J.; Alexandrov, V.; Semerádová, D.; Žalud, Z.

    2011-01-01

    Roč. 17, č. 7 (2011), s. 2298-2318 ISSN 1354-1013 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520; CEZ:AV0Z30420517 Keywords : agroclimatic extremes * agroclimatic index * climate- change impacts * crop production * environmental zones Subject RIV: EH - Ecology, Behaviour Impact factor: 6.862, year: 2011

  10. Slarti: A boundary condition editor for a coupled climate model

    Science.gov (United States)

    Mickelson, S. A.; Jacob, R. L.; Pierrehumbert, R.

    2006-12-01

    One of the largest barriers to making climate models more flexible is the difficulty in creating new boundary conditions, especially for "deep time" paleoclimate cases where continents are in different positions. Climate models consist of several mutually-interacting component models and the boundary conditions must be consistent between them. We have developed a program called Slarti which uses a Graphical User Interface and a set of consistency rules to aid researchers in creating new, consistent, boundary condition files for the Fast Ocean Atmosphere Model (FOAM). Users can start from existing mask, topography, or bathymetry data or can build a "world" entirely from scratch (e.g. a single island continent). Once a case has been started, users can modify mask, vegetation, bathymetry, topography, and river flow fields by drawing new data through a "paint" interface. Users activate a synchronization button which goes through the fields to eliminate inconsistencies. When the changes are complete and save is selected, Slarti creates all the necessary files for an initial run of FOAM. The data is edited at the highest resolution (the ocean-land surface in FOAM) and then interpolated to the atmosphere resolution. Slarti was implemented in Java to maintain portability across platforms. We also relied heavily on Java Swing components to create the interface. This allowed us to create an object-oriented interface that could be used on many different systems. Since Slarti allows users to visualize their changes, they are able to see areas that may cause problems when the model is ran. Some examples would be lakes from the river flow field and narrow trenches within the bathymetry. Through different checks and options available through its interface, Slarti makes the process of creating new boundary conditions for FOAM easier and faster while reducing the chance for user errors.

  11. Well Conditioned Formulations for Open Surface Scattering

    National Research Council Canada - National Science Library

    Ottusch, John J; Visher, John L

    2008-01-01

    .... This report describes an analytical preconditioner method for the EFIE on open surface PEC targets that converts the EFIE to a well conditioned, second-kind integral equation. We present theory and the results from a numerical implementation. We also discuss a 2d extension of the Poincare-Bertrand identity could be used to develop an explicitly second-kind integral equation for open surface scattering problems.

  12. Modeling current climate conditions for forest pest risk assessment

    Science.gov (United States)

    Frank H. Koch; John W. Coulston

    2010-01-01

    Current information on broad-scale climatic conditions is essential for assessing potential distribution of forest pests. At present, sophisticated spatial interpolation approaches such as the Parameter-elevation Regressions on Independent Slopes Model (PRISM) are used to create high-resolution climatic data sets. Unfortunately, these data sets are based on 30-year...

  13. Power engineering under conditions of climatic changes

    International Nuclear Information System (INIS)

    Wajs, K.

    1993-01-01

    One of the climatic phenomena fairly well connected with power engineering in the so called greenhouse effect. It is caused by increase of emission to the atmosphere of the so called greenhouse gases, especially CO 2 . Mechanism of this phenomenon and the relevant observations are discussed. Basic models of the circulation of greenhouse gases are outlined and the relevant conclusions as to various probable results, especially for a large time scale, are given. Tasks in the area of power engineering activity in the present situation are described. (author). 19 refs

  14. Surface radiation fluxes in transient climate simulations

    Science.gov (United States)

    Garratt, J. R.; O'Brien, D. M.; Dix, M. R.; Murphy, J. M.; Stephens, G. L.; Wild, M.

    1999-01-01

    Transient CO 2 experiments from five coupled climate models, in which the CO 2 concentration increases at rates of 0.6-1.1% per annum for periods of 75-200 years, are used to document the responses of surface radiation fluxes, and associated atmospheric properties, to the CO 2 increase. In all five models, the responses of global surface temperature and column water vapour are non-linear and fairly tightly constrained. Thus, global warming lies between 1.9 and 2.7 K at doubled, and between 3.1 and 4.1 K at tripled, CO 2, whilst column water vapour increases by between 3.5 and 4.5 mm at doubled, and between 7 and 8 mm at tripled, CO 2. Global cloud fraction tends to decrease by 1-2% out to tripled CO 2, mainly the result of decreases in low cloud. Global increases in column water, and differences in these increases between models, are mainly determined by the warming of the tropical oceans relative to the middle and high latitudes; these links are emphasised in the zonal profiles of warming and column water vapour increase, with strong water vapour maxima in the tropics. In all models the all-sky shortwave flux to the surface S↓ (global, annual average) changes by less than 5 W m -2 out to tripled CO 2, in some cases being essentially invariant in time. In contrast, the longwave flux to the surface L↓ increases significantly, by 25 W m -2 typically at tripled CO 2. The variations of S↓ and L↓ (clear-sky and all-sky fluxes) with increase in CO 2 concentration are generally non-linear, reflecting the effects of ocean thermal inertia, but as functions of global warming are close to linear in all five models. This is best illustrated for the clear-sky downwelling fluxes, and the net radiation. Regionally, as illustrated in zonal profiles and global distributions, greatest changes in both S↓ and L↓ are the result primarily of local maxima in warming and column water vapour increases.

  15. Effects of city expansion on heat stress under climate change conditions.

    Directory of Open Access Journals (Sweden)

    Daniel Argüeso

    Full Text Available We examine the joint contribution of urban expansion and climate change on heat stress over the Sydney region. A Regional Climate Model was used to downscale present (1990-2009 and future (2040-2059 simulations from a Global Climate Model. The effects of urban surfaces on local temperature and vapor pressure were included. The role of urban expansion in modulating the climate change signal at local scales was investigated using a human heat-stress index combining temperature and vapor pressure. Urban expansion and climate change leads to increased risk of heat-stress conditions in the Sydney region, with substantially more frequent adverse conditions in urban areas. Impacts are particularly obvious in extreme values; daytime heat-stress impacts are more noticeable in the higher percentiles than in the mean values and the impact at night is more obvious in the lower percentiles than in the mean. Urban expansion enhances heat-stress increases due to climate change at night, but partly compensates its effects during the day. These differences are due to a stronger contribution from vapor pressure deficit during the day and from temperature increases during the night induced by urban surfaces. Our results highlight the inappropriateness of assessing human comfort determined using temperature changes alone and point to the likelihood that impacts of climate change assessed using models that lack urban surfaces probably underestimate future changes in terms of human comfort.

  16. DEVELOPMENT OF AUTOMATED SYSTEM OF CLIMATE CONDITIONS MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Novikova L.V.

    2017-12-01

    Full Text Available The scientific work is devoted to the analysis and development of the automated control system of the climatic conditions of the minites. The analysis of existing automated control systems is carried out, in particular attention is paid to the systems of climate control of greenhouses. The technical means of the control system are determined. As a platform, Arduino®Uno is selected.

  17. Effect Of Climatic Conditions On Durability

    Directory of Open Access Journals (Sweden)

    Ibrahem M. Al Kiki

    2013-04-01

    Full Text Available Durability is one of the most important subjects in the soil stabilization. Since there is no specifications concerned the durability of lime stabilized soils, several factors were selected to show their effects on the durability, namely: wetting, drying, freezing, thawing and slaking.The effect of each one of the above factors as well as the combined effect of two or more factors, were studied on the volume change and soil strength and weight loss of soil samples stabilized with optimum lime content except the slaking test at which soil samples stabilized with different lime content.Tests results showed that the higher the lime content the lower the slaking effect, also its found the soil strength decreased when the period of immersion or freezing increased. The strength of the lime stabilized soils decreased when subjected to the cycles of wetting and drying or to the cycles freezing and thawing. However, the  combined effect of wetting, drying, freezing and thawing has a pronounced effect on reduction of the lime stabilized clayey soil. The worst condition recorded when lime stabilized soil undergo to freezing then drying then wetting which should be avoided in the field

  18. Unusual climatic conditions and infectious diseases: observations made by Hippocrates.

    Science.gov (United States)

    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.

  19. Impacts of Climate Change on Surface Ozone and Intercontinental Ozone Pollution: A Multi-Model Study

    Science.gov (United States)

    Doherty, R. M.; Wild, O.; Shindell, D. T.; Zeng, G.; MacKenzie, I. A.; Collins, W. J.; Fiore, A. M.; Stevenson, D. S.; Dentener, F. J.; Schultz, M. G.; hide

    2013-01-01

    The impact of climate change between 2000 and 2095 SRES A2 climates on surface ozone (O)3 and on O3 source-receptor (S-R) relationships is quantified using three coupled climate-chemistry models (CCMs). The CCMs exhibit considerable variability in the spatial extent and location of surface O3 increases that occur within parts of high NOx emission source regions (up to 6 ppbv in the annual average and up to 14 ppbv in the season of maximum O3). In these source regions, all three CCMs show a positive relationship between surface O3 change and temperature change. Sensitivity simulations show that a combination of three individual chemical processes-(i) enhanced PAN decomposition, (ii) higher water vapor concentrations, and (iii) enhanced isoprene emission-largely reproduces the global spatial pattern of annual-mean surface O3 response due to climate change (R2 = 0.52). Changes in climate are found to exert a stronger control on the annual-mean surface O3 response through changes in climate-sensitive O3 chemistry than through changes in transport as evaluated from idealized CO-like tracer concentrations. All three CCMs exhibit a similar spatial pattern of annual-mean surface O3 change to 20% regional O3 precursor emission reductions under future climate compared to the same emission reductions applied under present-day climate. The surface O3 response to emission reductions is larger over the source region and smaller downwind in the future than under present-day conditions. All three CCMs show areas within Europe where regional emission reductions larger than 20% are required to compensate climate change impacts on annual-mean surface O3.

  20. Improvement of greenhouse design and climate control in mediterranean conditions

    NARCIS (Netherlands)

    Tuzel, Yuksel; Zwart, de Feije; Sapounas, A.; Hemming, Silke; Stanghellini, Cecilia

    2017-01-01

    The Mediterranean Region is one of the most important areas of the world in terms of protected cultivation. Turkey, with its increasing greenhouse area, is one of the representative countries of the region. Thanks to the mild winter climatic conditions, cultivation of vegetables under simple

  1. Forecasting conditional climate-change using a hybrid approach

    Science.gov (United States)

    Esfahani, Akbar Akbari; Friedel, Michael J.

    2014-01-01

    A novel approach is proposed to forecast the likelihood of climate-change across spatial landscape gradients. This hybrid approach involves reconstructing past precipitation and temperature using the self-organizing map technique; determining quantile trends in the climate-change variables by quantile regression modeling; and computing conditional forecasts of climate-change variables based on self-similarity in quantile trends using the fractionally differenced auto-regressive integrated moving average technique. The proposed modeling approach is applied to states (Arizona, California, Colorado, Nevada, New Mexico, and Utah) in the southwestern U.S., where conditional forecasts of climate-change variables are evaluated against recent (2012) observations, evaluated at a future time period (2030), and evaluated as future trends (2009–2059). These results have broad economic, political, and social implications because they quantify uncertainty in climate-change forecasts affecting various sectors of society. Another benefit of the proposed hybrid approach is that it can be extended to any spatiotemporal scale providing self-similarity exists.

  2. Effects of future climate conditions on terrestrial export from coastal southern California

    Science.gov (United States)

    Feng, D.; Zhao, Y.; Raoufi, R.; Beighley, E.; Melack, J. M.

    2015-12-01

    The Santa Barbara Coastal - Long Term Ecological Research Project (SBC-LTER) is focused on investigating the relative importance of land and ocean processes in structuring giant kelp forest ecosystems. Understanding how current and future climate conditions influence terrestrial export is a central theme for the project. Here we combine the Hillslope River Routing (HRR) model and daily precipitation and temperature downscaled using statistical downscaling based on localized constructed Analogs (LOCA) to estimate recent streamflow dynamics (2000 to 2014) and future conditions (2015 to 2100). The HRR model covers the SBC-LTER watersheds from just west of the Ventura River to Point Conception; a land area of roughly 800 km2 with 179 watersheds ranging from 0.1 to 123 km2. The downscaled climate conditions have a spatial resolution of 6 km by 6 km. Here, we use the Penman-Monteith method with the Food and Agriculture Organization of the United Nations (FAO) limited climate data approximations and land surface conditions (albedo, leaf area index, land cover) measured from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra and Aqua satellites to estimate potential evapotranspiration (PET). The HRR model is calibrated for the period 2000 to 2014 using USGS and LTER streamflow. An automated calibration technique is used. For future climate scenarios, we use mean 8-day land cover conditions. Future streamflow, ET and soil moisture statistics are presented and based on downscaled P and T from ten climate model projections from the Coupled Model Intercomparison Project Phase 5 (CMIP5).

  3. Performance of desiccant air conditioning system with geothermal energy under different climatic conditions

    International Nuclear Information System (INIS)

    El-Agouz, S.A.; Kabeel, A.E.

    2014-01-01

    Highlights: • The performance of the hybrid air conditioning system is studied. • The influence of important operating parameters are estimated. • The ventilation, makeup and mix cycles are investigated at different climate. • The highest COP of the hybrid air conditioning system is 1.03. • The hybrid system provides a human thermal comfort at different climates. - Abstract: Energy saving still and continue a major seek in our life, due to the continuous increase in energy consumptions. So, a desiccant air conditioning system with geothermal energy is conducted in the current study. The thermal analysis of air conditioning system with its different components desiccant wheel, solar collector, heat exchanger, ground heat exchanger and water spray evaporative cooler is presented. Three different air conditioning cycles are simulated in the current study for different zones like: hot-dry zone, warm-dry zone, hot-humid zone and the warm-humid zone. The results show that the desiccant air conditioning system successfully provides a better thermal comfort condition in different climates. This hybrid system significantly decreases the supplied air temperature from 12.7 to 21.7 °C at different climate zones. When ω in , air and T Reg increasing, COP decreases and the ventilation cycle provides the better COP. The highest COP value of the desiccant air conditioning system is about 1.03 while the lowest value is about 0.15. The SHR of makeup cycle is higher than that ventilation cycle at warm and hot-humid zone and vice versa at warm and hot-dry zone. The highest SHR value of the desiccant air conditioning system is about 0.99 while the lowest value is about 0.2. The T sup,air , ω sup,air , COP and SHR isolines may easily be used for pre-evaluating of various cooling cycles in different climates. The hybrid system provides a human thermal comfort at different climates

  4. Land-surface initialisation improves seasonal climate prediction skill for maize yield forecast.

    Science.gov (United States)

    Ceglar, Andrej; Toreti, Andrea; Prodhomme, Chloe; Zampieri, Matteo; Turco, Marco; Doblas-Reyes, Francisco J

    2018-01-22

    Seasonal crop yield forecasting represents an important source of information to maintain market stability, minimise socio-economic impacts of crop losses and guarantee humanitarian food assistance, while it fosters the use of climate information favouring adaptation strategies. As climate variability and extremes have significant influence on agricultural production, the early prediction of severe weather events and unfavourable conditions can contribute to the mitigation of adverse effects. Seasonal climate forecasts provide additional value for agricultural applications in several regions of the world. However, they currently play a very limited role in supporting agricultural decisions in Europe, mainly due to the poor skill of relevant surface variables. Here we show how a combined stress index (CSI), considering both drought and heat stress in summer, can predict maize yield in Europe and how land-surface initialised seasonal climate forecasts can be used to predict it. The CSI explains on average nearly 53% of the inter-annual maize yield variability under observed climate conditions and shows how concurrent heat stress and drought events have influenced recent yield anomalies. Seasonal climate forecast initialised with realistic land-surface achieves better (and marginally useful) skill in predicting the CSI than with climatological land-surface initialisation in south-eastern Europe, part of central Europe, France and Italy.

  5. 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

  6. Wetlands inform how climate extremes influence surface water expansion and contraction

    Science.gov (United States)

    Vanderhoof, Melanie; Lane, Charles R.; McManus, Michael L.; Alexander, Laurie C.; Christensen, Jay R.

    2018-01-01

    Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985–2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic

  7. Wetlands inform how climate extremes influence surface water expansion and contraction

    Science.gov (United States)

    Vanderhoof, Melanie K.; Lane, Charles R.; McManus, Michael G.; Alexander, Laurie C.; Christensen, Jay R.

    2018-03-01

    Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985-2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic drainage

  8. Wetlands inform how climate extremes influence surface water expansion and contraction

    Directory of Open Access Journals (Sweden)

    M. K. Vanderhoof

    2018-03-01

    Full Text Available Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1 quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR and adjacent Northern Prairie (NP in the United States, and (2 explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985–2015. The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density. To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less

  9. Environmental risk of climate change and groundwater abstraction on stream ecological conditions

    DEFF Research Database (Denmark)

    Seaby, Lauren Paige; Bøgh, Eva; Jensen, Niels H.

    with DAISY, a one dimensional crop model describing soil water dynamics in the root zone, and MIKE SHE, a distributed groundwater-surface water model. The relative and combined impacts on low flows, groundwater levels, and nitrate leaching are quantified and compared to assess the water resource sensitivity...... and risk to stream ecological conditions. We find low flow and annual discharge to be most impacted by scenarios of climate change, with high variation across climate models (+/- 40% change). Doubling of current groundwater abstraction rates reduces annual discharge by approximately 20%, with higher...... flows and groundwater levels are of interest, as they relate to aquatic habitat and nitrate leaching, respectively. This study evaluates the risk to stream ecological conditions for a lowland Danish catchment under multiple scenarios of climate change and groundwater abstraction. Projections of future...

  10. Ceramic production during changing environmental/climatic conditions

    Science.gov (United States)

    Oestreich, Daniela B.; Glasmacher, Ulrich A.

    2015-04-01

    Ceramics, with regard to their status as largely everlasting everyday object as well as on the basis of their chronological sensitivity, reflect despite their simplicity the technological level of a culture and therefore also, directly or indirectly, the adaptability of a culture with respect to environmental and/or climatic changes. For that reason the question arises, if it is possible to identify changes in production techniques and raw material sources for ceramic production, as a response to environmental change, e.g. climate change. This paper will present results of a research about Paracas Culture (800 - 200 BC), southern Peru. Through several investigations (e.g. Schittek et al., 2014; Eitel and Mächtle, 2009) it is well known that during Paracas period changes in climate and environmental conditions take place. As a consequence, settlement patterns shifted several times through the various stages of Paracas time. Ceramics from three different sites (Jauranga, Cutamalla, Collanco) and temporal phases of the Paracas period are detailed archaeometric, geochemical and mineralogical characterized, e.g. Raman spectroscopy, XRD, and ICP-MS analyses. The aim of this research is to resolve potential differences in the chemical composition of the Paracas ceramics in space and time and to compare the data with the data sets of pre-Columbian environmental conditions. Thus influences of changing environmental conditions on human societies and their cultural conditions will be discussed. References Eitel, B. and Mächtle, B. 2009. Man and Environment in the eastern Atacama Desert (Southern Peru): Holocene climate changes and their impact on pre-Columbian cultures. In: Reindel, M. & Wagner, G. A. (eds.) New Technologies for Archaeology. Berlin Heidelberg: Springer-Verlag. Schittek, K., Mächtle, B., Schäbitz, F., Forbriger, M., Wennrich, V., Reindel, M., and Eitel, B.. Holocene environmental changes in the highlands of the southern Peruvian Andes (14° S) and their

  11. The transferability of hydrological models under nonstationary climatic conditions

    Directory of Open Access Journals (Sweden)

    C. Z. Li

    2012-04-01

    Full Text Available This paper investigates issues involved in calibrating hydrological models against observed data when the aim of the modelling is to predict future runoff under different climatic conditions. To achieve this objective, we tested two hydrological models, DWBM and SIMHYD, using data from 30 unimpaired catchments in Australia which had at least 60 yr of daily precipitation, potential evapotranspiration (PET, and streamflow data. Nash-Sutcliffe efficiency (NSE, modified index of agreement (d1 and water balance error (WBE were used as performance criteria. We used a differential split-sample test to split up the data into 120 sub-periods and 4 different climatic sub-periods in order to assess how well the calibrated model could be transferred different periods. For each catchment, the models were calibrated for one sub-period and validated on the other three. Monte Carlo simulation was used to explore parameter stability compared to historic climatic variability. The chi-square test was used to measure the relationship between the distribution of the parameters and hydroclimatic variability. The results showed that the performance of the two hydrological models differed and depended on the model calibration. We found that if a hydrological model is set up to simulate runoff for a wet climate scenario then it should be calibrated on a wet segment of the historic record, and similarly a dry segment should be used for a dry climate scenario. The Monte Carlo simulation provides an effective and pragmatic approach to explore uncertainty and equifinality in hydrological model parameters. Some parameters of the hydrological models are shown to be significantly more sensitive to the choice of calibration periods. Our findings support the idea that when using conceptual hydrological models to assess future climate change impacts, a differential split-sample test and Monte Carlo simulation should be used to quantify uncertainties due to

  12. Impact of possible climate changes on river runoff under different natural conditions

    Science.gov (United States)

    Gusev, Yeugeniy M.; Nasonova, Olga N.; Kovalev, Evgeny E.; Ayzel, Georgy V.

    2018-06-01

    The present study was carried out within the framework of the International Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) for 11 large river basins located in different continents of the globe under a wide variety of natural conditions. The aim of the study was to investigate possible changes in various characteristics of annual river runoff (mean values, standard deviations, frequency of extreme annual runoff) up to 2100 on the basis of application of the land surface model SWAP and meteorological projections simulated by five General Circulation Models (GCMs) according to four RCP scenarios. Analysis of the obtained results has shown that changes in climatic runoff are different (both in magnitude and sign) for the river basins located in different regions of the planet due to differences in natural (primarily climatic) conditions. The climatic elasticities of river runoff to changes in air temperature and precipitation were estimated that makes it possible, as the first approximation, to project changes in climatic values of annual runoff, using the projected changes in mean annual air temperature and annual precipitation for the river basins. It was found that for most rivers under study, the frequency of occurrence of extreme runoff values increases. This is true both for extremely high runoff (when the projected climatic runoff increases) and for extremely low values (when the projected climatic runoff decreases).

  13. Ecoclimatic indicators to study crop suitability in present and future climatic conditionsTIC CONDITIONS

    Science.gov (United States)

    Caubel, Julie; Garcia de Cortazar Atauri, Inaki; Huard, Frédéric; Launay, Marie; Ripoche, Dominique; Gouache, David; Bancal, Marie-Odile; Graux, Anne-Isabelle; De Noblet, Nathalie

    2013-04-01

    Climate change is expected to affect both regional and global food production through changes in overall agroclimatic conditions. It is therefore necessary to develop simple tools of crop suitability diagnosis in a given area so that stakeholders can envisage land use adaptations under climate change conditions. The most common way to investigate potential impacts of climate on the evolution of agrosystems is to make use of an array of agroclimatic indicators, which provide synthetic information derived from climatic variables and calculated within fixed periods (i.e. January first - 31th July). However, the information obtained during these periods does not enable to take account of the plant response to climate. In this work, we present some results of the research program ORACLE (Opportunities and Risks of Agrosystems & forests in response to CLimate, socio-economic and policy changEs in France (and Europe). We proposed a suite of relevant ecoclimatic indicators, based on temperature and rainfall, in order to evaluate crop suitability for both present and new climatic conditions. Ecoclimatic indicators are agroclimatic indicators (e.g., grain heat stress) calculated during specific phenological phases so as to take account of the plant response to climate (e.g., the grain filling period, flowering- harvest). These indicators are linked with the ecophysiological processes they characterize (for e.g., the grain filling). To represent this methodology, we studied the suitability of winter wheat in future climatic conditions through three distinct French sites, Toulouse, Dijon and Versailles. Indicators have been calculated using climatic data from 1950 to 2100 simulated by the global climate model ARPEGE forced by a greenhouse effect corresponding to the SRES A1B scenario. The Quantile-Quantile downscaling method was applied to obtain data for the three locations. Phenological stages (emergence, ear 1 cm, flowering, beginning of grain filling and harvest) have been

  14. Decision-Support System for Urban Air Pollution under Future Climate Conditions

    OpenAIRE

    Jensen , Steen ,; Brandt , Jørgen; Hvidberg , Martin; Ketzel , Matthias; Hedegaard , Gitte ,; Christensen , Jens ,

    2011-01-01

    Part 6: Climate Services and Environmental Tools for Urban Planning and Climate Change Applications and Services; International audience; Climate change is expected to influence urban living conditions and challenge the ability of cities to adapt to and mitigate climate change. Urban climates will be faced with elevated temperatures and future climate conditions are expected to cause higher ozone concentrations, increased biogenic emissions from vegetation, changes in the chemistry of the atm...

  15. Characterization of the solar climate in Malawi using NASA's surface ...

    African Journals Online (AJOL)

    user

    Characterization of the solar climate in Malawi using. NASA's surface meteorology and solar energy. (SSE) model. Senganimalunje, T. C.1 and Tenthani, C. M. 2*. 1Malawi Bureau of Standards, Metrology Services Department, Box 946, Blantyre, Malawi. 2Physics and Biochemical Sciences Department, Malawi Polytechnic, ...

  16. Diverging responses of tropical Andean biomes under future climate conditions.

    Directory of Open Access Journals (Sweden)

    Carolina Tovar

    Full Text Available Observations and projections for mountain regions show a strong tendency towards upslope displacement of their biomes under future climate conditions. Because of their climatic and topographic heterogeneity, a more complex response is expected for biodiversity hotspots such as tropical mountain regions. This study analyzes potential changes in the distribution of biomes in the Tropical Andes and identifies target areas for conservation. Biome distribution models were developed using logistic regressions. These models were then coupled to an ensemble of 8 global climate models to project future distribution of the Andean biomes and their uncertainties. We analysed projected changes in extent and elevational range and identified regions most prone to change. Our results show a heterogeneous response to climate change. Although the wetter biomes exhibit an upslope displacement of both the upper and the lower boundaries as expected, most dry biomes tend to show downslope expansion. Despite important losses being projected for several biomes, projections suggest that between 74.8% and 83.1% of the current total Tropical Andes will remain stable, depending on the emission scenario and time horizon. Between 3.3% and 7.6% of the study area is projected to change, mostly towards an increase in vertical structure. For the remaining area (13.1%-17.4%, there is no agreement between model projections. These results challenge the common believe that climate change will lead to an upslope displacement of biome boundaries in mountain regions. Instead, our models project diverging responses, including downslope expansion and large areas projected to remain stable. Lastly, a significant part of the area expected to change is already affected by land use changes, which has important implications for management. This, and the inclusion of a comprehensive uncertainty analysis, will help to inform conservation strategies in the Tropical Andes, and to guide similar

  17. Modelling climate change impacts on stream habitat conditions

    DEFF Research Database (Denmark)

    Boegh, Eva; Conallin, John; Karthikeyan, Matheswaran

    Impact from groundwater abstraction on freshwater resources and ecosystems is an issue of sincere concern in Denmark and many other countries worldwide. In addition, climate change projections add complexity to the existing conflict between water demands to satisfy human needs and water demands...... required to conserve streams as biologically diverse and healthy ecosystems. Solutions to this intensifying conflict require a holistic approach whereby stream biota is related to their physical environment at catchment scale, as also demanded by the EU Water Framework Directive. In the present study......, climate impacts on stream ecological conditions were quantified by combining a heat and mass stream flow with a habitat suitability modelling approach. Habitat suitability indices were developed for stream velocity, water depth, water temperature and substrate. Generally, water depth was found...

  18. Changing climatic conditions in the Upper Thames River Basin

    International Nuclear Information System (INIS)

    Simonovic, S.P.

    2009-01-01

    'Full text:' Many climate change impact studies have been conducted using a top-down approach. First, outputs from Global Circulation Models (GCMs) are considered which are downscaled in a second step to the river basin scale using either a statistical/empirical or a dynamic approach. The local climatic signal that is obtained is then used as input into a hydrological model to assess the direct consequences in the basin. Problems related to this approach include: a high degree of uncertainty associated with GCM outputs; and an increase in uncertainty due to the downscaling approach. An original inverse approach is developed in this work in order to improve the understanding of the processes leading to hydrological hazards, including both flood and drought events. The developed approach starts with the analysis of existing guidelines and management practices in a river basin with respect to critical hydrological exposures that may lead to failure of the water resources system or parts thereof. This implies that vulnerable components of the river basin have to be identified together with the risk exposure. In the next step the critical hydrologic exposures (flood levels for example) are transformed into corresponding critical meteorological conditions (extreme precipitation events for example). These local weather scenarios are then be statistically linked to possible large-scale climate conditions that are available from the GCMs. The developed procedure allows for the assessment of the vulnerability of river basins with respect to climate forcing. It also provides a tool for identifying the spatial distribution of the vulnerability and risk. Vulnerability is here characterized by the incremental losses, expressed either quantitatively or qualitatively, due to a change in the probability and magnitude of hazard events driven by climatic forcing. Vulnerability is seen as the basis for risk mitigation measures for hydrologic extremes at the basin level. The

  19. Future aridity under conditions of global climate change

    Science.gov (United States)

    Asadi Zarch, Mohammad Amin; Sivakumar, Bellie; Malekinezhad, Hossein; Sharma, Ashish

    2017-11-01

    Global climate change is anticipated to cause some major changes in hydroclimatic conditions around the world. As aridity is a reliable indicator of potential available water, assessment of its changes under future climatic conditions is important for proper management of water. This study employs the UNESCO aridity/humidity index, which is a derivative of precipitation (P) and potential evapotranspiration (PET), for assessment of aridity. Historical (1901-2005) simulations and future (2006-2100) projections of 22 global climate models (GCMs) from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) are studied. The Nested Bias Correction (NBC) approach is used to correct possible biases of precipitation (simulated directly by the GCMs) and PET (estimated by applying FAO56-Penman-Monteith model on simulated parameters of the GCMs). To detect future aridity changes, the areal extents of the aridity zones in the past and future periods as well as through four sub-periods (2006-2025, 2026-2050, 2051-2075, and 2076-2100) of the future are compared. The results indicate that changes in climate will alter the areal extents of aridity zones in the future. In general, from the first sub-period towards the last one, the area covered by hyper-arid, arid, semi-arid, and sub-humid zones will increase (by 7.46%, 7.01%, 5.80%, and 2.78%, respectively), while the area of the humid regions will decrease (by 4.76%), suggesting that there will be less water over the global land area in the future. To understand the cause of these changes, precipitation and PET are also separately assumed to be stationary throughout the four future sub-periods and the resulting aridity changes are then analyzed. The results reveal that the aridity changes are mostly caused by the positive PET trends, even though the slight precipitation increase lessens the magnitude of the changes.

  20. Collaborative Research. Quantifying Climate Feedbacks of the Terrestrial Biosphere under Thawing Permafrost Conditions in the Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Qianlai [Purdue Univ., West Lafayette, IN (United States); Schlosser, Courtney [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Melillo, Jerry [Marine Biological Lab. (MBL), Woods Hole, MA (United States); Walter, Katey [Univ. of Alaska, Fairbanks, AK (United States)

    2015-09-15

    Our overall goal is to quantify the potential for threshold changes in natural emission rates of trace gases, particularly methane and carbon dioxide, from pan-arctic terrestrial systems under the spectrum of anthropogenically-forced climate warming, and the conditions under which these emissions provide a strong feedback mechanism to global climate warming. This goal is motivated under the premise that polar amplification of global climate warming will induce widespread thaw and degradation of the permafrost, and would thus cause substantial changes to the landscape of wetlands and lakes, especially thermokarst (thaw) lakes, across the Arctic. Through a suite of numerical experiments that encapsulate the fundamental processes governing methane emissions and carbon exchanges – as well as their coupling to the global climate system - we intend to test the following hypothesis in the proposed research: There exists a climate warming threshold beyond which permafrost degradation becomes widespread and stimulates large increases in methane emissions (via thermokarst lakes and poorly-drained wetland areas upon thawing permafrost along with microbial metabolic responses to higher temperatures) and increases in carbon dioxide emissions from well-drained areas. Besides changes in biogeochemistry, this threshold will also influence global energy dynamics through effects on surface albedo, evapotranspiration and water vapor. These changes would outweigh any increased uptake of carbon (e.g. from peatlands and higher plant photosynthesis) and would result in a strong, positive feedback to global climate warming.

  1. Electron Conditioning of Technical Aluminium Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Le Pimpec, F

    2004-09-02

    The effect of electron conditioning on commercially aluminium alloys 1100 and 6063 were investigated. Contrary to the assumption that electron conditioning, if performed long enough, can reduce and stabilize the SEY to low values (= 1.3, value of many pure elements [1]), the SEY of aluminium did not go lower than 1.8. In fact, it reincreases with continued electron exposure dose.

  2. Challenges of using air conditioning in an increasingly hot climate

    Science.gov (United States)

    Lundgren-Kownacki, Karin; Hornyanszky, Elisabeth Dalholm; Chu, Tuan Anh; Olsson, Johanna Alkan; Becker, Per

    2018-03-01

    At present, air conditioning (AC) is the most effective means for the cooling of indoor space. However, its increased global use is problematic for various reasons. This paper explores the challenges linked to increased AC use and discusses more sustainable alternatives. A literature review was conducted applying a transdisciplinary approach. It was further complemented by examples from cities in hot climates. To analyse the findings, an analytical framework was developed which considers four societal levels—individual, community, city, and national. The main challenges identified from the literature review are as follows: environmental, organisational, socio-economical, biophysical and behavioural. The paper also identifies several measures that could be taken to reduce the fast growth of AC use. However, due to the complex nature of the problem, there is no single solution to provide sustainable cooling. Alternative solutions were categorised in three broad categories: climate-sensitive urban planning and building design, alternative cooling technologies, and climate-sensitive attitudes and behaviour. The main findings concern the problems arising from leaving the responsibility to come up with cooling solutions entirely to the individual, and how different societal levels can work towards more sustainable cooling options. It is concluded that there is a need for a more holistic view both when it comes to combining various solutions as well as involving various levels in society.

  3. Climate Impacts of Fire-Induced Land-Surface Changes

    Science.gov (United States)

    Liu, Y.; Hao, X.; Qu, J. J.

    2017-12-01

    One of the consequences of wildfires is the changes in land-surface properties such as removal of vegetation. This will change local and regional climate through modifying the land-air heat and water fluxes. This study investigates mechanism by developing and a parameterization of fire-induced land-surface property changes and applying it to modeling of the climate impacts of large wildfires in the United States. Satellite remote sensing was used to quantitatively evaluate the land-surface changes from large fires provided from the Monitoring Trends in Burning Severity (MTBS) dataset. It was found that the changes in land-surface properties induced by fires are very complex, depending on vegetation type and coverage, climate type, season and time after fires. The changes in LAI are remarkable only if the actual values meet a threshold. Large albedo changes occur in winter for fires in cool climate regions. The signs are opposite between the first post-fire year and the following years. Summer day-time temperature increases after fires, while nigh-time temperature changes in various patterns. The changes are larger in forested lands than shrub / grassland lands. In the parameterization scheme, the detected post-fire changes are decomposed into trends using natural exponential functions and fluctuations of periodic variations with the amplitudes also determined by natural exponential functions. The final algorithm is a combination of the trends, periods, and amplitude functions. This scheme is used with Earth system models to simulate the local and regional climate effects of wildfires.

  4. Free surface flows under compensated gravity conditions

    CERN Document Server

    Dreyer, Miachel E

    2007-01-01

    This book considers the behavior of fluids in a low-gravity environment with special emphasis on application in PMD (propellant management device) systems . In the compensated gravity environment of a spacecraft, the hydrostatic pressure decreases to very low values depending on the residual acceleration, and surface tension forces become dominant. Consequently, surface tension can be used to transport and position liquids if the residual acceleration and the resulting hydrostatic pressure are small compared to the capillary pressure. One prominent application is the use of PMDs in surface-tension satellite tanks. PMDs must ensure that the tank outlet is covered with liquid whenever outflow is demanded. Furthermore, PMDs are used to ensure expulsion and refilling of tanks for liquids and gases for life support, reactants, and experiment supplies. Since most of the PMD designs are not testable on ground and thus rely on analytical or numerical concepts, this book treats three different flow problems with analy...

  5. Photoelectron spectroscopy of surfaces under humid conditions

    International Nuclear Information System (INIS)

    Bluhm, Hendrik

    2010-01-01

    The interaction of water with surfaces plays a major role in many processes in the environment, atmosphere and technology. Weathering of rocks, adhesion between surfaces, and ionic conductance along surfaces are among many phenomena that are governed by the adsorption of molecularly thin water layers under ambient humidities. The properties of these thin water films, in particular their thickness, structure and hydrogen-bonding to the substrate as well as within the water film are up to now not very well understood. Ambient pressure photoelectron spectroscopy (APXPS) is a promising technique for the investigation of the properties of thin water films. In this article we will discuss the basics of APXPS as well as the particular challenges that are posed by investigations in water vapor at Torr pressures. We will also show examples of the application of APXPS to the study of water films on metals and oxides.

  6. Biocrust spectral response as affected by changing climatic conditions

    Science.gov (United States)

    Rodriguez-Caballero, Emilio; Guirado, Emilio; Escribano, Paula; Reyes, Andres; Weber, Bettina

    2017-04-01

    Drylands are characterized by scarce vegetation coverage and low rates of biological activity, both constrained by water scarcity. Under these conditions, biocrusts form key players of ecosystem functioning. They comprise complex poikilohydric communities of cyanobacteria, algae, lichens and bryophytes together with heterotrophic bacteria, archaea and fungi, which cover the uppermost soil layer. Biocrusts can cope with prolonged phases of drought, being rapidly re-activated when water becomes available again. Upon reactivation, biocrusts almost immediately turn green, fixing atmospheric carbon and nitrogen and increasing ecosystem productivity. However, due to their inconspicuous growth they have only rarely been analysed and spatially and temporally continuous information on their response to water pulses is missing. These data are particularly important under changing climatic conditions predicting an increase in aridity and variations in precipitation patterns within most of the dryland regions. In the present study, we used multi-temporal series of NDVI obtained from LANDSAT images to analyze biocrust and vegetation response to water pulses within the South African Succulent Karoo and we predicted their future response under different climate change scenarios. The results showed that biocrust and vegetation greenness are controlled by aridity, solar radiation and soil water content, showing similar annual patterns, with minimum values during dry periods that increased within the rainy season and decreased again after the onset of drought. However, biocrusts responded faster to water availability and turned green almost immediately after small rains, producing a small NDVI peak only few days after rainfall, whereas more time was needed for vegetation to grow new green tissue. However, once the photosynthetic tissue of vegetation was restored, it caused the highest increase of NDVI values after the rain. Predicted changes in precipitation patterns and aridity

  7. Mean versus extreme climate in the Mediterranean region and its sensitivity to future global warming conditions

    Energy Technology Data Exchange (ETDEWEB)

    Paeth, H.; Hense, A. [Meteorological Inst., Univ. Bonn (Germany)

    2005-06-01

    The Mediterranean region (MTR) has been supposed to be very sensitive to changes in land surface and atmospheric greenhouse-gas (GHG) concentrations. Particularly, an intensification of climate extremes may be associated with severe socio-economic implications. Here, we present an analysis of climate mean and extreme conditions in this subtropical area based on regional climate model experiments, simulating the present-day and possible future climate. The analysis of extreme values (EVs) is based on the assumption that the extremes of daily precipitation and near-surface temperature are well fitted by the Generalized Pareto distribution (GPD). Return values of extreme daily events are determined using the method of L-moments. Particular emphasis is laid on the evaluation of the return values with respect to the uncertainty range of the estimate as derived from a Monte Carlo sampling approach. During the most recent 25 years the MTR has become dryer in spring but more humid especially in the western part in autumn and winter. At the same time, the whole region has been subject to a substantial warming. The strongest rainfall extremes are simulated in autumn over the Mediterranean Sea around Italy. Temperature extremes are most pronounced over the land masses, especially over northern Africa. Given the large uncertainty of the EV estimate, only 1-year return values are further analysed. During recent decades, statistically significant changes in extremes are only found for temperature. Future climate conditions may come along with a decrease in mean and extreme precipitation during the cold season, whereas an intensification of the hydrological cycle is predicted in summer and autumn. Temperature is predominantly affected over the Iberian Peninsula and the eastern part of the MTR. In many grid boxes, the signals are blurred out due to the large amount of uncertainty in the EV estimate. Thus, a careful analysis is required when making inferences about the future

  8. The effects of climatic conditions on attitudinal changes towards ...

    African Journals Online (AJOL)

    changes associated with climate change and climatic events. The .... influence of rainfall on differences in perceptions towards building materials in poor ...... in the form of flash floods, cloud bursts, or sudden climatic events. Unusually high or ...

  9. Surface and subsurface conditions in permafrost areas - a literature review

    International Nuclear Information System (INIS)

    Vidstrand, Patrik

    2003-02-01

    This report contains a summary of some of the information within existing technical and scientific literature on permafrost. Permafrost is viewed as one of the future climate driven process domains that may exist in Scandinavia, and that may give rise to significantly different surface and subsurface conditions than the present. Except for changes in the biosphere, permafrost may impact hydraulic, mechanical, and chemical subsurface processes and conditions. Permafrost and its influences on the subsurface conditions are thus of interest for the performance and safety assessments of deep geological waste repositories. The definition of permafrost is 'ground that stays at or below 0 deg C for at least two consecutive years'. Permafrost will effect the geological subsurface to some depth. How deep the permafrost may grow is a function of the heat balance, thermal conditions at the surface and within the ground, and the geothermal heat flux from the Earth's inner parts. The main chapters of the report summaries the knowledge on permafrost evolution, occurrence and distribution, and extracts information concerning hydrology and mechanical and chemical impacts due to permafrost related conditions. The results of a literature review are always dependent on the available literature. Concerning permafrost there is some literature available from investigations in the field of long-term repositories and some from mining industries. However, reports of these investigations are few and the bulk of permafrost literature comes from the science departments concerned with surficial processes (e.g. geomorphology, hydrology, agriculture, etc) and from engineering concerns, such as foundation of constructions and pipeline design. This focus within the permafrost research inevitably yields a biased but also an abundant amount of information on localised surficial processes and a limited amount on regional and deep permafrost characteristics. Possible conclusions are that there is

  10. Surface and subsurface conditions in permafrost areas - a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Vidstrand, Patrik [Bergab, Goeteborg (Sweden)

    2003-02-01

    This report contains a summary of some of the information within existing technical and scientific literature on permafrost. Permafrost is viewed as one of the future climate driven process domains that may exist in Scandinavia, and that may give rise to significantly different surface and subsurface conditions than the present. Except for changes in the biosphere, permafrost may impact hydraulic, mechanical, and chemical subsurface processes and conditions. Permafrost and its influences on the subsurface conditions are thus of interest for the performance and safety assessments of deep geological waste repositories. The definition of permafrost is 'ground that stays at or below 0 deg C for at least two consecutive years'. Permafrost will effect the geological subsurface to some depth. How deep the permafrost may grow is a function of the heat balance, thermal conditions at the surface and within the ground, and the geothermal heat flux from the Earth's inner parts. The main chapters of the report summaries the knowledge on permafrost evolution, occurrence and distribution, and extracts information concerning hydrology and mechanical and chemical impacts due to permafrost related conditions. The results of a literature review are always dependent on the available literature. Concerning permafrost there is some literature available from investigations in the field of long-term repositories and some from mining industries. However, reports of these investigations are few and the bulk of permafrost literature comes from the science departments concerned with surficial processes (e.g. geomorphology, hydrology, agriculture, etc) and from engineering concerns, such as foundation of constructions and pipeline design. This focus within the permafrost research inevitably yields a biased but also an abundant amount of information on localised surficial processes and a limited amount on regional and deep permafrost characteristics. Possible conclusions are that

  11. Properties of volcanic soils in cold climate conditions

    Science.gov (United States)

    Kuznetsova, Elena

    2017-04-01

    Layers of volcanic ash and the Andosol soils derived from them may play an important role in preserving snow and ice as well as developing permafrost conditions in the immediate vicinity of volcanoes of high elevation or those situated at high latitudes, and land areas, often distant from volcanic activity that are either prone to permafrost or covered by snow and ice, but are affected by the deposition of subaerial ash. The special properties of volcanic ash that are responsible are critically reviewed particularly in relation to recent research in Kamchatka in the Far East of Russia. Of particular importance are the thermal properties and the unfrozen water contents of ash layers and the rate at which the weathering of volcanic glass takes place. Volcanic glass is the most easily weathered component of volcanic ejecta (Shoji et al., 1993; Kimble et al., 2000). There are many specific environmental conditions, including paleoclimate and present-day climate, the composition of volcanic tephra and glaciation history, which cause the differences in weathering and development of volcanic ash soils (Zehetner et al., 2003). The preservation of in situ, unweathered, and unaltered surficial ash-fall deposits in the cold regions has important implications for paleoclimate and glacial history. Ash-fall deposits, which trap and preserve the soils, sediments, and landforms on which they fall, can be used to resolve local climate conditions (temperature and moisture) at the ash site during ash-fall deposition. The preservation of detailed sedimentary features (e.g. bedding in the ash, sharpness of stratigraphic contacts) can tell us about their post-depositional history, whether they have been redeposited by wind or water, or overridden by glaciers (Marchant et al., 1996). Weathering of volcanic glass results in the development of amorphous clay minerals (e.g. allophane, opal, palagonite) but this takes place much slower in cold than under warmer climate conditions. Only few

  12. Analysis and mapping of present and future drought conditions over Greek areas with different climate conditions

    Science.gov (United States)

    Paparrizos, Spyridon; Maris, Fotios; Weiler, Markus; Matzarakis, Andreas

    2018-01-01

    Estimation of drought in a certain temporal and spatial scale is crucial in climate change studies. The current study targets on three agricultural areas widespread in Greece, Ardas River Basin in Northeastern Greece, Sperchios River Basin in Central Greece, and Geropotamos River Basin in Crete Island in South Greece that are characterized by diverse climates as they are located in various regions. The objective is to assess the spatiotemporal variation of drought conditions prevailing in these areas. The Standardized Precipitation Index (SPI) was used to identify and assess the present and future drought conditions. Future simulated data were derived from a number of Regional Climatic Models (RCMs) from the ENSEMBLES European Project. The analysis was performed for the future periods of 2021-2050 and 2071-2100, implementing A1B and B1 scenarios. The spatial analysis of the drought conditions was performed using a combined downscaling technique and the Ordinary Kriging. The Mann-Kendall test was implemented for trend investigation. During both periods and scenarios, drought conditions will tend to be more severe in the upcoming years. The decrease of the SPI values in the Sperchios River Basin is expected to be the strongest, as it is the only study area that will show a negative balance (in SPI values), regarding the drought conditions. For the Ardas and the Geropotamos River Basins, a great increase of the drought conditions will occur during the 2021-2050 period, while for 2071-2100 period, the decrease will continue but it will be tempered. Nevertheless, the situation in all study areas according to the SPI classification is characterized as "Near-normal", in terms of drought conditions.

  13. Sales down due to particularly mild climatic conditions

    International Nuclear Information System (INIS)

    2007-01-01

    Paris, 27 July 2007 - For the six months to 30 June 2007, Gaz de France's consolidated sales amounted to euro 13,778 million, down 11 per cent compared to the same period in 2006. This performance continues the trend seen over the first quarter of 2007 and in particular reflects the continuation into the second quarter of the climatic factors that affected the start of the year: an exceptionally warm 2006/2007 winter, followed by a spring season with particularly high temperatures. The average temperature of the first half of 2007 corresponds to a heat risk of less than one per cent, meaning that the probability of such a temperature taking place is less than one per cent. Over the first half of the year, volumes distributed in France were down by 25 TWh compared to a comparable period with average weather conditions, whereas in 2006 they were 15 TWh above average. The impact of the weather had similar effects outside of France. Under average weather conditions, the downturn in Group sales was limited to only 0.8 per cent mainly due to market conditions made difficult by the climate, leading to a lower level of gas production and arbitrage activities. Over the first six months of 2007, the Group sought to: - Continue to strengthen its international presence, currently with euro 5,602 million in sales outside of France. The percentage of sales generated outside of France represented 41 per cent of the Group total at the end of June 2007 and increased by 4 percentage points between the first half of 2006 and the first half of 2007. - Prepare for the deregulation of the markets on 1 July 2007 and a new commercial policy for retail customers that has been built around multi-energy and multi-service market offerings. - Create a new subsidiary for the distribution, a process which will be effective at the end of the year as announced. In spite of this unfavourable context, the Group maintains the financial objective for 2007 presented with the 2006 accounts: '2007 will

  14. Sales down due to particularly mild climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Paris, 27 July 2007 - For the six months to 30 June 2007, Gaz de France's consolidated sales amounted to euro 13,778 million, down 11 per cent compared to the same period in 2006. This performance continues the trend seen over the first quarter of 2007 and in particular reflects the continuation into the second quarter of the climatic factors that affected the start of the year: an exceptionally warm 2006/2007 winter, followed by a spring season with particularly high temperatures. The average temperature of the first half of 2007 corresponds to a heat risk of less than one per cent, meaning that the probability of such a temperature taking place is less than one per cent. Over the first half of the year, volumes distributed in France were down by 25 TWh compared to a comparable period with average weather conditions, whereas in 2006 they were 15 TWh above average. The impact of the weather had similar effects outside of France. Under average weather conditions, the downturn in Group sales was limited to only 0.8 per cent mainly due to market conditions made difficult by the climate, leading to a lower level of gas production and arbitrage activities. Over the first six months of 2007, the Group sought to: - Continue to strengthen its international presence, currently with euro 5,602 million in sales outside of France. The percentage of sales generated outside of France represented 41 per cent of the Group total at the end of June 2007 and increased by 4 percentage points between the first half of 2006 and the first half of 2007. - Prepare for the deregulation of the markets on 1 July 2007 and a new commercial policy for retail customers that has been built around multi-energy and multi-service market offerings. - Create a new subsidiary for the distribution, a process which will be effective at the end of the year as announced. In spite of this unfavourable context, the Group maintains the financial objective for 2007 presented with the 2006 accounts: &apos

  15. Smart city planning under the climate change condition

    Science.gov (United States)

    Deng, Dexiang; Zhao, Yue; Zhou, Xi

    2017-08-01

    With the aggravation of climate change, extreme weather events occur continuously, cities are not resilient to climate change, and we need to change the concept of urban planning, centering on climate research and its research achievements, combining with the modern intelligent technology and formulating a smart city that resilience to the climate change, realizing the sustainable development of human, city, environment and society.

  16. Impact of climate change on surface ozone and deposition of sulphur and nitrogen in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Langner, J.; Bergstroem, R.; Foltescu, V. [Swedish Meteorological and Hydrological Institute, Norrkoeping (Sweden)

    2005-02-01

    The potential impact of regional climate change on the distribution and deposition of air pollutants in Europe has been studied using a regional chemistry/transport/deposition model, MATCH. MATCH was set up using meteorological output from two 10-year climate change experiments made with the Rossby Centre regional Atmospheric climate model version 1 (RCA1). RCA1 was forced by boundary conditions from two different global climate models using the IPCC IS92a (business as usual) emission scenario. The global mean warming in both the GCMs was 2.6 K and was reached in the period 2050-2070. Simulations with MATCH indicate substantial potential impact of regional climate change on both deposition of oxidised nitrogen and concentrations of surface ozone. The simulations show a strong increase in surface ozone expressed as AOT40 and mean of daily maximum over southern and central Europe and a decrease in northern Europe. The simulated changes in April-September AOT40 are significant in relation to inter-annual variability over extended areas. Changes in deposition of oxidised nitrogen are much smaller and also less coherent due to the strong inter-annual variability in precipitation in the RCA1 simulations and differences in the regional climate change simulated with RCA1 in the two regional scenarios. Changes in simulated annual deposition are significant in relation to inter-annual variability only over small areas. This indicates that longer simulation periods are necessary to establish changes in deposition. (author)

  17. Impact of climate change on surface ozone and deposition of sulphur and nitrogen in Europe

    Science.gov (United States)

    Langner, Joakim; Bergström, Robert; Foltescu, Valentin

    The potential impact of regional climate change on the distribution and deposition of air pollutants in Europe has been studied using a regional chemistry/transport/deposition model, MATCH. MATCH was set up using meteorological output from two 10-year climate change experiments made with the Rossby Centre regional Atmospheric climate model version 1 (RCA1). RCA1 was forced by boundary conditions from two different global climate models using the IPCC IS92a (business as usual) emission scenario. The global mean warming in both the GCMs was 2.6 K and was reached in the period 2050-2070. Simulations with MATCH indicate substantial potential impact of regional climate change on both deposition of oxidised nitrogen and concentrations of surface ozone. The simulations show a strong increase in surface ozone expressed as AOT40 and mean of daily maximum over southern and central Europe and a decrease in northern Europe. The simulated changes in April-September AOT40 are significant in relation to inter-annual variability over extended areas. Changes in deposition of oxidised nitrogen are much smaller and also less coherent due to the strong inter-annual variability in precipitation in the RCA1 simulations and differences in the regional climate change simulated with RCA1 in the two regional scenarios. Changes in simulated annual deposition are significant in relation to inter-annual variability only over small areas. This indicates that longer simulation periods are necessary to establish changes in deposition.

  18. Impacts of Future Grassland Changes on Surface Climate in Mongolia

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    2013-01-01

    Full Text Available Climate change caused by land use/cover change (LUCC is becoming a hot topic in current global change, especially the changes caused by the grassland degradation. In this paper, based on the baseline underlying surface data of 1993, the predicted underlying surface data which can be derived through overlaying the grassland degradation information to the map of baseline underlying surface, and the atmospheric forcing data of RCP 6.0 from CMIP5, climatological changes caused by future grassland changes for the years 2010–2020 and 2040–2050 with the Weather Research Forecast model (WRF are simulated. The model-based analysis shows that future grassland degradation will significantly result in regional climate change. The grassland degradation in future could lead to an increasing trend of temperature in most areas and corresponding change range of the annual average temperature of −0.1°C–0.4°C, and it will cause a decreasing trend of precipitation and corresponding change range of the annual average precipitation of 10 mm–50 mm. This study identifies lines of evidence for effects of future grassland degradation on regional climate in Mongolia which provides meaningful decision-making information for the development and strategy plan making in Mongolia.

  19. The impact of runoff and surface hydrology on Titan's climate

    Science.gov (United States)

    Faulk, Sean; Lora, Juan; Mitchell, Jonathan

    2017-10-01

    Titan’s surface liquid distribution has been shown by general circulation models (GCMs) to greatly influence the hydrological cycle. Simulations from the Titan Atmospheric Model (TAM) with imposed polar methane “wetlands” reservoirs realistically produce many observed features of Titan’s atmosphere, whereas “aquaplanet” simulations with a global methane ocean are not as successful. In addition, wetlands simulations, unlike aquaplanet simulations, demonstrate strong correlations between extreme rainfall behavior and observed geomorphic features, indicating the influential role of precipitation in shaping Titan’s surface. The wetlands configuration is, in part, motivated by Titan’s large-scale topography featuring low-latitude highlands and high-latitude lowlands, with the implication being that methane may concentrate in the high-latitude lowlands by way of runoff and subsurface flow. However, the extent to which topography controls the surface liquid distribution and thus impacts the global hydrological cycle by driving surface and subsurface flow is unclear. Here we present TAM simulations wherein the imposed wetlands reservoirs are replaced by a surface runoff scheme that allows surface liquid to self-consistently redistribute under the influence of topography. To isolate the singular impact of surface runoff on Titan’s climatology, we run simulations without parameterizations of subsurface flow and topography-atmosphere interactions. We discuss the impact of surface runoff on the surface liquid distribution over seasonal timescales and compare the resulting hydrological cycle to observed cloud and surface features, as well as to the hydrological cycles of the TAM wetlands and aquaplanet simulations. While still idealized, this more realistic representation of Titan’s hydrology provides new insight into the complex interaction between Titan’s atmosphere and surface, demonstrates the influence of surface runoff on Titan’s global climate

  20. Hydrological Modeling in Northern Tunisia with Regional Climate Model Outputs: Performance Evaluation and Bias-Correction in Present Climate Conditions

    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

  1. The yield of eggplant depending on climate conditions and mulching

    Directory of Open Access Journals (Sweden)

    Adamczewska-Sowińska Katarzyna

    2016-06-01

    Full Text Available The field production of eggplant in moderate climates is difficult as it depends heavily on thermal conditions. Eggplant is a species that is sensitive to low temperatures, and temperatures below 16°C constrain the growth of young plants. Other disadvantageous factors include: temperatures that are too high, water shortage and excessive soil humidity. The growth conditions for eggplant can be improved by using mulches. The purpose of the experiment was the assessment of eggplant cropping while using synthetic mulches of polyethylene foil and polypropylene textile. The research took five years (2008-2012 and on the basis of the obtained results it was possible to determine the influence of weather conditions on the yielding of this species. It was proven that eggplant cropping significantly depended on the air temperature and the amount of rainfall during the vegetation period. The highest yield was observed when the average air temperature was high and at the same time rainfall was evenly distributed throughout the vegetation season. It also turned out that the agro-technical procedure which significantly increased eggplant fruit cropping was mulching the soil with polyethylene black foil, or transparent foil, previously having applied a herbicide.

  2. Highly variable Pliocene sea surface conditions in the Norwegian Sea

    Directory of Open Access Journals (Sweden)

    P. E. Bachem

    2017-09-01

    Full Text Available The Pliocene was a time of global warmth with small sporadic glaciations, which transitioned towards the larger-scale Pleistocene glacial–interglacial variability. Here, we present high-resolution records of sea surface temperature (SST and ice-rafted debris (IRD in the Norwegian Sea from 5.32 to 3.14 Ma, providing evidence that the Pliocene surface conditions of the Norwegian Sea underwent a series of transitions in response to orbital forcing and gateway changes. Average SSTs are 2 °C above the regional Holocene mean, with notable variability on millennial to orbital timescales. Both gradual changes and threshold effects are proposed for the progression of regional climate towards the Late Pliocene intensification of Northern Hemisphere glaciation. Cooling from 4.5 to 4.3 Ma may be linked to the onset of poleward flow through the Bering Strait. This cooling was further intensified by a period of cool summers due to weak obliquity forcing. A 7 °C warming of the Norwegian Sea at 4.0 Ma suggests a major increase in northward heat transport from the North Atlantic, leading to an enhanced zonal SST gradient in the Nordic Seas, which may be linked to the expansion of sea ice in the Arctic and Nordic Seas. A warm Norwegian Sea and enhanced zonal temperature gradient between 4.0 and 3.6 Ma may have been a priming factor for increased glaciation around the Nordic Seas due to enhanced evaporation and precipitation at high northern latitudes.

  3. Land surface and climate parameters and malaria features in Vietnam

    Science.gov (United States)

    Liou, Y. A.; Anh, N. K.

    2017-12-01

    Land surface parameters may affect local microclimate, which in turn alters the development of mosquito habitats and transmission risks (soil-vegetation-atmosphere-vector borne diseases). Forest malaria is a chromic issue in Southeast Asian countries, in particular, such as Vietnam (in 1991, approximate 2 million cases and 4,646 deaths were reported (https://sites.path.org)). Vietnam has lowlands, sub-tropical high humidity, and dense forests, resulting in wide-scale distribution and high biting rate of mosquitos in Vietnam, becoming a challenging and out of control scenario, especially in Vietnamese Central Highland region. It is known that Vietnam's economy mainly relies on agriculture and malaria is commonly associated with poverty. There is a strong demand to investigate the relationship between land surface parameters (land cover, soil moisture, land surface temperature, etc.) and climatic variables (precipitation, humidity, evapotranspiration, etc.) in association with malaria distribution. GIS and remote sensing have been proven their powerful potentials in supporting environmental and health studies. The objective of this study aims to analyze physical attributes of land surface and climate parameters and their links with malaria features. The outcomes are expected to illustrate how remotely sensed data has been utilized in geohealth applications, surveillance, and health risk mapping. In addition, a platform with promising possibilities of allowing disease early-warning systems with citizen participation will be proposed.

  4. Surface free energy for systems with integrable boundary conditions

    International Nuclear Information System (INIS)

    Goehmann, Frank; Bortz, Michael; Frahm, Holger

    2005-01-01

    The surface free energy is the difference between the free energies for a system with open boundary conditions and the same system with periodic boundary conditions. We use the quantum transfer matrix formalism to express the surface free energy in the thermodynamic limit of systems with integrable boundary conditions as a matrix element of certain projection operators. Specializing to the XXZ spin-1/2 chain we introduce a novel 'finite temperature boundary operator' which characterizes the thermodynamical properties of surfaces related to integrable boundary conditions

  5. Climate change and water table fluctuation: Implications for raised bog surface variability

    Science.gov (United States)

    Taminskas, Julius; Linkevičienė, Rita; Šimanauskienė, Rasa; Jukna, Laurynas; Kibirkštis, Gintautas; Tamkevičiūtė, Marija

    2018-03-01

    Cyclic peatland surface variability is influenced by hydrological conditions that highly depend on climate and/or anthropogenic activities. A low water level leads to a decrease of peatland surface and an increase of C emissions into the atmosphere, whereas a high water level leads to an increase of peatland surface and carbon sequestration in peatlands. The main aim of this article is to evaluate the influence of hydrometeorological conditions toward the peatland surface and its feedback toward the water regime. A regional survey of the raised bog water table fluctuation and surface variability was made in one of the largest peatlands in Lithuania. Two appropriate indicators for different peatland surface variability periods (increase and decrease) were detected. The first one is an 200 mm y- 1 average net rainfall over a three-year range. The second one is an average annual water depth of 25-30 cm. The application of these indicators enabled the reconstruction of Čepkeliai peatland surface variability during a 100 year period. Processes of peatland surface variability differ in time and in separate parts of peatland. Therefore, internal subbasins in peatland are formed. Subbasins involve autogenic processes that can later affect their internal hydrology, nutrient status, and vegetation succession. Internal hydrological conditions, surface fluctuation, and vegetation succession in peatland subbasins should be taken into account during evaluation of their state, nature management projects, and other peatland research works.

  6. Projecting climate change, drought conditions and crop productivity in Turkey

    NARCIS (Netherlands)

    Sen, B.; Topcu, S.; Türkes, M.; Warner, J.F.

    2012-01-01

    This paper focuses on the evaluation of regional climate model simulation for Turkey for the 21st century. A regional climate model, ICTP-RegCM3, with 20 km horizontal resolution, is used to downscale the reference and future climate scenario (IPCC-A2) simulations. Characteristics of droughts as

  7. Effect of surface conditions on blast wave propagation

    International Nuclear Information System (INIS)

    Song, Seung Ho; Li, Yi Bao; Lee, Chang Hoon; Choi, Jung Il

    2016-01-01

    We performed numerical simulations of blast wave propagations on surfaces by solving axisymmetric two-dimensional Euler equations. Assuming the initial stage of fireball at the breakaway point after an explosion, we investigated the effect of surface conditions considering surface convex or concave elements and thermal conditions on blast wave propagations near the ground surface. Parametric studies were performed by varying the geometrical factors of the surface element as well as thermal layer characteristics. We found that the peak overpressure near the ground zero was increased due to the surface elements, while modulations of the blast wave propagations were limited within a region for the surface elements. Because of the thermal layer, the precursor was formed in the propagations, which led to the attenuation of the peak overpressure on the ground surface

  8. Weather conditions conducive to Beijing severe haze more frequent under climate change

    Science.gov (United States)

    Cai, Wenju; Li, Ke; Liao, Hong; Wang, Huijun; Wu, Lixin

    2017-03-01

    The frequency of Beijing winter severe haze episodes has increased substantially over the past decades, and is commonly attributed to increased pollutant emissions from China’s rapid economic development. During such episodes, levels of fine particulate matter are harmful to human health and the environment, and cause massive disruption to economic activities, as occurred in January 2013. Conducive weather conditions are an important ingredient of severe haze episodes, and include reduced surface winter northerlies, weakened northwesterlies in the midtroposphere, and enhanced thermal stability of the lower atmosphere. How such weather conditions may respond to climate change is not clear. Here we project a 50% increase in the frequency and an 80% increase in the persistence of conducive weather conditions similar to those in January 2013, in response to climate change. The frequency and persistence between the historical (1950-1999) and future (2050-2099) climate were compared in 15 models under Representative Concentration Pathway 8.5 (RCP8.5). The increased frequency is consistent with large-scale circulation changes, including an Arctic Oscillation upward trend, weakening East Asian winter monsoon, and faster warming in the lower troposphere. Thus, circulation changes induced by global greenhouse gas emissions can contribute to the increased Beijing severe haze frequency.

  9. 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

  10. Icing Conditions Over Northern Eurasia in Changing Climate

    Science.gov (United States)

    Bulygina, O.; Arzhanova, N.; Groisman, P. Y.

    2013-12-01

    Climate of the Russian Federation for the national territory. This Reference Book addresses the current state of these weather phenomena. However, the ongoing and projected humidity changes in the high latitudes will strongly affect the circum-polar area (land and ocean) and impact the frequency and intensity of these potentially dangerous weather phenomena across the entire extratropical land area. Therefore the goal of the present study is to quantify icing conditions over the northern Eurasia. Our analysis includes data of 958 Russian stations from 1977 to 2012. Regional analysis of gololed characteristics was carried out using quasi-homogeneous climatic regions. Maps (climatology, trends) are presented mostly for visualization purposes. The area-averaging technique using station values converted to anomalies with respect to a common reference period (in this study, from 1977 to 2012). Anomalies were arithmetically averaged first within 1N x 2E grid cells and thereafter by a weighted average value derived over the quasi-homogeneous climatic regions. This approach provides a more uniform spatial field for averaging.

  11. Modelling land surface fluxes of CO2 in response to climate change and nitrogen deposition

    DEFF Research Database (Denmark)

    Hansen, Kristina; Ambelas Skjøth, Carsten; Geels, Camilla

    Climate change, land use variations, and impacts of atmospheric nitrogen (N) deposition represent uncertainties for the prediction of future greenhouse gas exchange between land surfaces and the atmosphere as the mechanisms describing nutritional effects are not well developed in climate...... climate feedback mechanisms of CO2 between changes in management, land use practise, and climate change....

  12. Climatic conditions governing extensive Azolla bloom during the Middle Eocene

    Science.gov (United States)

    Dekker, Rolande; Speelman, Eveline N.; Barke, Judith; Konijnendijk, Tiuri; Sinninge Damste, Jaap S.; Reichart, Gert-Jan

    2010-05-01

    Enormous amounts of intact mega- and microspores from the free floating aquatic fern Azolla were found in sediments recovered during Integrated Ocean Drilling Program expedition 302, indicating that Azolla grew and reproduced in situ in the Eocene Arctic Ocean. In general, the Early/Middle Eocene is characterized by enhanced greenhouse conditions with elevated sea surface temperatures (SSTs) in the Arctic (~10°C), while tropical sea surface temperatures (SSTs) were only a little warmer than today (with a mean annual temperature (MAT) of 32-34 °C) (Pearson et al., 2007). The consequently reduced temperature gradient between the equator and the poles and the presence of freshwater at the North Pole as indicated by the presence of the freshwater fern Azolla (Brinkhuis et al., 2006) provide important boundary conditions for understanding the hydrological cycle and latent heat transport during this interval. Here we reconstruct variations in SST and mean annual air temperature using the TEX86 and MBT temperature proxies for the Azolla interval. Sediments from around the Arctic Basin have been analyzed, including samples from Alaska, the Mackenzie Basin, Greenland (IODP core 913b), and Denmark. Furthermore, a high resolution sea surface temperature record for the Azolla interval has been constructed from sediment samples from the Lomonosov Ridge, showing a cyclic signal. Model experiments have shown that the here confirmed low equator-to-pole temperature gradient modulated the hydrological cycle. Since the growth of Azolla is restricted to low salinity conditions, changes in the hydrological cycle are proposed to coincide with the cyclic occurrence of Azolla throughout the interval. To confirm the overlapping presence of high quantities of Azolla and increased precipitation, changes in the hydrogen cycle are reconstructed by creating a high resolution hydrogen isotope record throughout the interval. By performing compound specific analyses (δD) on terrestrial derived

  13. Exergy characteristics of a ceiling-type residential air conditioning system operating under different climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ozbek, Arif [Dept. of Mechanical Engineering, Ceyhan Engineering Faculty, Cukurova University, Adana (Turkmenistan)

    2016-11-15

    In this study an energy and exergy analysis of a Ceiling-type residential air conditioning (CTRAC) system operating under different climatic conditions have been investigated for provinces within the different geographic regions of Turkey. Primarily, the hourly cooling load capacities of a sample building (Q{sub evap}) during the months of April, May, June, July, August and September were determined. The hourly total heat gain of the sample building was determined using the Hourly analysis program (HAP). The Coefficient of performance (COP), exergy efficiency (η) and exergy destruction (Ex{sub dest}) values for the whole system and for each component were obtained. The results showed that lower atmospheric temperature (T{sub atm}) influenced the performance of the system and each of its components.

  14. Impact of NaCl Contamination and Climatic Conditions on the Reliability of Printed Circuit Board Assemblies

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2014-01-01

    The effect of climatic conditions and ionic contamination on the reliability of printed circuit board assembly has been investigated in terms of leakage current (LC) and electrochemical migration susceptibility. The change in LC as a function of relative humidity (RH) and temperature was measured...... and 15 $^{\\circ}\\hbox{C}$ –65 $^{\\circ}\\hbox{C}$. The variation of RH at the surface of the test specimens was imposed by 1) increasing the RH of the surrounding air and 2) reducing the temperature of the printed circuit boards using a cooling stage, while maintaining a constant climatic condition...

  15. Characteristics of Eurasian snowmelt and its impacts on the land surface and surface climate

    Science.gov (United States)

    Ye, Kunhui; Lau, Ngar-Cheung

    2018-03-01

    The local hydrological and climatic impacts of Eurasian snowmelt are studied using advanced land surface and atmospheric data. It is found that intense melting of snow is located at mid-high latitudes in April and May. Snowmelt plays an important role in determining the seasonal cycles of surface runoff and soil moisture (SM). Specifically, melting is accompanied by sharp responses in surface runoff and surface SM while the impacts are delayed for deeper-layer of soil. This is particularly significant in the western sector of Eurasia. On interannual timescales, the responses of various surface parameters to snowmelt in the same month are rather significant. However, the persistence of surface SM anomalies is weak due to the strong soil evaporation anomalies and surplus of surface energy for evaporation. Strong impacts on the sensible heat flux, planetary boundary layer height and precipitation in the next month following the melting of snow are identified in west Russia and Siberia. Downward propagation of surface SM anomalies is observed and a positive evaporation-convection feedback is identified in west Russia. However, the subsequent impacts on the local convective precipitation in late spring-summer and its contribution to the total precipitation are seemingly weak. The atmospheric water vapor convergence has strong control over the total precipitation anomalies. Overall, snowmelt-produced SM anomalies are not found to significantly impact the late spring-summer local climate anomalies in Northern Eurasia. Therefore, the delayed remote-responses of atmospheric circulation and climate to the melting of Eurasian snow may be only possible near the melting period.

  16. Icing conditions over Northern Eurasia in changing climate

    International Nuclear Information System (INIS)

    Bulygina, Olga N; Arzhanova, Natalia M; Groisman, Pavel Ya

    2015-01-01

    Icing conditions, particularly in combination with wind, affect greatly the operation of overhead communication and transmission lines causing serious failures, which result in tremendous economic damage. Icing formation is dangerous to agriculture, forestry, high seas fishery, for land and off coast man-made infrastructure. Quantitative icing characteristics such as weight, thickness, and duration are very important for the economy and human wellbeing when their maximum values exceed certain thresholds. Russian meteorological stations perform both visual and instrumental monitoring of icing deposits. Visual monitoring is ocular estimation of the type and intensity of icing and the date of ice appearance and disappearance. Instrumental monitoring is performed by ice accretion indicator that in addition to the type, intensity and duration of ice deposits reports also their weight and size. We used observations at 958 Russian stations for the period 1977–2013 to analyze changes in the ice formation frequency at individual meteorological stations and on the territory of quasi-homogeneous climatic regions in Russia. It was found that hoar frosts are observed in most parts of Russia, but icing only occurs in European Russia and the Far East. On the Arctic coast of Russia, this phenomenon can even be observed in summer months. Statistically significant decreasing trends in occurrence of icing and hoar frost events are found over most of Russia. An increasing trend in icing weights (IWs) was found in the Atlantic Arctic region in autumn. Statistically significant large negative trends in IWs were found in the Pacific Arctic in winter and spring. (letter)

  17. Spirometry Changes in Cold Climatic Conditions of Antarctica.

    Science.gov (United States)

    Udaya, Iyamanda B; Laxmi, Chettangada C; Abhishekh, Hulegar A; Raju, Trichur R; Sathyaprabha, Talakad N

    2015-01-01

    Pulmonary function is one of the important physiological measures that is known to be affected during the changes in the altitude. There is dearth of literature on changes in the pulmonary function variables in the cold climate conditions of Antarctica. We carried out spirometry before, during and after one year stay at Antarctica in members of the Indian expedition. Spirometry was carried out on 23 members of the XXVI Indian Scientific Expedition to Antarctica at baseline, after six months of expedition and at the end of one year, using standard guidelines. The tests were carried out indoor in temperature controlled laboratory. The pulmonary function test parameters did not vary across the period. Although, both forced vital capacity (FVC) and forced expiratory volume in first second (FEV1) showed a decreasing trend but did not attain any statistical significance. However, peak expiratory flow (PEFR) rate was reduced significantly. Our study did not show consistently significant change in the pulmonary function parameters in the members of the Indian Antarctic expedition.

  18. Rainfall and net infiltration probabilities for future climate conditions at Yucca Mountain

    International Nuclear Information System (INIS)

    Long, A.; Childs, S.W.

    1993-01-01

    Performance assessment of repository integrity is a task rendered difficult because it requires predicting the future. This challenge has occupied many scientists who realize that the best assessments are required to maximize the probability of successful repository sitting and design. As part of a performance assessment effort directed by the EPRI, the authors have used probabilistic methods to assess the magnitude and timing of net infiltration at Yucca Mountain. A mathematical model for net infiltration previously published incorporated a probabilistic treatment of climate, surface hydrologic processes and a mathematical model of the infiltration process. In this paper, we present the details of the climatological analysis. The precipitation model is event-based, simulating characteristics of modern rainfall near Yucca Mountain, then extending the model to most likely values for different degrees of pluvial climates. Next the precipitation event model is fed into a process-based infiltration model that considers spatial variability in parameters relevant to net infiltration of Yucca Mountain. The model predicts that average annual net infiltration at Yucca Mountain will range from a mean of about 1 mm under present climatic conditions to a mean of at least 2.4 mm under full glacial (pluvial) conditions. Considerable variations about these means are expected to occur from year-to-year

  19. Groundwater flow modelling of periods with temperate climate conditions - Laxemar

    International Nuclear Information System (INIS)

    Joyce, Steven; Simpson, Trevor; Hartley, Lee; Applegate, David; Hoek, Jaap; Jackson, Peter; Roberts, David; Swan, David; Gylling, Bjoern; Marsic, Niko; Rhen, Ingvar

    2010-12-01

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. This report concerns the modelling of a repository at the Laxemar-Simpevarp site during temperate climate conditions as a comparison to corresponding modelling carried out for Forsmark /Joyce et al. 2010/. The collation and implementation of onsite hydrogeological and hydrogeochemical data from previous reports are used in the construction of a Hydrogeological base case (reference case conceptualisation) and then an examination of various areas of uncertainty within the current understanding by a series of model variants. The Hydrogeological base case models at three different scales, 'repository', 'site' and 'regional' make use of a discrete fracture network (DFN) and equivalent continuous porous medium (ECPM) models. The use of hydrogeological models allow for the investigation of the groundwater flow from a deep disposal facility to the biosphere and for the calculation of performance measures that will provide an input to the site performance assessment. The focus of the study described in this report has been to perform numerical simulations of the hydrogeological system from post-closure and throughout the temperate period up until the receding shoreline leaves the modelling domain at around 15,000 AD. Besides providing quantitative results for the immediate temperate period following post-closure, these results are also intended to give a qualitative indication of the evolution of the groundwater system during future temperate periods within an ongoing cycle of glacial/inter-glacial events

  20. Groundwater flow modelling of periods with temperate climate conditions - Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, Steven; Simpson, Trevor; Hartley, Lee; Applegate, David; Hoek, Jaap; Jackson, Peter; Swan, David (Serco Technical Consulting Services (United Kingdom)); Marsic, Niko (Kemakta Konsult AB (Sweden)); Follin, Sven (SF GeoLogic AB (Sweden))

    2010-11-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different climate conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. This report concerns the modelling of a repository at the Forsmark site during temperate conditions; i.e. from post-closure and throughout the temperate period up until the receding shoreline leaves the modelling domain at around 12,000 AD. The collation and implementation of onsite hydrogeological and hydrogeochemical data from previous reports are used in the construction of a hydrogeological base case (reference case conceptualisation) and then in an examination of various areas of uncertainty within the current understanding by a series of model variants. The hydrogeological base case models at three different scales, 'repository', 'site' and 'regional', make use of continuous porous medium (CPM), equivalent continuous porous medium (ECPM) and discrete fracture network (DFN) models. The use of hydrogeological models allow for the investigation of the groundwater flow from a deep disposal facility to the biosphere and for the calculation of performance measures that will provide an input to the site performance assessment. The focus of the study described in this report has been to perform numerical simulations of the hydrogeological system from post-closure and throughout the temperate period. Besides providing quantitative results for the immediate temperate period following post-closure, these results are also intended to give a qualitative indication of the evolution of the groundwater system during future temperate periods within an ongoing cycle of glacial/inter-glacial events

  1. Groundwater flow modelling of periods with temperate climate conditions - Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, Steven; Simpson, Trevor; Hartley, Lee; Applegate, David; Hoek, Jaap; Jackson, Peter; Roberts, David; Swan, David (Serco Technical Consulting Services (United Kingdom)); Gylling, Bjoern; Marsic, Niko (Kemakta Konsult AB, Stockholm (Sweden)); Rhen, Ingvar (SWECO Environment AB, Falun (Sweden))

    2010-12-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. This report concerns the modelling of a repository at the Laxemar-Simpevarp site during temperate climate conditions as a comparison to corresponding modelling carried out for Forsmark /Joyce et al. 2010/. The collation and implementation of onsite hydrogeological and hydrogeochemical data from previous reports are used in the construction of a Hydrogeological base case (reference case conceptualisation) and then an examination of various areas of uncertainty within the current understanding by a series of model variants. The Hydrogeological base case models at three different scales, 'repository', 'site' and 'regional' make use of a discrete fracture network (DFN) and equivalent continuous porous medium (ECPM) models. The use of hydrogeological models allow for the investigation of the groundwater flow from a deep disposal facility to the biosphere and for the calculation of performance measures that will provide an input to the site performance assessment. The focus of the study described in this report has been to perform numerical simulations of the hydrogeological system from post-closure and throughout the temperate period up until the receding shoreline leaves the modelling domain at around 15,000 AD. Besides providing quantitative results for the immediate temperate period following post-closure, these results are also intended to give a qualitative indication of the evolution of the groundwater system during future temperate periods within an ongoing cycle of glacial/inter-glacial events

  2. Testing of newly developed functional surfaces under pure sliding conditions

    DEFF Research Database (Denmark)

    Godi, Alessandro; Mohaghegh, Kamran; Grønbæk, J.

    2013-01-01

    the surfaces in an industrial context. In this paper, a number of experimental tests were performed using a novel test rig, called axial sliding test, simulating the contact of surfaces under pure sliding conditions. The aim of the experiments is to evaluate the frictional behavior of a new typology...... of textured surfaces, the so-called multifunctional surfaces, characterized by a plateau area able to bear loads and a deterministic pattern of lubricant pockets. Six surface typologies, namely three multifunctional and three machined using classical processes, were chosen to slide against a mirror....... The results comparison showed clearly how employing multifunctional surfaces can reduce friction forces up to 50 % at high normal loads compared to regularly ground or turned surfaces. Friction coefficients approximately equal to 0.12 were found for classically machined surfaces, whereas the values were 0...

  3. Statistical optimization of cultural conditions by response surface ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... Full Length Research Paper. Statistical optimization of cultural conditions by response surface methodology for phenol degradation by a novel ... Phenol is a hydrocarbon compound that is highly toxic, ... Microorganism.

  4. Climate Change and Crop Exposure to Adverse Weather: Changes to Frost Risk and Grapevine Flowering Conditions.

    Science.gov (United States)

    Mosedale, Jonathan R; Wilson, Robert J; Maclean, Ilya M D

    2015-01-01

    The cultivation of grapevines in the UK and many other cool climate regions is expected to benefit from the higher growing season temperatures predicted under future climate scenarios. Yet the effects of climate change on the risk of adverse weather conditions or events at key stages of crop development are not always captured by aggregated measures of seasonal or yearly climates, or by downscaling techniques that assume climate variability will remain unchanged under future scenarios. Using fine resolution projections of future climate scenarios for south-west England and grapevine phenology models we explore how risks to cool-climate vineyard harvests vary under future climate conditions. Results indicate that the risk of adverse conditions during flowering declines under all future climate scenarios. In contrast, the risk of late spring frosts increases under many future climate projections due to advancement in the timing of budbreak. Estimates of frost risk, however, were highly sensitive to the choice of phenology model, and future frost exposure declined when budbreak was calculated using models that included a winter chill requirement for dormancy break. The lack of robust phenological models is a major source of uncertainty concerning the impacts of future climate change on the development of cool-climate viticulture in historically marginal climatic regions.

  5. Groundwater-supported evapotranspiration within glaciated watersheds under conditions of climate change

    Science.gov (United States)

    Cohen, D.; Person, M.; Daannen, R.; Locke, S.; Dahlstrom, D.; Zabielski, V.; Winter, T.C.; Rosenberry, D.O.; Wright, H.; Ito, E.; Nieber, J.L.; Gutowski, W.J.

    2006-01-01

    This paper analyzes the effects of geology and geomorphology on surface-water/-groundwater interactions, evapotranspiration, and recharge under conditions of long-term climatic change. Our analysis uses hydrologic data from the glaciated Crow Wing watershed in central Minnesota, USA, combined with a hydrologic model of transient coupled unsaturated/saturated flow (HYDRAT2D). Analysis of historical water-table (1970-1993) and lake-level (1924-2002) records indicates that larger amplitude and longer period fluctuations occur within the upland portions of watersheds due to the response of the aquifer system to relatively short-term climatic fluctuations. Under drought conditions, lake and water-table levels fell by as much as 2-4 m in the uplands but by 1 m in the lowlands. The same pattern can be seen on millennial time scales. Analysis of Holocene lake-core records indicates that Moody Lake, located near the outlet of the Crow Wing watershed, fell by as much as 4 m between about 4400 and 7000 yr BP. During the same time, water levels in Lake Mina, located near the upland watershed divide, fell by about 15 m. Reconstructed Holocene climate as represented by HYDRAT2D gives somewhat larger drops (6 and 24 m for Moody Lake and Lake Mina, respectively). The discrepancy is probably due to the effect of three-dimensional flow. A sensitivity analysis was also carried out to study how aquifer hydraulic conductivity and land-surface topography can influence water-table fluctuations, wetlands formation, and evapotranspiration. The models were run by recycling a wet year (1985, 87 cm annual precipitation) over a 10-year period followed by 20 years of drier and warmer climate (1976, 38 cm precipitation). Model results indicated that groundwater-supported evapotranspiration accounted for as much as 12% (10 cm) of evapotranspiration. The aquifers of highest hydraulic conductivity had the least amount of groundwater-supported evapotranspiration owing to a deep water table. Recharge

  6. Assessing Lebanon's wildfire potential in association with current and future climatic conditions

    Science.gov (United States)

    George H. Mitri; Mireille G. Jazi; David McWethy

    2015-01-01

    The increasing occurrence and extent of large-scale wildfires in the Mediterranean have been linked to extended periods of warm and dry weather. We set out to assess Lebanon's wildfire potential in association with current and future climatic conditions. The Keetch-Byram Drought Index (KBDI) was the primary climate variable used in our evaluation of climate/fire...

  7. NOAA Climate Data Record (CDR) of Ocean Near Surface Atmospheric Properties, Version 2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Ocean Surface Bundle (OSB) Climate Data Record (CDR) consist of three parts: sea surface temperature; near-surface wind speed, air temperature, and specific...

  8. NOAA Climate Data Record (CDR) of Sea Surface Temperature - WHOI, Version 2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Ocean Surface Bundle (OSB) Climate Data Record (CDR) consist of three parts: sea surface temperature, near-surface atmospheric properties, and heat fluxes....

  9. Regularity conditions of the field on a toroidal magnetic surface

    International Nuclear Information System (INIS)

    Bouligand, M.

    1985-06-01

    We show that a field B vector which is derived from an analytic canonical potential on an ordinary toroidal surface is regular on this surface when the potential satisfies an elliptic equation (owing to the conservative field) subject to certain conditions of regularity of its coefficients [fr

  10. Surface Winds and Dust Biases in Climate Models

    Science.gov (United States)

    Evan, A. T.

    2018-01-01

    An analysis of North African dust from models participating in the Fifth Climate Models Intercomparison Project (CMIP5) suggested that, when forced by observed sea surface temperatures, these models were unable to reproduce any aspects of the observed year-to-year variability in dust from North Africa. Consequently, there would be little reason to have confidence in the models' projections of changes in dust over the 21st century. However, no subsequent study has elucidated the root causes of the disagreement between CMIP5 and observed dust. Here I develop an idealized model of dust emission and then use this model to show that, over North Africa, such biases in CMIP5 models are due to errors in the surface wind fields and not due to the representation of dust emission processes. These results also suggest that because the surface wind field over North Africa is highly spatially autocorrelated, intermodel differences in the spatial structure of dust emission have little effect on the relative change in year-to-year dust emission over the continent. I use these results to show that similar biases in North African dust from the NASA Modern Era Retrospective analysis for Research and Applications (MERRA) version 2 surface wind field biases but that these wind biases were not present in the first version of MERRA.

  11. Climate change and its potential impact on mechanical, hydraulic and chemical conditions

    International Nuclear Information System (INIS)

    Naslund, J.O.

    2009-01-01

    The strategy for managing climate related conditions in SKB ' s safety assessments are based on the notion that it is not possible to predict climate in a 100 000-year time perspective. Instead, the approach in the SR-Can safety assessment was to identify and analyse both moderate climate evolutions as well as extremes within which the climate in Scandinavia may vary. To this end, knowledge on general climate variations in Scandinavia was used to identify characteristic climate domains which in turn were used to build a number of selected climate scenarios. The relevant climate domains for the Forsmark and Laxemar sites in the 100 000-year time perspective are; 1) a temperate climate domain, 2) a peri-glacial climate domain, and 3) a glacial climate domain. Also submerged/non-submerged conditions at the sites are of importance. In the SR-Can safety assessment several climate scenarios were investigated, including a reference evolution based on a repetition of reconstructed conditions for last glacial cycle (the Weichselian glaciation and the Holocene interglacial). For this reconstruction, extensive numerical simulations of ice sheets, isostatic changes, and permafrost were conducted. The resulting scenario showed site-specific timing and duration of the three climate domains and submerged periods for the full glacial cycle. This scenario is not a prediction of a future climate evolution. Instead it is one example of a future evolution that in a realistic and consistent way covers all relevant climate related changes that can be expected in a 100 000-year time perspective. Subsequently, this scenario formed the basis for the construction of additional climate scenarios that were used to analyse the effects of more extreme climate evolutions than during the last glacial cycle. Examples of complementary scenarios are a warmer and wetter climate scenario caused by an increased greenhouse effect, and colder scenarios with deeper permafrost or thicker ice sheets than in

  12. Collaborative Research: Quantifying Climate Feedbacks of the Terrestrial Biosphere under Thawing Permafrost Conditions in the Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Melillo, Jerry [Marine Biological Lab., Woods Hole, MA (United States)

    2017-12-12

    Our overall goal in this research was to quantify the potential for threshold changes in natural emission rates of trace gases, particularly methane and carbon dioxide, from pan-arctic terrestrial systems under the spectrum of anthropogenically-forced climate warming, and the conditions under which these emissions provide a strong feedback mechanism to global climate warming. This goal was motivated under the premise that polar amplification of global climate warming will induce widespread thaw and degradation of the permafrost, and would thus cause substantial changes to the landscape of wetlands and lakes, especially thermokarst (thaw) lakes, across the Arctic. Through a suite of numerical experiments that encapsulate the fundamental processes governing methane emissions and carbon exchanges – as well as their coupling to the global climate system - we tested the following hypothesis in the proposed research: There exists a climate warming threshold beyond which permafrost degradation becomes widespread and stimulates large increases in methane emissions (via thermokarst lakes and poorly-drained wetland areas upon thawing permafrost along with microbial metabolic responses to higher temperatures) and increases in carbon dioxide emissions from well-drained areas. Besides changes in biogeochemistry, this threshold will also influence global energy dynamics through effects on surface albedo, evapotranspiration and water vapor. These changes would outweigh any increased uptake of carbon (e.g. from peatlands and higher plant photosynthesis) and would result in a strong, positive feedback to global climate warming. In collaboration with our Purdue and MIT colleagues, we have attempted to quantify global climate warming effects on land-atmosphere interactions, land-river network interactions, permafrost degradation, vegetation shifts, and land use influence water, carbon, and nitrogen fluxes to and from terrestrial ecosystems in the pan-arctic along with their

  13. Establishment and performance of an experimental green roof under extreme climatic conditions.

    Science.gov (United States)

    Klein, Petra M; Coffman, Reid

    2015-04-15

    Green roofs alter the surface energy balance and can help in mitigating urban heat islands. However, the cooling of green roofs due to evapotranspiration strongly depends on the climatic conditions, and vegetation type and density. In the Southern Central Plains of the United States, extreme weather events, such as high winds, heat waves and drought conditions pose challenges for successful implementation of green roofs, and likely alter their standard performance. The National Weather Center Experimental Green Roof, an interdisciplinary research site established in 2010 in Norman, OK, aimed to investigate the ecological performance and surface energy balance of green roof systems. Starting in May 2010, 26 months of vegetation studies were conducted and the radiation balance, air temperature, relative humidity, and buoyancy fluxes were monitored at two meteorological stations during April-October 2011. The establishment of a vegetative community trended towards prairie plant dominance. High mortality of succulents and low germination of grasses and herbaceous plants contributed to low vegetative coverage. In this condition succulent diversity declined. Bouteloua gracilis and Delosperma cooperi showed typological dominance in harsh climatic conditions, while Sedum species experienced high mortality. The plant community diversified through volunteers such as Euphorbia maculate and Portulaca maculate. Net radiation measured at a green-roof meteorological station was higher than at a control station over the original, light-colored roofing material. These findings indicate that the albedo of the green roof was lower than the albedo of the original roofing material. The low vegetative coverage during the heat and drought conditions in 2011, which resulted in the dark substrate used in the green roof containers being exposed, likely contributed to the low albedo values. Nevertheless, air temperatures and buoyancy fluxes were often lower over the green roof indicating

  14. Effect of multipactor conditioning on technical electrode surfaces

    International Nuclear Information System (INIS)

    Graves, T. P.; Spektor, R.; Stout, P.

    2009-01-01

    Historically, multipactor conditioning has been utilized to remove surface contaminants from rf electrodes by electron-stimulated gas desorption, and such conditioning has been shown to reduce multipactor susceptibility. Multipactor threshold improvements are due to increasing E 1 , the minimum energy for the secondary electron coefficient, δ>1, such that resonant electrons are incapable of producing discharge-sustaining secondary emission. Using an rf amplitude sweep technique, the evolution of the multipactor threshold is measured as a function of multipactor conditioning time for a series of technical electrode surfaces. Results show over +3 dB of threshold improvement in copper and gold electrodes, while the aluminum threshold actually decreases with conditioning exposure. Additionally, these conditioning results indicate the possible voltage region for transient-mode multipaction (TMM), which can cause significant risk to rf systems such as space satellite components for which in-situ conditioning is generally not possible. Experimental results and supporting Monte Carlo particle tracking simulation results are presented.

  15. Characteristics of modified martensitic stainless steel surfaces under tribocorrosion conditions

    International Nuclear Information System (INIS)

    Rozing, Goran; Marusic, Vlatko; Alar, Vesna

    2017-01-01

    Stainless steel samples were tested in the laboratory and under real conditions of tribocorrosion wear. Electrochemical tests were also carried out to verify the corrosion resistance of modified steel surfaces. Metallographic analysis and hardness testing were conducted on stainless steel samples X20Cr13 and X17CrNi16 2. The possibilities of applications of modified surfaces of the selected steels were investigated by testing the samples under real wear conditions. The results have shown that the induction hardened and subsequently nitrided martensitic steels achieved an average wear resistance of up to three orders of magnitude higher as compared to the delivered condition.

  16. Characteristics of modified martensitic stainless steel surfaces under tribocorrosion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Rozing, Goran [Osijek Univ. (Croatia). Chair of Mechanical Engineering; Marusic, Vlatko [Osijek Univ. (Croatia). Dept. of Engineering Materials; Alar, Vesna [Zagreb Univ. (Croatia). Dept. Materials

    2017-04-01

    Stainless steel samples were tested in the laboratory and under real conditions of tribocorrosion wear. Electrochemical tests were also carried out to verify the corrosion resistance of modified steel surfaces. Metallographic analysis and hardness testing were conducted on stainless steel samples X20Cr13 and X17CrNi16 2. The possibilities of applications of modified surfaces of the selected steels were investigated by testing the samples under real wear conditions. The results have shown that the induction hardened and subsequently nitrided martensitic steels achieved an average wear resistance of up to three orders of magnitude higher as compared to the delivered condition.

  17. Climate policy in developing countries and conditional transfers

    International Nuclear Information System (INIS)

    Ruebbelke, Dirk T.G.

    2006-01-01

    This paper analyzes the role international transfers may play in international climate policy in consideration of the policy's ancillary benefits, such as air quality improvements. Ancillary benefits are especially important in many developing countries, while climate protection benefits or primary benefits play a minor role on the political agenda of these countries. In contrast, industrialized countries have a strong interest in combating climate change. These often neglected asymmetries between the developing and industrialized world affect the impacts of transfers. Interestingly, as we will show, the cost differentials between different environmental technologies among countries are the crucial prerequisite for the functioning of a transfer scheme and not the cost differentials in the execution of climate policy. This result has been overlooked by standard pure public good approaches

  18. Uncertainties in extreme precipitation under climate change conditions

    DEFF Research Database (Denmark)

    Sunyer Pinya, Maria Antonia

    of adaptation strategies, but these changes are subject to uncertainties. The focus of this PhD thesis is the quantification of uncertainties in changes in extreme precipitation. It addresses two of the main sources of uncertainty in climate change impact studies: regional climate models (RCMs) and statistical...... downscaling methods (SDMs). RCMs provide information on climate change at the regional scale. SDMs are used to bias-correct and downscale the outputs of the RCMs to the local scale of interest in adaptation strategies. In the first part of the study, a multi-model ensemble of RCMs from the European ENSEMBLES...... project was used to quantify the uncertainty in RCM projections over Denmark. Three aspects of the RCMs relevant for the uncertainty quantification were first identified and investigated. These are: the interdependency of the RCMs; the performance in current climate; and the change in the performance...

  19. Food Security Under Shifting Economic, Demographic, and Climatic Conditions (Invited)

    Science.gov (United States)

    Naylor, R. L.

    2013-12-01

    Global demand for food, feed, and fuel will continue to rise in a more populous and affluent world. Meeting this demand in the future will become increasingly challenging with global climate change; when production shocks stemming from climate variability are added to the new mean climate state, food markets could become more volatile. This talk will focus on the interacting market effects of demand and supply for major food commodities, with an eye on climate-related supply trends and shocks. Lessons from historical patterns of climate variability (e.g., ENSO and its global teleconnections) will be used to infer potential food security outcomes in the event of abrupt changes in the mean climate state. Domestic food and trade policy responses to crop output and price volatility in key producing and consuming nations, such as export bans and import tariffs, will be discussed as a potentially major destabilizing force, underscoring the important influence of uncertainty in achieving--or failing to achieve--food security.

  20. Effect of climatic change on surface environments in the typical region of Horqin Sandy Land

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The town of Agura,a typical region in Horqin Sandy Land,was selected as the study area in this paper.Using 12 remote sensing images and climatic data from the past 20 years,the effects of climate change on surface environments were analyzed.The impact indices of climatic factors,along with their corresponding ranks,were used to characterize the responses of different types of surface environments to climate change.Results show that in the past 20 years,the surface environments of the study area have been deteriorating.Furthermore,there is a positive relationship between the changes in surface environments and those in climatic factors.Various climatic factors influence surface environments in different ways and at different levels.The most sensitive factor is relative humidity,followed by precipitation and evaporation.Overall,moisture is the key factor that affects the changes in surface environments of arid and semi-arid areas.

  1. Soil surface roughness decay in contrasting climates, tillage types and management systems

    Science.gov (United States)

    Vidal Vázquez, Eva; Bertol, Ildegardis; Tondello Barbosa, Fabricio; Paz-Ferreiro, Jorge

    2014-05-01

    results indicate that two or more parameters may be needed to characterize the spatial variability of the soil surface microrelief and to best describe the roughness decay in agricultural soils under the various climatic and anthropogenic conditions studied. Then, rates of soil surface roughness decay were used to evaluate the susceptibility to degradation of the soil surface under the main tillage ands management types studied. Finally the effects of soil surface roughness on soil losses and water losses under typical tillage and management systems of the two contrasting regions studied were outlined.

  2. The response of surface ozone to climate change over the Eastern United States

    Directory of Open Access Journals (Sweden)

    P. N. Racherla

    2008-02-01

    Full Text Available We investigate the response of surface ozone (O3 to future climate change in the eastern United States by performing simulations corresponding to present (1990s and future (2050s climates using an integrated model of global climate, tropospheric gas-phase chemistry, and aerosols. A future climate has been imposed using ocean boundary conditions corresponding to the IPCC SRES A2 scenario for the 2050s decade. Present-day anthropogenic emissions and CO2/CH4 mixing ratios have been used in both simulations while climate-sensitive emissions were allowed to vary with the simulated climate. The severity and frequency of O3 episodes in the eastern U.S. increased due to future climate change, primarily as a result of increased O3 chemical production. The 95th percentile O3 mixing ratio increased by 5 ppbv and the largest frequency increase occured in the 80–90 ppbv range; the US EPA's current 8-h ozone primary standard is 80 ppbv. The increased O3 chemical production is due to increases in: 1 natural isoprene emissions; 2 hydroperoxy radical concentrations resulting from increased water vapor concentrations; and, 3 NOx concentrations resulting from reduced PAN. The most substantial and statistically significant (p<0.05 increases in episode frequency occurred over the southeast and midatlantic U.S., largely as a result of 20% higher annual-average natural isoprene emissions. These results suggest a lengthening of the O3 season over the eastern U.S. in a future climate to include late spring and early fall months. Increased chemical production and shorter average lifetime are two consistent features of the seasonal response of surface O3, with increased dry deposition loss rates contributing most to the reduced lifetime in all seasons except summer. Significant interannual variability is observed in the frequency of O3

  3. Nitrous oxide emissions from manure handling - effects of storage conditions and climate

    International Nuclear Information System (INIS)

    Sommer, S.G.; Petersen, S.O.

    2002-01-01

    Stored animal manure and manure applied in the field contributes an estimated 20% to the total anthropogenic emissions of nitrous oxide (N 2 0) in Denmark. Manure composition, handling and climatic conditions may all influence the emission level during storage, but there are relatively few experimental data on emissions of N 2 0 from manure management, including animal houses, slurry stores and manure heaps. Among animal housing systems, very high emission rates have been found with pig deep lifter, and N 2 0 emissions are further stimulated by mechanical mixing. Slurry stores are anaerobic, but a recent study showed that N 2 0 can be produced in porous surface covers such as natural surface crusts, straw or leca pebbles, while no N 2 0 was emitted from uncovered slurry. The emission was significantly related to the water balance, i.e., the difference between evaporation and rain, during dry periods; during wet periods no N 2 0 was emitted. For solid manure, previous studies have typically found that less than 1 % of total N is emitted as N 2 0. Nitrous oxide may be produced throughout the manure heap, provided an environment with both aerobic and anaerobic pockets exists. Profiles from an experimental heap indicated that most of the N 2 0 emitted from solid manure was produced near the surface of the heap. Increasing density appears to stimulate N 2 0 emissions up to a point, where the air exchange is significantly impeded. The IPCC methodology calculates N 2 0 emissions from manure on the basis of total N content (that is, on the basis of volume) and climate region only. Possibly, estimates of N 2 0 emissions from slurry stores could be improved by considering surface area, ammonium content and water balance as input variables. Emissions from solid manure heaps should consider surface area and the potential for composting, as reflected in bulk density and moisture content. (au)

  4. A global map of suitability for coastal Vibrio cholerae under current and future climate conditions.

    Science.gov (United States)

    Escobar, Luis E; Ryan, Sadie J; Stewart-Ibarra, Anna M; Finkelstein, Julia L; King, Christine A; Qiao, Huijie; Polhemus, Mark E

    2015-09-01

    Vibrio cholerae is a globally distributed water-borne pathogen that causes severe diarrheal disease and mortality, with current outbreaks as part of the seventh pandemic. Further understanding of the role of environmental factors in potential pathogen distribution and corresponding V. cholerae disease transmission over time and space is urgently needed to target surveillance of cholera and other climate and water-sensitive diseases. We used an ecological niche model (ENM) to identify environmental variables associated with V. cholerae presence in marine environments, to project a global model of V. cholerae distribution in ocean waters under current and future climate scenarios. We generated an ENM using published reports of V. cholerae in seawater and freely available remotely sensed imagery. Models indicated that factors associated with V. cholerae presence included chlorophyll-a, pH, and sea surface temperature (SST), with chlorophyll-a demonstrating the greatest explanatory power from variables selected for model calibration. We identified specific geographic areas for potential V. cholerae distribution. Coastal Bangladesh, where cholera is endemic, was found to be environmentally similar to coastal areas in Latin America. In a conservative climate change scenario, we observed a predicted increase in areas with environmental conditions suitable for V. cholerae. Findings highlight the potential for vulnerability maps to inform cholera surveillance, early warning systems, and disease prevention and control. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Interactions of hydroxyapatite surfaces: conditioning films of human whole saliva.

    Science.gov (United States)

    Cárdenas, Marité; Valle-Delgado, Juan José; Hamit, Jildiz; Rutland, Mark W; Arnebrant, Thomas

    2008-07-15

    Hydroxyapatite is a very interesting material given that it is the main component in tooth enamel and because of its uses in bone implant applications. Therefore, not only the characterization of its surface is of high relevance but also designing reliable methods to study the interfacial properties of films adsorbed onto it. In this paper we apply the colloidal probe atomic force microscopy method to investigate the surface properties of commercially available hydroxyapatite surfaces (both microscopic particles and macroscopic discs) in terms of interfacial and frictional forces. In this way, we find that hydroxyapatite surfaces at physiological relevant conditions are slightly negatively charged. The surfaces were then exposed to human whole saliva, and the surface properties were re-evaluated. A thick film was formed that was very resistant to mechanical stress. The frictional measurements demonstrated that the film was indeed highly lubricating, supporting the argument that this system may prove to be a relevant model for evaluating dental and implant systems.

  6. Implications of Martian Phyllosilicate Formation Conditions to the Early Climate on Mars

    Science.gov (United States)

    Bishop, J. L.; Baker, L.; Fairén, A. G.; Michalski, J. R.; Gago-Duport, L.; Velbel, M. A.; Gross, C.; Rampe, E. B.

    2017-12-01

    We propose that short-term warmer and wetter environments, occurring sporadically in a generally cold early Mars, enabled formation of phyllosilicate-rich outcrops on the surface of Mars without requiring long-term warm and wet conditions. We are investigating phyllosilicate formation mechanisms including CO2 and H2O budgets to provide constraints on the early martian climate. We have evaluated the nature and stratigraphy of phyllosilicate-bearing surface units on Mars based on i) phyllosilicate-forming environments on Earth, ii) phyllosilicate reactions in the lab, and iii) modeling experiments involving phyllosilicates and short-range ordered (SRO) materials. The type of phyllosilicates that form on Mars depends on temperature, water/rock ratio, acidity, salinity and available ions. Mg-rich trioctahedral smectite mixtures are more consistent with subsurface formation environments (crustal, hydrothermal or alkaline lakes) up to 400 °C and are not associated with martian surface environments. In contrast, clay profiles dominated by dioctahedral Al/Fe-smectites are typically formed in subaqueous or subaerial surface environments. We propose models describing formation of smectite-rich outcrops and laterally extensive vertical profiles of Fe/Mg-smectites, sulfates, and Al-rich clay assemblages formed in surface environments. Further, the presence of abundant SRO materials without phyllosilicates could mark the end of the last warm and wet episode on Mars supporting smectite formation. Climate Implications for Early Mars: Clay formation reactions proceed extremely slowly at cool temperatures. The thick smectite outcrops observed on Mars through remote sensing would require standing water on Mars for hundreds of millions of years if they formed in waters 10-15 °C. However, warmer temperatures could have enabled faster production of these smectite-rich beds. Sporadic warming episodes to 30-40 °C could have enabled formation of these smectites over only tens or

  7. Regional feedbacks under changing climate and land-use conditions

    Science.gov (United States)

    Batlle Bayer, L.; van den Hurk, B. J. J. M.; Strengers, B. J.; van Minnen, J. G.

    2012-04-01

    Ecosystem responses to a changing climate and human-induced climate forcings (e.g. deforestation) might amplify (positive feedback) or dampen (negative feedback) the initial climate response. Feedbacks may include the biogeochemical (e.g. carbon cycle) and biogeophysical feedbacks (e.g. albedo and hydrological cycle). Here, we first review the most important feedbacks and put them into the context of a conceptual framework, including the major processes and interactions between terrestrial ecosystems and climate. We explore potential regional feedbacks in four hot spots with pronounced potential changes in land-use/management and local climate: sub-Saharan Africa (SSA), Europe, the Amazon Basin and South and Southeast Asia. For each region, the relevant human-induced climate forcings and feedbacks were identified based on published literature. When evapotranspiration is limited by a soil water deficit, heat waves in Europe are amplified (positive soil moisture-temperature feedback). Drought events in the Amazon lead to further rainfall reduction when water recycling processes are affected (positive soil moisture-precipitation feedback). In SSA, the adoption of irrigation in the commonly rainfed systems can modulate the negative soil moisture-temperature feedback. In contrast, future water shortage in South and Southeast Asia can turn the negative soil moisture-temperature feedback into a positive one. Further research including advanced modeling strategies is needed to isolate the dominant processes affecting the strength and sign of the feedbacks. In addition, the socio-economic dimension needs to be considered in the ecosystems-climate system to include the essential role of human decisions on land-use and land-cover change (LULCC). In this context, enhanced integration between Earth System (ES) and Integrated Assessment (IA) modeling communities is strongly recommended.

  8. Osteogenic potential of laser modified and conditioned titanium zirconium surfaces

    Directory of Open Access Journals (Sweden)

    P David Charles

    2016-01-01

    Full Text Available Statement of Problem: The osseointegration of dental implant is related to their composition and surface treatment. Titanium zirconium (TiZr has been introduced as an alternative to the commercially pure titanium and its alloys as dental implant material, which is attributed to its superior mechanical and biological properties. Surface treatments of TiZr have been introduced to enhance their osseointegration ability; however, reliable, easy to use surface modification technique has not been established. Purpose: The purpose of this study was to evaluate and compare the effect of neodymium-doped yttrium aluminum garnet (Nd-YAG laser surface treatment of TiZr implant alloy on their osteogenic potential. Materials and Methods: Twenty disc-shaped samples of 5 mm diameter and 2 mm height were milled from the TiZr alloy ingot. The polished discs were ultrasonically cleaned in distilled water. Ten samples each were randomly selected as Group A control samples and Group B consisted of Nd-YAG laser surface etched and conditioned test samples. These were evaluated for cellular response. Cellular adhesion and proliferation were quantified, and the results were statistically analyzed using nonparametric analysis. Cellular morphology was observed using electron and epiflurosence microscopy. Results: Nd-YAG laser surface modified and conditioned TiZr samples increased the osteogenic potential. Conclusion: Nd-YAG laser surface modification of TiZr, improves the cellular activity, surface roughness, and wettability, thereby increasing the osteogenic potential.

  9. "Intelligent Ensemble" Projections of Precipitation and Surface Radiation in Support of Agricultural Climate Change Adaptation

    Science.gov (United States)

    Taylor, Patrick C.; Baker, Noel C.

    2015-01-01

    Earth's climate is changing and will continue to change into the foreseeable future. Expected changes in the climatological distribution of precipitation, surface temperature, and surface solar radiation will significantly impact agriculture. Adaptation strategies are, therefore, required to reduce the agricultural impacts of climate change. Climate change projections of precipitation, surface temperature, and surface solar radiation distributions are necessary input for adaption planning studies. These projections are conventionally constructed from an ensemble of climate model simulations (e.g., the Coupled Model Intercomparison Project 5 (CMIP5)) as an equal weighted average, one model one vote. Each climate model, however, represents the array of climate-relevant physical processes with varying degrees of fidelity influencing the projection of individual climate variables differently. Presented here is a new approach, termed the "Intelligent Ensemble, that constructs climate variable projections by weighting each model according to its ability to represent key physical processes, e.g., precipitation probability distribution. This approach provides added value over the equal weighted average method. Physical process metrics applied in the "Intelligent Ensemble" method are created using a combination of NASA and NOAA satellite and surface-based cloud, radiation, temperature, and precipitation data sets. The "Intelligent Ensemble" method is applied to the RCP4.5 and RCP8.5 anthropogenic climate forcing simulations within the CMIP5 archive to develop a set of climate change scenarios for precipitation, temperature, and surface solar radiation in each USDA Farm Resource Region for use in climate change adaptation studies.

  10. Simulation of Deep Water Renewal in Crater Lake, Oregon, USA under Current and Future Climate Conditions

    Science.gov (United States)

    Piccolroaz, S.; Wood, T. M.; Wherry, S.; Girdner, S.

    2015-12-01

    We applied a 1-dimensional lake model developed to simulate deep mixing related to thermobaric instabilities in temperate lakes to Crater Lake, a 590-m deep caldera lake in Oregon's Cascade Range known for its stunning deep blue color and extremely clear water, in order to determine the frequency of deep water renewal in future climate conditions. The lake model was calibrated with 6 years of water temperature profiles, and then simulated 10 years of validation data with an RMSE ranging from 0.81°C at 50 m depth to 0.04°C at 350-460 m depth. The simulated time series of heat content in the deep lake accurately captured extreme years characterized by weak and strong deep water renewal. The lake model uses wind speed and lake surface temperature (LST) as boundary conditions. LST projections under six climate scenarios from the CMIP5 intermodel comparison project (2 representative concentration pathways X 3 general circulation models) were evaluated with air2water, a simple lumped model that only requires daily values of downscaled air temperature. air2water was calibrated with data from 1993-2011, resulting in a RMSE between simulated and observed daily LST values of 0.68°C. All future climate scenarios project increased water temperature throughout the water column and a substantive reduction in the frequency of deepwater renewal events. The least extreme scenario (CNRM-CM5, RCP4.5) projects the frequency of deepwater renewal events to decrease from about 1 in 2 years in the present to about 1 in 3 years by 2100. The most extreme scenario (HadGEM2-ES, RCP8.5) projects the frequency of deepwater renewal events to be less than 1 in 7 years by 2100 and lake surface temperatures never cooling to less than 4°C after 2050. In all RCP4.5 simulations the temperature of the entire water column is greater than 4°C for increasing periods of time. In the RCP8.5 simulations, the temperature of the entire water column is greater than 4°C year round by the year 2060 (HadGEM2

  11. Climate conditions, and changes, affect microalgae communities… should we worry?

    Science.gov (United States)

    Gimenez Papiol, Gemma

    2018-03-01

    Microalgae play a pivotal role in the regulation of Earth's climate and its cycles, but are also affected by climate change, mainly by changes in temperature, light, ocean acidification, water stratification, and precipitation-induced nutrient inputs. The changes and impacts on microalgae communities are difficult to study, predict, and manage, but there is no doubt that there will be changes. These changes will have impacts beyond microalgae communities, and many of them will be negative. Some actions are currently ongoing for the mitigation of some of the negative impacts, such as harmful algal blooms and water quality, but global efforts for reducing CO 2 emissions, temperature rises, and ocean acidification are paramount for reducing the impact of climate change on microalgae communities, and eventually, on human well-being. Integr Environ Assess Manag 2018;14:181-184. © 2018 SETAC. © 2018 SETAC.

  12. Dynamic data analysis of climate and recharge conditions over time in the Edwards Aquifer, Texas

    Science.gov (United States)

    Pierce, S. A.; Collins, J.; Banner, J.

    2017-12-01

    Understanding the temporal patterns in datasets related to climate, recharge, and water resource conditions is important for informing water management and policy decisions. Data analysis and pipelines for evaluating these disparate sources of information are challenging to set up and rely on emerging informatics tools to complete. This project gathers data from both historical and recent sources for the Edwards Aquifer of central Texas. The Edwards faces a unique array of challenges, as it is composed of karst limestone, is susceptible to contaminants and climate change, and is expected to supply water for a rapidly growing population. Given these challenges, new approaches to integrating data will be particularly important. Case study data from the Edwards is used to evaluate aquifer and hydrologic system conditions over time as well as to discover patterns and possible relationships across the information sources. Prior research that evaluated trends in discharge and recharge of the aquifer is revisited by considering new data from 1992-2015, and the sustainability of the Edwards as a water resource within the more recent time period is addressed. Reusable and shareable analytical data pipelines are constructed using Jupyter Notebooks and Python libraries, and an interactive visualization is implemented with the information. In addition to the data sources that are utilized for the water balance analyses, the Global Surface Water Monitoring System from the University of Minnesota, a tool that integrates a wide number of satellite datasets with known surface water dynamics and machine learning, is used to evaluate water body persistence and change over time at regional scales. Preliminary results indicate that surface water body over the Edwards with differing aerial extents are declining, excepting some dam-controlled lakes in the region. Other existing tools and machine learning applications are also considered. Results are useful to the Texas Water Research

  13. Distribution of near-surface permafrost in Alaska: estimates of present and future conditions

    Science.gov (United States)

    Pastick, Neal J.; Jorgenson, M. Torre; Wylie, Bruce K.; Nield, Shawn J.; Johnson, Kristofer D.; Finley, Andrew O.

    2015-01-01

    High-latitude regions are experiencing rapid and extensive changes in ecosystem composition and function as the result of increases in average air temperature. Increasing air temperatures have led to widespread thawing and degradation of permafrost, which in turn has affected ecosystems, socioeconomics, and the carbon cycle of high latitudes. Here we overcome complex interactions among surface and subsurface conditions to map nearsurface permafrost through decision and regression tree approaches that statistically and spatially extend field observations using remotely sensed imagery, climatic data, and thematic maps of a wide range of surface and subsurface biophysical characteristics. The data fusion approach generated medium-resolution (30-m pixels) maps of near-surface (within 1 m) permafrost, active-layer thickness, and associated uncertainty estimates throughout mainland Alaska. Our calibrated models (overall test accuracy of ~85%) were used to quantify changes in permafrost distribution under varying future climate scenarios assuming no other changes in biophysical factors. Models indicate that near-surface permafrost underlies 38% of mainland Alaska and that near-surface permafrost will disappear on 16 to 24% of the landscape by the end of the 21st Century. Simulations suggest that near-surface permafrost degradation is more probable in central regions of Alaska than more northerly regions. Taken together, these results have obvious implications for potential remobilization of frozen soil carbon pools under warmer temperatures. Additionally, warmer and drier conditions may increase fire activity and severity, which may exacerbate rates of permafrost thaw and carbon remobilization relative to climate alone. The mapping of permafrost distribution across Alaska is important for land-use planning, environmental assessments, and a wide-array of geophysical studies.

  14. Climatic condition of Calabar as typified by some meteorological ...

    African Journals Online (AJOL)

    This study aims at analysing some meteorological data collected by the meteorological department of the Margaret Ekpo International Airport, Calabar between 1985 and 2003. The main objectives were to provide average figures and curves of Calabar climate, and to identify possible trends since 1985. Results show that ...

  15. Accounts from 19th-century Canadian Arctic explorers' logs reflect present climate conditions

    Science.gov (United States)

    Overland, James E.; Wood, Kevin

    The widely perceived failure of 19th-century expeditions to find and transit the Northwest Passage in the Canadian Arctic is often attributed to extraordinary cold climatic conditions associated with the “Little Ice Age” evident in proxy records. However, examination of 44 explorers' logs for the western Arctic from 1818 to 1910 reveals that climate indicators such as navigability, the distribution and thickness of annual sea ice, monthly surface air temperature, and the onset of melt and freeze were within the present range of variability.The quest for the Northwest Passage through the Canadian archipelago during the 19th century is frequently seen as a vain and tragic failure. Polar exploration during the Victorian era seems to us today to have been a costly exercise in heroic futility, which in many respects it was. This perspective has been reinforced since the 1970s, when paleoclimate reconstructions based on Arctic ice core stratigraphy appeared to confirm the existence of exceptionally cold conditions consistent with the period glaciologists had termed the “Little Ice Age” (Figure 1a), with temperatures more than one standard deviation colder relative to an early 20th-century mean [Koerner, 1977; Koerner and Fisher, 1990; Overpeck et al., 1998]. In recent years, the view of the Little Ice Age as a synchronous worldwide and prolonged cold epoch that ended with modern warming has been questioned [Bradley and Jones, 1993; Jones and Briffa, 2001 ;Ogilvie, 2001].

  16. A robust empirical seasonal prediction of winter NAO and surface climate.

    Science.gov (United States)

    Wang, L; Ting, M; Kushner, P J

    2017-03-21

    A key determinant of winter weather and climate in Europe and North America is the North Atlantic Oscillation (NAO), the dominant mode of atmospheric variability in the Atlantic domain. Skilful seasonal forecasting of the surface climate in both Europe and North America is reflected largely in how accurately models can predict the NAO. Most dynamical models, however, have limited skill in seasonal forecasts of the winter NAO. A new empirical model is proposed for the seasonal forecast of the winter NAO that exhibits higher skill than current dynamical models. The empirical model provides robust and skilful prediction of the December-January-February (DJF) mean NAO index using a multiple linear regression (MLR) technique with autumn conditions of sea-ice concentration, stratospheric circulation, and sea-surface temperature. The predictability is, for the most part, derived from the relatively long persistence of sea ice in the autumn. The lower stratospheric circulation and sea-surface temperature appear to play more indirect roles through a series of feedbacks among systems driving NAO evolution. This MLR model also provides skilful seasonal outlooks of winter surface temperature and precipitation over many regions of Eurasia and eastern North America.

  17. Land surface phenology of Northeast China during 2000-2015: temporal changes and relationships with climate changes.

    Science.gov (United States)

    Zhang, Yue; Li, Lin; Wang, Hongbin; Zhang, Yao; Wang, Naijia; Chen, Junpeng

    2017-10-01

    As an important crop growing area, Northeast China (NEC) plays a vital role in China's food security, which has been severely affected by climate change in recent years. Vegetation phenology in this region is sensitive to climate change, and currently, the relationship between the phenology of NEC and climate change remains unclear. In this study, we used a satellite-derived normalized difference vegetation index (NDVI) to obtain the temporal patterns of the land surface phenology in NEC from 2000 to 2015 and validated the results using ground phenology observations. We then explored the relationships among land surface phenology, temperature, precipitation, and sunshine hours for relevant periods. Our results showed that the NEC experienced great phenological changes in terms of spatial heterogeneity during 2000-2015. The spatial patterns of land surface phenology mainly changed with altitude and land cover type. In most regions of NEC, the start date of land surface phenology had advanced by approximately 1.0 days year -1 , and the length of land surface phenology had been prolonged by approximately 1.0 days year -1 except for the needle-leaf and cropland areas, due to the warm conditions. We found that a distinct inter-annual variation in land surface phenology related to climate variables, even if some areas presented non-significant trends. Land surface phenology was coupled with climate variables and distinct responses at different combinations of temperature, precipitation, sunshine hours, altitude, and anthropogenic influence. These findings suggest that remote sensing and our phenology extracting methods hold great potential for helping to understand how land surface phenology is sensitive to global climate change.

  18. Measurement of heat stress conditions at cow level and comparison to climate conditions at stationary locations inside a dairy barn.

    Science.gov (United States)

    Schüller, Laura K; Heuwieser, Wolfgang

    2016-08-01

    The objectives of this study were to examine heat stress conditions at cow level and to investigate the relationship to the climate conditions at 5 different stationary locations inside a dairy barn. In addition, we compared the climate conditions at cow level between primiparous and multiparous cows for a period of 1 week after regrouping. The temperature-humidity index (THI) differed significantly between all stationary loggers. The lowest THI was measured at the window logger in the experimental stall and the highest THI was measured at the central logger in the experimental stall. The THI at the mobile cow loggers was 2·33 THI points higher than at the stationary loggers. Furthermore, the mean daily THI was higher at the mobile cow loggers than at the stationary loggers on all experimental days. The THI in the experimental pen was 0·44 THI points lower when the experimental cow group was located inside the milking parlour. The THI measured at the mobile cow loggers was 1·63 THI points higher when the experimental cow group was located inside the milking parlour. However, there was no significant difference for all climate variables between primiparous and multiparous cows. These results indicate, there is a wide range of climate conditions inside a dairy barn and especially areas with a great distance to a fresh air supply have an increased risk for the occurrence of heat stress conditions. Furthermore, the heat stress conditions are even higher at cow level and cows not only influence their climatic environment, but also generate microclimates within different locations inside the barn. Therefore climate conditions should be obtained at cow level to evaluate the heat stress conditions that dairy cows are actually exposed to.

  19. Collaborative Research for Water Resource Management under Climate Change Conditions

    Science.gov (United States)

    Brundiers, K.; Garfin, G. M.; Gober, P.; Basile, G.; Bark, R. H.

    2010-12-01

    We present an ongoing project to co-produce science and policy called Collaborative Planning for Climate Change: An Integrated Approach to Water-Planning, Climate Downscaling, and Robust Decision-Making. The project responds to motivations related to dealing with sustainability challenges in research and practice: (a) state and municipal water managers seek research that addresses their planning needs; (b) the scientific literature and funding agencies call for more meaningful engagement between science and policy communities, in ways that address user needs, while advancing basic research; and (c) empirical research contributes to methods for the design and implementation of collaborative projects. To understand how climate change might impact water resources and management in the Southwest US, our project convenes local, state, and federal water management practitioners with climate-, hydrology-, policy-, and decision scientists. Three areas of research inform this collaboration: (a) the role of paleo-hydrology in water resources scenario construction; (b) the types of uncertainties that impact decision-making beyond climate and modeling uncertainty; and (c) basin-scale statistical and dynamical downscaling of climate models to generate hydrologic projections for regional water resources planning. The project engages all participants in the research process, from research design to workshops that build capacity for understanding data generation and sources of uncertainty to the discussion of water management decision contexts. A team of “science-practice translators” facilitates the collaboration between academic and professional communities. In this presentation we contextualize the challenges and opportunities of use-inspired science-policy research collaborations by contrasting the initial project design with the process of implementation. We draw from two sources to derive lessons learned: literature on collaborative research, and evaluations provided by

  20. Boundary conditions for free surface inlet and outlet problems

    KAUST Repository

    Taroni, M.; Breward, C. J. W.; Howell, P. D.; Oliver, J. M.

    2012-01-01

    We investigate and compare the boundary conditions that are to be applied to free-surface problems involving inlet and outlets of Newtonian fluid, typically found in coating processes. The flux of fluid is a priori known at an inlet, but unknown

  1. Hot house global climate change and the human condition

    CERN Document Server

    Strom, Robert G

    2007-01-01

    Global warming is addressed by almost all sciences including many aspects of geosciences, atmospheric, the biological sciences, and even astronomy. It has recently become the concern of other diverse disciplines such as economics, agriculture, demographics and population statistics, medicine, engineering, and political science. This book addresses these complex interactions, integrates them, and derives meaningful conclusions and possible solutions. The text provides an easy-to-read explanation of past and present global climate change, causes and possible solutions to the problem, including t

  2. Changing Energy Requirements in the Mediterranean Under Changing Climatic Conditions

    Directory of Open Access Journals (Sweden)

    George Demosthenous

    2009-09-01

    Full Text Available This study investigates the impacts of climate change on energy requirements in the Mediterranean. Energy requirements, especially for space heating and cooling, are closely linked to several weather variables, mainly air temperature. The analysis is based on daily temperature outputs from several regional climate models run at a resolution of 25 km × 25 km in the framework of EU project ENSEMBLES using the A1B emissions scenario. The impacts of changes in temperature on energy requirements are investigated using the concept of degree days, defined as the difference of mean air temperature from a base temperature. Base temperature should be chosen to coincide with the minimum energy consumption. In this way, changes in heating and cooling requirements between the reference and the future period are calculated and areas about to undergo large changes identified. These changes are calculated between a 30-year reference period 1961–1990 and a near future period 2021–2050 taking the ensemble mean of all regional climate models. The near-term future has been chosen instead of the frequently used end-of-the-century period to assist policy makers in their planning. In general, a decrease in energy requirements is projected under future milder winters and an increase under hotter summers.

  3. The interdecadal worsening of weather conditions affecting aerosol pollution in the Beijing area in relation to climate warming

    Science.gov (United States)

    Zhang, Xiaoye; Zhong, Junting; Wang, Jizhi; Wang, Yaqiang; Liu, Yanju

    2018-04-01

    The weather conditions affecting aerosol pollution in Beijing and its vicinity (BIV) in wintertime have worsened in recent years, particularly after 2010. The relation between interdecadal changes in weather conditions and climate warming is uncertain. Here, we analyze long-term variations of an integrated pollution-linked meteorological index (which is approximately and linearly related to aerosol pollution), the extent of changes in vertical temperature differences in the boundary layer (BL) in BIV, and northerly surface winds from Lake Baikal during wintertime to evaluate the potential contribution of climate warming to changes in meteorological conditions directly related to aerosol pollution in this area; this is accomplished using NCEP reanalysis data, surface observations, and long-term vertical balloon sounding observations since 1960. The weather conditions affecting BIV aerosol pollution are found to have worsened since the 1960s as a whole. This worsening is more significant after 2010, with PM2.5 reaching unprecedented high levels in many cities in China, particularly in BIV. The decadal worsening of meteorological conditions in BIV can partly be attributed to climate warming, which is defined by more warming in the higher layers of the boundary layer (BL) than the lower layers. This worsening can also be influenced by the accumulation of aerosol pollution, to a certain extent (particularly after 2010), because the increase in aerosol pollution from the ground leads to surface cooling by aerosol-radiation interactions, which facilitates temperature inversions, increases moisture accumulations, and results in the extra deterioration of meteorological conditions. If analyzed as a linear trend, weather conditions have worsened by ˜ 4 % each year from 2010 to 2017. Given such a deterioration rate, the worsening of weather conditions may lead to a corresponding amplitude increase in PM2.5 in BIV during wintertime in the next 5 years (i.e., 2018 to 2022

  4. The potential for cold climate conditions and permafrost in Forsmark in the next 60 000 years

    International Nuclear Information System (INIS)

    Brandefelt, Jenny; Naeslund, Jens-Ove; Zhang, Qiong; Hartikainen, Juha

    2013-05-01

    This report presents results of a study devoted to extend the current knowledge of the climate in Sweden in the next ∼60,000 years (60 ka). Specifically, the potential of cold climate and permafrost development in south-central Sweden, and in the Forsmark region, over this time horizon was investigated. The climate system is an interactive system consisting of five major components: the atmosphere, the hydrosphere, the cryo sphere, the land surface and the biosphere, forced or influenced by various external forcing mechanisms, of which the most important is the Sun. Also the direct effect of human activities on the climate system is considered an external forcing. The latitudinal and seasonal distribution of incoming solar radiation (insolation) varies on millennial time scales due to variations in the Earth's orbit and axial tilt. These variations, together with variations in the atmospheric CO 2 concentration, are viewed as two main factors in determining the climate variation between interglacial (warmer) and glacial (colder) climates. Summer insolation at high northern latitudes is at a minimum 17 ka and 54 ka after present (AP). These periods were therefore identified as potential future periods of cold climate conditions in high northern latitudes in general and in south-central Sweden in particular. Due to human emissions of carbon to the atmosphere, the atmospheric CO 2 concentration is currently 392 ppmv (2011 AD), a substantial increase as compared to the range of atmospheric CO 2 concentrations of 180-295 ppmv found in ice cores for the last 400 ka. The future atmospheric CO 2 concentration is determined by i) future human carbon emissions to the atmosphere, ii) possible emissions due to feedbacks in the climate system, and iii) by the global carbon cycle. To investigate the potential of cold climate conditions in south-central Sweden in the next 60 ka the future air temperature in Forsmark was estimated based on simulations with an Earth system model

  5. Establishment and performance of an experimental green roof under extreme climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Petra M., E-mail: pkklein@ou.edu [School of Meteorology, University of Oklahoma, Norman, OK (United States); Coffman, Reid, E-mail: rcoffma4@kent.edu [College of Architecture and Environmental Design, Kent State University, Kent, OH (United States)

    2015-04-15

    Green roofs alter the surface energy balance and can help in mitigating urban heat islands. However, the cooling of green roofs due to evapotranspiration strongly depends on the climatic conditions, and vegetation type and density. In the Southern Central Plains of the United States, extreme weather events, such as high winds, heat waves and drought conditions pose challenges for successful implementation of green roofs, and likely alter their standard performance. The National Weather Center Experimental Green Roof, an interdisciplinary research site established in 2010 in Norman, OK, aimed to investigate the ecological performance and surface energy balance of green roof systems. Starting in May 2010, 26 months of vegetation studies were conducted and the radiation balance, air temperature, relative humidity, and buoyancy fluxes were monitored at two meteorological stations during April–October 2011. The establishment of a vegetative community trended towards prairie plant dominance. High mortality of succulents and low germination of grasses and herbaceous plants contributed to low vegetative coverage. In this condition succulent diversity declined. Bouteloua gracilis and Delosperma cooperi showed typological dominance in harsh climatic conditions, while Sedum species experienced high mortality. The plant community diversified through volunteers such as Euphorbia maculate and Portulaca maculate. Net radiation measured at a green-roof meteorological station was higher than at a control station over the original, light-colored roofing material. These findings indicate that the albedo of the green roof was lower than the albedo of the original roofing material. The low vegetative coverage during the heat and drought conditions in 2011, which resulted in the dark substrate used in the green roof containers being exposed, likely contributed to the low albedo values. Nevertheless, air temperatures and buoyancy fluxes were often lower over the green roof indicating

  6. Establishment and performance of an experimental green roof under extreme climatic conditions

    International Nuclear Information System (INIS)

    Klein, Petra M.; Coffman, Reid

    2015-01-01

    Green roofs alter the surface energy balance and can help in mitigating urban heat islands. However, the cooling of green roofs due to evapotranspiration strongly depends on the climatic conditions, and vegetation type and density. In the Southern Central Plains of the United States, extreme weather events, such as high winds, heat waves and drought conditions pose challenges for successful implementation of green roofs, and likely alter their standard performance. The National Weather Center Experimental Green Roof, an interdisciplinary research site established in 2010 in Norman, OK, aimed to investigate the ecological performance and surface energy balance of green roof systems. Starting in May 2010, 26 months of vegetation studies were conducted and the radiation balance, air temperature, relative humidity, and buoyancy fluxes were monitored at two meteorological stations during April–October 2011. The establishment of a vegetative community trended towards prairie plant dominance. High mortality of succulents and low germination of grasses and herbaceous plants contributed to low vegetative coverage. In this condition succulent diversity declined. Bouteloua gracilis and Delosperma cooperi showed typological dominance in harsh climatic conditions, while Sedum species experienced high mortality. The plant community diversified through volunteers such as Euphorbia maculate and Portulaca maculate. Net radiation measured at a green-roof meteorological station was higher than at a control station over the original, light-colored roofing material. These findings indicate that the albedo of the green roof was lower than the albedo of the original roofing material. The low vegetative coverage during the heat and drought conditions in 2011, which resulted in the dark substrate used in the green roof containers being exposed, likely contributed to the low albedo values. Nevertheless, air temperatures and buoyancy fluxes were often lower over the green roof indicating

  7. The static friction response of non-glabrous skin as a function of surface energy and environmental conditions

    NARCIS (Netherlands)

    Klaassen, Michel; de Vries, Erik G.; Masen, Marc Arthur

    2017-01-01

    The (local) environmental conditions have a significant effect on the interaction between skin and products. Plasticisation of the stratum corneum occurs at high humidity, causing this layer to soften and change its surface free energy. In this work we study the effects of the micro-climate on the

  8. Surface area changes of Himalayan ponds as a proxy of hydrological climate-driven fluctuations

    Science.gov (United States)

    Salerno, Franco; Thakuri, Sudeep; Guyennon, Nicolas; Viviano, Gaetano; Tartari, Gianni

    2016-04-01

    The meteorological measurements at high-elevations of the Himalayan range are scarce due to the harsh conditions of these environments which limit the suitable maintenance of weather stations. As a consequence, the meager knowledge on how the climate is changed in the last decades at Himalayan high-elevations sets a serious limit upon the interpretation of relationships between causes and recent observed effects on the cryosphere. Although the glaciers masses reduction in Himalaya is currently sufficiently well described, how changes in climate drivers (precipitation and temperature) have influenced the melting and shrinkage processes are less clear. Consequently, the uncertainty related to the recent past amplifies when future forecasts are done, both for climate and impacts. In this context, a substantial body of research has already demonstrated the high sensitivity of lakes and ponds to climate. Some climate-related signals are highly visible and easily measurable in lakes. For example, climate-driven fluctuations in lake surface area have been observed in many remote sites. On interior Tibetan Plateau the lake growth since the late 1990s is mainly attributed to increased regional precipitation and weakened evaporation. Differently, other authors attribute at the observed increases of lake surfaces at the enhanced glacier melting. In our opinion these divergences found in literature are due to the type of glacial lakes considered in the study and in particular their relationship with glaciers. In general, in Himalaya three types of glacial lakes can be distinguished: (i) lakes that are not directly connected with glaciers, but that may have a glacier located in their basin (unconnected glacial lakes); (ii) supraglacial lakes, which develop on the surface of the glacier downstream; or (iii) proglacial lakes, which are moraine-dammed lakes that are in contact with the glacier front. Some of these lakes store large quantities of water and are susceptible to GLOFs

  9. Sustainability Challenges from Climate Change and Air Conditioning Use in Urban Areas

    Directory of Open Access Journals (Sweden)

    Karin Lundgren

    2013-07-01

    Full Text Available Global climate change increases heat loads in urban areas causing health and productivity risks for millions of people. Inhabitants in tropical and subtropical urban areas are at especial risk due to high population density, already high temperatures, and temperature increases due to climate change. Air conditioning is growing rapidly, especially in South and South-East Asia due to income growth and the need to protect from high heat exposures. Studies have linked increased total hourly electricity use to outdoor temperatures and humidity; modeled future predictions when facing additional heat due to climate change, related air conditioning with increased street level heat and estimated future air conditioning use in major urban areas. However, global and localized studies linking climate variables with air conditioning alone are lacking. More research and detailed data is needed looking at the effects of increasing air conditioning use, electricity consumption, climate change and interactions with the urban heat island effect. Climate change mitigation, for example using renewable energy sources, particularly photovoltaic electricity generation, to power air conditioning, and other sustainable methods to reduce heat exposure are needed to make future urban areas more climate resilient.

  10. Transformational leadership climate : Performance linkages, mechanisms, and boundary conditions at the organizational level

    NARCIS (Netherlands)

    Menges, J.; Walter, F.; Vogel, B.; Bruch, H.

    2011-01-01

    Transformational leadership (TFL) climate describes the degree to which leaders throughout an organization engage in TFL behaviors. In this study, we investigate performance linkages, mechanisms, and boundary conditions of TFL climate at the organizational level of analysis. In a sample of 158

  11. Projected climatic changes on drought conditions over Spain

    Science.gov (United States)

    García-Valdecasas Ojeda, Matilde; Quishpe-Vásquez, César; Raquel Gámiz-Fortis, Sonia; Castro-Díez, Yolanda; Jesús Esteban-Parra, María

    2017-04-01

    In a context of global warming, the evapotranspiration processes will have a strong influence on drought severity. For this reason, the Standardized Precipitation Evapotranspiration Index (SPEI) was computed at different timescales in order to explore the projected drought changes for the main watersheds in Spain. For that, the Weather Research and Forecasting (WRF) model has been used in order to obtain current (1980-2010) and future (2021-2050 and 2071-2100) climate output fields. WRF model was used over a domain that spans the Iberian Peninsula with a spatial resolution of 0.088°, and nested in the coarser 0.44° EURO-CORDEX domain, and driving by the global bias-corrected climate model output data from version 1 of NCAR's Community Earth System Model (CESM1), using two different Representative Concentration Pathway (RCP) scenarios: RCP 4.5 and RCP 8.5. Besides, to examine the behavior of this drought index, a comparison with the Standardized Precipitation Index (SPI), which does not consider the evapotranspiration effects, was also performed. Additionally the relationship between the SPEI index and the soil moisture has also been analyzed. The results of this study suggest an increase in the severity and duration of drought, being larger when the SPEI index is used to define drought events. This fact confirms the relevance of taking into account the evapotranspiration processes to detect future drought events. The results also show a noticeable relationship between the SPEI and the simulated soil moisture content, which is more significant at higher timescales. Keywords: Drought, SPEI, SPI, Climatic change, Projections, WRF. Acknowledgements: This work has been financed by the projects P11-RNM-7941 (Junta de Andalucía-Spain) and CGL2013-48539-R (MINECO-Spain, FEDER).

  12. The potential for cold climate conditions and permafrost in Forsmark in the next 60 000 years

    Energy Technology Data Exchange (ETDEWEB)

    Brandefelt, Jenny; Naeslund, Jens-Ove [Svensk Kaernbraenslehantering, Stockholm (Sweden); Zhang, Qiong [Dept. of Meteorology, Stockholm Univ., Stockholm (Sweden); Hartikainen, Juha [School of Engineering, Aalto Univ., Aalto (Finland)

    2013-05-15

    This report presents results of a study devoted to extend the current knowledge of the climate in Sweden in the next {approx}60,000 years (60 ka). Specifically, the potential of cold climate and permafrost development in south-central Sweden, and in the Forsmark region, over this time horizon was investigated. The climate system is an interactive system consisting of five major components: the atmosphere, the hydrosphere, the cryo sphere, the land surface and the biosphere, forced or influenced by various external forcing mechanisms, of which the most important is the Sun. Also the direct effect of human activities on the climate system is considered an external forcing. The latitudinal and seasonal distribution of incoming solar radiation (insolation) varies on millennial time scales due to variations in the Earth's orbit and axial tilt. These variations, together with variations in the atmospheric CO{sub 2} concentration, are viewed as two main factors in determining the climate variation between interglacial (warmer) and glacial (colder) climates. Summer insolation at high northern latitudes is at a minimum 17 ka and 54 ka after present (AP). These periods were therefore identified as potential future periods of cold climate conditions in high northern latitudes in general and in south-central Sweden in particular. Due to human emissions of carbon to the atmosphere, the atmospheric CO{sub 2} concentration is currently 392 ppmv (2011 AD), a substantial increase as compared to the range of atmospheric CO{sub 2} concentrations of 180-295 ppmv found in ice cores for the last 400 ka. The future atmospheric CO{sub 2} concentration is determined by i) future human carbon emissions to the atmosphere, ii) possible emissions due to feedbacks in the climate system, and iii) by the global carbon cycle. To investigate the potential of cold climate conditions in south-central Sweden in the next 60 ka the future air temperature in Forsmark was estimated based on

  13. Soil Moisture and Sea Surface Temperatures equally important for Land Climate in the Warm Season

    Science.gov (United States)

    Orth, R.; Seneviratne, S. I.

    2015-12-01

    Both sea surface temperatures (SSTs) and soil moisture (SM) are important drivers of climate variability over land. In this study we present a comprehensive comparison of SM versus SST impacts on land climate in the warm season. We perform ensemble experiments with the Community Earth System Model (CESM) where we set SM or SSTs to median conditions, respectively, to remove their inter-annual variability, whereby the other component - SST or SM - is still interactively computed. In contrast to earlier experiments performed with prescribed SSTs, our experiments suggest that SM is overall as important as SSTs for land climate, not only in the midlatitudes but also in the tropics and subtropics. Mean temperature and precipitation are reduced by 0.1-0.5 K and 0-0.2 mm, respectively, whereas their variability at different time scales decreases by 10-40% (temperature) and 0-10% (precipitation) when either SM or SSTs are prescribed. Also drought occurrence is affected, with mean changes in the maximum number of cumulative dry days of 0-0.75 days. Both SM and SST-induced changes are strongest for hot temperatures (up to 0.7 K, and 50%), extreme precipitation (up to 0.4 mm, and 20%), and strong droughts (up to 2 days). Local climate changes in response to removed SM variability are controlled - to first order - by the land-atmosphere coupling and the natural SM variability. SST-related changes are partly controlled by the relation of local temperature or precipitation with the El Niño-Southern Oscillation. Moreover removed SM or SST variabilities both induce remote effects by impacting the atmospheric circulation. Our results are similar for the present day and the end of the century. We investigate the inter-dependency between SM and SST and find a sufficient degree of independence for the purpose of this study. The robustness of our findings is shown by comparing the response of CESM to removed SM variability with four other global climate models. In summary, SM and SSTs

  14. DOE Final Report on Collaborative Research. Quantifying Climate Feedbacks of the Terrestrial Biosphere under Thawing Permafrost Conditions in the Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Qianlai [Purdue Univ., West Lafayette, IN (United States); Schlosser, C. Adam [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Melillo, Jerry M. [Marine Biological Lab. (MBL), Woods Hole, MA (United States); Anthony, Katey Walter [Univ. of Alaska, Fairbanks, AK (United States); Kicklighter, David [Marine Biological Lab. (MBL), Woods Hole, MA (United States); Gao, Xiang [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2015-11-03

    Our overall goal is to quantify the potential for threshold changes in natural emission rates of trace gases, particularly methane and carbon dioxide, from pan-arctic terrestrial systems under the spectrum of anthropogenically-forced climate warming, and the conditions under which these emissions provide a strong feedback mechanism to global climate warming. This goal is motivated under the premise that polar amplification of global climate warming will induce widespread thaw and degradation of the permafrost, and would thus cause substantial changes to the landscape of wetlands and lakes, especially thermokarst (thaw) lakes, across the Arctic. Through a suite of numerical experiments that encapsulate the fundamental processes governing methane emissions and carbon exchanges – as well as their coupling to the global climate system - we intend to test the following hypothesis in the proposed research: There exists a climate warming threshold beyond which permafrost degradation becomes widespread and stimulates large increases in methane emissions (via thermokarst lakes and poorly-drained wetland areas upon thawing permafrost along with microbial metabolic responses to higher temperatures) and increases in carbon dioxide emissions from well-drained areas. Besides changes in biogeochemistry, this threshold will also influence global energy dynamics through effects on surface albedo, evapotranspiration and water vapor. These changes would outweigh any increased uptake of carbon (e.g. from peatlands and higher plant photosynthesis) and would result in a strong, positive feedback to global climate warming.

  15. Tourism and climate conditions in San Juan, Puerto Rico, 2000-2010

    Directory of Open Access Journals (Sweden)

    Pablo A. Méndez-Lázaro

    2014-06-01

    Full Text Available The general behavior of the tourism sector in Puerto Rico, with its marked seasonality, hints at a close relationship between tourism activities and climate conditions. Even if weather condition is only one of many variables considered by travelling tourists, climate conditions weigh heavily in the majority of the decisions. The effect of climate variability on the environment could be manifested in warmer temperature, heat waves, and changes in the frequency of extreme weather events, such as severe storms and hurricanes, floods, and sea level rise. These conditions affect different sectors of society, among them public health and the economy. Therefore, our research has two main objectives: to establish a tourism climate index (TCI for Puerto Rico and to analyze if occupancy rates in hotels correspond to local weather conditions. Even though there are many other variables that could have positive or negative effects on tourism activities, results showed a significant association between occupancy rate in Puerto Rico and climate indexes. According to both TCI and the mean historical climate for tourism indexes, the most favorable months for tourism in Puerto Rico were February and March (winter, whereas the worst season was the end of August and the beginning of September (summer-fall. Although winter represents dry conditions and lower temperatures in San Juan, it also represents the highest occupancy rate during the years examined. In summer and fall, data showed high occupancy rates, yet climate conditions were not suitable; these months also correspond to the hurricane season. During this season, high relative occupancy rates responded to internal and local tourism patterns. It can therefore be assumed that until the climate-tourism relationship is well characterized, there is little hope of fully understanding the potential economic effects, detrimental or beneficial, of global climate change, not only on tourism in Puerto Rico, but on

  16. The impact of climatic and non-climatic factors on land surface temperature in southwestern Romania

    Science.gov (United States)

    Roşca, Cristina Florina; Harpa, Gabriela Victoria; Croitoru, Adina-Eliza; Herbel, Ioana; Imbroane, Alexandru Mircea; Burada, Doina Cristina

    2017-11-01

    Land surface temperature is one of the most important parameters related to global warming. It depends mainly on soil type, discontinuous vegetation cover, or lack of precipitation. The main purpose of this paper is to investigate the relationship between high LST, synoptic conditions and air masses trajectories, vegetation cover, and soil type in one of the driest region in Romania. In order to calculate the land surface temperature and normalized difference vegetation index, five satellite images of LANDSAT missions 5 and 7, covering a period of 26 years (1986-2011), were selected, all of them collected in the month of June. The areas with low vegetation density were derived from normalized difference vegetation index, while soil types have been extracted from Corine Land Cover database. HYSPLIT application was employed to identify the air masses origin based on their backward trajectories for each of the five study cases. Pearson, logarithmic, and quadratic correlations were used to detect the relationships between land surface temperature and observed ground temperatures, as well as between land surface temperature and normalized difference vegetation index. The most important findings are: strong correlation between land surface temperature derived from satellite images and maximum ground temperature recorded in a weather station located in the area, as well as between areas with land surface temperature equal to or higher than 40.0 °C and those with lack of vegetation; the sandy soils are the most prone to high land surface temperature and lack of vegetation, followed by the chernozems and brown soils; extremely severe drought events may occur in the region.

  17. Conditions for Emergence, Stability and Change in New Organizations in the Field of Citizens Climate Action

    DEFF Research Database (Denmark)

    Figueroa, Maria Josefina

    Climate change represents a crisis of tangible measure and the emergence of a field of action within which acting today needs to be motivated for what can contribute to benefit climate and transform society into a low carbon tomorrow. With the breadth and scope of citizen action on climate change....... This contribution is concerned with the latter. It proposes that using field analysis it is possible to understand conditions of emergence, stability and change in citizen engagement in climate action. The present contribution offers only a preliminary exploration of possibilities for how using field theory can...

  18. Village-level supply reliability of surface water irrigation in rural China: effects of climate change

    Science.gov (United States)

    Li, Yanrong; Wang, Jinxia

    2018-06-01

    Surface water, as the largest part of water resources, plays an important role on China's agricultural production and food security. And surface water is vulnerable to climate change. This paper aims to examine the status of the supply reliability of surface water irrigation, and discusses how it is affected by climate change in rural China. The field data we used in this study was collected from a nine-province field survey during 2012 and 2013. Climate data are offered by China's National Meteorological Information Center which contains temperature and precipitation in the past 30 years. A Tobit model (or censored regression model) was used to estimate the influence of climate change on supply reliability of surface water irrigation. Descriptive results showed that, surface water supply reliability was 74 % in the past 3 years. Econometric results revealed that climate variables significantly influenced the supply reliability of surface water irrigation. Specifically, temperature is negatively related with the supply reliability of surface water irrigation; but precipitation positively influences the supply reliability of surface water irrigation. Besides, climate influence differs by seasons. In a word, this paper improves our understanding of the impact of climate change on agriculture irrigation and water supply reliability in the micro scale, and provides a scientific basis for relevant policy making.

  19. Long-term changes in the surface conditions of PLT

    International Nuclear Information System (INIS)

    Cohen, S.A.; Dylla, H.F.; Rossnagel, S.M.; Picraux, S.T.; Borders, J.A.; Magee, C.W.

    1977-01-01

    Long-term changes in the surface conditions of the PLT vacuum vessel wall have been monitored by the periodic analysis of a variety of sample substrates (stainless steel, alumina, silicon), exposed to PLT discharges for periods of up to several months and subsequently removed for analysis by Auger electron spectroscopy (AES), photoelectron spectroscopy, ion backscattering, nuclear reaction analysis, secondary ion mass spectroscopy, and scanning electron microscopy

  20. Effect of surface wettability caused by radiation induced surface activation on leidenfrost condition

    International Nuclear Information System (INIS)

    Takamasa, T.; Hazuku, T.; Tamura, N.; Okamoto, K.; Mishima, K.; Furuya, M.

    2003-01-01

    Improving the limit of boiling heat transfer or critical heat flux requires that the cooling liquid can contact the heating surface, or a high-wettability, highly hydrophilic heating surface, even if a vapor bubble layer is generated on the surface. From this basis, we investigated surface wettability and Leidenfrost condition using metal oxides irradiated by γ-rays. In our previous study, contact angle, an indicator of macroscopic wettability, of a water droplet on metal oxide at room temperature was measured by image processing of the images obtained by a CCD video camera. The results showed that the surface wettability on metal oxide pieces of titanium, Zircaloy No. 4, SUS-304, and copper was improved significantly by the Radiation Induced Surface Activation (RISA) phenomenon. To delineate the effect of Radiation Induced Surface Activation (RISA) on heat transferring phenomena, the Leidenfrost condition and quenching of metal oxides irradiated by γ-rays were investigated. In the Leidenfrost experiment, when the temperature of the heating surface reached the wetting limit temperature, water-solid contact vanished because a stable vapor film existed between the droplet and the metal surface; i.e., a Leidenfrost condition obtained. The wetting limit temperature increased with integrated irradiation dose. After irradiation, the wet length and the duration of contact increased, and the contact angle decreased. In the quenching test, high surface wettability, or a highly hydrophilic condition, of a simulated fuel rod made of SUS was achieved, and the quenching velocities were increased up to 20-30% after 300 kGy 60Co γ-ray irradiation

  1. Effect of surface wettability caused by radiation induced surface activation on leidenfrost condition

    Energy Technology Data Exchange (ETDEWEB)

    Takamasa, T.; Hazuku, T.; Tamura, N.; Okamoto, K. [Tokyo Univ., Tokyo (Japan); Mishima, K. [Kyoto Univ., Kyoto (Japan); Furuya, M. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    2003-07-01

    Improving the limit of boiling heat transfer or critical heat flux requires that the cooling liquid can contact the heating surface, or a high-wettability, highly hydrophilic heating surface, even if a vapor bubble layer is generated on the surface. From this basis, we investigated surface wettability and Leidenfrost condition using metal oxides irradiated by {gamma}-rays. In our previous study, contact angle, an indicator of macroscopic wettability, of a water droplet on metal oxide at room temperature was measured by image processing of the images obtained by a CCD video camera. The results showed that the surface wettability on metal oxide pieces of titanium, Zircaloy No. 4, SUS-304, and copper was improved significantly by the Radiation Induced Surface Activation (RISA) phenomenon. To delineate the effect of Radiation Induced Surface Activation (RISA) on heat transferring phenomena, the Leidenfrost condition and quenching of metal oxides irradiated by {gamma}-rays were investigated. In the Leidenfrost experiment, when the temperature of the heating surface reached the wetting limit temperature, water-solid contact vanished because a stable vapor film existed between the droplet and the metal surface; i.e., a Leidenfrost condition obtained. The wetting limit temperature increased with integrated irradiation dose. After irradiation, the wet length and the duration of contact increased, and the contact angle decreased. In the quenching test, high surface wettability, or a highly hydrophilic condition, of a simulated fuel rod made of SUS was achieved, and the quenching velocities were increased up to 20-30% after 300 kGy 60Co {gamma}-ray irradiation.

  2. Skating on thin ice: surface chemistry under interstellar conditions

    Science.gov (United States)

    Fraser, H.; van Dishoeck, E.; Tielens, X.

    Solid CO2 has been observed towards both active star forming regions and quiescent clouds (Gerakines et. al. (1999)). The high abundance of CO2 in the solid phase, and its low abundance in the gas phase, support the idea that CO2 is almost exclusively formed in the solid state. Several possible formation mechanisms have been postulated (Ruffle &Herbst (2001): Charnley &Kaufman (2000)), and the detection of CO2 towards quiescent sources such as Elias 16 (Whittet et. al. (1998)) clearly suggests that CO2 can be produced in the absence of UV or electron mediated processes. The most likely route is via the surface reactions between O atoms, or OH radicals, and CO. The tools of modern surface- science offer us the potential to determine many of the physical and chemical attributes of icy interstellar grain mantles under highly controlled conditions, that closely mimic interstellar environments. The Leiden Surface Reaction Simulation Device ( urfreside) combines UHV (UltraS High Vacuum) surface science techniques with an atomic beam to study chemical reactions occurring on the SURFACE and in the BULK of interstellar ice grain mimics. By simultaneously combining two or more surface analysis techniques, the chemical kinetics, reaction mechanisms and activation energies can be determined directly. The experiment is aimed at identifying the key barrierless reactions and desorption pathways on and in H2 O and CO ices under interstellar conditions. The results from traditional HV (high vacuum) and UHV studies of the CO + O and CO + OH reactions will be presented in this paper. Charnley, S.B., & Kaufman, M.J., 2000, ApJ, 529, L111 Gerakines, P.A., 1999, ApJ, 522, 357 Ruffle, D.P., & Herbst, E., 2001, MNRAS, 324, 1054 Whittet, D.C.B., et.al., 1998, ApJ, 498, L159

  3. Surface Acoustic Wave (SAW Resonators for Monitoring Conditioning Film Formation

    Directory of Open Access Journals (Sweden)

    Siegfried Hohmann

    2015-05-01

    Full Text Available We propose surface acoustic wave (SAW resonators as a complementary tool for conditioning film monitoring. Conditioning films are formed by adsorption of inorganic and organic substances on a substrate the moment this substrate comes into contact with a liquid phase. In the case of implant insertion, for instance, initial protein adsorption is required to start wound healing, but it will also trigger immune reactions leading to inflammatory responses. The control of the initial protein adsorption would allow to promote the healing process and to suppress adverse immune reactions. Methods to investigate these adsorption processes are available, but it remains difficult to translate measurement results into actual protein binding events. Biosensor transducers allow user-friendly investigation of protein adsorption on different surfaces. The combination of several transduction principles leads to complementary results, allowing a more comprehensive characterization of the adsorbing layer. We introduce SAW resonators as a novel complementary tool for time-resolved conditioning film monitoring. SAW resonators were coated with polymers. The adsorption of the plasma proteins human serum albumin (HSA and fibrinogen onto the polymer-coated surfaces were monitored. Frequency results were compared with quartz crystal microbalance (QCM sensor measurements, which confirmed the suitability of the SAW resonators for this application.

  4. Effect of Climate Change on Surface Ozone over North America, Europe, and East Asia

    Science.gov (United States)

    Schnell, Jordan L.; Prather, Michael J.; Josse, Beatrice; Naik, Vaishali; Horowitz, Larry W.; Zeng, Guang; Shindell, Drew T.; Faluvegi, Greg

    2016-01-01

    The effect of future climate change on surface ozone over North America, Europe, and East Asia is evaluated using present-day (2000s) and future (2100s) hourly surface ozone simulated by four global models. Future climate follows RCP8.5, while methane and anthropogenic ozone precursors are fixed at year-2000 levels. Climate change shifts the seasonal surface ozone peak to earlier in the year and increases the amplitude of the annual cycle. Increases in mean summertime and high-percentile ozone are generally found in polluted environments, while decreases are found in clean environments. We propose climate change augments the efficiency of precursor emissions to generate surface ozone in polluted regions, thus reducing precursor export to neighboring downwind locations. Even with constant biogenic emissions, climate change causes the largest ozone increases at high percentiles. In most cases, air quality extreme episodes become larger and contain higher ozone levels relative to the rest of the distribution.

  5. Starch degradation in rumen fluid as influenced by genotype, climatic conditions and maturity stage of maize, grown under controlled conditions

    NARCIS (Netherlands)

    Ali, M.; Cone, J.W.; Hendriks, W.H.; Struik, P.C.

    2014-01-01

    Starch is the major component of maize kernels, contributing significantly to the feeding value of forage maize when fed to ruminants. The effects of genotype, climatic conditions and maturity stage on starch content in the kernels and on in vitro starch degradability in rumen fluid were

  6. The Modern Near-Surface Martian Climate: A Review of In-Situ Meteorological Data from Viking to Curiosity

    Science.gov (United States)

    Martinez, G. M.; Newman, C. N.; De Vicente-Retortillo, A.; Fischer, E.; Renno, N. O.; Richardson, M. I.; Fairén, A. G.; Genzer, M.; Guzewich, S. D.; Haberle, R. M.; hide

    2017-01-01

    We analyze the complete set of in-situ meteorological data obtained from the Viking landers in the 1970s to todays Curiosity rover to review our understanding of the modern near-surface climate of Mars, with focus on the dust, CO2 and H2O cycles and their impact on the radiative and thermodynamic conditions near the surface. In particular, we provide values of the highest confidence possible for atmospheric opacity, atmospheric pressure, near-surface air temperature, ground temperature, near-surface wind speed and direction, and near-surface air relative humidity and water vapor content. Then, we study the diurnal, seasonal and interannual variability of these quantities over a span of more than twenty Martian years. Finally, we propose measurements to improve our understanding of the Martian dust and H2O cycles, and discuss the potential for liquid water formation under Mars present day conditions and its implications for future Mars missions.

  7. Modified hot-conditioning of PHT system surfaces of PHWRs

    Energy Technology Data Exchange (ETDEWEB)

    Venkateswaran, G [Bhabha Atomic Research Centre, Trombay, Bombay (India)

    1997-02-01

    The increased awareness on the importance of controlling activity transport and radiation buildup on out-of-core surfaces of water cooled nuclear reactors is leading to a host of measures both from chemistry as well as engineering sides being undertaken. Passivation of the surfaces of structural materials is one such. Pressurised Heavy Water Reactors of CANDU design use large surface area of carbon steel alloy in the Primary Heat Transport System. Hot-conditioning of the PHT system with deoxygenated light water at temperatures {approx_equal} 473 - 523 K during commissioning stage is done to form a protective magnetite film on the surfaces of carbon steel essentially to guard this material from corrosion during the intervening period between initial commissioning and first fuel loading and achieving nuclear heat. However, a need is felt to improve the quality of this magnetite film and control the crud release so that the twin objectives of controlling the corrosion of carbon steel and reducing a possible deposition of corrosion products on surfaces of fuel clad could be achieved. Laboratory static autoclave investigations have been carried out on the formation of protective magnetite film on carbon steel at 473 K, pH 10 (pH at 298 K) deoxygenated aqueous solutions of chelants like HEDTA, DTPA, NTA apart from EDTA. Additionally, influence of AVT chemicals like hydrazine, cyclohexylamine, morpholine and additives like glucose, boric acid has been studied. The data have been compared with the standard procedure of hot-conditioning namely with simple LiOH. It is found that chelants increase the base metal loss but the oxide formed is more protective than the one formed under simple LiOH treatment. The efficiency of passivation is greatly enhanced by hydrazine and boric acid while it is adversely affected by glucose. AVT chemicals acts as effective corrosion inhibitors. (author). 14 refs, 2 figs, 4 tabs.

  8. Modified hot-conditioning of PHT system surfaces of PHWRs

    International Nuclear Information System (INIS)

    Venkateswaran, G.

    1997-01-01

    The increased awareness on the importance of controlling activity transport and radiation buildup on out-of-core surfaces of water cooled nuclear reactors is leading to a host of measures both from chemistry as well as engineering sides being undertaken. Passivation of the surfaces of structural materials is one such. Pressurised Heavy Water Reactors of CANDU design use large surface area of carbon steel alloy in the Primary Heat Transport System. Hot-conditioning of the PHT system with deoxygenated light water at temperatures ≅ 473 - 523 K during commissioning stage is done to form a protective magnetite film on the surfaces of carbon steel essentially to guard this material from corrosion during the intervening period between initial commissioning and first fuel loading and achieving nuclear heat. However, a need is felt to improve the quality of this magnetite film and control the crud release so that the twin objectives of controlling the corrosion of carbon steel and reducing a possible deposition of corrosion products on surfaces of fuel clad could be achieved. Laboratory static autoclave investigations have been carried out on the formation of protective magnetite film on carbon steel at 473 K, pH 10 (pH at 298 K) deoxygenated aqueous solutions of chelants like HEDTA, DTPA, NTA apart from EDTA. Additionally, influence of AVT chemicals like hydrazine, cyclohexylamine, morpholine and additives like glucose, boric acid has been studied. The data have been compared with the standard procedure of hot-conditioning namely with simple LiOH. It is found that chelants increase the base metal loss but the oxide formed is more protective than the one formed under simple LiOH treatment. The efficiency of passivation is greatly enhanced by hydrazine and boric acid while it is adversely affected by glucose. AVT chemicals acts as effective corrosion inhibitors. (author). 14 refs, 2 figs, 4 tabs

  9. Repairability of Compomers with Different Methods of Surface Conditioning

    Directory of Open Access Journals (Sweden)

    P.Samimi

    2005-06-01

    Full Text Available Statement of Problem: Considering the cost and amount of time and also the quantity of tooth loss in the process of cavity preparation, repair of the restoration instead of itsreplacement would be much more efficient.Purpose: The aim of this study was to determine the effect of different methods of surface conditioning on the shear bond strength of repaired compomers.Materials and Methods: Sixty blocks of compomer were prepared in acrylic molds and then they were randomly divided into five groups of 12. Group I (control groupreceived no treatment. The remaining samples were immersed in 37 ºC distilled water for one week, then the surfaces were roughened with a coarse diamond bur. Samples ineach group were prepared by different surface treatment and conditioning: In group II specimens were conditioned with 35% phosphoric acid for 20s. Specimens in group III were etched with 10% polyacrylic acid for 20s. In group IV 1.23% acidulated phosphatefluoride was applied for 30s, and compomer surfaces were sandblasted with 50μm Al2O3 powder in group V. After the initial preparations, all groups were treated with silane and resin before bonding of the second mix of compomer. Shear forces were applied with a universal testing machine at a cross-head speed of 5mm/min. The data were analyzed using one-way ANOVA and Duncan's multiple range tests.Results: The mean shear bond strengths and standard deviations (in parentheses for groups I to V were 31.56(10.86, 20.02(5.49, 17.74(7.34, 19.31(4.31 and 27.7(6.33MPa, respectively. The mean bond strengths for Groups I and V were significantly higher than that of the other groups (P<0.05.Conclusion: The results showed that among the surface treatments used in this study,sandblasting with alumina could be the best surface preparation method for repairing compomer restorations.

  10. Conditions affecting the release of phosphorus from surface lake sediments.

    Science.gov (United States)

    Christophoridis, Christophoros; Fytianos, Konstantinos

    2006-01-01

    Laboratory studies were conducted to determine the effect of pH and redox conditions, as well as the effect of Fe, Mn, Ca, Al, and organic matter, on the release of ortho-phosphates in lake sediments taken from Lakes Koronia and Volvi (Northern Greece). Results were evaluated in combination with experiments to determine P fractionation in the sediment. The study revealed the major effect of redox potential and pH on the release of P from lake sediments. Both lakes showed increased release rates under reductive conditions and high pH values. The fractionation experiments revealed increased mobility of the reductive P fraction as well as of the NaOH-P fraction, indicating participation of both fractions in the overall release of sediment-bound P, depending on the prevailing environmental conditions. The results were assessed in combination with the release patterns of Fe, Mn, Ca, Al, and organic matter, enabling the identification of more specific processes of P release for each lake. The basic release patterns included the redox induced reductive dissolution of P-bearing metal oxides and the competitive exchange of phosphate anions with OH- at high pH values. The formation of an oxidized surface microlayer under oxic conditions acted as a protective film, preventing further P release from the sediments of Lake Volvi, while sediments from Lake Koronia exhibited a continuous and increased tendency to release P under various physicochemical conditions, acting as a constant source of internal P loading.

  11. An AES Study of the Room Temperature Surface Conditioning of Technological Metal Surfaces by Electron Irradiation

    OpenAIRE

    Scheuerlein, C; Hilleret, Noël; Taborelli, M; Brown, A; Baker, M A

    2002-01-01

    The modifications to technological copper and niobium surfaces induced by 2.5 keV electron irradiation have been investigated in the context of the conditioning process occurring in particle accelerator ultra high vacuum systems. Changes in the elemental surface composition have been found using Scanning Auger Microscopy (SAM) by monitoring the carbon, oxygen and metal Auger peak intensities as a function of electron irradiation in the dose range 10-6 to 10-2 C mm-2. The surface analysis resu...

  12. Cooling the vertical surface by conditionally single pulses

    Directory of Open Access Journals (Sweden)

    Karpov Pavel

    2017-01-01

    Full Text Available You Sprays with periodic supply of the droplet phase have great opportunities to control the heat exchange processes. Varying pulse duration and frequency of their repetition, we can achieve the optimal conditions of evaporative cooling with minimization of the liquid flow rate. The paper presents experimental data on studying local heat transfer on a large subcooled surface, obtained on the original setup with multinozzle controlled system of impact irrigation by the gas-droplet flow. A contribution to intensification of the spray parameters (flow rate, pulse duration, repetition frequency per a growth of integral heat transfer was studied. Data on instantaneous distribution of the heat flux value helped us to describe the processes occurring on the studied surface. These data could describe the regime of “island” film cooling.

  13. Boundary conditions for free surface inlet and outlet problems

    KAUST Repository

    Taroni, M.

    2012-08-10

    We investigate and compare the boundary conditions that are to be applied to free-surface problems involving inlet and outlets of Newtonian fluid, typically found in coating processes. The flux of fluid is a priori known at an inlet, but unknown at an outlet, where it is governed by the local behaviour near the film-forming meniscus. In the limit of vanishing capillary number Ca it is well known that the flux scales with Ca 2/3, but this classical result is non-uniform as the contact angle approaches π. By examining this limit we find a solution that is uniformly valid for all contact angles. Furthermore, by considering the far-field behaviour of the free surface we show that there exists a critical capillary number above which the problem at an inlet becomes over-determined. The implications of this result for the modelling of coating flows are discussed. © 2012 Cambridge University Press.

  14. Cooling the vertical surface by conditionally single pulses

    Science.gov (United States)

    Karpov, Pavel; Nazarov, Alexander; Serov, Anatoly; Terekhov, Victor

    2017-10-01

    You Sprays with periodic supply of the droplet phase have great opportunities to control the heat exchange processes. Varying pulse duration and frequency of their repetition, we can achieve the optimal conditions of evaporative cooling with minimization of the liquid flow rate. The paper presents experimental data on studying local heat transfer on a large subcooled surface, obtained on the original setup with multinozzle controlled system of impact irrigation by the gas-droplet flow. A contribution to intensification of the spray parameters (flow rate, pulse duration, repetition frequency) per a growth of integral heat transfer was studied. Data on instantaneous distribution of the heat flux value helped us to describe the processes occurring on the studied surface. These data could describe the regime of "island" film cooling.

  15. Hydrological Responses to Land-Use Change Scenarios under Constant and Changed Climatic Conditions.

    Science.gov (United States)

    Zhang, Ling; Nan, Zhuotong; Yu, Wenjun; Ge, Yingchun

    2016-02-01

    This study quantified the hydrological responses to land-use change scenarios in the upper and middle Heihe River basin (HRB), northwest China, under constant and changed climatic conditions by combining a land-use/cover change model (dynamic conversion of land use and its effects, Dyna-CLUE) and a hydrological model (soil and water assessment tool, SWAT). Five land-use change scenarios, i.e., historical trend (HT), ecological protection (EP), strict ecological protection (SEP), economic development (ED), and rapid economic development (RED) scenarios, were established. Under constant climatic condition, hydrological variations are only induced by land-use changes in different scenarios. The changes in mean streamflow at the outlets of the upper and the middle HRB are not pronounced, although the different scenarios produce different outcomes. However, more pronounced changes are observed on a subbasin level. The frequency of extreme flood is projected to decrease under the SEP scenario, while under the other scenarios, no changes can be found. Two emission scenarios (A1B and B1) of three general circulation models (HadCM3, CGCM3, and CCSM3) were employed to generate future possible climatic conditions. Under changed climatic condition, hydrological variations are induced by the combination of land-use and climatic changes. The results indicate that the impacts of land-use changes become secondary when the changed climatic conditions have been considered. The frequencies of extreme flood and drought are projected to decrease and increase, respectively, under all climate scenarios. Although some agreements can be reached, pronounced difference of hydrological responses can be observed for different climate scenarios of different GCMs.

  16. The future bioclimatic conditions in Austria under the aspect of climate change scenarios

    Science.gov (United States)

    Rudel, E.; Matzarakis, A.; Neumke, R.; Endler, Ch,; Koch, E.

    2009-09-01

    The IPCC quantifies Heat Stress as a combination of air temperature and air humidity. In order to describe the future bioclimatic conditions in a human-biometeorological manner the analysis a modern thermal index has been chosen. The PET (Physiologically Equivalent Temperature) allows the assessment of the effect of the thermal environment based on the energy balance of humans including thermo-physiological information. The data for the calculation of the PET came from climate models. The required data are for the climatic parameters air temperature, relative humidity, wind velocity and mean cloud cover as the necessary inputs for Physiologically Equivalents Temperature. Regarding future climatic changes PET calculations for the time slices 1961 and 1990 and also 2070 and 2100 have been run in 0.5 ° resolution. By the use of statistical regression for the 0.5 ° resolution the results have been downscaled to 1 km resolution in order to identify and quantify the areas in Austria, which will be more affected bioclimatologically. The constructed maps present current and future climatic conditions and also differences for the different time slices and SRES-scenarios of the IPCC. Maps of the difference between the Physiological Equivalent temperature and air temperature have been constructed to show that the used thermal indices, which have been applied by the IPCC underestimate the expected thermal bioclimate conditions for future climate. The results offer fundamental information for tourism and recreation authorities for present and expected climatic and bioclimatic conditions.

  17. Late Quaternary Palaeoceanographic Changes in Sea Surface Conditions in the Tropical Atlantic

    Science.gov (United States)

    Fischel, Andrea; Seidenkrantz, Marit-Solveig; Kuijpers, Antoon; Nürnberg, Dirk

    2013-04-01

    Palaeoceanographic changes and the variability in surface water mass hydrography are reconstructed in order to track tropical ocean and climate variability and inter-hemispheric heat exchange through the last 42,000 year BP. Our studies are based on the relative abundance of planktonic foraminifera combined with sea surface temperature approximation based Mg/Ca measurements, XRF scanning and stable oxygen isotope analyses in a 5 m long gravity core Ga307-Win-12GC (17°50.80N, 64°48.7290W), retrieved in the Virgin Island Basin in approx. 3,960 m water depth. The Virgin Island Basin is the deepest part of the Anegada-Jungfern Passage in the northeast Caribbean, one of the most important pathways for water mass exchange between the Central Atlantic and the Caribbean Sea. Due to its bathymetry surface waters as well as deep water mass strata from the northern and southern hemisphere enter the basin, comprising Caribbean Surface Water (CSW), Antarctic Intermediate Water (AAIW), Atlantic Intermediate Water (AIW) and North Atlantic Deep Water (NADW). The planktonic foraminiferal assemblage suggests rather stable sea-surface conditions during the Holocene in the NE Caribbean. However, major changes in the hydrographic setting could be identified within the glacial period. During the glacial period, clear millennial-scale variability in sea-surface temperature and productivity are present. Fluctuations in the relative abundance of Globigerinoides ruber in the sediment core may be correlated to Dansgaard-Oeschger events in the northern North Atlantic. Furthermore an increase in relative abundance of Globorotalia rubescens occurs synchronous with ice rafted debris layers described from the North Atlantic. The faunal changes in the tropical Atlantic may thus be correlated to major climate changes in the North Atlantic, mainly D-O cyclicity as well as Heinrich events. Thus, the synchronous change in water mass distribution and hydrographic cyclicity suggests a possible linkage

  18. Evaluation of thermal perception in schoolyards under Mediterranean climate conditions

    Science.gov (United States)

    Antoniadis, D.; Katsoulas, N.; Papanastasiou, D.; Christidou, V.; Kittas, C.

    2016-03-01

    The aim of this paper was to study qualitatively and quantitatively the thermal perception and corresponding heat stress conditions that prevail in two schoolyards in a coastal city in central Greece. For this purpose, meteorological parameters (i.e., wind speed, temperature, relative humidity, solar radiation) were recorded at 70 and 55 measuring points in the schoolyards, from 14:00 to 15:30 local time, during May and June of 2011. The measuring points were distributed so as to get measurements at points (a) directly exposed to the sun, (b) under the shadow of trees and building structures, and (c) near building structures. Cluster analysis was applied to group observations and revealed places that are microclimatically homogeneous. Thermal perception and heat stress conditions were assessed by means of the physiologically equivalent temperature (PET, °C), and the results are presented in relevant charts. The impact of material's albedo, radiation's reflection by structures and obstacles, and different tree species on thermal perception and heat stress conditions was also assessed. The analysis showed that trees triggered a reduction of incident solar radiation that ranged between 79 and 94 % depending on tree's species, crown dimension, tree height, and leaf area. PET values were mainly affected by solar radiation and wind speed. Trees caused a reduction of up to 37 % in PET values, while a 1-m s-1 increase in wind speed triggered a reduction of 3.7-5.0 °C in PET value. The effective shading area in the two schoolyards was small, being 27.5 and 11 %. The results of this study could be exploited by urban planning managers when designing or improving the outdoor environment of a school complex.

  19. Effects of future climate conditions on streamflow dynamics in coastal southern California watersheds

    Science.gov (United States)

    Feng, D.; Zhao, Y.; Raoufi, R.; Beighley, E.; Melack, J.

    2017-12-01

    The Santa Barbara Coastal - Long Term Ecological Research Project is focused on investigating the relative importance of land and ocean processes in structuring giant kelp forest ecosystems. Understanding how current and future climate conditions influence terrestrial export of water is a central theme for the project. In this study, the Hillslope River Routing (HRR) model is forced with past measurement-based (1950 to 2005) and future model-based (2006 to 2100) precipitation and temperature to estimate daily streamflow dynamics. The study region is roughly 800 km2 with 179 watersheds ranging from 0.1 to 123 km2. The model-based forcings are downscaled to a spatial resolution of 6 km by 6 km. The Priestley and Taylor method is used to estimate potential evapotranspiration based on the Food and Agriculture Organization of the United Nations limited climate data approximations and land surface conditions (albedo, leaf area index, land cover) measured from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra and Aqua satellites. The HRR model is calibrated for the period 1984 to 2013 using USGS streamflow. Median changes in downscaled precipitation projections from 10 models and two emission scenarios (RCP 4.5 and 8.5) combined with significance testing, suggest that the distribution of precipitation throughout the rainy season will change: decrease at the beginning of the rainy season (Oct-Dec), increase during peak season (Jan-Mar) and decrease at the end (Apr-Jun). Annually, results suggest a slight increase in precipitation. The decrease of rainfall in spring and fall and increase in winter will lead to a shorter (10-15 days, 8-14%), more intense wet season. Both the magnitude and frequency of large storms (>36 mm/day) are likely to increase. Following the precipitation patterns, streamflow in spring and fall is likely to decrease while winter streamflow and annual peak flows are likely to increase due to increased winter precipitation and

  20. Climate-induced hotspots in surface energy fluxes from 1948 to 2000

    International Nuclear Information System (INIS)

    Sheng Li; Liu Shuhua; Liu Heping

    2010-01-01

    Understanding how land surfaces respond to climate change requires knowledge of land-surface processes, which control the degree to which interannual variability and mean trends in climatic variables affect the surface energy budget. We use the latest version of the Community Land Model version 3.5 (CLM3.5), which is driven by the latest updated hybrid reanalysis-observation atmospheric forcing dataset constructed by Princeton University, to obtain global distributions of the surface energy budget from 1948 to 2000. We identify climate change hotspots and surface energy flux hotspots from 1948 to 2000. Surface energy flux hotspots, which reflect regions with strong changes in surface energy fluxes, reveal seasonal variations with strong signals in winter, spring, and autumn and weak ones in summer. Locations for surface energy flux hotspots are not, however, fully linked with those for climate change hotspots, suggesting that only in some regions are land surfaces more responsive to climate change in terms of interannual variability and mean trends.

  1. Clay Mineralogy and Crystallinity as a Climatic Indicator: Evidence for Both Cold and Temperate Conditions on Early Mars

    Science.gov (United States)

    Horgan, B.; Rutledge, A.; Rampe, E. B.

    2015-01-01

    Surface weathering on Earth is driven by precipitation (rain/snow melt). Here we summarize the influence of climate on minerals produced during surface weathering, based on terrestrial literature and our new laboratory analyses of weathering products from glacial analog sites. By comparison to minerals identified in likely surface environments on Mars, we evaluate the implications for early martian climate.

  2. Impact of future climatic conditions on the potential for soil organic matter priming

    DEFF Research Database (Denmark)

    Reinsch, Sabine; Ambus, Per; Thornton, Barry

    2013-01-01

    Terrestrial carbon (C) storage and turnover are of major interest under changing climatic conditions. We present a laboratory microcosm study investigating the effects of anticipated climatic conditions on the soil microbial community and related changes in soil organic matter (SOM) decomposition....... Soil samples were taken from a heath-land after six years of exposure to elevated carbon dioxide (eCO2) in combination with summer drought (D) and increased temperature (T). Soil C-dynamics were investigated in soils from: (i) ambient, (ii) eCO2, and (iii) plots exposed to the combination of factors...... simulating future climatic conditions (TDeCO2) that simulate conditions predicted for Denmark in 2075. 13C enriched glucose (3 atom% excess) was added to soil microcosms, soil CO2 efflux was measured over a period of two weeks and separated into glucose- and SOM-derived C. Microbial biomass was measured...

  3. Environmental impacts of barley cultivation under current and future climatic conditions

    DEFF Research Database (Denmark)

    Dijkman, Teunis Johannes; Birkved, Morten; Saxe, Henrik

    2017-01-01

    for the increased impacts. This finding was confirmed by the sensitivity analysis. Because this study focused solely on the impacts of climate change, technological improvements and political measures to reduce impacts in the 2050 scenario are not taken into account. Options to mitigate the environmental impacts......The purpose of this work is to compare the environmental impacts of spring barley cultivation in Denmark under current (year 2010) and future (year 2050) climatic conditions. Therefore, a Life Cycle Assessment was carried out for the production of 1 kg of spring barley in Denmark, at farm gate....... Both under 2010 and 2050 climatic conditions, four subscenarios were modelled, based on a combination of two soil types and two climates. Included in the assessment were seed production, soil preparation, fertilization, pesticide application, and harvest. When processes in the life cycle resulted in co...

  4. Quantifying the impact of climate change on enteric waterborne pathogen concentrations in surface water

    NARCIS (Netherlands)

    Hofstra, N.

    2011-01-01

    Climate change, among other factors, will impact waterborne pathogen concentrations in surface water worldwide, possibly increasing the risk of diseases caused by these pathogens. So far, the impacts are only determined qualitatively and thorough quantitative estimates of future pathogen

  5. ClimoBase: Rouse Canadian Surface Observations of Weather, Climate, and Hydrological Variables, 1984-1998

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — ClimoBase is a collection of surface climate measurements collected in Northern Canada by Dr. Wayne Rouse between 1984 and 1998 in three locations: Churchill,...

  6. Morro do Cruzeiro UFOP Campus evaluation of indoors climatic conditions

    Directory of Open Access Journals (Sweden)

    Marcela A. Faria

    Full Text Available Abstract The comfort conditions of a given environment can directly influence the performance of the activities performed therein. When considering the school space in relationship with the user, the environment is even more important, since it may reflect fully on the learning process. This article evaluates the thermal comfort perceptions of classroom users of the Federal University of Ouro Preto, specifically the School of Mining, the Institute of Physical and Biological Sciences and the Building Block of Classrooms. The research is conducted through questionnaires and measurements of environmental variables in loco simultaneously in the three areas throughout the months of June, July and September 2011. The results were statistically analyzed using the calculation of the standard deviation from the mean operative temperature and humidity to give comfort zone. Approximately 75% of the users were satisfied with the thermal environment.

  7. Attributing Climate Conditions for Stable Malaria Transmission to Human Activity in sub-Saharan Africa

    Science.gov (United States)

    Sheldrake, L.; Mitchell, D.; Allen, M. R.

    2015-12-01

    Temperature and precipitation limit areas of stable malaria transmission, but the effects of climate change on the disease remain controversial. Previously, studies have not separated the influence of anthropogenic climate change and natural variability, despite being an essential step in the attribution of climate change impacts. Ensembles of 2900 simulations of regional climate in sub-Saharan Africa for the year 2013, one representing realistic conditions and the other how climate might have been in the absence of human influence, were used to force a P.falciparium climate suitability model developed by the Mapping Malaria Risk in Africa project. Strongest signals were detected in areas of unstable transmission, indicating their heightened sensitivity to climatic factors. Evidently, impacts of human-induced climate change were unevenly distributed: the probability of conditions being suitable for stable malaria transmission were substantially reduced (increased) in the Sahel (Greater Horn of Africa (GHOA), particularly in the Ethiopian and Kenyan highlands). The length of the transmission season was correspondingly shortened in the Sahel and extended in the GHOA, by 1 to 2 months, including in Kericho (Kenya), where the role of climate change in driving recent malaria occurrence is hotly contested. Human-induced warming was primarily responsible for positive anomalies in the GHOA, while reduced rainfall caused negative anomalies in the Sahel. The latter was associated with anthropogenic impacts on the West African Monsoon, but uncertainty in the RCM's ability to reproduce precipitation trends in the region weakens confidence in the result. That said, outputs correspond well with broad-scale changes in observed endemicity, implying a potentially important contribution of anthropogenic climate change to the malaria burden during the past century. Results support the health-framing of climate risk and help indicate hotspots of climate vulnerability, providing

  8. Sustainability Challenges from Climate Change and Air Conditioning Use in Urban Areas

    OpenAIRE

    Lundgren, Karin; Kjellström, Tord

    2013-01-01

    Global climate change increases heat loads in urban areas causing health and productivity risks for millions of people. Inhabitants in tropical and subtropical urban areas are at especial risk due to high population density, already high temperatures, and temperature increases due to climate change. Air conditioning is growing rapidly, especially in South and South-East Asia due to income growth and the need to protect from high heat exposures. Studies have linked increased total hourly elect...

  9. Conditions for a market uptake of climate services for adaptation in France

    Directory of Open Access Journals (Sweden)

    Romain Cavelier

    2017-04-01

    Full Text Available This perspective paper reports the results of a collaborative survey of French research institutes concerned with environmental issues, which examined the potential for a market uptake of climate services for adaptation in France. The study is based on a review of existing reports on the market of climate services, and on interviews of 68 climate service providers and users in public and private organizations. Although the study does not allow to provide quantified estimations regarding the present and future size of the market, its results offer new perspectives with implications extending far beyond the sole case of France: first, while the market is still in its infancy, significant opportunities exist in sectors such as flooding risks, and, to a slightly lesser extent, hydro and nuclear energy and viticulture. In addition, the study identifies critical conditions for the uptake in climate services: (1 a coordinated delivery of data, information, expertise and training by public research institutes concerned with climate change and its impacts; (2 the inclusion of adaptation in the regulation and in public and private tenders. Finally, (3 uncertainties in climate projections appear as a major barrier to the uptake of climate services. However, ambitious greenhouse gas emission reduction as planned by the COP-21 Paris Agreement contribute to reducing this uncertainties by allowing users to select a subset of climate change projections, avoiding those for which adaptation is most problematic.

  10. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    International Nuclear Information System (INIS)

    Reeves, T.L.; Turner, J.P.; Hasfurther, V.R.; Skinner, Q.D.

    1992-06-01

    The scope of this program is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 x 3.0 x 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by RBOSC to carry out this study. Research objectives were designed to evaluate hydrologic, geotechnical, and chemical properties and conditions which would affect the design and performance of large-scale embankments. The objectives of this research are: assess the unsaturated movement and redistribution of water and the development of potential saturated zones and drainage in disposed processed oil shale under natural and simulated climatic conditions; assess the unsaturated movement of solubles and major chemical constituents in disposed processed oil shale under natural and simulated climatic conditions; assess the physical and constitutive properties of the processed oil shale and determine potential changes in these properties caused by disposal and weathering by natural and simulated climatic conditions; assess the use of previously developed computer model(s) to describe the infiltration, unsaturated movement, redistribution, and drainage of water in disposed processed oil shale; evaluate the stability of field scale processed oil shale solid waste embankments using computer models

  11. Projections of meteorological and snow conditions in the Pyrenees using adjusted EURO-CORDEX climate projections

    Science.gov (United States)

    Verfaillie, Deborah; Déqué, Michel; Morin, Samuel; Soubeyroux, Jean-Michel; Lafaysse, Matthieu

    2017-04-01

    Current and future availability of seasonal snow is a recurring topic in mountain regions such as the Pyrenees, where winter tourism and hydropower production are large contributors to the regional revenues in France, Spain and Andorra. Associated changes in river discharges, their consequences on water storage management, the future vulnerability of Pyrenean ecosystems as well as the occurrence of climate-related hazards such as debris flows and avalanches are also under consideration. However, to generate projections of snow conditions, a traditional dynamical downscaling approach featuring spatial resolutions typically between 10 and 50 km is not sufficient to capture the fine-scale processes and thresholds at play. Indeed, the altitudinal resolution matters, since the phase of precipitation is mainly controlled by the temperature which is altitude-dependent. Moreover, simulations from general circulation models (GCMs) and regional climate models (RCMs) suffer from biases compared to local observations, and often provide outputs at too coarse time resolution to drive impact models. RCM simulations must therefore be adjusted before they can be used to drive specific models such as land surface models. In this study, time series of hourly temperature, precipitation, wind speed, humidity, and short- and longwave radiation were generated over the Pyrenees for the period 1950-2100, by using a new approach (named ADAMONT for ADjustment of RCM outputs to MOuNTain regions) based on quantile mapping applied to daily data, followed by time disaggregation accounting for weather patterns selection. Meteorological observations used for the quantile mapping consist of the regional scale reanalysis SAFRAN, which operates at the scale of homogeneous areas on the order of 1000 km2 within which meteorological conditions vary only with elevation. SAFRAN combines large-scale NWP reanalysis (ERA40, ARPEGE) with in-situ meteorological observations. The SAFRAN reanalysis is available

  12. Reductive precipitation of neptunium on iron surfaces under anaerobic conditions

    Science.gov (United States)

    Yang, H.; Cui, D.; Grolimund, D.; Rondinella, V. V.; Brütsch, R.; Amme, M.; Kutahyali, C.; Wiss, A. T.; Puranen, A.; Spahiu, K.

    2017-12-01

    Reductive precipitation of the radiotoxic nuclide 237Np from nuclear waste on the surface of iron canister material at simulated deep repository conditions was investigated. Pristine polished as well as pre-corroded iron specimens were interacted in a deoxygenated solution containing 10-100 μM Np(V), with 10 mM NaCl and 2 mM NaHCO3 as background electrolytes. The reactivity of each of the two different systems was investigated by analyzing the temporal evolution of the Np concentration in the reservoir. It was observed that pre-oxidized iron specimen with a 40 μm Fe3O4 corrosion layer are considerably more reactive regarding the reduction and immobilization of aqueous Np(V) as compared to pristine polished Fe(0) surfaces. 237Np immobilized by the reactive iron surfaces was characterized by scanning electron microscopy as well as synchrotron-based micro-X-ray fluorescence and X-ray absorption spectroscopy. At the end of experiments, a 5-8 μm thick Np-rich layer was observed to be formed ontop of the Fe3O4 corrosion layer on the iron specimen. The findings from this work are significant in the context of performance assessments of deep geologic repositories using iron as high level radioactive waste (HLW) canister material and are of relevance regarding removing pollutants from contaminated soil or groundwater aquifer systems.

  13. Satellite-based climate data records of surface solar radiation from the CM SAF

    Science.gov (United States)

    Trentmann, Jörg; Cremer, Roswitha; Kothe, Steffen; Müller, Richard; Pfeifroth, Uwe

    2017-04-01

    The incoming surface solar radiation has been defined as an essential climate variable by GCOS. Long term monitoring of this part of the earth's energy budget is required to gain insights on the state and variability of the climate system. In addition, climate data sets of surface solar radiation have received increased attention over the recent years as an important source of information for solar energy assessments, for crop modeling, and for the validation of climate and weather models. The EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF) is deriving climate data records (CDRs) from geostationary and polar-orbiting satellite instruments. Within the CM SAF these CDRs are accompanied by operational data at a short time latency to be used for climate monitoring. All data from the CM SAF is freely available via www.cmsaf.eu. Here we present the regional and the global climate data records of surface solar radiation from the CM SAF. The regional climate data record SARAH (Surface Solar Radiation Dataset - Heliosat, doi: 10.5676/EUM_SAF_CM/SARAH/V002) is based on observations from the series of Meteosat satellites. SARAH provides 30-min, daily- and monthly-averaged data of the effective cloud albedo, the solar irradiance (incl. spectral information), the direct solar radiation (horizontal and normal), and the sunshine duration from 1983 to 2015 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° allowing for detailed regional studies. The global climate data record CLARA (CM SAF Clouds, Albedo and Radiation dataset from AVHRR data, doi: 10.5676/EUM_SAF_CM/CLARA_AVHRR/V002) is based on observations from the series of AVHRR satellite instruments. CLARA provides daily- and monthly-averaged global data of the solar irradiance (SIS) from 1982 to 2015 with a spatial resolution of 0.25°. In addition to the solar surface

  14. The Modern Near-Surface Martian Climate: A Review of In-situ Meteorological Data from Viking to Curiosity

    Science.gov (United States)

    Martínez, G. M.; Newman, C. N.; De Vicente-Retortillo, A.; Fischer, E.; Renno, N. O.; Richardson, M. I.; Fairén, A. G.; Genzer, M.; Guzewich, S. D.; Haberle, R. M.; Harri, A.-M.; Kemppinen, O.; Lemmon, M. T.; Smith, M. D.; de la Torre-Juárez, M.; Vasavada, A. R.

    2017-10-01

    We analyze the complete set of in-situ meteorological data obtained from the Viking landers in the 1970s to today's Curiosity rover to review our understanding of the modern near-surface climate of Mars, with focus on the dust, CO2 and H2O cycles and their impact on the radiative and thermodynamic conditions near the surface. In particular, we provide values of the highest confidence possible for atmospheric opacity, atmospheric pressure, near-surface air temperature, ground temperature, near-surface wind speed and direction, and near-surface air relative humidity and water vapor content. Then, we study the diurnal, seasonal and interannual variability of these quantities over a span of more than twenty Martian years. Finally, we propose measurements to improve our understanding of the Martian dust and H2O cycles, and discuss the potential for liquid water formation under Mars' present day conditions and its implications for future Mars missions. Understanding the modern Martian climate is important to determine if Mars could have the conditions to support life and to prepare for future human exploration.

  15. On the appropriate definition of soil profile configuration and initial conditions for land surface-hydrology models in cold regions

    Science.gov (United States)

    Sapriza-Azuri, Gonzalo; Gamazo, Pablo; Razavi, Saman; Wheater, Howard S.

    2018-06-01

    Arctic and subarctic regions are amongst the most susceptible regions on Earth to global warming and climate change. Understanding and predicting the impact of climate change in these regions require a proper process representation of the interactions between climate, carbon cycle, and hydrology in Earth system models. This study focuses on land surface models (LSMs) that represent the lower boundary condition of general circulation models (GCMs) and regional climate models (RCMs), which simulate climate change evolution at the global and regional scales, respectively. LSMs typically utilize a standard soil configuration with a depth of no more than 4 m, whereas for cold, permafrost regions, field experiments show that attention to deep soil profiles is needed to understand and close the water and energy balances, which are tightly coupled through the phase change. To address this gap, we design and run a series of model experiments with a one-dimensional LSM, called CLASS (Canadian Land Surface Scheme), as embedded in the MESH (Modélisation Environmentale Communautaire - Surface and Hydrology) modelling system, to (1) characterize the effect of soil profile depth under different climate conditions and in the presence of parameter uncertainty; (2) assess the effect of including or excluding the geothermal flux in the LSM at the bottom of the soil column; and (3) develop a methodology for temperature profile initialization in permafrost regions, where the system has an extended memory, by the use of paleo-records and bootstrapping. Our study area is in Norman Wells, Northwest Territories of Canada, where measurements of soil temperature profiles and historical reconstructed climate data are available. Our results demonstrate a dominant role for parameter uncertainty, that is often neglected in LSMs. Considering such high sensitivity to parameter values and dependency on the climate condition, we show that a minimum depth of 20 m is essential to adequately represent

  16. Iodine isotopes species fingerprinting environmental conditions in surface water along the northeastern Atlantic Ocean

    DEFF Research Database (Denmark)

    He, Peng; Hou, Xiaolin; Aldahan, Ala

    2013-01-01

    Concentrations and species of iodine isotopes (127I and 129I) provide vital information about iodine geochemistry, environmental conditions and water masses exchange in oceans. Despite extensive investigations of anthropogenic 129I in the Arctic Ocean and the Nordic Seas, concentrations of the is...... 129I in ocean environments and impact on climate at the ocean boundary layer.......Concentrations and species of iodine isotopes (127I and 129I) provide vital information about iodine geochemistry, environmental conditions and water masses exchange in oceans. Despite extensive investigations of anthropogenic 129I in the Arctic Ocean and the Nordic Seas, concentrations...... of the isotope in the Atlantic Ocean are, however, still unknown. We here present first data on 129I and 127I, and their species (iodide and iodate) in surface water transect along the northeastern Atlantic between 30° and 50°N. The results show iodate as the predominant species in the analyzed marine waters...

  17. An AES Study of the Room Temperature Surface Conditioning of Technological Metal Surfaces by Electron Irradiation

    CERN Document Server

    Scheuerlein, C; Taborelli, M; Brown, A; Baker, M A

    2002-01-01

    The modifications to technological copper and niobium surfaces induced by 2.5 keV electron irradiation have been investigated in the context of the conditioning process occurring in particle accelerator ultra high vacuum systems. Changes in the elemental surface composition have been found using Scanning Auger Microscopy (SAM) by monitoring the carbon, oxygen and metal Auger peak intensities as a function of electron irradiation in the dose range 10-6 to 10-2 C mm-2. The surface analysis results are compared with electron dose dependent secondary electron and electron stimulated desorption yield measurements. Initially the electron irradiation causes a surface cleaning through electron stimulated desorption, in particular of hydrogen. During this period both the electron stimulated desorption and secondary electron yield decrease as a function of electron dose. When the electron dose exceeds 10-4 C mm-2 electron stimulated desorption yields are reduced by several orders of magnitude and the electron beam indu...

  18. Impact of surface waves in a Regional Climate Model

    DEFF Research Database (Denmark)

    Rutgersson, Anna; Sætra, Oyvind; Semedo, Alvaro

    2010-01-01

    A coupled regional atmosphere-wave model system is developed with the purpose of investigating the impact of climate changes on the wave field, as well as feed-back effects of the wave field on the atmospheric parameters. This study focuses on the effects of introducing a two-way atmosphere...

  19. Unravelling Diurnal Asymmetry of Surface Temperature in Different Climate Zones.

    Science.gov (United States)

    Vinnarasi, R; Dhanya, C T; Chakravorty, Aniket; AghaKouchak, Amir

    2017-08-04

    Understanding the evolution of Diurnal Temperature Range (DTR), which has contradicting global and regional trends, is crucial because it influences environmental and human health. Here, we analyse the regional evolution of DTR trend over different climatic zones in India using a non-stationary approach known as the Multidimensional Ensemble Empirical Mode Decomposition (MEEMD) method, to explore the generalized influence of regional climate on DTR, if any. We report a 0.36 °C increase in overall mean of DTR till 1980, however, the rate has declined since then. Further, arid deserts and warm-temperate grasslands exhibit negative DTR trends, while the west coast and sub-tropical forest in the north-east show positive trends. This transition predominantly begins with a 0.5 °C increase from the west coast and spreads with an increase of 0.25 °C per decade. These changes are more pronounced during winter and post-monsoon, especially in the arid desert and warm-temperate grasslands, the DTR decreased up to 2 °C, where the rate of increase in minimum temperature is higher than the maximum temperature. We conclude that both maximum and minimum temperature increase in response to the global climate change, however, their rates of increase are highly local and depend on the underlying climatic zone.

  20. Prediction of thermal sensation in non-air-conditioned buildings in warm climates

    DEFF Research Database (Denmark)

    Fanger, Povl Ole; Toftum, Jørn

    2002-01-01

    The PMV model agrees well with high-quality field studies in buildings with HVAC systems, situated in cold, temperate and warm climates, studied during both summer and winter. In non-air-conditioned buildings in warm climates, occupants may sense the warmth as being less severe than the PMV...... predicts. The main reason is low expectations, but a metabolic rate that is estimated too high can also contribute to explaining the difference. An extension of the PMV model that includes an expectancy factor is introduced for use in non-air-conditioned buildings in warm climates. The extended PMV model...... agrees well with quality field studies in non-air-conditioned buildings of three continents....

  1. Extension of the PMV model to non-air-conditioned building in warm climates

    DEFF Research Database (Denmark)

    Fanger, Povl Ole; Toftum, Jørn

    2002-01-01

    The PMV model agrees well with high-quality field studies in buildings with HVAC systems, situated in cold, temperate and warm climates, studied during both summer and winter. In non-air-conditioned buildings in warm climates, occupants may sense the warmth as being less severe than the PMV...... predicts. The main reason is low expectations, but a metabolic rate that is estimated too high can also contribute to explaining the difference. An extension of the PMV model that includes an expectancy factor is introduced for use in non-air-conditioned buildings in warm climates. The extended PMV model...... agrees well with quality field studies in non-air-conditioned buildings of three continents....

  2. Does safety climate moderate the influence of staffing adequacy and work conditions on nurse injuries?

    Science.gov (United States)

    Mark, Barbara A; Hughes, Linda C; Belyea, Michael; Chang, Yunkyung; Hofmann, David; Jones, Cheryl B; Bacon, Cynthia T

    2007-01-01

    Hospital nurses have one of the highest work-related injury rates in the United States. Yet, approaches to improving employee safety have generally focused on attempts to modify individual behavior through enforced compliance with safety rules and mandatory participation in safety training. We examined a theoretical model that investigated the impact on nurse injuries (back injuries and needlesticks) of critical structural variables (staffing adequacy, work engagement, and work conditions) and further tested whether safety climate moderated these effects. A longitudinal, non-experimental, organizational study, conducted in 281 medical-surgical units in 143 general acute care hospitals in the United States. Work engagement and work conditions were positively related to safety climate, but not directly to nurse back injuries or needlesticks. Safety climate moderated the relationship between work engagement and needlesticks, while safety climate moderated the effect of work conditions on both needlesticks and back injuries, although in unexpected ways. DISCUSSION AND IMPACT ON INDUSTRY: Our findings suggest that positive work engagement and work conditions contribute to enhanced safety climate and can reduce nurse injuries.

  3. Surface layer conditions of the atmosphere over western Bay of Bengal during Monex

    Digital Repository Service at National Institute of Oceanography (India)

    Anto, A.F.; Rao, L.V.G.; Somayajulu, Y.K.

    Based on surface meteorological data and wave data collected from 2 stations in the western Bay of Bengal in July 1979, surface layer (SL) conditions of the atmosphere for different situations of surface circulations and the associated sea surface...

  4. Description of climate, surface hydrology, and near-surface hydrogeology. Simpevarp 1.2

    International Nuclear Information System (INIS)

    Werner, Kent; Bosson, Emma; Berglund, Sten

    2005-04-01

    This report presents and evaluates the site investigations and primary data on meteorology, surface hydrology and near-surface hydrogeology that are available in the Simpevarp 1.2 'data freeze'. The main objective is to update the previous Simpevarp 1.1 description of the meteorological, surface hydrological and near-surface hydrogeological conditions in the Simpevarp area. Based on the Simpevarp 1.2 dataset, an updated conceptual and descriptive model of the surface and near-surface water flow conditions in the Simpevarp area is presented. In cases where site investigation data are not yet available, regional and/or generic data are used as input to the modelling. GIS- and process-based tools, used for initial quantitative flow modelling, are also presented. The objectives of this initial quantitative modelling are to illustrate, quantify and support the site descriptive model, and also to produce relevant input data to the ecological systems modelling within the SKB SurfaceNet framework.For the Simpevarp 1.2 model, the relevant site investigations include the establishment of one local meteorological station and surface-hydrological stations for discharge measurements, delineation and description of catchment areas, manual discharge measurements in water courses, slug tests in groundwater monitoring wells, and manual groundwater level measurements. In addition, other investigations have also contributed to the modelling, providing data on geometry (including topography), data from surface-based geological investigations and boreholes in Quaternary deposits, and data on the hydrogeological properties of the bedrock. The conceptual and descriptive modelling includes an identification and basic description of type areas, domains and interfaces between domains within the model area. The surface and near-surface flow system is described, including the assignment of hydrogeological properties to HSDs (Hydraulic Soil Domains) of Quaternary deposits based on a

  5. Description of climate, surface hydrology, and near-surface hydrogeology. Simpevarp 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Kent [SWECO VIAK AB/Golder Associates AB, Stockholm (Sweden); Bosson, Emma; Berglund, Sten [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2005-04-01

    This report presents and evaluates the site investigations and primary data on meteorology, surface hydrology and near-surface hydrogeology that are available in the Simpevarp 1.2 'data freeze'. The main objective is to update the previous Simpevarp 1.1 description of the meteorological, surface hydrological and near-surface hydrogeological conditions in the Simpevarp area. Based on the Simpevarp 1.2 dataset, an updated conceptual and descriptive model of the surface and near-surface water flow conditions in the Simpevarp area is presented. In cases where site investigation data are not yet available, regional and/or generic data are used as input to the modelling. GIS- and process-based tools, used for initial quantitative flow modelling, are also presented. The objectives of this initial quantitative modelling are to illustrate, quantify and support the site descriptive model, and also to produce relevant input data to the ecological systems modelling within the SKB SurfaceNet framework.For the Simpevarp 1.2 model, the relevant site investigations include the establishment of one local meteorological station and surface-hydrological stations for discharge measurements, delineation and description of catchment areas, manual discharge measurements in water courses, slug tests in groundwater monitoring wells, and manual groundwater level measurements. In addition, other investigations have also contributed to the modelling, providing data on geometry (including topography), data from surface-based geological investigations and boreholes in Quaternary deposits, and data on the hydrogeological properties of the bedrock. The conceptual and descriptive modelling includes an identification and basic description of type areas, domains and interfaces between domains within the model area. The surface and near-surface flow system is described, including the assignment of hydrogeological properties to HSDs (Hydraulic Soil Domains) of Quaternary deposits based on a

  6. Surface chemistry of tribochemical reactions explored in ultrahigh vacuum conditions

    International Nuclear Information System (INIS)

    Lara-Romero, Javier; Maya-Yescas, Rafael; Rico-Cerda, Jose Luis; Rivera-Rojas, Jose Luis; Castillo, Fernando Chinas; Kaltchev, Matey; Tysoe, Wilfred T.

    2006-01-01

    The thermal decomposition of model extreme-pressure lubricant additives on clean iron was studied in ultrahigh vacuum conditions using molecular beam strategies. Methylene chloride and chloroform react to deposit a solid film consisting of FeCl 2 and carbon, and evolve only hydrogen into the gas phase. No gas-phase products and less carbon on the surface are detected in the case of carbon tetrachloride. Dimethyl and diethyl disulfide react on clean iron to deposit a saturated sulfur plus carbon layer at low temperatures (∼600 K) and an iron sulfide film onto a Fe + C underlayer at higher temperatures (∼950 K). Methane is the only gas-phase product when dimethyl disulfide reacts with iron. Ethylene and hydrogen are detected when diethyl disulfide is used

  7. Performance Based Evaluation of Concrete Strength under Various Curing Conditions to Investigate Climate Change Effects

    Directory of Open Access Journals (Sweden)

    Tae-Kyun Kim

    2015-07-01

    Full Text Available Recently, the manifestation of global warming-induced climate change has been observed through super typhoons, heavy snowfalls, torrential rains, and extended heat waves. These climate changes have been occurring all over the world and natural disasters have caused severe damage and deterioration of concrete structures and infrastructure. In an effort to deal with these problems due to extreme and abnormal climate changes, studies have been conducted to develop construction technologies and design guidelines. Nevertheless, study results applicable to construction sites continue to be ineffective and insufficient. Therefore, this study proposes ways to cope with climate change by considering the effect of concrete curing condition variations on concrete material performance. More specifically, the 3-, 7- and 28-day compressive and split tensile strength properties of concrete mix cured under various climatic factors including temperature, relative humidity, wind speed, and sunlight exposure time were evaluated to determine whether the concrete meets the current design requirements. Thereafter, a performance based evaluation (PBE was performed using satisfaction probabilities based on the test values to understand the problems associated with the current mix proportion design practice and to identify countermeasures to deal with climate change-induced curing conditions.

  8. Regression-based season-ahead drought prediction for southern Peru conditioned on large-scale climate variables

    Science.gov (United States)

    Mortensen, Eric; Wu, Shu; Notaro, Michael; Vavrus, Stephen; Montgomery, Rob; De Piérola, José; Sánchez, Carlos; Block, Paul

    2018-01-01

    Located at a complex topographic, climatic, and hydrologic crossroads, southern Peru is a semiarid region that exhibits high spatiotemporal variability in precipitation. The economic viability of the region hinges on this water, yet southern Peru is prone to water scarcity caused by seasonal meteorological drought. Meteorological droughts in this region are often triggered during El Niño episodes; however, other large-scale climate mechanisms also play a noteworthy role in controlling the region's hydrologic cycle. An extensive season-ahead precipitation prediction model is developed to help bolster the existing capacity of stakeholders to plan for and mitigate deleterious impacts of drought. In addition to existing climate indices, large-scale climatic variables, such as sea surface temperature, are investigated to identify potential drought predictors. A principal component regression framework is applied to 11 potential predictors to produce an ensemble forecast of regional January-March precipitation totals. Model hindcasts of 51 years, compared to climatology and another model conditioned solely on an El Niño-Southern Oscillation index, achieve notable skill and perform better for several metrics, including ranked probability skill score and a hit-miss statistic. The information provided by the developed model and ancillary modeling efforts, such as extending the lead time of and spatially disaggregating precipitation predictions to the local level as well as forecasting the number of wet-dry days per rainy season, may further assist regional stakeholders and policymakers in preparing for drought.

  9. Ecoclimatic indicators to study crop suitability in present and future climatic conditions

    Science.gov (United States)

    Caubel, Julie; Garcia de Cortazar Atauri, Inaki; Huard, Frédéric; Launay, Marie; Ripoche, Dominique; Gouache, David; Bancal, Marie-Odile; Graux, Anne-Isabelle; De Noblet, Nathalie

    2013-04-01

    Climate change is expected to affect both regional and global food production through changes in overall agroclimatic conditions. It is therefore necessary to develop simple tools of crop suitability diagnosis in a given area so that stakeholders can envisage land use adaptations under climate change conditions. The most common way to investigate potential impacts of climate on the evolution of agrosystems is to make use of an array of agroclimatic indicators, which provide synthetic information derived from climatic variables and calculated within fixed periods (i.e. January first - 31th July). However, the information obtained during these periods does not enable to take account of the plant response to climate. In this work, we present some results of the research program ORACLE (Opportunities and Risks of Agrosystems & forests in response to CLimate, socio-economic and policy changEs in France (and Europe). We proposed a suite of relevant ecoclimatic indicators, based on temperature and rainfall, in order to evaluate crop suitability for both present and new climatic conditions. Ecoclimatic indicators are agroclimatic indicators (e.g., grain heat stress) calculated during specific phenological phases so as to take account of the plant response to climate (e.g., the grain filling period, flowering- harvest). These indicators are linked with the ecophysiological processes they characterize (for e.g., the grain filling). To represent this methodology, we studied the suitability of winter wheat in future climatic conditions through three distinct French sites, Toulouse, Dijon and Versailles. Indicators have been calculated using climatic data from 1950 to 2100 simulated by the global climate model ARPEGE forced by a greenhouse effect corresponding to the SRES A1B scenario. The Quantile-Quantile downscaling method was applied to obtain data for the three locations. Phenological stages (emergence, ear 1 cm, flowering, beginning of grain filling and harvest) have been

  10. Sensitivity of Distributions of Climate System Properties to Surface Temperature Datasets

    Science.gov (United States)

    Libardoni, A. G.; Forest, C. E.

    2011-12-01

    Predictions of climate change from models depend strongly on the representation of climate system properties emerging from the processes and feedbacks in the models. The quality of any model prediction can be evaluated by determining how well its output reproduces the observed climate system. With this evaluation, the reliability of climate projections derived from the model and provided for policy makers is assessed and quantified. In this study, surface temperature, upper-air temperature, and ocean heat content data are used to constrain the distributions of the parameters that define three climate system properties in the MIT Integrated Global Systems Model: climate sensitivity, the rate of ocean heat uptake into the deep ocean, and net anthropogenic aerosol forcing. In particular, we explore the sensitivity of the distributions to the surface temperature dataset used to estimate the likelihood of model output given the observed climate records. In total, five different reconstructions of past surface temperatures are used and the resulting parameter distribution functions differ from each other. Differences in estimates of climate sensitivity mode and mean are as great as 1 K between the datasets, with an overall range of 1.2 to 5.3 K using the 5-95 confidence intervals. Ocean effective diffusivity is poorly constrained regardless of which dataset is used. All distributions show broad distributions and only three show signs of a distribution mode. When a mode is present, they tend to be for low diffusivity values. Distributions for the net aerosol forcing show similar shapes and cluster into two groups that are shifted by approximately 0.1 watts per square meter. However, the overall spread of forcing values from the 5-95 confidence interval, -0.19 to -0.83 watts per square meter, is small compared to other uncertainties in climate forcings. Transient climate response estimates derived from these distributions range between 0.87 and 2.41 K. Similar to the

  11. Near-surface wind pattern in regional climate projections over the broader Adriatic region

    Science.gov (United States)

    Belušić, Andreina; Telišman Prtenjak, Maja; Güttler, Ivan; Ban, Nikolina; Leutwyler, David; Schär, Christoph

    2017-04-01

    The Adriatic region is characterized by the complex coastline, strong topographic gradients and specific wind regimes. This represents excellent test area for the latest generation of the regional climate models (RCMs) applied over the European domain. The most famous wind along the Adriatic coast is bora, which due to its strength, has a strong impact on all types of human activities in the Adriatic region. The typical bora wind is a severe gusty downslope flow perpendicular to the mountains. Besides bora, in the Adriatic region, typical winds are sirocco (mostly during the wintertime) and sea/land breezes (dominantly in the warm part of the year) as a part of the regional Mediterranean wind system. Thus, it is substantial to determine future changes in the wind filed characteristics (e.g., changes in strength and frequencies). The first step was the evaluation of a suite of ten EURO- and MED-CORDEX models (at 50 km and 12.5 km resolution), and two additional high resolution models from the Swiss Federal Institute of Technology in Zürich (ETHZ, at 12.5 km and 2.2. km resolution) in the present climate. These results provided a basis for the next step where wind field features, in an ensemble of RCMs forced by global climate models (GCMs) in historical and future runs are examined. Our aim is to determine the influence of the particular combination of RCMs and GCMs, horizontal resolution and emission scenario on the future changes in the near-surface wind field. The analysis reveals strong sensitivity of the simulated wind flow and its statistics to both season and location analyzed, to the horizontal resolution of the RCM and on the choice of the particular GCM that provides boundary conditions.

  12. Surface clay formation during short-term warmer and wetter conditions on a largely cold ancient Mars

    Science.gov (United States)

    Bishop, Janice L.; Fairén, Alberto G.; Michalski, Joseph R.; Gago-Duport, Luis; Baker, Leslie L.; Velbel, Michael A.; Gross, Christoph; Rampe, Elizabeth B.

    2018-03-01

    The ancient rock record for Mars has long been at odds with climate modelling. The presence of valley networks, dendritic channels and deltas on ancient terrains points towards running water and fluvial erosion on early Mars1, but climate modelling indicates that long-term warm conditions were not sustainable2. Widespread phyllosilicates and other aqueous minerals on the Martian surface3-6 provide additional evidence that an early wet Martian climate resulted in surface weathering. Some of these phyllosilicates formed in subsurface crustal environments5, with no association with the Martian climate, while other phyllosilicate-rich outcrops exhibit layered morphologies and broad stratigraphies7 consistent with surface formation. Here, we develop a new geochemical model for early Mars to explain the formation of these clay-bearing rocks in warm and wet surface locations. We propose that sporadic, short-term warm and wet environments during a generally cold early Mars enabled phyllosilicate formation without requiring long-term warm and wet conditions. We conclude that Mg-rich clay-bearing rocks with lateral variations in mixed Fe/Mg smectite, chlorite, talc, serpentine and zeolite occurrences formed in subsurface hydrothermal environments, whereas dioctahedral (Al/Fe3+-rich) smectite and widespread vertical horizonation of Fe/Mg smectites, clay assemblages and sulphates formed in variable aqueous environments on the surface of Mars. Our model for aluminosilicate formation on Mars is consistent with the observed geological features, diversity of aqueous mineralogies in ancient surface rocks and state-of-the-art palaeoclimate scenarios.

  13. A Coupled Surface Nudging Scheme for use in Retrospective Weather and Climate Simulations for Environmental Applications

    Science.gov (United States)

    A surface analysis nudging scheme coupling atmospheric and land surface thermodynamic parameters has been implemented into WRF v3.8 (latest version) for use with retrospective weather and climate simulations, as well as for applications in air quality, hydrology, and ecosystem mo...

  14. Investigation of the effect of sealed surfaces on local climate in urban areas

    Science.gov (United States)

    Weihs, Philipp; Hasel, Stefan; Mursch-Radlgruber, Erich; Gützer, Christian; Krispel, Stefan; Peyerl, Martin; Trimmel, Heidi

    2015-04-01

    Local climate is driven by the interaction between energy balance and energy transported by advected air. Short-wave and long-wave radiation are major components in this interaction. Some few studies (e.g. Santamouris et al.) showed that adjusting the grade of reflection of surfaces is an efficient way to influence temperature. The present study investigates the influence of high albedo concrete surfaces on local climate. The first step of the study consisted of experimental investigations: routine measurements of the short and longwave radiation balance, of the ground and of the air temperature and humidity at different heights above 6 different types of sealed surfaces were performed. During this measurement campaign the above mentioned components were measured over a duration of 4 months above two conventional asphalt surfaces, one conventional concrete and three newly developed concrete surfaces with increased reflectances. Measured albedo values amounted to 0.12±0.02 for the asphalt surfaces and to maximum values of 0.56 for high albedo concrete. The maximum difference in surface temperature between the asphalt surfaces and the high albedo concrete surfaces amounted to 15°C. In addition the emission constants of the different sealed surfaces were also determined and were compared to values from literature.. In a second step the urban energy balance model Envi_Met was used to simulate the surface temperature of the six surfaces. The simulated surface temperatures were compared to the measured surface temperatures and statements as to uncertainties of the model simulations were made In a third step, Envi_Met was used to simulate the local climate of an urban district in Vienna. The surface and air temperature and the SW, LW fluxes were calculated for different types of sealed surfaces. By performing calculations of thermal stress indices (UTCI, PMV), statements as to the influence of the type of sealed surface on thermal stress on humans was made.

  15. Relation between the Atmospheric Boundary Layer and Impact Factors under Severe Surface Thermal Conditions

    Directory of Open Access Journals (Sweden)

    Yinhuan Ao

    2017-01-01

    Full Text Available This paper reported a comprehensive analysis on the diurnal variation of the Atmospheric Boundary Layer (ABL in summer of Badain Jaran Desert and discussed deeply the effect of surface thermal to ABL, including the Difference in Surface-Air Temperature (DSAT, net radiation, and sensible heat, based on limited GPS radiosonde and surface observation data during two intense observation periods of experiments. The results showed that (1 affected by topography of the Tibetan Plateau, the climate provided favorable external conditions for the development of Convective Boundary Layer (CBL, (2 deep CBL showed a diurnal variation of three- to five-layer structure in clear days and five-layer ABL structure often occurred about sunset or sunrise, (3 the diurnal variation of DSAT influenced thickness of ABL through changes of turbulent heat flux, (4 integral value of sensible heat which rapidly converted by surface net radiation had a significant influence on the growth of CBL throughout daytime. The cumulative effect of thick RML dominated the role after CBL got through SBL in the development stage, especially in late summer, and (5 the development of CBL was promoted and accelerated by the variation of wind field and distribution of warm advection in high and low altitude.

  16. Assessment of monitored energy use and thermal comfort conditions in mosques in hot-humid climates

    Energy Technology Data Exchange (ETDEWEB)

    Al-Homoud, Mohammad S.; Abdou, Adel A.; Budaiwi, Ismail M. [Architectural Engineering Department, KFUPM, Dhahran 31261 (Saudi Arabia)

    2009-06-15

    In harsh climatic regions, buildings require air-conditioning in order to provide an acceptable level of thermal comfort. In many situations buildings are over cooled or the HVAC system is kept running for a much longer time than needed. In some other situations thermal comfort is not achieved due to improper operation practices coupled with poor maintenance and even lack it, and consequently inefficient air-conditioning systems. Mosques represent one type of building that is characterized by their unique intermittent operating schedule determined by prayer times, which vary continuously according to the local solar time. This paper presents the results of a study designed to monitor energy use and thermal comfort conditions of a number of mosques in a hot-humid climate so that both energy efficiency and the quality of thermal comfort conditions especially during occupancy periods in such intermittently operated buildings can be assessed accurately. (author)

  17. Adapting to Mother Nature's changing climatic conditions: Flexible stocking for enhancing profitability of Wyoming ranchers

    Science.gov (United States)

    Ranching is a dynamic business in which profitability is impacted by changing weather and climatic conditions. A ranch-level model using a representative ranch in southeastern Wyoming was used to compare economic outcomes from growing season precipitation scenarios of: 1) historical precipitation da...

  18. Long-term sustainability of the landscape in new climatic conditions

    Science.gov (United States)

    Kubeckova, D.; Krocova, S.

    2017-10-01

    The long-term sustainability of the landscape and its natural environment must be the decisive task of the public administration and, in the wider concept, of every citizen. In new climatic conditions, this need has intensified. The following article suggests in a basic scope whether the above-mentioned task can be accomplished, and what means of solution should be used.

  19. Simple model for daily evaporation from fallow tilled soil under spring conditions in a temperate climate.

    NARCIS (Netherlands)

    Boesten, J.J.T.I.; Stroosnijder, L.

    1986-01-01

    A simple parametric model is presented to estimate daily evaporation from fallow tilled soil under spring conditions in a temperate climate. In this model, cumulative actual evaporation during a drying cycle is directly proportional to the square root of cumulative potential evaporation. The model

  20. Surface-Water Conditions in Georgia, Water Year 2005

    Science.gov (United States)

    Painter, Jaime A.; Landers, Mark N.

    2007-01-01

    INTRODUCTION The U.S. Geological Survey (USGS) Georgia Water Science Center-in cooperation with Federal, State, and local agencies-collected surface-water streamflow, water-quality, and ecological data during the 2005 Water Year (October 1, 2004-September 30, 2005). These data were compiled into layers of an interactive ArcReaderTM published map document (pmf). ArcReaderTM is a product of Environmental Systems Research Institute, Inc (ESRI?). Datasets represented on the interactive map are * continuous daily mean streamflow * continuous daily mean water levels * continuous daily total precipitation * continuous daily water quality (water temperature, specific conductance dissolved oxygen, pH, and turbidity) * noncontinuous peak streamflow * miscellaneous streamflow measurements * lake or reservoir elevation * periodic surface-water quality * periodic ecological data * historical continuous daily mean streamflow discontinued prior to the 2005 water year The map interface provides the ability to identify a station in spatial reference to the political boundaries of the State of Georgia and other features-such as major streams, major roads, and other collection stations. Each station is hyperlinked to a station summary showing seasonal and annual stream characteristics for the current year and for the period of record. For continuous discharge stations, the station summary includes a one page graphical summary page containing five graphs, a station map, and a photograph of the station. The graphs provide a quick overview of the current and period-of-record hydrologic conditions of the station by providing a daily mean discharge graph for the water year, monthly statistics graph for the water year and period of record, an annual mean streamflow graph for the period of record, an annual minimum 7-day average streamflow graph for the period of record, and an annual peak streamflow graph for the period of record. Additionally, data can be accessed through the layer's link

  1. A New Framework to Evaluate Urban Design Using Urban Microclimatic Modeling in Future Climatic Conditions

    Directory of Open Access Journals (Sweden)

    Dasaraden Mauree

    2018-04-01

    Full Text Available Building more energy-efficient and sustainable urban areas that will both mitigate the effects of climate change and anticipate living conditions in future climate scenarios requires the development of new tools and methods that can help urban planners, architects and communities achieve this goal. In the current study, we designed a workflow that links different methodologies developed separately, to derive the energy consumption of a university school campus for the future. Three different scenarios for typical future years (2039, 2069, 2099 were run, as well as a renovation scenario (Minergie-P. We analyzed the impact of climate change on the heating and cooling demand of buildings and determined the relevance of taking into account the local climate in this particular context. The results from the simulations confirmed that in the future, there will be a constant decrease in the heating demand, while the cooling demand will substantially increase. Significantly, it was further demonstrated that when the local urban climate was taken into account, there was an even higher rise in the cooling demand, but also that a set of proposed Minergie-P renovations were not sufficient to achieve resilient buildings. We discuss the implication of this work for the simulation of building energy consumption at the neighborhood scale and the impact of future local climate on energy system design. We finally give a few perspectives regarding improved urban design and possible pathways for future urban areas.

  2. Screening variability and change of soil moisture under wide-ranging climate conditions: Snow dynamics effects.

    Science.gov (United States)

    Verrot, Lucile; Destouni, Georgia

    2015-01-01

    Soil moisture influences and is influenced by water, climate, and ecosystem conditions, affecting associated ecosystem services in the landscape. This paper couples snow storage-melting dynamics with an analytical modeling approach to screening basin-scale, long-term soil moisture variability and change in a changing climate. This coupling enables assessment of both spatial differences and temporal changes across a wide range of hydro-climatic conditions. Model application is exemplified for two major Swedish hydrological basins, Norrström and Piteälven. These are located along a steep temperature gradient and have experienced different hydro-climatic changes over the time period of study, 1950-2009. Spatially, average intra-annual variability of soil moisture differs considerably between the basins due to their temperature-related differences in snow dynamics. With regard to temporal change, the long-term average state and intra-annual variability of soil moisture have not changed much, while inter-annual variability has changed considerably in response to hydro-climatic changes experienced so far in each basin.

  3. Baumholder, Germany (West), Limited Surface Observations Climatic Summary (LISOCS).

    Science.gov (United States)

    1984-01-09

    PERCENTAGE FREQWJENCY OF OCCURRENCE OF WEATHER CONDITIONS FROM HOURLY OBSERVATIONS ON h HOURS TH NE.-R AI FREEZING SNOW % OF 1 S O EDUST Of O RS TOTAL MNH ...OF OCCURRENCE OF wEATHER CONDITIONS FROM HOURLY OBSERVATIONS MNH HOURS THUNDER- RMAIN FREEZING SNOW OF SMOKE DUS 06F5IL TOTAL MNH (LST) STORMS AD Olt

  4. The uncertainty cascade in flood risk assessment under changing climatic conditions - the Biala Tarnowska case study

    Science.gov (United States)

    Doroszkiewicz, Joanna; Romanowicz, Renata

    2016-04-01

    Uncertainty in the results of the hydraulic model is not only associated with the limitations of that model and the shortcomings of data. An important factor that has a major impact on the uncertainty of the flood risk assessment in a changing climate conditions is associated with the uncertainty of future climate scenarios (IPCC WG I, 2013). Future climate projections provided by global climate models are used to generate future runoff required as an input to hydraulic models applied in the derivation of flood risk maps. Biala Tarnowska catchment, situated in southern Poland is used as a case study. Future discharges at the input to a hydraulic model are obtained using the HBV model and climate projections obtained from the EUROCORDEX project. The study describes a cascade of uncertainty related to different stages of the process of derivation of flood risk maps under changing climate conditions. In this context it takes into account the uncertainty of future climate projections, an uncertainty of flow routing model, the propagation of that uncertainty through the hydraulic model, and finally, the uncertainty related to the derivation of flood risk maps. One of the aims of this study is an assessment of a relative impact of different sources of uncertainty on the uncertainty of flood risk maps. Due to the complexity of the process, an assessment of total uncertainty of maps of inundation probability might be very computer time consuming. As a way forward we present an application of a hydraulic model simulator based on a nonlinear transfer function model for the chosen locations along the river reach. The transfer function model parameters are estimated based on the simulations of the hydraulic model at each of the model cross-section. The study shows that the application of the simulator substantially reduces the computer requirements related to the derivation of flood risk maps under future climatic conditions. Acknowledgements: This work was supported by the

  5. Energy Saving Potential of PCMs in Buildings under Future Climate Conditions

    Directory of Open Access Journals (Sweden)

    Abdo Abdullah Ahmed Gassar

    2017-11-01

    Full Text Available Energy consumption reduction under changing climate conditions is a major challenge in buildings design, where excessive energy consumption creates an economic and environmental burden. Improving thermal performance of the buildings through support applying phase change material (PCM is a promising strategy for reducing building energy consumption under future climate change. Therefore, this study aims to investigate the energy saving potentials in buildings under future climate conditions in the humid and snowy regions in the hot continental and humid subtropical climates of the east Asia (Seoul, Tokyo and Hong Kong when various PCMs with different phase change temperatures are applied to a lightweight building envelope. Methodology in this work is implemented in two phases: firstly, investigation of energy saving potentials in buildings through inclusion of three types of PCMs with different phase temperatures into the building envelop separately and use weather file in the present (2017; and, secondly, evaluation of the effect of future climate change on the performance of PCMs by analyzing energy saving potentials of PCMs with 2020, 2050 and 2080 weather data. The results show that the inclusion of PCM into the building envelope is a promising strategy to increase the energy performance in buildings during both heating and cooling seasons in Seoul, Tokyo and Hong Kong under future climate conditions. The energy savings achieved by using PCMs in those regions are electricity savings of 4.48–8.21%, 3.81–9.69%, and 1.94–5.15%, and gas savings of 1.65–16.59%, 7.60–61.76%, and 62.07–93.33% in Seoul, Tokyo and Hong Kong, respectively, for the years 2017, 2020, 2050 and 2080. In addition, BioPCM and RUBITHERMPCM are the most efficient for improving thermal performance and saving energy in buildings in the tested regions and years.

  6. The impact of changing climate on surface and ground water quality in southeast of Ireland

    Science.gov (United States)

    Tribak, Kamal

    2015-04-01

    In the current changing climate globally, Ireland have been experiencing a yearly recurrent extreme heavy rainfall events in the last decade, with damaging visible effects socially, economically and on the environment. Ireland intensive agriculture production is a major treat to the aquatic environment, Nitrogen and phosphorus losses to the water courses are major causes to eutrophication. The European Water Frame Directive (WFD 2000/60/EC) and Nitrates Directive (91/676/EEC) sets a number of measures to better protect and improve water status. Five years of high temporal resolution river water quality data measurement from two contrasting catchment in the southeast of Ireland were correlated with rain fall and nutrients losses to the ground and surface water, additional to the integrated Southeast River District Basin ground and surface water quality to establish spatiotemporal connection to the agriculture activities, the first well-drained soil catchment had high coefficient correlation with rain fall with higher losses to groundwater, on the other hand higher nutrients losses to surface water were higher with less influence from groundwater recharge of N and P transfer, the poorly clay base soil contributed to higher increased losses to surface water during excessive rain fall. Agriculture activities, hydrology, geology and human interaction can interact according to their site specific setting and the effects will fluctuate dependent on the conditions influencing the impact on water quality, there is a requirement to better distinguish those effects together and identify areas and land uses control and nutrients management to improve the water quality, stakeholders co-operation along with effective polices, long term monitoring, nutrients pathways management and better understanding of the environmental factors interaction on national, regional and catchment scale to enable planning policies and enforcement measures to be more focused on areas of high risk

  7. HF Surface Wave Radar Operation in Adverse Conditions

    National Research Council Canada - National Science Library

    Ponsford, Anthony M; Dizaji, Reza M; McKerracher, Richard

    2005-01-01

    ...) system based on HF Surface Wave Radar (HFSWR). the primary objective behind the programme was to demonstrate the capability of HFSWR to continuously detect and track surface targets (ships and icebergs...

  8. Design parameters of a non-air-conditioned cinema hall for thermal comfort under arid-zone climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, G.N. (Indian Inst. of Tech., New Delhi (India). Centre for Energy Studies); Lugani, N. (Indian Inst. of Tech., New Delhi (India). Centre for Energy Studies); Singh, A.K. (Indian Inst. of Tech., New Delhi (India). Centre for Energy Studies)

    1993-01-01

    In this communication, a design of a cinema hall suitable for climatic conditions in an arid zone has been presented. The various cooling techniques, namely evaporative cooling, wind tower, ventilation/infiltration and natural cooling, have been incorporated in the design to achieve thermal comfort during the period of operation. The design parameters have been optimized on the basis of numerical computations after establishing an energy balance for each component of a cinema hall. It is observed that cooling treatment, i.e., a wind tower with a cooling pool on the roof provides reasonable thermal comfort inside the enclosure. (orig.)

  9. Can climate sensitivity be estimated from short-term relationships of top-of-atmosphere net radiation and surface temperature?

    International Nuclear Information System (INIS)

    Lin Bing; Min Qilong; Sun Wenbo; Hu Yongxiang; Fan, Tai-Fang

    2011-01-01

    Increasing the knowledge in climate radiative feedbacks is critical for current climate studies. This work focuses on short-term relationships between global mean surface temperature and top-of-atmosphere (TOA) net radiation. The relationships may be used to characterize the climate feedback as suggested by some recent studies. As those recent studies, an energy balance model with ocean mixed layer and both radiative and non-radiative heat sources is used here. The significant improvement of current model is that climate system memories are considered. Based on model simulations, short-term relationship between global mean surface temperature and TOA net radiation (or the linear striation feature as suggested by previous studies) might represent climate feedbacks when the system had no memories. However, climate systems with the same short-term feedbacks but different memories would have a similar linear striation feature. This linear striation feature reflects only fast components of climate feedbacks and may not represent the total climate feedback even when the memory length of climate systems is minimal. The potential errors in the use of short-term relationships in estimations of climate sensitivity could be big. In short time scales, fast climate processes may overwhelm long-term climate feedbacks. Thus, the climate radiative feedback parameter obtained from short-term data may not provide a reliable estimate of climate sensitivity. This result also suggests that long-term observations of global surface temperature and TOA radiation are critical in the understanding of climate feedbacks and sensitivities.

  10. Catchment-scale contaminant transport under changing hydro-climatic conditions in the Aral Sea Drainage Basin, Central Asia

    Science.gov (United States)

    Jarsjö, Jerker; Törnqvist, Rebecka; Su, Ye

    2013-04-01

    Dependable projections of future water availability and quality are essential in the management of water resources. Changes in land use, water use and climate can have large impacts on water and contaminant flows across extensive catchments that may contain different administrative regions where shared water resources must be managed. We consider the extensive Aral Sea Drainage Basin (ASDB) and the Amu Darya River Delta in Central Asia, which are currently under severe water stress due to large-scale irrigation expansion. We interpret data on hydro-climatic conditions, main contaminants of surface water and shallow groundwater systems, location of rivers and canal networks, and groundwater flow directions. The data are used together with climate change projections from general circulation models (GCMs) as input to hydrological and (advective) transport modelling. The main goal is to assess how regional transport pathways and travel times have changed, and are likely to change further, in response to past and projected future hydro-climatic changes. More specifically, the hydrological modelling was based on temperature and precipitation change (ΔT and ΔP) results from 65 GCM projections of 21st century conditions (specifically considering time periods around 2025, 2050, and 2100), relative to reference conditions around 1975 (taken from the reference period 1961-1990). Whereas ΔT is robustly projected to increase with time, the projected magnitude of ΔP differs more among projections for the distant future (2100) than for the near future (2025), with uncertainty remaining even about the direction of change (i.e., positive or negative ΔP). However, mainly due to the projected temperature-driven increases in evapotranspiration, ensemble average results show that the Amu Darya river discharge Q in the downstream ASDB is likely to show a decreasing trend throughout the 21st century. Notably, projected changes in the upstream, mountainous regions have a relatively

  11. Climate Prediction Center (CPC) Global Land Surface Air Temperature Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A station observation-based global land monthly mean surface air temperature dataset at 0.5 0.5 latitude-longitude resolution for the period from 1948 to the present...

  12. Climate Prediction Center (CPC) Global Land Surface Air Temperature Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A station observation-based global land monthly mean surface air temperature dataset at 0.5 x 0.5 latitude-longitude resolution for the period from 1948 to the...

  13. The influence of climatic conditions changes on grain yield in Winter Triticale (X Triticosecale Wittm.

    Directory of Open Access Journals (Sweden)

    Ionuț RACZ

    2017-05-01

    Full Text Available The aim of this paper is making out the influence of climatic changes on grain yield of winter triticale in relation with applied fertilizer. The influence of environmental conditions on growing and development of triticale plants depends of grow stages and their duration. During five experimental years (2010-2015 the climatic conditions were different year to year, with an accentuated heating trend, influencing plant phenology, accelerating or slowing down some important processes disturbing grain yield formation. The influence of drought is more accentuated by heating stress and prolonging of these conditions during the main phenological processes have a negative influence on plant growth or development with effect on the grain yield formation process.

  14. Effects of baseline conditions on the simulated hydrologic response to projected climate change

    Science.gov (United States)

    Koczot, Kathryn M.; Markstrom, Steven L.; Hay, Lauren E.

    2011-01-01

    Changes in temperature and precipitation projected from five general circulation models, using one late-twentieth-century and three twenty-first-century emission scenarios, were downscaled to three different baseline conditions. Baseline conditions are periods of measured temperature and precipitation data selected to represent twentieth-century climate. The hydrologic effects of the climate projections are evaluated using the Precipitation-Runoff Modeling System (PRMS), which is a watershed hydrology simulation model. The Almanor Catchment in the North Fork of the Feather River basin, California, is used as a case study. Differences and similarities between PRMS simulations of hydrologic components (i.e., snowpack formation and melt, evapotranspiration, and streamflow) are examined, and results indicate that the selection of a specific time period used for baseline conditions has a substantial effect on some, but not all, hydrologic variables. This effect seems to be amplified in hydrologic variables, which accumulate over time, such as soil-moisture content. Results also indicate that uncertainty related to the selection of baseline conditions should be evaluated using a range of different baseline conditions. This is particularly important for studies in basins with highly variable climate, such as the Almanor Catchment.

  15. Projected Changes on the Global Surface Wave Drift Climate towards the END of the Twenty-First Century

    Science.gov (United States)

    Carrasco, Ana; Semedo, Alvaro; Behrens, Arno; Weisse, Ralf; Breivik, Øyvind; Saetra, Øyvind; Håkon Christensen, Kai

    2016-04-01

    The global wave-induced current (the Stokes Drift - SD) is an important feature of the ocean surface, with mean values close to 10 cm/s along the extra-tropical storm tracks in both hemispheres. Besides the horizontal displacement of large volumes of water the SD also plays an important role in the ocean mix-layer turbulence structure, particularly in stormy or high wind speed areas. The role of the wave-induced currents in the ocean mix-layer and in the sea surface temperature (SST) is currently a hot topic of air-sea interaction research, from forecast to climate ranges. The SD is mostly driven by wind sea waves and highly sensitive to changes in the overlaying wind speed and direction. The impact of climate change in the global wave-induced current climate will be presented. The wave model WAM has been forced by the global climate model (GCM) ECHAM5 wind speed (at 10 m height) and ice, for present-day and potential future climate conditions towards the end of the end of the twenty-first century, represented by the Intergovernmental Panel for Climate Change (IPCC) CMIP3 (Coupled Model Inter-comparison Project phase 3) A1B greenhouse gas emission scenario (usually referred to as a ''medium-high emissions'' scenario). Several wave parameters were stored as output in the WAM model simulations, including the wave spectra. The 6 hourly and 0.5°×0.5°, temporal and space resolution, wave spectra were used to compute the SD global climate of two 32-yr periods, representative of the end of the twentieth (1959-1990) and twenty-first (1969-2100) centuries. Comparisons of the present climate run with the ECMWF (European Centre for Medium-Range Weather Forecasts) ERA-40 reanalysis are used to assess the capability of the WAM-ECHAM5 runs to produce realistic SD results. This study is part of the WRCP-JCOMM COWCLIP (Coordinated Ocean Wave Climate Project) effort.

  16. Worsened physical condition due to climate change contributes to the increasing hypoxia in Chesapeake Bay.

    Science.gov (United States)

    Du, Jiabi; Shen, Jian; Park, Kyeong; Wang, Ya Ping; Yu, Xin

    2018-07-15

    There are increasing concerns about the impact of worsened physical condition on hypoxia in a variety of coastal systems, especially considering the influence of changing climate. In this study, an EOF analysis of the DO data for 1985-2012, a long-term numerical simulation of vertical exchange, and statistical analysis were applied to understand the underlying mechanisms for the variation of DO condition in Chesapeake Bay. Three types of analysis consistently demonstrated that both biological and physical conditions contribute equally to seasonal and interannual variations of the hypoxic condition in Chesapeake Bay. We found the physical condition (vertical exchange+temperature) determines the spatial and seasonal pattern of the hypoxia in Chesapeake Bay. The EOF analysis showed that the first mode, which was highly related to the physical forcings and correlated with the summer hypoxia volume, can be well explained by seasonal and interannual variations of physical variables and biological activities, while the second mode is significantly correlated with the estuarine circulation and river discharge. The weakened vertical exchange and increased water temperature since the 1980s demonstrated a worsened physical condition over the past few decades. Under changing climate (e.g., warming, accelerated sea-level rise, altered precipitation and wind patterns), Chesapeake Bay is likely to experience a worsened physical condition, which will amplify the negative impact of anthropogenic inputs on eutrophication and consequently require more efforts for nutrient reduction to improve the water quality condition in Chesapeake Bay. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Tolerance and potential for adaptation of a Baltic Sea rockweed under predicted climate change conditions.

    Science.gov (United States)

    Rugiu, Luca; Manninen, Iita; Rothäusler, Eva; Jormalainen, Veijo

    2018-03-01

    Climate change is threating species' persistence worldwide. To predict species responses to climate change we need information not just on their environmental tolerance but also on its adaptive potential. We tested how the foundation species of rocky littoral habitats, Fucus vesiculosus, responds to combined hyposalinity and warming projected to the Baltic Sea by 2070-2099. We quantified responses of replicated populations originating from the entrance, central, and marginal Baltic regions. Using replicated individuals, we tested for the presence of within-population tolerance variation. Future conditions hampered growth and survival of the central and marginal populations whereas the entrance populations fared well. Further, both the among- and within-population variation in responses to climate change indicated existence of genetic variation in tolerance. Such standing genetic variation provides the raw material necessary for adaptation to a changing environment, which may eventually ensure the persistence of the species in the inner Baltic Sea. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Quantifying conditional risks for water and energy systems using climate information

    Science.gov (United States)

    Lall, U.

    2016-12-01

    There has been a growing recognition of the multi-scale spatio-temporal organization of climate dynamics, and its implications for predictable, structured risk exposure to populations and infrastructure systems. At the most base level is an understanding that there are some identifiable climate modes, such as ENSO, that are associated with such outcomes. This has led to the emergence of a small cottage industry of analysts who relate different "climate indices" to specific regional outcomes. Such efforts and the associated media interest in these simplified "stories" have led to an increasing appreciation of the phenomenon, and some formal and informal efforts at decision making using such information. However, as was demonstrated through the 2014-16 El Nino forecasting season, many climate scientists over-emphasized the potential risks, while others cautioned the media as to the caveats and uncertainties associated with assuming that the forecasts of ENSO and the expected teleconnections may pan out. At least in certain sectors and regions, significant efforts or expectations as to outcomes were put in place, and some were beneficial, while others failed to manifest. Climate informed predictions for water and energy systems can be thought of as efforts to infer conditional distributions of specific outcomes given information on climate state. Invariably, the climate state may be presented as a very high dimensional spatial set of variables, with limited temporal sampling, while the water and energy attributes may be regional and constitute a much smaller dimension. One may, of course, be interested in the fact that the same climate state may lead to synchronous positive and negative effects across many locations, as may be expected under mid-latitude stationary and transient wave interaction. In this talk, I will provide examples of a few modern statistical and machine learning tools that allow a decomposition of the high dimensional climate state and its relation

  19. An application of a hydraulic model simulator in flood risk assessment under changing climatic conditions

    Science.gov (United States)

    Doroszkiewicz, J. M.; Romanowicz, R. J.

    2016-12-01

    The standard procedure of climate change impact assessment on future hydrological extremes consists of a chain of consecutive actions, starting from the choice of GCM driven by an assumed CO2 scenario, through downscaling of climatic forcing to a catchment scale, estimation of hydrological extreme indices using hydrological modelling tools and subsequent derivation of flood risk maps with the help of a hydraulic model. Among many possible sources of uncertainty, the main are the uncertainties related to future climate scenarios, climate models, downscaling techniques and hydrological and hydraulic models. Unfortunately, we cannot directly assess the impact of these different sources of uncertainties on flood risk in future due to lack of observations of future climate realizations. The aim of this study is an assessment of a relative impact of different sources of uncertainty on the uncertainty of flood risk maps. Due to the complexity of the processes involved, an assessment of total uncertainty of maps of inundation probability might be very computer time consuming. As a way forward we present an application of a hydraulic model simulator based on a nonlinear transfer function model for the chosen locations along the river reach. The transfer function model parameters are estimated based on the simulations of the hydraulic model at each of the model cross-sections. The study shows that the application of a simulator substantially reduces the computer requirements related to the derivation of flood risk maps under future climatic conditions. Biala Tarnowska catchment, situated in southern Poland is used as a case study. Future discharges at the input to a hydraulic model are obtained using the HBV model and climate projections obtained from the EUROCORDEX project. The study describes a cascade of uncertainty related to different stages of the process of derivation of flood risk maps under changing climate conditions. In this context it takes into account the

  20. Assessment of the Impact of Climate Change on the Water Balances and Flooding Conditions of Peninsular Malaysia watersheds by a Coupled Numerical Climate Model - Watershed Hydrology Model

    Science.gov (United States)

    Ercan, A.; Kavvas, M. L.; Ishida, K.; Chen, Z. Q.; Amin, M. Z. M.; Shaaban, A. J.

    2017-12-01

    Impacts of climate change on the hydrologic processes under future climate change conditions were assessed over various watersheds of Peninsular Malaysia by means of a coupled regional climate and physically-based hydrology model that utilized an ensemble of future climate change projections. An ensemble of 15 different future climate realizations from coarse resolution global climate models' (GCMs) projections for the 21st century were dynamically downscaled to 6 km resolution over Peninsular Malaysia by a regional numerical climate model, which was then coupled with the watershed hydrology model WEHY through the atmospheric boundary layer over the selected watersheds of Peninsular Malaysia. Hydrologic simulations were carried out at hourly increments and at hillslope-scale in order to assess the impacts of climate change on the water balances and flooding conditions at the selected watersheds during the 21st century. The coupled regional climate and hydrology model was simulated for a duration of 90 years for each of the 15 realizations. It is demonstrated that the increase in mean monthly flows due to the impact of expected climate change during 2040-2100 is statistically significant at the selected watersheds. Furthermore, the flood frequency analyses for the selected watersheds indicate an overall increasing trend in the second half of the 21st century.

  1. The role of seasonal, climatic and meteorological conditions in modifying nuclear accident consequences

    International Nuclear Information System (INIS)

    Mueller, H.; Proehl, G.

    1989-01-01

    One of the most important factors which influence the ingestion doses after an accidental release of radionuclides is the season of the year at which the release occurs. This is demonstrated with some examples for German conditions. This seasonal effect depends strongly on the growing periods of the different plants. Therefore it is influenced by the climatic conditions which vary to a large degree in the different countries causing very different growing periods. The influence of the meteorological conditions during and after the passing of a radioactive cloud on the initial contamination of the plants is discussed

  2. Attribution of soil moisture dynamics - Initial conditions vs. atmospheric forcing and the role of climate change

    Science.gov (United States)

    Orth, Rene; Seneviratne, Sonia I.

    2014-05-01

    The world's climate has started to change more quickly in recent decades and a stronger and faster shift is expected in the future. Even if the public perception is mostly limited to a widespread warming, climate change is a complex phenomenon impacting numerous variables of the climate system in different ways, also depending on time and location. Furthermore, extreme events may change more drastically than the mean climate. There is growing evidence that climate change is mostly man-made. However, it is still a matter of debate to which extent changes of the mean climate but also of particular (extreme) events are due to human impact. These questions are addressed by the growing science of climate attribution. Pointing out the anthropogenic influence on extreme events such as the 2010 Russian heatwave or the 2002 floods in Central Europe may help to support adaptation to climate change. This study investigates soil moisture in Europe in the context of climate change, because of its role as a key variable of the land-climate system and its practical importance for instance to agriculture. To derive soil moisture dynamics from 1984-2007 we use E-OBS forcing data together with SRB radiation data and employ an observation-based approach where soil moisture is computed from a water balance equation in which runoff (normalized with precipitation) and ET (normalized with net radiation) are simple functions of soil moisture. The constant runoff function is prescribed for the whole continent, and the ET function is calibrated using temperature data. After performing a validation of the inferred soil moisture data we use it in order to analyze changes in the likelihood of droughts. Our results show increased drought risk especially in north-eastern Europe and the Mediterranean, whereby the probability of extreme droughts increases stronger as for mild dryness episodes. To assess the potential for drought forecasting we furthermore study the importance of the initial

  3. The Role of Meteorology and Surface Condition to Multi-Decadal Variations of Dust Emission in Sahara and Sahel

    Science.gov (United States)

    Kim, D.; Chin, M.; Diehl, T. L.; Bian, H.; Brown, M. E.; Remer, L. A.; Stockwell, W. R.

    2014-12-01

    North Africa is the world's largest dust source region influencing regional and global climate, human health, and even the local economy. However North Africa as a dust source is not uniform but it consists of the arid region (Sahara) and the semi-arid region (Sahel) with emission rates depending on meteorological and surface conditions. Several recent studies have shown that dust from North Africa seems to have a decreasing trend in the past three decades. The goal of this study is to better understand the controlling factors that determine the change of dust in North Africa using observational data and model simulations. First we analyze surface bareness conditions determined from a long-term satellite observed Normalized Difference Vegetation Index for 1980-2008. Then we examine the key meteorological variables of precipitation and surface winds. Modeling experiments were conducted using the NASA Goddard Chemistry Aerosol Radiation and Transport (GOCART) model, which has been recently updated with a dynamic dust source function. Using the method we separate the dust originating from the Sahel from that of the Sahara desert. We find that the surface wind speed is the most dominant factor affecting Sahelian dust emission while vegetation has a modulating effect. We will show regional differences in meteorological variables, surface conditions, dust emission, and dust distribution and address the relationships among meteorology, surface conditions, and dust emission/loading in the past three decades (1980-2008).

  4. Impact of Urban Climate Landscape Patterns on Land Surface Temperature in Wuhan, China

    Directory of Open Access Journals (Sweden)

    Yasha Wang

    2017-09-01

    Full Text Available Facing urban warming, mitigation and adaptation strategies are not efficient enough to tackle excessive urban heat, especially at the local scale. The local climate zone (LCZ classification scheme is employed to examine the diversity and complexity of the climate response within a city. This study suggests that zonal practice could be an efficient way to bridge the knowledge gap between climate research and urban planning. Urban surfaces classified by LCZ are designated as urban climate landscapes, which extends the LCZ concept to urban planning applications. Selecting Wuhan as a case study, we attempt to explore the climatic effect of landscape patterns. Thermal effects are compared across the urban climate landscapes, and the relationships between patch metrics and land surface temperature (LST are quantified. Results indicate that climate landscape layout is a considerable factor impacting local urban climate. For Wuhan, 500 m is an optimal scale for exploring landscape pattern-temperature relationships. Temperature contrast between surrounding landscape patches has a major influence on LST. Generally, fragmental landscape patches contribute to heat release. For most climate landscape types, patch metrics also have a significant effect on thermal response. When three metrics are included as predictive variables, 53.3% of the heating intensity variation can be explained for the Large Lowrise landscape, while 57.4% of the cooling intensity variation can be explained for the Water landscape. Therefore, this article claims that land-based layout optimization strategy at local scale, which conforms to planning manner, should be taken into account in terms of heat management.

  5. Optimization of Photovoltaic Electrolyzer Hybrid systems; taking into account the effect of climate conditions

    International Nuclear Information System (INIS)

    Sayedin, Farid; Maroufmashat, Azadeh; Sattari, Sourena; Elkamel, Ali; Fowler, Michael

    2016-01-01

    Highlights: • The optimal size of directly coupled Photovoltaic–Electrolyzer (PV/EL) is studied. • The effect of climate condition on the performance of PV/EL is studied. • PV/EL energy transfer loss and the levelized cost of hydrogen production minimized. • The model is applied to locations with different climate and solar irradiations. • Solar to electricity/electricity to hydrogen/solar to hydrogen efficiencies are derived. - Abstract: Solar energy will make a valuable contribution for power generation in the future. However the intermittency of solar energy has become an important issue in the utilization of PV system, especially small scale distributed solar energy conversion systems. The issue can be addressed through the management of production and storage of the energy in the form of hydrogen. The hydrogen can be produced by solar photovoltaic (PV) powered electrolysis of water. The amount of transferred energy to an electrolyzer from a PV module is a function of the distance between maximum power points (MPP) of PV module and the electrolyzer operating points. The distance can be minimized by optimizing the number of series and parallel units of the electrolyzer. However the maximum power points are subject to PV module characteristics, solar irradiation and ambient temperature. This means the climate condition can substantially influence the MPP and therefore the optimal size of the PV–Electrolyzer (PV/EL) system. On the other hand, system size can affect the levelized cost of hydrogen production as well. In this paper, the impact of climate conditions on the optimal size and operating conditions of a direct coupled photovoltaic–electrolyzer system has been studied. For this purpose, the optimal size of electrolyzer for six cities which have different climate condition is obtained by considering two solution scenarios, regarding two objectives which are annual energy transfer loss and levelized costs of hydrogen production and then the

  6. Hydro-climatic conditions and thermoelectric electricity generation – Part I: Development of models

    International Nuclear Information System (INIS)

    Koch, Hagen; Vögele, Stefan

    2013-01-01

    In recent years there have been several heat waves affecting the use of thermoelectric power plants, e.g. in Europe and the U.S. In this paper the linkage between hydro-climatic conditions and possible electricity generation restrictions is described. The coupling of hydrological models and a power plant model is presented. In this approach each power plant is considered separately with its technical specifications. Also environmental regulations, e.g. permissible rise in the cooling water temperature, are considered for the respective power plant. The hydrological models developed to simulate river runoff and water temperature are also site specific. The approach presented is applied to Krümmel nuclear power plant in Germany. Analysed are the uncertainties with regard to electricity generation restrictions on account of climatic developments and corresponding higher water temperatures and low flows. Overall, increased water temperatures and declining river runoff lead to more frequent and more severe generation restrictions. It is concluded that the site-specific approach is necessary to reliably simulate power plants water demand, river runoff and water temperature. Using a simulation time step of one day, electricity generation restrictions are significantly higher than for simulations at monthly time step. - Highlights: • An approach to assess climate effects on electricity generation is presented. • Site specific models for power plants, water temperature and discharge are used. • Monthly and daily simulation time-steps give different results. • Climate change effects on generation depend on cooling system and climate scenario

  7. Comparison of elevation and remote sensing derived products as auxiliary data for climate surface interpolation

    Science.gov (United States)

    Alvarez, Otto; Guo, Qinghua; Klinger, Robert C.; Li, Wenkai; Doherty, Paul

    2013-01-01

    Climate models may be limited in their inferential use if they cannot be locally validated or do not account for spatial uncertainty. Much of the focus has gone into determining which interpolation method is best suited for creating gridded climate surfaces, which often a covariate such as elevation (Digital Elevation Model, DEM) is used to improve the interpolation accuracy. One key area where little research has addressed is in determining which covariate best improves the accuracy in the interpolation. In this study, a comprehensive evaluation was carried out in determining which covariates were most suitable for interpolating climatic variables (e.g. precipitation, mean temperature, minimum temperature, and maximum temperature). We compiled data for each climate variable from 1950 to 1999 from approximately 500 weather stations across the Western United States (32° to 49° latitude and −124.7° to −112.9° longitude). In addition, we examined the uncertainty of the interpolated climate surface. Specifically, Thin Plate Spline (TPS) was used as the interpolation method since it is one of the most popular interpolation techniques to generate climate surfaces. We considered several covariates, including DEM, slope, distance to coast (Euclidean distance), aspect, solar potential, radar, and two Normalized Difference Vegetation Index (NDVI) products derived from Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS). A tenfold cross-validation was applied to determine the uncertainty of the interpolation based on each covariate. In general, the leading covariate for precipitation was radar, while DEM was the leading covariate for maximum, mean, and minimum temperatures. A comparison to other products such as PRISM and WorldClim showed strong agreement across large geographic areas but climate surfaces generated in this study (ClimSurf) had greater variability at high elevation regions, such as in the Sierra

  8. The cold climate geomorphology of the Eastern Cape Drakensberg: A reevaluation of past climatic conditions during the last glacial cycle in Southern Africa

    OpenAIRE

    Mills, SC; Barrows, TT; Telfer, MW; Fifield, LK

    2017-01-01

    publisher: Elsevier articletitle: The cold climate geomorphology of the Eastern Cape Drakensberg: A reevaluation of past climatic conditions during the last glacial cycle in Southern Africa journaltitle: Geomorphology articlelink: http://dx.doi.org/10.1016/j.geomorph.2016.11.011 content_type: article copyright: Crown Copyright © 2016 Published by Elsevier B.V. All rights reserved.

  9. Groundwater flow modelling of periods with periglacial and glacial climate conditions - Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Vidstrand, Patrik (TerraSolve AB, Floda (Sweden)); Rhen, Ingvar (SWECO Environment AB, Falun (Sweden)); Zugec, Nada (Bergab, Goeteborg (Sweden))

    2010-12-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. This report is concerned with the modelling of a repository at the Laxemar-Simpevarp site during periglacial and glacial climate conditions as a comparison to corresponding modelling carried out for Forsmark /Vidstrand et al. 2010/. The groundwater flow modelling study reported here comprises a coupled thermal-hydraulic-chemical (T-H-C) analysis of periods with periglacial and glacial climate conditions. The objective of the report is to provide bounding hydrogeological estimates at different stages during glaciation and deglaciation of a glacial cycle at Laxemar. Three cases with different climate conditions are analysed here: (i) Temperate case, (ii) Glacial case without permafrost, and (iii) Glacial case with permafrost. The glacial periods are transient and encompass approximately 13,000 years. The simulation results comprise pressures, Darcy fluxes, and water salinities, as well as advective transport performance measures obtained by particle tracking such as flow path lengths, travel times and flow-related transport resistances. The modelling is accompanied by a sensitivity study that addresses the impact of the following matters: the direction of the ice sheet advance and the bedrock hydraulic and transport properties

  10. How do Changes in Hydro-Climate Conditions Alter the Risk of Infection With Fasciolosis?

    Science.gov (United States)

    Beltrame, L.; Dunne, T.; Rose, H.; Walker, J.; Morgan, E.; Vickerman, P.; Wagener, T.

    2017-12-01

    Fasciolosis is a widespread parasitic disease of livestock and is emerging as a major zoonosis. Since the parasite and its intermediate host live and develop in the environment, risk of infection is directly affected by climatic-environmental conditions. Changes in disease prevalence, seasonality and distribution have been reported in recent years and attributed to altered temperature and rainfall patterns, raising concerns about the effects of climate change in the future. Therefore, it is urgent to understand how changes in climate-environmental drivers may alter the dynamics of disease risk in a quantitative way, to guide parasite control strategies and interventions in the coming decades. In a previous work, we developed and tested a novel mechanistic hydro-epidemiological model for Fasciolosis, which explicitly represents the parasite life-cycle in connection with key environmental processes, allowing to capture the impact of previously unseen conditions. In this study, we use the new mechanistic model to assess the sensitivity of infection rates to changes in climate-environmental factors. This is challenging as processes underlying disease transmission are complex and interacting, and may have contrasting effects on the parasite life-cycle stages. To this end, we set up a sensitivity analysis framework to investigate in a structured way which factors play a key role in controlling the magnitude, timing and spread of infection, and how the sensitivity of disease risk varies in time and space. Moreover, we define synthetic scenarios to explore the space of possible variability of the hydro-climate drivers and investigate conditions that lead to critical levels of infection. The study shows how the new model combined with the sensitivity analysis framework can support decision-making, providing useful information for disease management.

  11. Assessment of tourism and recreation destinations under climate change conditions in Austria

    Energy Technology Data Exchange (ETDEWEB)

    Matzarakis, Andreas; Haemmerle, Martin [Freiburg Univ. (Germany). Meteorological Inst.; Endler, Christina [Freiburg Univ. (Germany). Meteorological Inst.; Research Center Human Biometeorology, Freiburg (Germany). German Weather Service; Muthers, Stefan [Freiburg Univ. (Germany). Meteorological Inst.; Bern Univ. (Switzerland). Climate and Environmental Physics; Bern Univ. (Switzerland). Oeschger Centre for Climate Change Research; Koch, Elisabeth [Central Institute for Meteorology and Geodynamcis, Vienna (Austria)

    2012-04-15

    Tourism and recreation are important economic factors which are directly connected to weather and climate of a specific destination. Based on the observation network of the Central Institute of Meteorology and Geodynamics of Austria (ZAMG), data of 37 stations has been collected and analysed for tourism and recreation purposes. The analysis was based on long term data sets which were processed in relevant ways for tourism and recreation, resulting in frequency diagrams of Physiologically Equivalent Temperature (PET) and precipitation. Additionally, we prepared the results according to the demands of tourism and recreation authorities and industry using the Climate-Tourism/Transfer-Information-Scheme (CTIS). Applying data from the regional climate models REMO and CLM we can provide information on future climate conditions in Austria's recreation areas. We chose two different time slices (2021-2050, 2071-2100) and IPCC emission scenarios (A1B, B1). The data was processed based on the threshold factors which are included in the CTIS (e.g. thermal comfort, heat stress, cold stress, sunshine, etc.). For the time slice 2021-2050 only moderate changes can be expected. But for 2071-2100 one can observe a distinct decrease of cold stress and the skiing potential. On the other hand, moderate increases of thermal comfort, heat stress, sultriness and sunshine are expected. No tendencies can be seen in precipitation and wind conditions. (orig.)

  12. Sea Surface Temperature for Climate Applications: A New Dataset from the European Space Agency Climate Change Initiative

    Science.gov (United States)

    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

  13. Climatic variability of river outflow in the Pantanal region and the influence of sea surface temperature

    Science.gov (United States)

    Silva, Carlos Batista; Silva, Maria Elisa Siqueira; Ambrizzi, Tércio

    2017-07-01

    This paper investigates possible linear relationships between climate, hydrology, and oceanic surface variability in the Pantanal region (in South America's central area), over interannual and interdecadal time ranges. In order to verify the mentioned relations, lagged correlation analysis and linear adjustment between river discharge at the Pantanal region and sea surface temperature were used. Composite analysis for atmospheric fields, air humidity flux divergence, and atmospheric circulation at low and high levels, for the period between 1970 and 2003, was analyzed. Results suggest that the river discharge in the Pantanal region is linearly associated with interdecadal and interannual oscillations in the Pacific and Atlantic oceans, making them good predictors to continental hydrological variables. Considering oceanic areas, 51 % of the annual discharge in the Pantanal region can be linearly explained by mean sea surface temperature (SST) in the Subtropical North Pacific, Tropical North Pacific, Extratropical South Pacific, and Extratropical North Atlantic over the period. Considering a forecast approach in seasonal scale, 66 % of the monthly discharge variance in Pantanal, 3 months ahead of SST, is explained by the oceanic variables, providing accuracy around 65 %. Annual discharge values in the Pantanal region are strongly related to the Pacific Decadal Oscillation (PDO) variability (with 52 % of linear correlation), making it possible to consider an interdecadal variability and a consequent subdivision of the whole period in three parts: 1st (1970-1977), 2nd (1978-1996), and 3rd (1997-2003) subperiods. The three subperiods coincide with distinct PDO phases: negative, positive, and negative, respectively. Convergence of humidity flux at low levels and the circulation pattern at high levels help to explain the drier and wetter subperiods. During the wetter 2nd subperiod, the air humidity convergence at low levels is much more evident than during the other two

  14. Changes in surface area of the Böön Tsagaan and Orog lakes (Mongolia, Valley of the Lakes, 1974-2013) compared to climate and permafrost changes

    Science.gov (United States)

    Szumińska, Danuta

    2016-07-01

    The main aim of the study is the analysis of changes in surface area of lake Böön Tsagaan (45°35‧N, 99°8‧E) and lake Orog (45°3‧N, 100°44‧E) taking place in the last 40 years in the context of climate conditions and permafrost degradation. The lakes, located in Central Mongolia, at the borderline of permafrost range are fed predominantly by river waters and groundwater from the surrounding mountain areas, characterized by continuous and discontinuous permafrost occurrence - mostly the Khangai. The analysis of the Böön Tsagaan and Orog lake surface area in 1974-2013 was conducted based on satellite images, whereas climate conditions were analysed using the NOAA climate data and CRU dataset. Principal Component Analysis (PCA) was used to study the relationship patterns between the climatic factors and changes in the surface area of the lakes. A tendency for a decrease in surface area, intermittent with short episodes of resupply, was observed in both studied lakes. Climate changes recorded in the analysed period had both direct and indirect impacts on water supply to lakes. Taking into account the results of PCA analysis, the most significant factors include: fluctuation of annual precipitation, increase in air temperature and thickness of snow cover. The extended duration of snow cover in the last decades of the 20th century may constitute a key factor in relation to permafrost degradation.

  15. Future projections of the climate and surface mass balance of Svalbard with the regional climate model MAR

    Science.gov (United States)

    Lang, C.; Fettweis, X.; Erpicum, M.

    2015-01-01

    We have performed future projections of the climate and surface mass balance (SMB) of Svalbard with the MAR regional climate model forced by the MIROC5 global model, following the RCP8.5 scenario at a spatial resolution of 10 km. MAR predicts a similar evolution of increasing surface melt everywhere in Svalbard followed by a sudden acceleration of the melt around 2050, with a larger melt increase in the south compared to the north of the archipelago and the ice caps. This melt acceleration around 2050 is mainly driven by the albedo-melt feedback associated with the expansion of the ablation/bare ice zone. This effect is dampened in part as the solar radiation itself is projected to decrease due to cloudiness increase. The near-surface temperature is projected to increase more in winter than in summer as the temperature is already close to 0 °C in summer. The model also projects a strong winter west-to-east temperature gradient, related to the large decrease of sea ice cover around Svalbard. At the end of the century (2070-2099 mean), SMB is projected to be negative over the entire Svalbard and, by 2085, all glaciated regions of Svalbard are predicted to undergo net ablation, meaning that, under the RCP8.5 scenario, all the glaciers and ice caps are predicted to start their irreversible retreat before the end of the 21st century.

  16. Impact of environmental conditions on sub-surface storage tanks ...

    African Journals Online (AJOL)

    Cast iron made storage tanks with gasoline fluid were buried under the soil at a depth of 4 m under various environment conditions. The simulated conditions include natural rain fail, temperature and acidic, alkaline and neutral soils. A control condition of neutral sea sand as base and filling materials were also investigated.

  17. Sensitivity of Greenland Ice Sheet surface mass balance to surface albedo parameterization: a study with a regional climate model

    OpenAIRE

    Angelen, J. H.; Lenaerts, J. T. M.; Lhermitte, S.; Fettweis, X.; Kuipers Munneke, P.; Broeke, M. R.; Meijgaard, E.; Smeets, C. J. P. P.

    2012-01-01

    We present a sensitivity study of the surface mass balance (SMB) of the Greenland Ice Sheet, as modeled using a regional atmospheric climate model, to various parameter settings in the albedo scheme. The snow albedo scheme uses grain size as a prognostic variable and further depends on cloud cover, solar zenith angle and black carbon concentration. For the control experiment the overestimation of absorbed shortwave radiation (+6%) at the K-transect (west Greenland) for the period 2004–2009 is...

  18. Ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions

    DEFF Research Database (Denmark)

    Selsted, Merete Bang

    on ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions, shows that extended summer drought in combination with elevated temperature will ensure permanent dryer soil conditions, which decreases carbon turnover, while elevated atmospheric CO2 concentrations will increase...... carbon turnover. In the full future climate scenario, carbon turnover is over all expected to increase and the heathland to become a source of atmospheric CO2. The methodology of static chamber CO2 flux measurements and applying the technology in a FACE (free air CO2 enrichment) facility is a challenge...... on the atmospheric CO2 concentration. Photosynthesis and respiration run in parallel during measurements of net ecosystem exchange, and these measurements should therefore be performed with care to both the atmospheric CO2 concentration and the CO2 soil-atmosphere gradient....

  19. Effects of Climate Change and Human Activities on Surface Runoff in the Luan River Basin

    Directory of Open Access Journals (Sweden)

    Sidong Zeng

    2015-01-01

    Full Text Available Quantifying the effects of climate change and human activities on runoff changes is the focus of climate change and hydrological research. This paper presents an integrated method employing the Budyko-based Fu model, hydrological modeling, and climate elasticity approaches to separate the effects of the two driving factors on surface runoff in the Luan River basin, China. The Budyko-based Fu model and the double mass curve method are used to analyze runoff changes during the period 1958~2009. Then two types of hydrological models (the distributed Soil and Water Assessment Tool model and the lumped SIMHYD model and seven climate elasticity methods (including a nonparametric method and six Budyko-based methods are applied to estimate the contributions of climate change and human activities to runoff change. The results show that all quantification methods are effective, and the results obtained by the nine methods are generally consistent. During the study period, the effects of climate change on runoff change accounted for 28.3~46.8% while those of human activities contributed with 53.2~71.7%, indicating that both factors have significant effects on the runoff decline in the basin, and that the effects of human activities are relatively stronger than those of climate change.

  20. Climatic and physiographic controls of spatial variability in surface water balance over the contiguous United States using the Budyko relationship

    Science.gov (United States)

    Abatzoglou, John T.; Ficklin, Darren L.

    2017-09-01

    The geographic variability in the partitioning of precipitation into surface runoff (Q) and evapotranspiration (ET) is fundamental to understanding regional water availability. The Budyko equation suggests this partitioning is strictly a function of aridity, yet observed deviations from this relationship for individual watersheds impede using the framework to model surface water balance in ungauged catchments and under future climate and land use scenarios. A set of climatic, physiographic, and vegetation metrics were used to model the spatial variability in the partitioning of precipitation for 211 watersheds across the contiguous United States (CONUS) within Budyko's framework through the free parameter ω. A generalized additive model found that four widely available variables, precipitation seasonality, the ratio of soil water holding capacity to precipitation, topographic slope, and the fraction of precipitation falling as snow, explained 81.2% of the variability in ω. The ω model applied to the Budyko equation explained 97% of the spatial variability in long-term Q for an independent set of watersheds. The ω model was also applied to estimate the long-term water balance across the CONUS for both contemporary and mid-21st century conditions. The modeled partitioning of observed precipitation to Q and ET compared favorably across the CONUS with estimates from more sophisticated land-surface modeling efforts. For mid-21st century conditions, the model simulated an increase in the fraction of precipitation used by ET across the CONUS with declines in Q for much of the eastern CONUS and mountainous watersheds across the western United States.

  1. Comparison of winter wheat yield sensitivity to climate variables under irrigated and rain-fed conditions

    Science.gov (United States)

    Xiao, Dengpan; Shen, Yanjun; Zhang, He; Moiwo, Juana P.; Qi, Yongqing; Wang, Rende; Pei, Hongwei; Zhang, Yucui; Shen, Huitao

    2016-09-01

    Crop simulation models provide alternative, less time-consuming, and cost-effective means of determining the sensitivity of crop yield to climate change. In this study, two dynamic mechanistic models, CERES (Crop Environment Resource Synthesis) and APSIM (Agricultural Production Systems Simulator), were used to simulate the yield of wheat ( Triticum aestivum L.) under well irrigated (CFG) and rain-fed (YY) conditions in relation to different climate variables in the North China Plain (NCP). The study tested winter wheat yield sensitivity to different levels of temperature, radiation, precipitation, and atmospheric carbon dioxide (CO2) concentration under CFG and YY conditions at Luancheng Agro-ecosystem Experimental Stations in the NCP. The results from the CERES and APSIM wheat crop models were largely consistent and suggested that changes in climate variables influenced wheat grain yield in the NCP. There was also significant variation in the sensitivity of winter wheat yield to climate variables under different water (CFG and YY) conditions. While a temperature increase of 2°C was the threshold beyond which temperature negatively influenced wheat yield under CFG, a temperature rise exceeding 1°C decreased winter wheat grain yield under YY. A decrease in solar radiation decreased wheat grain yield under both CFG and YY conditions. Although the sensitivity of winter wheat yield to precipitation was small under the CFG, yield decreased significantly with decreasing precipitation under the rainfed YY treatment. The results also suggest that wheat yield under CFG linearly increased by ≈3.5% per 60 ppm (parts per million) increase in CO2 concentration from 380 to 560 ppm, and yield under YY increased linearly by ≈7.0% for the same increase in CO2 concentration.

  2. Evaluation of growth and flowering potential of rosa hybrida cultivars under Faisalabad climatic conditions

    International Nuclear Information System (INIS)

    Nadeem, M.; Khan, M.A.; Riaz, A.

    2011-01-01

    Exotic cultivars of hybrid roses respond uncertainly to new habitat. It is necessary to explore the potential of the introduced cultivars to judge the suitability in a new habitat. In the present study, nine Rosa hybrida cultivars including Autumn Sunset, Ice Berg, Paradise, Angel Face, Louise Odier, Casino, Grand Margina, Handel and Gruss-an-Teplitz were evaluated for growth and yield attributed under the climatic conditions of Faisalabad. Results indicated that there was decreasing trend in the growth and flowering of the bushes as the temperature increased above 32 degree C and humidity decreased to 29 %. Number of flowers per bush and diameter of flower decreased as the temperature increased and humidity decreased in contrast to increment in height of the plant and num ber of primary branches per plant in succeeding months. Interaction between yield traits and months was also significant. Overall, significant variations were observed in each cultivar for length and number of petals per flower, number of prickles, fragrance, flower persistence life and color, bush shape and overall performance with respect to climatic conditions of Faisalabad. It is concluded that the cultivars 'Autumn Sunset' and Gruss-an-Teplitz performed better in climatic conditions of Faisalabad. (author)

  3. Life cycle cost analysis of HPVT air collector under different Indian climatic conditions

    International Nuclear Information System (INIS)

    Raman, Vivek; Tiwari, G.N.

    2008-01-01

    In this communication, a study is carried out to evaluate an annual thermal and exergy efficiency of a hybrid photovoltaic thermal (HPVT) air collector for different Indian climate conditions, of Srinagar, Mumbai, Jodhpur, New Delhi and Banglore. The study has been based on electrical, thermal and exergy output of the HPVT air collector. Further, the life cycle analysis in terms of cost/kWh has been carried out. The main focus of the study is to see the effect of interest rate, life of the HPVT air collector, subsidy, etc. on the cost/kWh HPVT air collector. A comparison is made keeping in view the energy matrices. The study reveals that (i) annual thermal and electrical efficiency decreases with increase in solar radiation and (ii) the cost/kWh is higher in case of exergy when compared with cost/kWh on the basis of thermal energy for all climate conditions. The cost/kWh for climate conditions of Jodhpur is most economical

  4. Performance of three saudi arabian date palm varieties under the agro-climatic conditions of khairpur

    International Nuclear Information System (INIS)

    Soad, A.A.A.

    2013-01-01

    Date palms of 10 year old Ajwa, Safawi and Ruthana varieties from Al-Madina, Saudi Arabia were evaluated under the agro-climatic conditions of Khairpur, Sindh, Pakistan throughout the growing seasons from 2009 to 2011. The results obtained indicated better fruit quality similar to those fruits obtained from the original place of origin. The palms of the three varieties were thriving successfully. The edible stage of vars. Ajwa and Safawi is tamer and rutab for var. Ruthana. The fruit was harvested early from 13 to 20th of July before the onset of monsoons. The fruit size of vars. Ajwa, Safawi and Ruthana at their edible stages were 3.16, 4.25 and 3.52 cm long, and 2.31, 2.05 and 2.38 cm in diameter, respectively. The average fruit and seed weight of vars. Ajwa, Safawi and Ruthana were 11.42, 10.49 and 12.42 g, and 1.23, 0.88 and 1.1 g, respectively. The fruit flesh percentage in vars. Ajwa, Safawi and Ruthana reached 89.14%, 90.84% and 90.92%, respectively. It was found that the climatic conditions of Khairpur are suitable for the cultivation of these three exotic varieties. The vegetative, flowering and fruit characteristics of the three varieties were described, and the impact of climatic conditions on fruit quality was discussed in this study. (author)

  5. Development of streamflow projections under changing climate conditions over Colorado River basin headwaters

    Directory of Open Access Journals (Sweden)

    W. P. Miller

    2011-07-01

    Full Text Available The current drought over the Colorado River Basin has raised concerns that the US Department of the Interior, Bureau of Reclamation (Reclamation may impose water shortages over the lower portion of the basin for the first time in history. The guidelines that determine levels of shortage are affected by relatively short-term (3 to 7 month forecasts determined by the Colorado Basin River Forecast Center (CBRFC using the National Weather Service (NWS River Forecasting System (RFS hydrologic model. While these forecasts by the CBRFC are useful, water managers within the basin are interested in long-term projections of streamflow, particularly under changing climate conditions. In this study, a bias-corrected, statistically downscaled dataset of projected climate is used to force the NWS RFS utilized by the CBRFC to derive projections of streamflow over the Green, Gunnison, and San Juan River headwater basins located within the Colorado River Basin. This study evaluates the impact of changing climate to evapotranspiration rates and contributes to a better understanding of how hydrologic processes change under varying climate conditions. The impact to evapotranspiration rates is taken into consideration and incorporated into the development of streamflow projections over Colorado River headwater basins in this study. Additionally, the NWS RFS is modified to account for impacts to evapotranspiration due to changing temperature over the basin. Adjusting evapotranspiration demands resulted in a 6 % to 13 % average decrease in runoff over the Gunnison River Basin when compared to static evapotranspiration rates. Streamflow projections derived using projections of future climate and the NWS RFS provided by the CBRFC resulted in decreased runoff in 2 of the 3 basins considered. Over the Gunnison and San Juan River basins, a 10 % to 15 % average decrease in basin runoff is projected through the year 2099. However, over the Green River basin, a 5 % to 8

  6. Higher surface mass balance of the Greenland ice sheet revealed by high - resolution climate modeling

    NARCIS (Netherlands)

    Ettema, Janneke; van den Broeke, Michiel R.; van Meijgaard, Erik; van de Berg, Willem Jan; Bamber, Jonathan L.; Box, Jason E.; Bales, Roger C.

    2009-01-01

    High‐resolution (∼11 km) regional climate modeling shows total annual precipitation on the Greenland ice sheet for 1958–2007 to be up to 24% and surface mass balance up to 63% higher than previously thought. The largest differences occur in coastal southeast Greenland, where the much higher

  7. Effect of climate change on runoff of Campylobacter and Cryptosporidium from land to surface water.

    Science.gov (United States)

    Sterk, Ankie; Schijven, Jack; de Roda Husman, Ana Maria; de Nijs, Ton

    2016-05-15

    Faeces originating from wildlife, domestic animals or manure-fertilized fields, is considered an important source of zoonotic pathogens to which people may be exposed by, for instance, bathing or drinking-water consumption. An increase in runoff, and associated wash-off of animal faeces from fields, is assumed to contribute to the increase of disease outbreaks during periods of high precipitation. Climate change is expected to increase winter precipitation and extreme precipitation events during summer, but has simultaneously also other effects such as temperature rise and changes in evapotranspiration. The question is to what extent the combination of these effects influence the input of zoonotic pathogens to the surface waters. To quantitatively analyse the impacts of climate change on pathogen runoff, pathogen concentrations reaching surface waters through runoff were calculated by combining an input model for catchment pathogen loads with the Wageningen Lowland Runoff Simulator (WALRUS). Runoff of Cryptosporidium and Campylobacter was evaluated under different climate change scenarios and by applying different scenarios for sources of faecal pollution in the catchments, namely dairy cows and geese and manure fertilization. Model evaluation of these scenarios shows that climate change has little overall impact on runoff of Campylobacter and Cryptosporidium from land to the surface waters. Even though individual processes like runoff fluxes, pathogen release and dilution are affected, either positively or negatively, the net effect on the pathogen concentration in surface waters and consequently also on infection risks through recreation seems limited. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Signal and noise in Gravity Recovery and Climate Experiment (GRACE) observed surface mass variations

    NARCIS (Netherlands)

    Schrama, E.J.O.; Wouters, B.; Lavallée, D.A.

    2007-01-01

    The Gravity Recovery and Climate Experiment (GRACE) product used for this study consists of 43 monthly potential coefficient sets released by the GRACE science team which are used to generate surface mass thickness grids expressed as equivalent water heights (EQWHs). We optimized both the smoothing

  9. Impacts of Climate Change and Land use Changes on Land Surface Radiation and Energy Budgets

    Science.gov (United States)

    Land surface radiation and energy budgets are critical to address a variety of scientific and application issues related to climate trends, weather predictions, hydrologic and biogeophysical modeling, and the monitoring of ecosystem health and agricultural crops. This is an introductory paper to t...

  10. Greenland ice sheet surface mass balance: evaluating simulations and making projections with regional climate models

    NARCIS (Netherlands)

    Rae, J.G.L.; Aðalgeirsdóttir, G.; Edwards, T.L.; Fettweis, X.; Gregory, J.M.; Hewitt, H.T.; Lowe, J.A.; Lucas-Picher, P.; Mottram, R.H.; Payne, A.J.; Ridley, J.K.; Shannon, S.R.; van de Berg, W.J.; van de Wal, R.S.W.; van den Broeke, M.R.

    2012-01-01

    Four high-resolution regional climate models (RCMs) have been set up for the area of Greenland, with the aim of providing future projections of Greenland ice sheet surface mass balance (SMB), and its contribution to sea level rise, with greater accuracy than is possible from coarser-resolution

  11. An experimental study on decontamination by surface condition

    International Nuclear Information System (INIS)

    Lee, Young Hae

    1974-01-01

    Surface decontamination is one of the very important problem to be completely solved in the isotope laboratory where there is always the possibility of radioactive contamination, i.e., on the floors, walls, working tables and benches etc., Isotope laboratories require surface covering of material which can be easily and effectively decontaminated. These experiment were done to find an effective decontamination procedure for kind of surfaces which usually are found in radioisotope laboratories and the best type of surface material, that is, one which is easily decontaminated from the point of view of radiation health and safely. This study is presented to guide radioisotope laboratories in Korea which may need to renovate existing unsafe facilities. In some contaminated facilities entirely new installations may be required. Twelve types of surface material are used for study in this experiment. These include 10 cm square of stainless steel, aluminum, ceramic and mosaic tiles, glass, acrylic, formica board, asphalt tile and coated wood with 4 kinds of paints. Stepwise decontamination was performed with various decontamination procedures following a spill of I 1 31 on the center of the surface material being tested. Twelve different decontamination procedures were tested. These included wet wiping with water and detergent, or dry wiping, or removing with gummed paper. Additional chemical procedures used 10% solution of hydrochloric acid, or surface acid, or ammonium citrate, or potassium iodide, or acetone or carbon tetrachloride. The final testing method was abrasion of the test surfaces. Brief analysis of experimental results on the decontaminability on the tested surface showed: 1. Metallic surfaces such as stainless steel or aluminum, or glass, or a piece of ceramic tile or acrylic are recommended as the surface materials for isotope laboratories because these are easily decontaminated by wet wiping only. 2. Formica board, asphalt tile and wood are not easily

  12. Multi-Annual Climate Predictions for Fisheries: An Assessment of Skill of Sea Surface Temperature Forecasts for Large Marine Ecosystems

    Directory of Open Access Journals (Sweden)

    Desiree Tommasi

    2017-06-01

    Full Text Available Decisions made by fishers and fisheries managers are informed by climate and fisheries observations that now often span more than 50 years. Multi-annual climate forecasts could further inform such decisions if they were skillful in predicting future conditions relative to the 50-year scope of past variability. We demonstrate that an existing multi-annual prediction system skillfully forecasts the probability of next year, the next 1–3 years, and the next 1–10 years being warmer or cooler than the 50-year average at the surface in coastal ecosystems. Probabilistic forecasts of upper and lower seas surface temperature (SST terciles over the next 3 or 10 years from the GFDL CM 2.1 10-member ensemble global prediction system showed significant improvements in skill over the use of a 50-year climatology for most Large Marine Ecosystems (LMEs in the North Atlantic, the western Pacific, and Indian oceans. Through a comparison of the forecast skill of initialized and uninitialized hindcasts, we demonstrate that this skill is largely due to the predictable signature of radiative forcing changes over the 50-year timescale rather than prediction of evolving modes of climate variability. North Atlantic LMEs stood out as the only coastal regions where initialization significantly contributed to SST prediction skill at the 1 to 10 year scale.

  13. Climate change and future overwintering conditions of horticultural woody-plants in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Laapas, M.; Jylhae, K.; Tuomenvirta, H. (Finnish Meteorological Inst., Helsinki (Finland))

    2012-07-01

    Climate in Finland offers challenging conditions for commercial horticulture. The short and insufficient growing season together with risky overwintering strongly limits species suitable for cultivation. The aim of this study was to examine the climatic conditions around Finland in the aspect of horticulture, focusing on processes relevant to woody plants and species with photoperiod controlled growth cessation, and how these conditions may be expected to change due to the projected global warming. For this, a set of temperature-related indices and threshold events were used. These indices represent the severity of coldness during winter, wintertime thaws, and frost events close to the onset and ending of the growing season. The combined results of 19 GCMs (General Circulation Model) from the CMIP3 (Coupled Model Intercomparison Project 3) multi-model data set under SRES-B1 and SRES-A2 (Special Report on Emission Scenarios) emission scenarios were used to produce the future projections. By mid-century our results suggest wintertime conditions with reduced cold stress, caused by less frequent and shorter periods of severe frost together with a rise in the extreme minimum temperature. Conversely, an increase in the number and intensity of wintertime thaw events leads to a higher risk in overwintering. Also the risk of spring frost damage is projected to decrease slightly, and the conditions for cold hardening process to improve, as the first autumnal frosts occur later. (orig.)

  14. Under which climate and soil conditions the plant productivity-precipitation relationship is linear or nonlinear?

    Science.gov (United States)

    Ye, Jian-Sheng; Pei, Jiu-Ying; Fang, Chao

    2018-03-01

    Understanding under which climate and soil conditions the plant productivity-precipitation relationship is linear or nonlinear is useful for accurately predicting the response of ecosystem function to global environmental change. Using long-term (2000-2016) net primary productivity (NPP)-precipitation datasets derived from satellite observations, we identify >5600pixels in the North Hemisphere landmass that fit either linear or nonlinear temporal NPP-precipitation relationships. Differences in climate (precipitation, radiation, ratio of actual to potential evapotranspiration, temperature) and soil factors (nitrogen, phosphorous, organic carbon, field capacity) between the linear and nonlinear types are evaluated. Our analysis shows that both linear and nonlinear types exhibit similar interannual precipitation variabilities and occurrences of extreme precipitation. Permutational multivariate analysis of variance suggests that linear and nonlinear types differ significantly regarding to radiation, ratio of actual to potential evapotranspiration, and soil factors. The nonlinear type possesses lower radiation and/or less soil nutrients than the linear type, thereby suggesting that nonlinear type features higher degree of limitation from resources other than precipitation. This study suggests several factors limiting the responses of plant productivity to changes in precipitation, thus causing nonlinear NPP-precipitation pattern. Precipitation manipulation and modeling experiments should combine with changes in other climate and soil factors to better predict the response of plant productivity under future climate. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Coupling climate conditions, sediment sources and sediment transport in an alpine basin

    Science.gov (United States)

    Rainato, Riccardo; Picco, Lorenzo; Cavalli, Marco; Mao, Luca; Neverman, Andrew J.; Tarolli, Paolo

    2017-04-01

    In a fluvial system, mountain basins control sediment export to the lowland rivers. Hence, the analysis of the erosion processes and sediment delivery patterns that act in mountain basins is important. Several studies have investigated the alterations triggered by recent climatic change on the hydrological regime, whilst only a few works have explored the consequences on the sediment dynamics. Here we combined and analyzed the quasi-unique dataset of climatic conditions, landscape response, and sediment export produced, since 1986 in the Rio Cordon basin (5 km2, Eastern Italian Alps) to examine the sediment delivery processes occurring in the last three decades. The temperature, precipitation, and fluvial sediment fluxes in the basin were analyzed using continuous measurement executed by a permanent monitoring station, while the landscape evolution was investigated by three sediment source inventories established in 1994, 2006, and 2016. Thus, the analysis focused on the trends exhibited during the periods 1986-1993, 1994-2006, and 2007-2015. In terms of climatic conditions, three distinct climate forcing stages can be observed in the periods analyzed: a relatively stable phase (1986-1993), a period characterized by temperature and rainfall fluctuations (1994-2006), and a more recent warmer and wetter phase (2007-2015). In the 1986-1993 period, the fluvial sediment fluxes reflected the stable trend exhibited by the climatic conditions. In the subsequent 1994-2006 period, the average temperature and precipitation were in line with that previously observed, although with higher interannual variability. Notwithstanding the climate forcing and the occurrence of high magnitude/low frequency floods that strongly influenced the source areas, between 1994 and 2006 the Rio Cordon basin showed relatively limited erosion activity. Hence, the climatic conditions and the landscape response can only partially explain the strong increase of sediment export recorded in the 1994

  16. The vertical distribution of climate forcings and feedbacks from the surface to top of atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Previdi, Michael [Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY (United States); Liepert, Beate G. [NorthWest Research Associates, Redmond, WA (United States)

    2012-08-15

    The radiative forcings and feedbacks that determine Earth's climate sensitivity are typically defined at the top-of-atmosphere (TOA) or tropopause, yet climate sensitivity itself refers to a change in temperature at the surface. In this paper, we describe how TOA radiative perturbations translate into surface temperature changes. It is shown using first principles that radiation changes at the TOA can be equated with the change in energy stored by the oceans and land surface. This ocean and land heat uptake in turn involves an adjustment of the surface radiative and non-radiative energy fluxes, with the latter being comprised of the turbulent exchange of latent and sensible heat between the surface and atmosphere. We employ the radiative kernel technique to decompose TOA radiative feedbacks in the IPCC Fourth Assessment Report climate models into components associated with changes in radiative heating of the atmosphere and of the surface. (We consider the equilibrium response of atmosphere-mixed layer ocean models subjected to an instantaneous doubling of atmospheric CO{sub 2}). It is shown that most feedbacks, i.e., the temperature, water vapor and cloud feedbacks, (as well as CO{sub 2} forcing) affect primarily the turbulent energy exchange at the surface rather than the radiative energy exchange. Specifically, the temperature feedback increases the surface turbulent (radiative) energy loss by 2.87 W m{sup -2} K{sup -1} (0.60 W m{sup -2} K{sup -1}) in the multimodel mean; the water vapor feedback decreases the surface turbulent energy loss by 1.07 W m{sup -2} K{sup -1} and increases the surface radiative heating by 0.89 W m{sup -2} K{sup -1}; and the cloud feedback decreases both the turbulent energy loss and the radiative heating at the surface by 0.43 and 0.24 W m{sup -2} K{sup -1}, respectively. Since changes to the surface turbulent energy exchange are dominated in the global mean sense by changes in surface evaporation, these results serve to highlight

  17. Modeling daily soil temperature over diverse climate conditions in Iran—a comparison of multiple linear regression and support vector regression techniques

    Science.gov (United States)

    Delbari, Masoomeh; Sharifazari, Salman; Mohammadi, Ehsan

    2018-02-01

    The knowledge of soil temperature at different depths is important for agricultural industry and for understanding climate change. The aim of this study is to evaluate the performance of a support vector regression (SVR)-based model in estimating daily soil temperature at 10, 30 and 100 cm depth at different climate conditions over Iran. The obtained results were compared to those obtained from a more classical multiple linear regression (MLR) model. The correlation sensitivity for the input combinations and periodicity effect were also investigated. Climatic data used as inputs to the models were minimum and maximum air temperature, solar radiation, relative humidity, dew point, and the atmospheric pressure (reduced to see level), collected from five synoptic stations Kerman, Ahvaz, Tabriz, Saghez, and Rasht located respectively in the hyper-arid, arid, semi-arid, Mediterranean, and hyper-humid climate conditions. According to the results, the performance of both MLR and SVR models was quite well at surface layer, i.e., 10-cm depth. However, SVR performed better than MLR in estimating soil temperature at deeper layers especially 100 cm depth. Moreover, both models performed better in humid climate condition than arid and hyper-arid areas. Further, adding a periodicity component into the modeling process considerably improved the models' performance especially in the case of SVR.

  18. Rainfall Downscaling Conditional on Upper-air Variables: Assessing Rainfall Statistics in a Changing Climate

    Science.gov (United States)

    Langousis, Andreas; Deidda, Roberto; Marrocu, Marino; Kaleris, Vassilios

    2014-05-01

    Due to its intermittent and highly variable character, and the modeling parameterizations used, precipitation is one of the least well reproduced hydrologic variables by both Global Climate Models (GCMs) and Regional Climate Models (RCMs). This is especially the case at a regional level (where hydrologic risks are assessed) and at small temporal scales (e.g. daily) used to run hydrologic models. In an effort to remedy those shortcomings and assess the effect of climate change on rainfall statistics at hydrologically relevant scales, Langousis and Kaleris (2013) developed a statistical framework for simulation of daily rainfall intensities conditional on upper air variables. The developed downscaling scheme was tested using atmospheric data from the ERA-Interim archive (http://www.ecmwf.int/research/era/do/get/index), and daily rainfall measurements from western Greece, and was proved capable of reproducing several statistical properties of actual rainfall records, at both annual and seasonal levels. This was done solely by conditioning rainfall simulation on a vector of atmospheric predictors, properly selected to reflect the relative influence of upper-air variables on ground-level rainfall statistics. In this study, we apply the developed framework for conditional rainfall simulation using atmospheric data from different GCM/RCM combinations. This is done using atmospheric data from the ENSEMBLES project (http://ensembleseu.metoffice.com), and daily rainfall measurements for an intermediate-sized catchment in Italy; i.e. the Flumendosa catchment. Since GCM/RCM products are suited to reproduce the local climatology in a statistical sense (i.e. in terms of relative frequencies), rather than ensuring a one-to-one temporal correspondence between observed and simulated fields (i.e. as is the case for ERA-interim reanalysis data), we proceed in three steps: a) we use statistical tools to establish a linkage between ERA-Interim upper-air atmospheric forecasts and

  19. Prominent Midlatitude Circulation Signature in High Asia's Surface Climate During Monsoon

    Science.gov (United States)

    Mölg, Thomas; Maussion, Fabien; Collier, Emily; Chiang, John C. H.; Scherer, Dieter

    2017-12-01

    High Asia has experienced strong environmental changes in recent decades, as evident in records of glaciers, lakes, tree rings, and vegetation. The multiscale understanding of the climatic drivers, however, is still incomplete. In particular, few systematic assessments have evaluated to what degree, if at all, the midlatitude westerly circulation modifies local surface climates in the reach of the Indian Summer Monsoon. This paper shows that a southward shift of the upper-tropospheric westerlies contributes significantly to climate variability in the core monsoon season (July-September) by two prominent dipole patterns at the surface: cooling in the west of High Asia contrasts with warming in the east, while moist anomalies in the east and northwest occur with drying along the southwestern margins. Circulation anomalies help to understand the dipoles and coincide with shifts in both the westerly wave train and the South Asian High, which imprint on air mass advection and local energy budgets. The relation of the variabilities to a well-established index of midlatitude climate dynamics allows future research on climate proxies to include a fresh hypothesis for the interpretation of environmental changes.

  20. Response of the North Atlantic surface and intermediate ocean structure to climate warming of MIS 11.

    Science.gov (United States)

    Kandiano, Evgenia S; van der Meer, Marcel T J; Schouten, Stefan; Fahl, Kirsten; Sinninghe Damsté, Jaap S; Bauch, Henning A

    2017-04-10

    Investigating past interglacial climates not only help to understand how the climate system operates in general, it also forms a vital basis for climate predictions. We reconstructed vertical stratification changes in temperature and salinity in the North Atlantic for a period some 400 ka ago (MIS11), an interglacial time analogue of a future climate. As inferred from a unique set of biogeochemical, geochemical, and faunal data, the internal upper ocean stratification across MIS 11 shows distinct depth-dependent dynamical changes related to vertical as well as lateral shifts in the upper Atlantic meridional circulation system. Importantly, transient cold events are recognized near the end of the long phase of postglacial warming at surface, subsurface, mid, and deeper water layers. These data demonstrate that MIS 11 coolings over the North Atlantic were initially triggered by freshwater input at the surface and expansion of cold polar waters into the Subpolar Gyre. The cooling signal was then transmitted downwards into mid-water depths. Since the cold events occurred after the main deglacial phase we suggest that their cause might be related to continuous melting of the Greenland ice sheet, a mechanism that might also be relevant for the present and upcoming climate.

  1. Lithium Wall Conditioning And Surface Dust Detection On NSTX

    International Nuclear Information System (INIS)

    Skinner, C.H.; Allain, J.P.; Bell, M.G.; Friesen, F.Q.L.; Heim, B.; Jaworski, M.A.; Kugel, H.; Maingi, R.; Rais, B.; Taylor, C.N.

    2011-01-01

    Lithium evaporation onto NSTX plasma facing components (PFC) has resulted in improved energy confinement, and reductions in the number and amplitude of edge-localized modes (ELMs) up to the point of complete ELM suppression. The associated PFC surface chemistry has been investigated with a novel plasma material interface probe connected to an in-vacuo surface analysis station. Analysis has demonstrated that binding of D atoms to the polycrystalline graphite material of the PFCs is fundamentally changed by lithium - in particular deuterium atoms become weakly bonded near lithium atoms themselves bound to either oxygen or the carbon from the underlying material. Surface dust inside NSTX has been detected in real-time using a highly sensitive electrostatic dust detector. In a separate experiment, electrostatic removal of dust via three concentric spiral-shaped electrodes covered by a dielectric and driven by a high voltage 3-phase waveform was evaluated for potential application to fusion reactors

  2. Simulating runoff under changing climatic conditions: Revisiting an apparent deficiency of conceptual rainfall-runoff models

    Science.gov (United States)

    Fowler, Keirnan J. A.; Peel, Murray C.; Western, Andrew W.; Zhang, Lu; Peterson, Tim J.

    2016-03-01

    Hydrologic models have potential to be useful tools in planning for future climate variability. However, recent literature suggests that the current generation of conceptual rainfall runoff models tend to underestimate the sensitivity of runoff to a given change in rainfall, leading to poor performance when evaluated over multiyear droughts. This research revisited this conclusion, investigating whether the observed poor performance could be due to insufficient model calibration and evaluation techniques. We applied an approach based on Pareto optimality to explore trade-offs between model performance in different climatic conditions. Five conceptual rainfall runoff model structures were tested in 86 catchments in Australia, for a total of 430 Pareto analyses. The Pareto results were then compared with results from a commonly used model calibration and evaluation method, the Differential Split Sample Test. We found that the latter often missed potentially promising parameter sets within a given model structure, giving a false negative impression of the capabilities of the model. This suggests that models may be more capable under changing climatic conditions than previously thought. Of the 282[347] cases of apparent model failure under the split sample test using the lower [higher] of two model performance criteria trialed, 155[120] were false negatives. We discuss potential causes of remaining model failures, including the role of data errors. Although the Pareto approach proved useful, our aim was not to suggest an alternative calibration strategy, but to critically assess existing methods of model calibration and evaluation. We recommend caution when interpreting split sample results.

  3. Spectroscopic study of cystine adsorption on pyrite surface: From vacuum to solution conditions

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Arenillas, M.; Mateo-Marti, E., E-mail: mateome@cab.inta-csic.es

    2015-09-08

    Highlights: • Successful adsorption of cystine on pyrite surface under several conditions. • Detailed XPS spectroscopic characterization of cystine adsorption on pyrite surface. • Spectroscopy evidence, oxidation and anoxic conditions adjust molecular adsorption. • Molecular chemistry on pyrite is driven depending on the surrounding conditions. • The cystine/pyrite(100) model is in good agreement with Wächtershäuser’s theory. - Abstract: We characterized the adsorption of cystine molecules on pyrite surface via X-ray photoelectron spectroscopy. Anoxic conditions were simulated under ultra-high-vacuum conditions. In contrast, to simulate oxidation conditions, the molecules were adsorbed on pyrite surface from solution. A novel comparative analysis revealed remarkable differences with respect to molecular adsorption and surface chemistry induced by environmental conditions. Molecular adsorption under anoxic conditions was observed to be more favorable, concentrating a large number of molecules on the surface and two different chemical species. In contrast, the presence of oxygen induced an autocatalytic oxidation process on the pyrite surface, which facilitated water binding on pyrite surface and partially blocked molecular adsorption. Pyrite is a highly reactive surface and contains two crucial types of surface functional groups that drive molecular chemistry on the surface depending on the surrounding conditions. Therefore, the system explored in this study holds interesting implications for supporting catalyzed prebiotic chemistry reactions.

  4. Spectroscopic study of cystine adsorption on pyrite surface: From vacuum to solution conditions

    International Nuclear Information System (INIS)

    Sanchez-Arenillas, M.; Mateo-Marti, E.

    2015-01-01

    Highlights: • Successful adsorption of cystine on pyrite surface under several conditions. • Detailed XPS spectroscopic characterization of cystine adsorption on pyrite surface. • Spectroscopy evidence, oxidation and anoxic conditions adjust molecular adsorption. • Molecular chemistry on pyrite is driven depending on the surrounding conditions. • The cystine/pyrite(100) model is in good agreement with Wächtershäuser’s theory. - Abstract: We characterized the adsorption of cystine molecules on pyrite surface via X-ray photoelectron spectroscopy. Anoxic conditions were simulated under ultra-high-vacuum conditions. In contrast, to simulate oxidation conditions, the molecules were adsorbed on pyrite surface from solution. A novel comparative analysis revealed remarkable differences with respect to molecular adsorption and surface chemistry induced by environmental conditions. Molecular adsorption under anoxic conditions was observed to be more favorable, concentrating a large number of molecules on the surface and two different chemical species. In contrast, the presence of oxygen induced an autocatalytic oxidation process on the pyrite surface, which facilitated water binding on pyrite surface and partially blocked molecular adsorption. Pyrite is a highly reactive surface and contains two crucial types of surface functional groups that drive molecular chemistry on the surface depending on the surrounding conditions. Therefore, the system explored in this study holds interesting implications for supporting catalyzed prebiotic chemistry reactions

  5. Reconstructing Sea Surface Conditions in the Bay of Bengal during the Mid-Pleistocene Transition

    Science.gov (United States)

    Lagos, A. D.; Dekens, P.; Reilly, B. T.; Selkin, P. A.; Meynadier, L.; Savian, J. F.

    2017-12-01

    During the Mid-Pleistocene Transition (MPT, 0.8-1.2Ma) Earth's glacial cycles transitioned from responding primarily to 41kyr obliquity cycles to responding to 100kyr eccentricity cycles. In the tropics, sea surface temperature (SST) in the eastern tropical Pacific cooled through the MPT, suggesting a strengthening of the equatorial Pacific zonal temperature gradient (Medina-Elizalde & Lea, 2005). The strong SST gradient would have intensified Walker Cell convection during the MPT and built up latent heat in the western Pacific, which could cause cold SST anomalies in the northern Indian Ocean (Liu et al., 2015). Due to a scarcity of records, it is unclear how climate and oceanic conditions evolved in the Indian Ocean during the MPT. A set of recent IODP expeditions, including 353 and 354, cored sediment from the Bay of Bengal. Several sites recovered by expedition 353 will be ideal for reconstructing monsoon intensity through time, while the expedition 354 cores from a longitudinal transect at 8°N are in a region not directly impacted by changes in freshwater input due to direct precipitation or run off. The sites are influenced by the northeastern migration of equatorial Indian Ocean water via the Southwest Monsoon Current, which supplies significant moisture to the monsoon. Expedition 354's southern Bay of Bengal sites are well situated for better understanding the link between the tropical Indian Ocean and the northern Bay of Bengal. We reconstructed sea surface conditions at IODP site 1452 (8°N, 87°E, 3670m water depth) in the distal Bengal Fan. A 3 meter long section of the core has been identified as the MPT using the Bruhnes/Matuyama, Jaramillo, and Cobb Mountain paleomagnetic reversals (France-Lanord et al., 2016). This section of site 1452 was sampled every 2cm ( 2kyr resolution). Approximately 30 G. sacculifer, a surface dwelling planktonic foraminifera, were picked from the 355-425μm size fraction. We measured Mg/Ca and δ18O on splits of the same

  6. Coccolithophore response to climate and surface hydrography in Santa Barbara Basin, California, AD 1917–2004

    Directory of Open Access Journals (Sweden)

    M. Grelaud

    2009-10-01

    Full Text Available The varved sedimentary AD 1917–2004 record from the depositional center of the Santa Barbara Basin (SBB, California was analyzed with monthly to triannual resolution to yield relative abundances of six coccolithophore species representing at least 96% of the coccolithophore assemblage. Seasonal/annual relative abundances respond to climatic and surface hydrographic conditions in the SBB, whereby (i the three species G. oceanica, H. carteri and F. profunda are characteristic of the strength of the northward flowing warm California Counter Current, (ii the two species G. ericsonii and G. muellerae are associated with the cold equatorward flowing California Current, (iii and E. huxleyi appears to be endemic to the SBB. Spectral analyses on relative abundances of these species show that all are influenced by the El Niño Southern Oscillation (ENSO and/or by the Pacific Decadal Oscillation (PDO. Increased relative abundances of G. oceanica and H. carteri are associated with warm ENSO events, G. muellerae responds to warm PDO events and the abundance of G. ericsonii increases during cold PDO events. Morphometric parameters measured on E. huxleyi, G. muellerae and G. oceanica indicate increasing coccolithophore shell carbonate mass from ~1917 until 2004 concomitant with rising pCO2 and sea surface temperature in the region of the SBB.

  7. The Influence of Runoff and Surface Hydrology on Titan's Weather and Climate

    Science.gov (United States)

    Faulk, S.; Lora, J. M.; Mitchell, J.; Moon, S.

    2017-12-01

    Titan's surface liquid distribution has been shown by general circulation models (GCMs) to greatly influence the hydrological cycle, producing characteristic weather and seasonal climate patterns. Simulations from the Titan Atmospheric Model (TAM) with imposed polar methane "wetlands" reservoirs realistically produce observed cloud features and temperature profiles of Titan's atmosphere, whereas "aquaplanet" simulations with a global methane ocean are not as successful. In addition, wetlands simulations, unlike aquaplanet simulations, demonstrate strong correlations between extreme rainfall behavior and observed geomorphic features, indicating the influential role of precipitation in shaping Titan's surface. The wetlands configuration is, in part, motivated by Titan's large-scale topography featuring low-latitude highlands and high-latitude lowlands, with the implication being that methane may concentrate in the high-latitude lowlands by way of runoff and subsurface flow of a global or regional methane table. However, the extent to which topography controls the surface liquid distribution and thus impacts the global hydrological cycle by driving surface and subsurface flow is unclear. Here we present TAM simulations wherein the imposed wetlands reservoirs are replaced by a surface runoff scheme that allows surface liquid to self-consistently redistribute under the influence of topography. We discuss the impact of surface runoff on the surface liquid distribution over seasonal timescales and compare the resulting hydrological cycle to observed cloud and surface features, as well as to the hydrological cycles of the TAM wetlands and aquaplanet simulations. While still idealized, this more realistic representation of Titan's hydrology provides new insight into the complex interaction between Titan's atmosphere and surface, demonstrates the influence of surface runoff on Titan's global climate, and lays the groundwork for further surface hydrology developments in Titan

  8. Effect of road surfacing condition on tyre life

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2005-07-01

    Full Text Available simple patching of potholes and sealing of cracks to a reseal of the road or even recycling and rehabilitation of the failed sections of the road. These maintenance actions affect the surfacing of the road and therefore the experience of the tyre...

  9. A new CM SAF Solar Surface Radiation Climate Data Set derived from Meteosat Satellite Observations

    Science.gov (United States)

    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.

  10. Modeling large-scale human alteration of land surface hydrology and climate

    Science.gov (United States)

    Pokhrel, Yadu N.; Felfelani, Farshid; Shin, Sanghoon; Yamada, Tomohito J.; Satoh, Yusuke

    2017-12-01

    Rapidly expanding human activities have profoundly affected various biophysical and biogeochemical processes of the Earth system over a broad range of scales, and freshwater systems are now amongst the most extensively altered ecosystems. In this study, we examine the human-induced changes in land surface water and energy balances and the associated climate impacts using a coupled hydrological-climate model framework which also simulates the impacts of human activities on the water cycle. We present three sets of analyses using the results from two model versions—one with and the other without considering human activities; both versions are run in offline and coupled mode resulting in a series of four experiments in total. First, we examine climate and human-induced changes in regional water balance focusing on the widely debated issue of the desiccation of the Aral Sea in central Asia. Then, we discuss the changes in surface temperature as a result of changes in land surface energy balance due to irrigation over global and regional scales. Finally, we examine the global and regional climate impacts of increased atmospheric water vapor content due to irrigation. Results indicate that the direct anthropogenic alteration of river flow in the Aral Sea basin resulted in the loss of 510 km3 of water during the latter half of the twentieth century which explains about half of the total loss of water from the sea. Results of irrigation-induced changes in surface energy balance suggest a significant surface cooling of up to 3.3 K over 1° grids in highly irrigated areas but a negligible change in land surface temperature when averaged over sufficiently large global regions. Results from the coupled model indicate a substantial change in 2 m air temperature and outgoing longwave radiation due to irrigation, highlighting the non-local (regional and global) implications of irrigation. These results provide important insights on the direct human alteration of land surface

  11. Impact of climate change on commercial sector air conditioning energy consumption in subtropical Hong Kong

    International Nuclear Information System (INIS)

    Lam, Tony N.T.; Wan, Kevin K.W.; Wong, S.L.; Lam, Joseph C.

    2010-01-01

    Past and future trend of electricity use for air conditioning in the entire commercial sector in subtropical climates using 1979-2008 measured meteorological data as well as predictions for 2009-2100 from a general circulation model (MIROC3.2-H) was investigated. Air conditioning consumption showed an increasing trend over the past 30 years from 1979 to 2008. Principal component analysis (PCA) of measured and predicted monthly mean dry-bulb temperature, wet-bulb temperature and global solar radiation was conducted to determine a new climatic index Z for 1979-2008 and future 92 years (2009-2100) based on two emissions scenarios B1 and A1B (low and medium forcing). Through regression analysis, electricity use in air conditioning for the 92-year period was estimated. For low forcing, average consumption in 2009-2038, 2039-2068 and 2069-2100 would be, respectively, 5.7%, 12.8% and 18.4% more than the 1979-2008 average, with a mean 12.5% increase for the entire 92-year period. Medium forcing showed a similar increasing trend, but 1-4% more. Standard deviations of the monthly air conditioning consumption were found to be smaller suggesting possible reduction in seasonal variations in future years.

  12. Assessing potential changes of chestnut productivity in Europe under future climate conditions

    Science.gov (United States)

    Calheiros, T.; Pereira, M. G.; Pinto, J. G.; Caramelo, L.; Gomes-Laranjo, J.; Dacamara, C. C.

    2012-04-01

    The European chestnut is cultivated for its nuts and wood. Several studies point to the dependency of chestnut productivity on specific soil and climate characteristics. For instance, this species dislikes chalky and poorly drained soils, appreciates sedimentary, siliceous and acidic to neutral soils. Chestnut trees also seems to appreciate annual mean values of sunlight spanning between 2400 and 2600 h, rainfall ranging between 600 and 1500 mm, mean annual temperature between 9 and 13°C, 27°C being the mean of the maximum temperature (Heiniger and Conedera, 1992; Gomes-Laranjo et al.,2008). The amount of heat between May and October must range between 1800°D and 2400°D (Dinis et al., 2011) . In Poland, the growing season is defined as the period of time when the mean 24-h temperature is greater than 5°C (Wilczynski and Podalski, 2007). In Portugal, maximum photosynthetic activity occurs at 24-28°C for adult trees, but exhibits more than 50% of termoinhibition when the air temperature is above 32°C, which is frequent during summer (Gomes- Laranjo et al., 2006, 2008). Recently Pereira et al (2011) identified a set of meteorological variables/parameters with high impact on chestnut productivity. The main purpose of this work is to assess the potential impacts of future climate change on chestnut productivity in Portugal as well as on European chestnut orchards. First, observed data from the European Climate assessment (ECA) and simulations with the Regional Circulation Model (RCM) COSMO-CLM for recent climate conditions are used to assess the ability of the RCM to model the actual meteorological conditions. Then, ensemble projections from the ECHAM5/COSMO-CLM model chain for two climate scenarios (A1B and B1) are used to estimate the values of relevant meteorological variables and parameters und future climate conditions. Simulated values are then compared with those obtained for present climate. Results point to changes in the spatial and temporal

  13. The Effect of Body Weight on Heat Strain Indices in Hot and Dry Climatic Conditions

    Directory of Open Access Journals (Sweden)

    Habibi

    2016-03-01

    Full Text Available Background Being overweight is a characteristic that may influence a person’s heat exchange. Objectives The purpose of this study was to assess the effect of body weight on heat strain indices in hot and dry climatic conditions. Materials and Methods This study was completed with a sample of 30 participants with normal weights, as well as 25 participants who were overweight. The participants were physically inactive for a period of 120 minutes in a climatic chamber with hot and dry conditions (22 - 32°C and with 40% relative humidity (RH.The physiological strain index (PSI and heat strain score index (HSSI questionnaires were used. Simultaneous measurements were completed during heat exposure for periods of five minutes. The resting periods acted as the initial measurements for 15 minutes. Results In both groups, oral temperature, heart rate, and thermal perceptual responses increased during heat exposure. The means and standard deviations of heart rate and oral temperature were gathered when participants were in hot and dry climatic conditions and were not physically active. The heart rates and oral temperatures were 79.21 ± 5.93 bpm and 36.70 ± 0.45°C, respectively, for those with normal weights. For overweight individuals, the measurements for heart rate and oral temperature reached 82.21 ± 8.9 bpm and 37.84 ± 0.37°C, respectively. Conclusions The results showed that, compared to participants with normal weights, physiological and thermal perceptual responses were higher in overweight participants. Therefore, overweight individuals should avoid hot/dry weather conditions to decrease the amount of heat strain.

  14. Climatic impacts of fresh water hosing under Last Glacial Maximum conditions: a multi-model study

    Directory of Open Access Journals (Sweden)

    M. Kageyama

    2013-04-01

    Full Text Available Fresh water hosing simulations, in which a fresh water flux is imposed in the North Atlantic to force fluctuations of the Atlantic Meridional Overturning Circulation, have been routinely performed, first to study the climatic signature of different states of this circulation, then, under present or future conditions, to investigate the potential impact of a partial melting of the Greenland ice sheet. The most compelling examples of climatic changes potentially related to AMOC abrupt variations, however, are found in high resolution palaeo-records from around the globe for the last glacial period. To study those more specifically, more and more fresh water hosing experiments have been performed under glacial conditions in the recent years. Here we compare an ensemble constituted by 11 such simulations run with 6 different climate models. All simulations follow a slightly different design, but are sufficiently close in their design to be compared. They all study the impact of a fresh water hosing imposed in the extra-tropical North Atlantic. Common features in the model responses to hosing are the cooling over the North Atlantic, extending along the sub-tropical gyre in the tropical North Atlantic, the southward shift of the Atlantic ITCZ and the weakening of the African and Indian monsoons. On the other hand, the expression of the bipolar see-saw, i.e., warming in the Southern Hemisphere, differs from model to model, with some restricting it to the South Atlantic and specific regions of the southern ocean while others simulate a widespread southern ocean warming. The relationships between the features common to most models, i.e., climate changes over the north and tropical Atlantic, African and Asian monsoon regions, are further quantified. These suggest a tight correlation between the temperature and precipitation changes over the extra-tropical North Atlantic, but different pathways for the teleconnections between the AMOC/North Atlantic region

  15. Effects of climatic conditions and soil properties on Cabernet Sauvignon berry growth and anthocyanin profiles.

    Science.gov (United States)

    Cheng, Guo; He, Yan-Nan; Yue, Tai-Xin; Wang, Jun; Zhang, Zhen-Wen

    2014-09-02

    Climatic conditions and soil type have significant influence on grape ripening and wine quality. The reported study was conducted in two "Cabernet Sauvignon (Vitis vinifera L.V)" vineyards located in Xinjiang, a semiarid wine-producing region of China during two vintages (2011 and 2012). The results indicate that soil and climate affected berry growth and anthocyanin profiles. These two localities were within a distance of 5 km from each other and had soils of different physical and chemical composition. For each vineyard, the differences of anthocyanin concentrations, and parameters concerning berry growth and composition between the two years could be explained by different climatic conditions. Soil effect was studied by investigation of differences in berry composition and anthocyanin profiles between the two vineyards in the same year, which could be explained mainly by the different soil properties, vine water and nitrogen status. Specifically, the soils with less water and organic matter produced looser clusters, heavier berry skins and higher TSS, which contributed to the excellent performance of grapes. Compared with 2011, the increases in anthocyanin concentrations for each vineyard in 2012 could be attributed to smaller number of extreme temperature (>35 °C) days and rainfall, lower vine water status and N level. The explanation for higher anthocyanin concentrations in grape skins from the soils with less water and organic matter could be the vine status differences, lighter berry weight and heavier skin weight at harvest. In particular, grapes from the soils with less water and organic matter had higher levels of 3'5'-substituded, O-methylated and acylated anthocyanins, which represented a positive characteristic conferring more stable pigmentation to the corresponding wine in the future. The present work clarifies the effects of climate and soil on berry growth and anthocyanin profiles, thus providing guidance for production of high-quality wine grapes

  16. Effects of Climatic Conditions and Soil Properties on Cabernet Sauvignon Berry Growth and Anthocyanin Profiles

    Directory of Open Access Journals (Sweden)

    Guo Cheng

    2014-09-01

    Full Text Available Climatic conditions and soil type have significant influence on grape ripening and wine quality. The reported study was conducted in two “Cabernet Sauvignon (Vitis vinifera L.V” vineyards located in Xinjiang, a semiarid wine-producing region of China during two vintages (2011 and 2012. The results indicate that soil and climate affected berry growth and anthocyanin profiles. These two localities were within a distance of 5 km from each other and had soils of different physical and chemical composition. For each vineyard, the differences of anthocyanin concentrations, and parameters concerning berry growth and composition between the two years could be explained by different climatic conditions. Soil effect was studied by investigation of differences in berry composition and anthocyanin profiles between the two vineyards in the same year, which could be explained mainly by the different soil properties, vine water and nitrogen status. Specifically, the soils with less water and organic matter produced looser clusters, heavier berry skins and higher TSS, which contributed to the excellent performance of grapes. Compared with 2011, the increases in anthocyanin concentrations for each vineyard in 2012 could be attributed to smaller number of extreme temperature (>35 °C days and rainfall, lower vine water status and N level. The explanation for higher anthocyanin concentrations in grape skins from the soils with less water and organic matter could be the vine status differences, lighter berry weight and heavier skin weight at harvest. In particular, grapes from the soils with less water and organic matter had higher levels of 3′5′-substituded, O-methylated and acylated anthocyanins, which represented a positive characteristic conferring more stable pigmentation to the corresponding wine in the future. The present work clarifies the effects of climate and soil on berry growth and anthocyanin profiles, thus providing guidance for production of

  17. Estimates of late Cenozoic climate change relevant to Earth surface processes in tectonically active orogens

    Science.gov (United States)

    Mutz, Sebastian G.; Ehlers, Todd A.; Werner, Martin; Lohmann, Gerrit; Stepanek, Christian; Li, Jingmin

    2018-04-01

    The denudation history of active orogens is often interpreted in the context of modern climate gradients. Here we address the validity of this approach and ask what are the spatial and temporal variations in palaeoclimate for a latitudinally diverse range of active orogens? We do this using high-resolution (T159, ca. 80 × 80 km at the Equator) palaeoclimate simulations from the ECHAM5 global atmospheric general circulation model and a statistical cluster analysis of climate over different orogens (Andes, Himalayas, SE Alaska, Pacific NW USA). Time periods and boundary conditions considered include the Pliocene (PLIO, ˜ 3 Ma), the Last Glacial Maximum (LGM, ˜ 21 ka), mid-Holocene (MH, ˜ 6 ka), and pre-industrial (PI, reference year 1850). The regional simulated climates of each orogen are described by means of cluster analyses based on the variability in precipitation, 2 m air temperature, the intra-annual amplitude of these values, and monsoonal wind speeds where appropriate. Results indicate the largest differences in the PI climate existed for the LGM and PLIO climates in the form of widespread cooling and reduced precipitation in the LGM and warming and enhanced precipitation during the PLIO. The LGM climate shows the largest deviation in annual precipitation from the PI climate and shows enhanced precipitation in the temperate Andes and coastal regions for both SE Alaska and the US Pacific Northwest. Furthermore, LGM precipitation is reduced in the western Himalayas and enhanced in the eastern Himalayas, resulting in a shift of the wettest regional climates eastward along the orogen. The cluster-analysis results also suggest more climatic variability across latitudes east of the Andes in the PLIO climate than in other time slice experiments conducted here. Taken together, these results highlight significant changes in late Cenozoic regional climatology over the last ˜ 3 Myr. Comparison of simulated climate with proxy-based reconstructions for the MH and

  18. Target surface condition during reactive glow discharge sputtering of copper

    International Nuclear Information System (INIS)

    Depla, D; Haemers, J; Gryse, R De

    2002-01-01

    During reactive glow discharge sputtering of copper in an argon/nitrogen plasma, we noticed an abrupt change of the target voltage and the deposition rate when the nitrogen concentration in the plasma exceeds a critical value. To explain this behaviour, the target surface after reactive glow discharge sputtering was examined by x-ray photoelectron spectroscopy (XPS). An experimental arrangement was constructed that allows direct transfer of the glow discharge cathode to the XPS analysis chamber without air exposure. These XPS measurements revealed that several different chemical states of nitrogen are present in the layer that forms on the target surface. The relative concentration of these different states changes when the critical nitrogen concentration in the plasma is exceeded

  19. Surface CO2 Exchange Dynamics across a Climatic Gradient in McKenzie Valley: Effect of Landforms, Climate and Permafrost

    Directory of Open Access Journals (Sweden)

    Natalia Startsev

    2016-11-01

    Full Text Available Northern regions are experiencing considerable climate change affecting the state of permafrost, peat accumulation rates, and the large pool of carbon (C stored in soil, thereby emphasizing the importance of monitoring surface C fluxes in different landform sites along a climate gradient. We studied surface net C exchange (NCE and ecosystem respiration (ER across different landforms (upland, peat plateau, collapse scar in mid-boreal to high subarctic ecoregions in the Mackenzie Valley of northwestern Canada for three years. NCE and ER were measured using automatic CO2 chambers (ADC, Bioscientific LTD., Herts, England, and soil respiration (SR was measured with solid state infrared CO2 sensors (Carbocaps, Vaisala, Vantaa, Finland using the concentration gradient technique. Both NCE and ER were primarily controlled by soil temperature in the upper horizons. In upland forest locations, ER varied from 583 to 214 g C·m−2·year−1 from mid-boreal to high subarctic zones, respectively. For the bog and peat plateau areas, ER was less than half that at the upland locations. Of SR, nearly 75% was generated in the upper 5 cm layer composed of live bryophytes and actively decomposing fibric material. Our results suggest that for the upland and bog locations, ER significantly exceeded NCE. Bryophyte NCE was greatest in continuously waterlogged collapsed areas and was negligible in other locations. Overall, upland forest sites were sources of CO2 (from 64 g·C·m−2·year−1 in the high subarctic to 588 g C·m−2·year−1 in mid-boreal zone; collapsed areas were sinks of C, especially in high subarctic (from 27 g·C·m−2 year−1 in mid-boreal to 86 g·C·m−2·year−1 in high subarctic and peat plateaus were minor sources (from 153 g·C·m−2·year−1 in mid-boreal to 6 g·C·m−2·year−1 in high subarctic. The results are important in understanding how different landforms are responding to climate change and would be useful in modeling the

  20. Evaluation of Haney-Type Surface Thermal Boundary Conditions Using a Coupled Atmosphere and Ocean Model

    National Research Council Canada - National Science Library

    Chu, Peter C; Chen, Yuchun; Lu, Shihua

    2001-01-01

    ... (Russell et al,, 1995) was used to verify the validity of Haney-type surface thermal boundary condition, which linearly connects net downward surface heat flux Q to air / sea temperature difference DeltaT by a relaxation coefficient K...

  1. Mars analog minerals' spectral reflectance characteristics under Martian surface conditions

    Science.gov (United States)

    Poitras, J. T.; Cloutis, E. A.; Salvatore, M. R.; Mertzman, S. A.; Applin, D. M.; Mann, P.

    2018-05-01

    We investigated the spectral reflectance properties of minerals under a simulated Martian environment. Twenty-eight different hydrated or hydroxylated phases of carbonates, sulfates, and silica minerals were selected based on past detection on Mars through spectral remote sensing data. Samples were ground and dry sieved to <45 μm grain size and characterized by XRD before and after 133 days inside a simulated Martian surface environment (pressure 5 Torr and CO2 fed). Reflectance spectra from 0.35 to 4 μm were taken periodically through a sapphire (0.35-2.5 μm) and zinc selenide (2.5-4 μm) window over a 133-day period. Mineral stability on the Martian surface was assessed through changes in spectral characteristics. Results indicate that the hydrated carbonates studied would be stable on the surface of Mars, only losing adsorbed H2O while maintaining their diagnostic spectral features. Sulfates were less stable, often with shifts in the band position of the SO, Fe, and OH absorption features. Silicas displayed spectral shifts related to SiOH and hydration state of the mineral surface, while diagnostic bands for quartz were stable. Previous detection of carbonate minerals based on 2.3-2.5 μm and 3.4-3.9 μm features appears to be consistent with our results. Sulfate mineral detection is more questionable since there can be shifts in band position related to SO4. The loss of the 0.43 μm Fe3+ band in many of the sulfates indicate that there are fewer potential candidates for Fe3+ sulfates to permanently exist on the Martian surface based on this band. The gypsum sample changed phase to basanite during desiccation as demonstrated by both reflectance and XRD. Silica on Mars has been detected using band depth ratio at 1.91 and 1.96 μm and band minimum position of the 1.4 μm feature, and the properties are also used to determine their age. This technique continues to be useful for positive silica identifications, however, silica age appears to be less consistent

  2. Behavior of crushed rock aggregates used in road construction exposed to cold climate conditions

    Science.gov (United States)

    Kuznetsova, Elena; Pérez Fortes, Ana Patricia; Anastasio, Sara; Willy Danielsen, Svein

    2016-04-01

    Presently, about 90% of the aggregate production in Europe comes from naturally occurring resources: quarries and pits. Due to the increased demand for sand and gravel for construction purposes, not only in building but also in road construction, the last decade has seen a significant trend towards the use of more crushed rock aggregates. This resource has been more and more preferred to sand and gravel thanks to the significant technological development of its process and use phase. The performance of the aggregates is generally evaluated depending on three main factors: the geological origin (mineral composition, texture, structure, degree of weathering), the aggregate processing (crushing, sieving, washing, storing) and the user technology for a specific area of use (e.g. road construction, asphalt binders). Nevertheless climatic conditions should carefully be taken into account in application such as road construction. Large temperature gradients and high levels of humidity are known to significantly affect the performance of the material. Although the problem is, at least in the asphalt field, considered mostly from the binder point of view, this article aims to investigate the effect of aggregate properties on road performance in cold climatic conditions. Two different climatic areas will be taken into account: Norway and Spain. While both these countries are listed among the main European producers of aggregates, they represent significantly different climatic regions. While Norwegian weather is characterized by humid cold winters and relatively mild summers, Spain has temperate climate with cold regions in mountainous and internal areas. Both countries have been significantly affected by climate change with increasing temperature variations and instability. At the same time, similar winter maintenance measures, including the use of a considerable amount of solid and liquid chemicals to avoid ice formation (e.g. NaCl) and/or to provide better friction, are

  3. Untreated runoff quality from roof and road surfaces in a low intensity rainfall climate.

    Science.gov (United States)

    Charters, Frances J; Cochrane, Thomas A; O'Sullivan, Aisling D

    2016-04-15

    Sediment and heavy metals in stormwater runoff are key pollutants of urban waterways, and their presence in stormwater is driven by climatic factors such as rainfall intensity. This study describes the total suspended solids (TSS) and heavy metal concentrations found in runoff from four different urban surfaces within a residential/institutional catchment, in a climate where rainfall is typically of low intensity (runoff quality from a compilation of international studies. The road runoff had the highest TSS concentrations, while copper and galvanized roof runoff had the highest copper and zinc concentrations, respectively. Pollutant concentrations were found to be significantly different between surfaces; quantification and prediction of pollutant contributions from urban surfaces should thus take account of the different surface materials, instead of being aggregated into more generalized categories such as land use. The TSS and heavy metal concentrations were found to be at the low to medium end of ranges observed internationally, except for total copper and zinc concentrations generated by dissolution of copper and galvanized roofing material respectively; these concentrations were at least as high as those reported internationally. TSS wash-off from the roofs was seen to be a source-limited process, where all available TSS is washed off during the rain event despite the low intensity rainfall, whereas both road TSS and heavy metals wash-off from roof and road surfaces appeared to all be transport-limited and therefore some carryover of pollutants occurs between rain events. A first flush effect was seen from most surfaces for TSS, but not for heavy metals. This study demonstrates that in low intensity rainfall climates, quantification of untreated runoff quality from key individual surface types in a catchment are needed to enable development of targeted and appropriately sized stormwater treatment systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. A Database for Climatic Conditions around Europe for Promoting GSHP Solutions

    Directory of Open Access Journals (Sweden)

    Michele De Carli

    2018-02-01

    Full Text Available Weather plays an important role for energy uses in buildings. For this reason, it is required to define the proper boundary conditions in terms of the different parameters affecting energy and comfort in buildings. They are also the basis for determining the ground temperature in different locations, as well as for determining the potential for using geothermal energy. This paper presents a database for climates in Europe that has been used in a freeware tool developed as part of the H2020 research project named “Cheap-GSHPs”. The standard Köppen-Geiger climate classification has been matched with the weather data provided by the ENERGYPLUS and METEONORM software database. The Test Reference Years of more than 300 locations have been considered. These locations have been labelled according to the degree-days for heating and cooling, as well as by the Köppen-Geiger scale. A comprehensive data set of weather conditions in Europe has been created and used as input for a GSHP sizing software, helping the user in selecting the weather conditions closest to the location of interest. The proposed method is based on lapse rates and has been tested at two locations in Switzerland and Ireland. It has been demonstrated as quite valid for the project purposes, considering the spatial distribution and density of available data and the lower computing load, in particular for locations where altitude is the main factor controlling on the temperature variations.

  5. Variation of moisture content of some varnished woods in indoor climatic conditions

    Directory of Open Access Journals (Sweden)

    Kemal Üçüncü

    2017-11-01

    Full Text Available In this study, moisture change of varnished wood of black poplar (Populus nigra and yellow pine (Pinus silvestris L. used in indoor climate conditions with central heating in Trabzon (Turkey were investigated. 300 mm length wood specimens, with cross section of 12.5 mm in tangential and in radial and with the square sections of 25mm and 50 mm, were obtained from two species grown in Kanuni Campus of the Karadeniz Technical University. In this research, un-varnished wood samples were also used for reference. The wood moisture content was determined by the weighing method, the wood equilibrium moisture content by the Hailwood-Horrobin equation, and the relative humidity in the indoor climatic conditions by humid air thermodynamic principles. As a result; it was observed that the moisture content of varnished wood samples has a strong relationship with equilibrium moisture content, temperature and relative humidity. It was found that the moisture content of varnished woods was higher than the moisture content of un-varnished woods in the same climatic conditions. It was observed that the difference between the monthly average moisture content was lower in varnished woods in proportion to un-varnished woods. According to these results, it can be indicated that it would be more appropriate to select higher moisture content in the drying of wood than the equilibrium moisture content. Such an application would also reduce drying costs. Further, it can be recommended to use varnished wood in various applications because the low change range of average moisture content can affect the swelling or shrinking of wood.

  6. New insights into thermal growing conditions of Portuguese grapevine varieties under changing climates

    Science.gov (United States)

    Santos, João A.; Costa, Ricardo; Fraga, Helder

    2018-03-01

    New decision support tools for Portuguese viticulture are urging under a climate change context. In the present study, heat and chilling accumulation conditions of a collection of 44 grapevine cultivars currently grown in Portugal are assessed at very high spatial resolution ( 1 km) and for 1981-2015. Two bioclimatic indices that incorporate non-linear plant-temperature relationships are selected for this purpose: growing degree hours—GDH (February-October) and chilling portions—CP (October-February). The current thermal growing conditions of each variety are examined and three clusters of grapevine cultivars are identified based on their GDH medians, thus assembling varieties with close heat accumulation requirements and providing more physiologically consistent information when compared to previous studies, as non-linear plant-temperature relationships are herein taken into account. These new clusters are also a complement to previous bioclimatic zoning. Ensemble mean projections under two anthropogenic-driven scenarios (RCP4.5 and RCP8.5, 2041-2070), from four EURO-CORDEX simulations, reveal a widespread increase of GDH and decrease of CP, but with spatial heterogeneities. The spatial variability of these indices throughout Portugal is projected to decrease (strongest increases of GDH in the coolest regions of the northeast) and to increase (strongest decreases of CP in the warmest regions of the south and west), respectively. The typical heat accumulation conditions of each cluster are projected to gradually shift north-eastwards and to higher-elevation areas, whereas insufficient chilling may represent a new challenge in warmer future climates. An unprecedented level of detail for a large collection of grapevine varieties in Portugal is provided, thus promoting a better planning of climate change adaptation measures.

  7. Long-Term Variability of Surface Albedo and Its Correlation with Climatic Variables over Antarctica

    Directory of Open Access Journals (Sweden)

    Minji Seo

    2016-11-01

    Full Text Available The cryosphere is an essential part of the earth system for understanding climate change. Components of the cryosphere, such as ice sheets and sea ice, are generally decreasing over time. However, previous studies have indicated differing trends between the Antarctic and the Arctic. The South Pole also shows internal differences in trends. These phenomena indicate the importance of continuous observation of the Polar Regions. Albedo is a main indicator for analyzing Antarctic climate change and is an important variable with regard to the radiation budget because it can provide positive feedback on polar warming and is related to net radiation and atmospheric heating in the mainly snow- and ice-covered Antarctic. Therefore, in this study, we analyzed long-term temporal and spatial variability of albedo and investigated the interrelationships between albedo and climatic variables over Antarctica. We used broadband surface albedo data from the Satellite Application Facility on Climate Monitoring and data for several climatic variables such as temperature and Antarctic oscillation index (AAO during the period of 1983 to 2009. Time series analysis and correlation analysis were performed through linear regression using albedo and climatic variables. The results of this research indicated that albedo shows two trends, west trend and an east trend, over Antarctica. Most of the western side of Antarctica showed a negative trend of albedo (about −0.0007 to −0.0015 year−1, but the other side showed a positive trend (about 0.0006 year−1. In addition, albedo and surface temperature had a negative correlation, but this relationship was weaker in west Antarctica than in east Antarctica. The correlation between albedo and AAO revealed different relationships in the two regions; west Antarctica had a negative correlation and east Antarctica showed a positive correlation. In addition, the correlation between albedo and AAO was weaker in the west. This

  8. The importance of moisture buffering for indoor climate and energy conditions of buildings

    DEFF Research Database (Denmark)

    Rode, Carsten; Grau, Karl

    2007-01-01

    A new Nordic test method specifies a test protocol for determination of the so-called Moisture Buffer Value (MBV) of building materials. But how important is moisture buffering to determine the indoor humidity condition of buildings? The paper will present the new MBV-definition. Although...... buffering to save energy by reducing the requirement for ventilation in periods, and still maintain the same quality of the indoor climate? The paper will outline some possibilities for analytical/numerical calculations, and will answer some of the posed questions on the probable benefit of taking moisture...

  9. Solar water heaters: possibilities of using in the climatic conditions of the Russia medium area

    International Nuclear Information System (INIS)

    Popel', O.S.; Frid, S.E.

    2001-01-01

    On the basis of mathematical simulation of the simplest solar water heating facility using up-to-date software and data of typical meteorological year it was shown that under the real climatic conditions peculiar to Russia central region it is appropriate to use seasonal solar water heaters operating from March up to September. It is shown that to promote solar water heaters in the Russian market one should elaborate engineering approaches and should introduce new materials ensuring reduction of cost of solar water heaters with the availability of high quality and durability [ru

  10. Microclimatic conditions at the external surface of building envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Kragh, M.K.

    1998-12-31

    The project is described, the motivation for the research and the microclimate is defined in relation to both building physics research and applications. Air temperatur, air humidity, solar radiation and air velocity are briefly considered, whilst driving rain and long-wave radiation are described in more detail. Convective heat transfer and surface coefficients are discussed, although they are not microclimatic factors, merely resulting from combinations of such factors. They are included as they are important in relation to transfer of heat and moisture at the surface of the building envelope. Driving rain measurement is the main area of interest, including development of measurement equipment. Long-wave irradiation is measured and compared with empirical formulae from the literature. Window convection heat transfer is another main area of interest. Nocturnal convective heat transfer from a double pane glazing is studied and measurement principles are discussed. Finally, a compilation of meteorological data for hygrothermal simulations, including estimation of driving rain, is described. System error estimation in relation to the window convection measurements, design notes on an apparatus for external convection measurement, formulae for conversion of relative humitity and dry-bulb temperature into dew point temperature. (EG) 66 refs.

  11. Microclimatic conditions at the external surface of building envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Kragh, M K

    1999-12-31

    The project is described, the motivation for the research and the microclimate is defined in relation to both building physics research and applications. Air temperatur, air humidity, solar radiation and air velocity are briefly considered, whilst driving rain and long-wave radiation are described in more detail. Convective heat transfer and surface coefficients are discussed, although they are not microclimatic factors, merely resulting from combinations of such factors. They are included as they are important in relation to transfer of heat and moisture at the surface of the building envelope. Driving rain measurement is the main area of interest, including development of measurement equipment. Long-wave irradiation is measured and compared with empirical formulae from the literature. Window convection heat transfer is another main area of interest. Nocturnal convective heat transfer from a double pane glazing is studied and measurement principles are discussed. Finally, a compilation of meteorological data for hygrothermal simulations, including estimation of driving rain, is described. System error estimation in relation to the window convection measurements, design notes on an apparatus for external convection measurement, formulae for conversion of relative humitity and dry-bulb temperature into dew point temperature. (EG) 66 refs.

  12. Changes in Hydrologic Conditions and Greenhouse Gas Emissions in Circumpolar Regions due to Climate Change Induced Permafrost Retreat

    Energy Technology Data Exchange (ETDEWEB)

    Whiticar, M. J. [School of Earth and Ocean Sciences, University of Victoria, Victoria (Canada); Bhatti, J.; Startsev, N. [Northern Forestry Centre, St Edmonton, AB (Canada)

    2013-07-15

    Thawing permafrost peatlands substantially influence Canadian northern ecosystems by changing the regional hydrology and mobilizing the vast carbon (C) reserves that results in increased greenhouse gas (GHGs) emissions to the atmosphere. With permafrost distribution controlled largely by topography and climate, our International polar y ear (IPY) study intensively monitored the local C cycling processes and GHG fluxes associated with different hydrologic and permafrost environments at 4 sites along a climatic gradient extending from the Isolated patches permafrost Zone (northern alberta), to the continuous permafrost Zone (Inuvik, NWT). Each site encompasses a local gradient from upland forest and peat plateau to collapse scar. Our multi-year measurements of peatland profiles and flux chambers for CH{sub 4} and CO{sub 2} concentrations and stable isotope ratios indicate processes, including methanogenesis, methanotrophy, transport and emission that control the distribution of these GHGs. These relationships are modulated by fluctuating local soil water and corresponding ecosystem conditions. The gas geochemistry shows that significant surface CH{sub 4} production occurs by both hydrogenotrophic and acetoclastic methanogenesis in submerged, anaerobic peats, e.g., collapse scars, whereas methane oxidation is restricted to aerobic, drier environments, e.g., upland sites and peat-atmosphere interface. The most active methanogenesis and emissions are in areas of actively thawing permafrost contrasting with sites under continuous permafrost. This degree of methanogenesis is being amplified by the increased rate of Arctic warming and the rapid retreat of permafrost in canada's arctic (approximately. 2.5 km/a). (author)

  13. Phytoremdiation Species And Their Modification Under By Weed Varying Climatic Condition A Changing Scenario

    Directory of Open Access Journals (Sweden)

    Anita Singh

    2015-08-01

    Full Text Available Abstract The major reasons for environmental contamination are population explosion increase in industrial and other urban activities. One of the consequent effect of these activities is heavy metal pollution. It is one of the serious issue to be discussed by the scientists and academicians that how to solve this problem to protect the environment. As heavy metals are non-biodegradable so they require effective cleanup technology. Most of the traditional methods such as excavation solidification and burial are very costly or they simply involve the isolation of the metals from contaminated sites. Among different technologies phytoremediation is best approach for removing metal contamination from environment. It involves plants to remove detoxify or immobilize metals from environment. Weed plants are found to be play very important role in metal remediation. They get affected by climatic variation which is also a consequent effect of environmental pollution. The physiology of plants as well as physiochemical properties of soil gets affected by varying climatic condition. Therefore the present review gives the information on metal remediation processes and how these process particularly phytoremediation by weed plants get affected by climatic changes.

  14. Wall conditioning and plasma surface interactions in DIII-D

    International Nuclear Information System (INIS)

    Jackson, G.L.; Petersen, P.I.; Schaffer, M.S.; Taylor, P.L.; Taylor, T.S.; Doyle, B.L.; Walsh, D.S.; Hill, D.N.; Hsu, W.L.; Winter, J.

    1990-09-01

    Wall conditioning is used in DIII-D for both reduction of impurity influxes and particle control. The methods used include: baking, pulsed discharge cleaning, hydrogen glow cleaning, helium and neon glow conditioning, and carbonization. Helium glow wall conditioning applied before every tokamak discharge has been effective in impurity removal and particle control and has significantly expanded the parameter space in which DIII-D operates to include limiter and ohmic H-mode discharges and higher β T at low q. The highest values of divertor plasma current (3.0 MA) and stored energy (3.6 MJ) and peaked density profiles in H-mode discharges have been observed after carbonization. Divertor physics studies in DIII-D include sweeping the X-point to reduce peak heat loads, measurement of particle and heat fluxes in the divertor region, and erosion studies. The DIII-D Advanced Divertor has been installed and bias and baffle experiments will begin in the fall of 1991. 15 refs., 4 figs

  15. Climate and surface water hydrology baseline data for Aurora Mine EIA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    A climate and hydrology database was assembled to describe the existing climatic and surface water hydrological characteristics of the proposed Aurora Mine area in Leases 10, 12, 13, 31, and 34 east of the Athabasca River near Fort McKay. The study was based upon data available from the regional hydrometeorological monitoring network operated by the Governments of Canada and Alberta. The study also included the installation and monitoring of one climate station and five streamflow gauging stations on small watersheds in the area. The representative climatic and hydrologic characteristics of the area, including precipitation, evaporation, evapotranspiration, temperature and wind, were determined. Streamflow characteristics such as flood frequencies, low flow frequencies, water yield and flow durations representative of large gauged watersheds within the study area were also determined. The results offer a good basis for preliminary design of surface water management systems. It was recommended that the monitoring program should be continued to monitor potential environmental impacts of proposed development activities. 9 refs., 29 tabs., 32 figs.

  16. Dynamical Downscaling over Siberia: Is there an added value in representing recent climate conditions?

    Science.gov (United States)

    Klehmet, K.; Rockel, B.

    2012-04-01

    The analysis of long-term changes and variability of climate variables for the large areal extent of Siberia - covering arctic, subarctic and temperate northern latitudes - is hampered by the sparseness of in-situ observations. To counteract this deficiency we aimed to provide a reconstruction of regional climate for the period 1948-2010 getting homogenous, consistent fields of various terrestrial and atmospheric parameters for Siberia. In order to obtain in addition a higher temporal and spatial resolution than global datasets can provide, we performed the reconstruction using the regional climate model COSMO-CLM (climate mode of the limited area model COSMO developed by the German weather service). However, the question arises whether the dynamically downscaled data of reanalysis can improve the representation of recent climate conditions. As global forcing for the initialization and the regional boundaries we use NCEP-1 Reanalysis of the National Centers for Environmental Prediction since it has the longest temporal data coverage among the reanalysis products. Additionally, spectral nudging is applied to prevent the regional model from deviating from the prescribed large-scale circulation within the whole simulation domain. The area of interest covers a region in Siberia, spanning from the Laptev Sea and Kara Sea to Northern Mongolia and from the West Siberian Lowland to the border of Sea of Okhotsk. The current horizontal resolution is of about 50 km which is planned to be increased to 25 km. To answer the question, we investigate spatial and temporal characteristics of temperature and precipitation of the model output in comparison to global reanalysis data (NCEP-1, ERA40, ERA-Interim). As reference Russian station data from the "Global Summary of the Day" data set, provided by NCDC, is used. Temperature is analyzed with respect to its climatologically spatial patterns across the model domain and its variability of extremes based on climate indices derived

  17. Performance evaluation of a solar adsorption chiller under different climatic conditions

    International Nuclear Information System (INIS)

    Alahmer, Ali; Wang, Xiaolin; Al-Rbaihat, Raed; Amanul Alam, K.C.; Saha, B.B.

    2016-01-01

    Highlights: • A solar adsorption cooling system was studied at different climatic conditions. • Effect of hot water temperature and flow rate on system performance was evaluated. • Solar collector area and tilting angle largely affected the system performance. • Economics of the solar adsorption cooling was analysed at real weather conditions. • Adsorption cooling could be potentially applied in cities with good solar radiation. - Abstract: Performance of an adsorption cooling system driven by solar thermal energy was studied under different climatic conditions. The effects of solar collector area, collector slope, hot water temperature and flow rate on the system performance were investigated using the real-time weather data of two cities: Perth, Australia (a representative city in the southern hemisphere) and Amman, Jordan (a representative city in the northern hemisphere). The simulation results showed that the two cities had similar solar radiation during the summer period and that the solar adsorption chiller could reliably provide cooling at a reasonably high system COP. For residential cooling with a total CPC (Compound Parabolic Collector) solar collector area of 36.22 m"2, the average system COP was 0.491 for Perth weather conditions and 0.467 for Amman weather conditions, respectively while the cooling capacity was 10.3 kW for Perth and 8.46 kW for Amman, respectively at peak times. Optimum performance occurred when the system run with the CPC collector slope of around 30°, the solar water storage tank volume of 1.4 m"3, inlet hot water temperature of 80 °C, and a hot water flow rate of 0.33 kg/s. An economic analysis was further investigated and the results showed that the solar driven adsorption cooling system could reduce the electricity consumption for Perth and Amman cities by 34% and 28%, respectively in comparison to a conventional vapour compression cooling system.

  18. Thermal comfort in air-conditioned mosques in the dry desert climate

    Energy Technology Data Exchange (ETDEWEB)

    Al-ajmi, Farraj F. [Department of Civil Engineering, College of Technological Studies, Shuwaikh 70654 (Kuwait)

    2010-11-15

    In Kuwait, as in most countries with a typical dry desert climate, the summer season is long with a mean daily maximum temperature of 45 C. Centralized air-conditioning, which is generally deployed from the beginning of April to the end of October, can have tremendous impact on the amount of electrical energy utilized to mechanically control the internal environment in mosque buildings. The indoor air temperature settings for all types of air-conditioned buildings and mosque buildings in particular, are often calculated based on the analytical model of ASHRAE 55-2004 and ISO 7730. However, a field study was conducted in six air-conditioned mosque buildings during the summers of 2007 to investigate indoor climate and prayers thermal comfort in state of Kuwait. The paper presents statistical data about the indoor environmental conditions in Kuwait mosque buildings, together with an analysis of prayer thermal comfort sensations for a total of 140 subjects providing 140 sets of physical measurements and subjective questionnaires were used to collect data. Results show that the neutral temperature (T{sub n}) of the prayers is found to be 26.1 C, while that for PMV is 23.3 C. Discrepancy of these values is in fact about 2.8 C higher than those predicted by PMV model. Therefore, thermal comfort temperature in Kuwait cannot directly correlate with ISO 7730 and ASHRAE 55-2004 standards. Findings from this study should be considered when designing air conditioning for mosque buildings. This knowledge can contribute towards the development of future energy-related design codes for Kuwait. (author)

  19. Environmental conditioning on uranium surface distribution in the tropical region

    International Nuclear Information System (INIS)

    Silva, Heitor Evangelista da; Licinio, Marcus V.S.; Miranda, Marcio R.

    2001-01-01

    Based on a high resolution aerogammaspectrometer survey over the State of Rio de Janeiro, it is presented an associative study of equivalent uranium concentration and environmental parameters. The aspects considered in this study included geological domains like Sandys, Gnaisses, Granites, Xists; soils domains like Organic and Alluvial ones, Litolic, Glei, Podzolic, Red-yellow, Latossolo, Planossolo, Red bruizem, Cambissolo, Hidromorphic Podzol, Yellow latossolo; geomorphology (Coast Plains and River Accumulation Land, Coast Tabulators, Pomba-Muriae Rivers Spread Depression, Northern Mantiqueira, main Hills and Coastal Rock Massifs, Steep slopes and Reverses of Serra do Mar Mountain Range ,Serra dos Orgaos Mountain Range and Bocaina Tablelands), Paraiba do Sul Crests Alignment, Medium Paraiba do Sul Depression); influence of mean annual rain intensity and hydrographical categories were also evaluated. Geoprocessing of each environmental data base at the same cartographical base of uranium surface distribution was the basic methodology employed. (author)

  20. Climate and Health Vulnerability to Vector-Borne Diseases: Increasing Resilience under Climate Change Conditions in Africa

    Science.gov (United States)

    Ceccato, P.

    2015-12-01

    The International Research Institute for Climate and Society (IRI), the City University of New York (CUNY) and NASA Jet Propulsion Laboratory (JPL) in collaboration with NASA SERVIR are developing tools to monitor climate variables (precipitation, temperature, vegetation, water bodies, inundation) that help projects in Africa to increase resilience to climate change for vector-borne diseases ( malaria, trypanosomiasis, leishmaniasis, and schistosomiasis). Through the development of new products to monitor precipitation, water bodies and inundation, IRI, CUNY and JPL provide tools and capacity building to research communities; ministries of health; the WMO Global Framework for Climate and Services; and World Health Organization in Africa to: 1) Develop research teams' ability to appropriately use climate data as part of their research 2) Enable research teams and ministries to integrate climate information into social and economic drivers of vulnerability and opportunities for adaptation to climate change 3) Inform better policies and programs for climate change adaptation. This oral presentation will demonstrate how IRI, CUNY, and JPL developed new products, tools and capacity building to achieve the three objectives mentioned above with examples in South Africa, Zimbabwe, Tanzania and Malawi.

  1. Condition Assessment for Wastewater Pipes: Method for Assessing Cracking and Surface Damage of Concrete Pipes

    OpenAIRE

    Hauge, Petter

    2013-01-01

    The objective of the Master Thesis has been to provide an improved method for condition assessment, which will give a better correlation between Condition class and actual Condition of concrete pipes with cracking and/or surface damages. Additionally improvement of the characterization of cracking (SR) and surface (KO) damages was a sub goal.Based on the findings described in my Thesis and my Specialization Project (Hauge 2012), I recommend that the Norwegian condition assessment method based...

  2. Assimilation and High Resolution Forecasts of Surface and Near Surface Conditions for the 2010 Vancouver Winter Olympic and Paralympic Games

    Science.gov (United States)

    Bernier, Natacha B.; Bélair, Stéphane; Bilodeau, Bernard; Tong, Linying

    2014-01-01

    A dynamical model was experimentally implemented to provide high resolution forecasts at points of interests in the 2010 Vancouver Olympics and Paralympics Region. In a first experiment, GEM-Surf, the near surface and land surface modeling system, is driven by operational atmospheric forecasts and used to refine the surface forecasts according to local surface conditions such as elevation and vegetation type. In this simple form, temperature and snow depth forecasts are improved mainly as a result of the better representation of real elevation. In a second experiment, screen level observations and operational atmospheric forecasts are blended to drive a continuous cycle of near surface and land surface hindcasts. Hindcasts of the previous day conditions are then regarded as today's optimized initial conditions. Hence, in this experiment, given observations are available, observation driven hindcasts continuously ensure that daily forecasts are issued from improved initial conditions. GEM-Surf forecasts obtained from improved short-range hindcasts produced using these better conditions result in improved snow depth forecasts. In a third experiment, assimilation of snow depth data is applied to further optimize GEM-Surf's initial conditions, in addition to the use of blended observations and forecasts for forcing. Results show that snow depth and summer temperature forecasts are further improved by the addition of snow depth data assimilation.

  3. Effect of Residue Nitrogen Concentration and Time Duration on Carbon Mineralization Rate of Alfalfa Residues in Regions with Different Climatic Conditions

    Directory of Open Access Journals (Sweden)

    saeid shafiei

    2017-08-01

    Full Text Available Introduction Various factors like climatic conditions, vegetation, soil properties, topography, time, plant residue quality and crop management strategies affect the decomposition rate of organic carbon (OC and its residence time in soil. Plant residue management concerns nutrients recycling, carbon recycling in ecosystems and the increasing CO2 concentration in the atmosphere. Plant residue decomposition is a fundamental process in recycling of organic matter and elements in most ecosystems. Soil management, particularly plant residue management, changes soil organic matter both qualitatively and quantitatively. Soil respiration and carbon loss are affected by soil temperature, soil moisture, air temperature, solar radiation and precipitation. In natural agro-ecosystems, residue contains different concentrations of nitrogen. It is important to understand the rate and processes involved in plant residue decomposition, as these residues continue to be added to the soil under different weather conditions, especially in arid and semi-arid climates. Material and methods Organic carbon mineralization of alfalfa residue with different nitrogen concentrations was assessed in different climatic conditions using split-plot experiments over time and the effects of climate was determined using composite analysis. The climatic conditions were classified as warm-arid (Jiroft, temperate arid (Narab and cold semi-arid (Sardouiyeh using cluster analysis and the nitrogen (N concentrations of alfalfa residue were low, medium and high. The alfalfa residue incubated for four different time periods (2, 4, 6 and 8 months. The dynamics of organic carbon in different regions measured using litter bags (20×10 cm containing 20 g alfalfa residue of 2-10 mm length which were placed on the soil surface. Results and discussion The results of this study showed that in a warm-arid (Jiroft, carbon loss and the carbon decomposition rate constant were low in a cold semi

  4. Future climate impact on unfavorable meteorological conditions for the dispersion of air pollution in Brussels

    Science.gov (United States)

    De Troch, Rozemien; Berckmans, Julie; Giot, Olivier; Hamdi, Rafiq; Termonia, Piet

    2015-04-01

    Belgium is one of the several countries in Europe where air quality levels of different pollutants such as ozone, NOx, and Particulate Matter (PM) still exceed the prescribed European norms multiple times a year (EEA, 2014). These pollution peaks have a great impact on health and environment, in particular in large cities and urban environments. It is well known that observed concentrations of air pollutants are strongly influenced by emissions and meteorological conditions and therefore is sensitive to climate change. As the effects of global climate change are increasingly felt in Belgium, policy makers express growing interest in quantifying its effect on air pollution and the effort required to meet the air quality targets in the next years and decennia (Lauwaet et al., 2014). In this study, two different stability indices are calculated for a 9-year period using present (1991-1999) and future (2047-2055) climate data that has been obtained from a dynamically downscaling of Global Climate Model data from the Arpège model using the ALARO model at 4 km spatial resolution. The ALARO model is described in detail in previous validation studies from De Troch et al. (2013) and Hamdi et al. (2013). The first index gives a measure of the horizontal and vertical transport of nonreactive pollutants in stable atmospheric conditions and has been proposed and tested by Termonia and Quinet (2004). It gives a characteristic length scale l which is the ratio of the mean horizontal wind speed and the Brunt-Väisälä frequency. In this way low values for l in the lower part of the boundary layer during an extended time span of 12 hours, correspond to calm situations and a stable atmosphere and thus indicate unfavorable conditions for the dispersion of air pollution. This transport index is similar to an index used in an old Pasquill-type scheme but is more convenient to use to detect the strongest pollution peaks. The well known Pasquill classes are also calculated in order to

  5. Arctic Storms and Their Influence on Surface Climate in the Chukchi-Beaufort Seas

    Science.gov (United States)

    Yang, Y.; Zhang, X.; Rinke, A.; Zhang, J.

    2017-12-01

    Increases in the frequency and intensity of Arctic storms and resulting weather hazards may endanger the offshore environment, coastal community, and energy infrastructure in the Arctic as sea ice retreats. Advancing ability to identify fine-scale variations in surface climate produced by progressively stronger storm would be extremely helpful to resources management and sustainable development for coastal community. In this study, we analyzed the storms and their impacts on surface climate over the Beaufort-Chukchi seas by employing the date sets from both the hindcast simulations of the coupled Arctic regional climate model HIRHAM-NAOSIM and the recently developed Chukchi-Beaufort High-resolution Atmospheric Reanalysis (CBHAR). Based on the characteristics of spatial pattern and temporal variability of the Arctic storm activity, we categorized storms to three groups with their different origins: the East Siberia Sea, Alaska and the central Arctic Ocean. The storms originating from the central Arctic Ocean have the strongest intensity in winter with relatively less storm number. Storms traveling from Alaska to the Beaufort Sea most frequently occurred in autumn with weaker intensity. A large portion of storms originated from the East Siberia Sea region in summer. Further statistical analysis suggests that increase in surface air temperature and wind speed could be attributed to the increased frequency of storm occurrence in autumn (September to November) along the continental shelf in the Beaufort Sea.

  6. Climate forcing and response to idealized changes in surface latent and sensible heat

    International Nuclear Information System (INIS)

    Ban-Weiss, George A; Cao Long; Pongratz, Julia; Caldeira, Ken; Bala, Govindasamy

    2011-01-01

    Land use and land cover changes affect the partitioning of latent and sensible heat, which impacts the broader climate system. Increased latent heat flux to the atmosphere has a local cooling influence known as 'evaporative cooling', but this energy will be released back to the atmosphere wherever the water condenses. However, the extent to which local evaporative cooling provides a global cooling influence has not been well characterized. Here, we perform a highly idealized set of climate model simulations aimed at understanding the effects that changes in the balance between surface sensible and latent heating have on the global climate system. We find that globally adding a uniform 1 W m -2 source of latent heat flux along with a uniform 1 W m -2 sink of sensible heat leads to a decrease in global mean surface air temperature of 0.54 ± 0.04 K. This occurs largely as a consequence of planetary albedo increases associated with an increase in low elevation cloudiness caused by increased evaporation. Thus, our model results indicate that, on average, when latent heating replaces sensible heating, global, and not merely local, surface temperatures decrease.

  7. Uncertainty in Land Cover observations and its impact on near surface climate

    Science.gov (United States)

    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

  8. Carryover effects and climatic conditions influence the postfledging survival of greater sage-grouse

    Science.gov (United States)

    Blomberg, Erik J.; Sedinger, James S.; Gibson, Daniel; Coates, Peter S.; Casazza, Michael L.

    2014-01-01

    Prebreeding survival is an important life history component that affects both parental fitness and population persistence. In birds, prebreeding can be separated into pre- and postfledging periods; carryover effects from the prefledging period may influence postfledging survival. We investigated effects of body condition at fledging, and climatic variation, on postfledging survival of radio-marked greater sage-grouse (Centrocercus urophasianus) in the Great Basin Desert of the western United States. We hypothesized that body condition would influence postfledging survival as a carryover effect from the prefledging period, and we predicted that climatic variation may mediate this carryover effect or, alternatively, would act directly on survival during the postfledging period. Individual body condition had a strong positive effect on postfledging survival of juvenile females, suggesting carryover effects from the prefledging period. Females in the upper 25th percentile of body condition scores had a postfledging survival probability more than twice that (Φ = 0.51 ± 0.06 SE) of females in the bottom 25th percentile (Φ = 0.21 ± 0.05 SE). A similar effect could not be detected for males. We also found evidence for temperature and precipitation effects on monthly survival rates of both sexes. After controlling for site-level variation, postfledging survival was nearly twice as great following the coolest and wettest growing season (Φ = 0.77 ± 0.05 SE) compared with the hottest and driest growing season (Φ = 0.39 ± 0.05 SE). We found no relationships between individual body condition and temperature or precipitation, suggesting that carryover effects operated independently of background climatic variation. The temperature and precipitation effects we observed likely produced a direct effect on mortality risk during the postfledging period. Conservation actions that focus on improving prefledging habitat for sage-grouse may have indirect benefits

  9. Long term impact of organic amendments on forest soil properties under semiarid Mediterranean climatic conditions

    Science.gov (United States)

    Hueso González, Paloma; Francisco Martinez Murillo, Juan; Damian Ruiz Sinoga, Jose

    2017-04-01

    postafforestation); (iv) spring 2015 (42 months postafforestation) and; (v) spring 2016 (54 months postafforestation). The sampling strategy for each plot involved the collection of four disturbed soil samples taken from the surface (0 to 10-cm depth). The soil properties analyzed were as follows: (i) soil organic carbon (SOC); (ii) pH; (iii) electrical conductivity (EC); (iv) aggregates stability (AS) and; (v) texture (TE). Regarding to soil aggregate stability, 54 month after the afforestation, the percentage of stable aggregates has increased slightly in all the treatments (HP, RU, PM, SM and SH) in relation to control. Specifically, the differences were recorded in the fraction of macroaggregates (≥ 0.250 mm). The largest increases have been associated with SM, PM and RU treatments. Although the SM, PM and RU treatments helped to maintain the SOC at high levels in the 54 months following application. Conversely, not significant differences relative to the control plots were found for the pH, EC or texture, 54 months following afforestation. To conclude, these results showed an increase in the SOC and the stability of the macroaggregates when soil is amended with sludge, pinus mulch and straw much. This fact has been due to an increase in the number cementing agents due to: (i) the application of pinus, straw and sludge had resulted in the release of carbohydrates to the soil; and thus (ii) it has favored the development of a protective vegetation cover, which has increased the number of roots in the soil and the organic contribution to it. References: Casals P, Cortina J, Bottner P, Coûteaux MM, Vallejo VR.: CO2 efflux from a Mediterranean semi-arid forest soil. I. Seasonality and effects of stoniness. Biogeochemistry 48: 261-281, 2000. Eaton JM, McGoff NM, Byrne KA, Leahy P, Kiely G.: Land cover change and soil organic C stocks in the Republic of Ireland 1851-2000. Climatic Change 91: 317-334, 2008. García-Orenes F, Guerrero C, Roldán A, Mataix-Solera J, Cerdà A, Campoy

  10. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    International Nuclear Information System (INIS)

    Turner, J.P.; Hasfurther, V.

    1992-01-01

    The scope of the research program and the continuation is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 x 3.0 x 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by Rio Blanco Oil Shale Co., Inc. (RBOSC) through a separate cooperative agreement with the University of Wyoming (UW) to carry out this study. Three of the lysimeters were established at the RBOSC Tract C-a in the Piceance Basin of Colorado. Two lysimeters were established in the Environmental Simulation Laboratory (ESL) at UW. The ESL was specifically designed and constructed so that a large range of climatic conditions could be physically applied to the processed oil shale which was filled in the lysimeter cells

  11. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    International Nuclear Information System (INIS)

    Turner, J.P.; Reeves, T.L.; Skinner, Q.D.; Hasfurther, V.

    1992-11-01

    The scope of the original research program and of its continuation is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large-scale testing sufficient to describe commercial-scale embankment behavior. The large-scale testing was accomplished by constructing five lysimeters, each 7.3x3.0x3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process (Schmalfield 1975). Approximately 400 tons of Lurgi processed oil shale waste was provided by Rio Blanco Oil Shale Co., Inc. to carry out this study. Three of the lysimeters were established at the RBOSC Tract C-a in the Piceance Basin near Rifle, Colorado. Two lysimeters were established in the Environmental Simulation Laboratory (ESL) at UW. The ESL was specifically designed and constructed so that a large range of climatic conditions could be physically applied to the processed oil shale which was placed in the lysimeter cells. This report discusses and summarizes results from scientific efforts conducted between October 1991 and September 1992 for Fiscal Year 1992

  12. Flight activity and responses to climatic conditions of two subspecies of Melipona marginata Lepeletier (Apidae, Meliponinae)

    Energy Technology Data Exchange (ETDEWEB)

    Kleinert-Giovannini, A; Imperatriz-Fonseca, V L

    1986-01-01

    The flight activity of two colonies of M. m. marginata and six colonies of M. m. obscurior was studied in Sao Paulo, Brazil during three periods in 1981-1983. All colonies were hived except for one colony of M. m. obscurior which nested in a hollow tree. The two subspecies showed the same responses to the climatic factors analyzed. Flight activity was correlated positively with temperature and negatively with RH. In favorable conditions foraging took place throughout the day but both species were most active between 11 and 13 h. In the last observation period (October 1982-January 1983), when only two obscurior colonies were studied, flight activity was not correlated to RH, occurring even when RH was unfavorably high. This was a very rainy season, and it is suggested that the behavior of the bees indicates a flexible response to prevailing weather conditions.

  13. Determination of optimal irrigation rates of agricultural crops under consideration of soil properties and climatic conditions

    Directory of Open Access Journals (Sweden)

    Irakli Kruashvili

    2016-09-01

    Full Text Available In conditions of increasing water shortage, further development of irrigated agriculture production is impossible without improving the methods of cultivation of agricultural crops, primarily irrigation technology. In 2015 the experiment have been conducted on the territory of irrigation farming area of village Tamarisi (Marneuli Municipality, according to which comprehensive study of local climatic and soil conditions were conducted. Received data were used for computation crop water requirements for tomato and melon under the different irrigation treatments. Obtained results have shown the possibility of water use efficiency and obtaining sufficiently high yields of crops that participated in the experiment that became possible in a case of usage of drip irrigation technology in combination with plastic mulch.

  14. Seasonal variations of Saanen goat milk composition and the impact of climatic conditions.

    Science.gov (United States)

    Kljajevic, Nemanja V; Tomasevic, Igor B; Miloradovic, Zorana N; Nedeljkovic, Aleksandar; Miocinovic, Jelena B; Jovanovic, Snezana T

    2018-01-01

    The aim of this research was to investigate the effect of climatic conditions and their impact on seasonal variations of physico-chemical characteristics of Saanen goat milk produced over a period of 4 years. Lactation period (early, mid and late) and year were considered as factors that influence physico-chemical composition of milk. Pearson's coefficient of correlation was calculated between the physico-chemical characteristics of milk (fat, proteins, lactose, non-fat dry matter, density, freezing point, pH, titrable acidity) and climatic condition parameters (air temperature, temperature humidity index-THI, solar radiation duration, relative humidity). Results showed that all physico-chemical characteristics of Saanen goat milk varied significantly throughout the lactation period and years. The decrease of fat, protein, non-fat dry matter and lactose content in goat milk during the mid-lactation period was more pronounced than was previously reported in the literature. The highest values for these characteristics were recorded in the late lactation period. Observed variations were explained by negative correlation between THI and the physico-chemical characteristics of Saanen goat milk. This indicated that Saanen goats were very prone to heat stress, which implied the decrease of physico-chemical characteristics during hot summers.

  15. Ions, metabolites, and cells: Water as a reporter of surface conditions during bacterial growth

    Science.gov (United States)

    Jarisz, Tasha A.; Lane, Sarah; Gozdzialski, Lea; Hore, Dennis K.

    2018-06-01

    Surface-specific nonlinear vibrational spectroscopy, combined with bulk solution measurements and imaging, is used to study the surface conditions during the growth of E. coli. As a result of the silica high surface charge density, the water structure at the silica-aqueous interface is known to be especially sensitive to pH and ionic strength, and surface concentration profiles develop that can be appreciably different from the bulk solution conditions. We illustrate that, in the presence of growing cells, a unique surface micro-environment is established as a result of metabolites accumulating on the silica surface. Even in the subsequent absence of the cells, this surface layer works to reduce the interfacial ionic strength as revealed by the enhanced signal from surface water molecules. In the presence of growing cells, an additional boost in surface water signal is attributed to a local pH that is higher than that of the bulk solution.

  16. Groundwater flow modelling of periods with periglacial and glacial climate conditions - Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Vidstrand, Patrik (TerraSolve AB, Floda (Sweden)); Follin, Sven (SF GeoLogic AB, Taeby (Sweden)); Zugec, Nada (Bergab, Stockholm (Sweden))

    2010-12-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The groundwater flow modelling study reported here comprises a coupled thermal-hydraulic-chemical (T-H-C) analysis of periods with periglacial and glacial climate conditions. Hydraulic-mechanical (H-M) issues are also handled but no coupled flow modelling is done. The objective of the report is to provide bounding hydrogeological estimates at different stages during glaciation and deglaciation of a glacial cycle for subsequent use in safety assessment applications within SKB's project SR-Site. Three cases with different climate conditions are analysed here: (i) Temperate case, (ii) Glacial case without permafrost, and (iii) Glacial case with permafrost. The glacial periods are transient and encompass approximately 19,000 years. The simulation results comprise residual fluid pressures, Darcy fluxes, and water salinities, as well as advective transport performance measures obtained by particle tracking such as flow path lengths, travel times and flow-related transport resistances. The modelling is accompanied by a sensitivity study that addresses the impact of the following matters: the direction of the ice sheet advance, the speed of the ice sheet margin, the bedrock hydraulic and transport properties, the temperature at the ice-subsurface interface close to the ice sheet margin, and the initial hydrochemical conditions.

  17. Groundwater flow modelling of periods with periglacial and glacial climate conditions - Forsmark

    International Nuclear Information System (INIS)

    Vidstrand, Patrik; Follin, Sven; Zugec, Nada

    2010-12-01

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The groundwater flow modelling study reported here comprises a coupled thermal-hydraulic-chemical (T-H-C) analysis of periods with periglacial and glacial climate conditions. Hydraulic-mechanical (H-M) issues are also handled but no coupled flow modelling is done. The objective of the report is to provide bounding hydrogeological estimates at different stages during glaciation and deglaciation of a glacial cycle for subsequent use in safety assessment applications within SKB's project SR-Site. Three cases with different climate conditions are analysed here: (i) Temperate case, (ii) Glacial case without permafrost, and (iii) Glacial case with permafrost. The glacial periods are transient and encompass approximately 19,000 years. The simulation results comprise residual fluid pressures, Darcy fluxes, and water salinities, as well as advective transport performance measures obtained by particle tracking such as flow path lengths, travel times and flow-related transport resistances. The modelling is accompanied by a sensitivity study that addresses the impact of the following matters: the direction of the ice sheet advance, the speed of the ice sheet margin, the bedrock hydraulic and transport properties, the temperature at the ice-subsurface interface close to the ice sheet margin, and the initial hydrochemical conditions

  18. Climate and Population Health Vulnerabilities to Vector-Borne Diseases: Increasing Resilience Under Climate Change Conditions in Africa

    Science.gov (United States)

    Ceccato, P.; McDonald, K. C.; Podest, E.; De La Torre Juarez, M.; Kruczkiewicz, A.; Lessel, J.; Jensen, K.; Thomson, M. C.

    2014-12-01

    The International Research Institute for Climate and Society (IRI), the City University of New York (CUNY) and NASA Jet Propulsion Laboratory (JPL) in collaboration with NASA SERVIR are developing tools to monitor climate variables (precipitation, temperature, vegetation, water bodies, inundation) that help projects in Africa to increase resilience to climate change for vector-borne diseases (i.e. malaria, trypanosomiasis, leishmaniasis, and schistosomiasis). Through the development of new products to monitor precipitation, water bodies and inundation, IRI, CUNY and JPL provide tools and capacity building to research communities, ministries of health and World Health Organization in Africa to: 1) Develop research teams' ability to appropriately use climate data as part of their research 2) Enable research teams and ministries to integrate climate information into social and economic drivers of vulnerability and opportunities for adaptation to climate change 3) Inform better policies and programs for climate change adaptation. This oral presentation will demonstrate how IRI, CUNY, and JPL developed new products, tools and capacity building to achieve the three objectives mentioned above.

  19. Lake-level increasing under the climate cryoaridization conditions during the Last Glacial Maximum

    Science.gov (United States)

    Amosov, Mikhail; Strelkov, Ivan

    2017-04-01

    A lake genesis and lake-level increasing during the Last Glacial Maximum (LGM) are the paramount issues in paleoclimatology. Investigating these problems reveals the regularities of lake development and figures out an arid territory conditions at the LGM stage. Pluvial theory is the most prevalent conception of lake formation during the LGM. This theory is based on a fact that the water bodies emerged and their level increased due to torrential rainfalls. In this study, it is paid attention to an alternative assumption of lake genesis at the LGM stage, which is called climate cryoaridization. In accordance with this hypothesis, the endorheic water basins had their level enlarged because of a simultaneous climate aridity and temperature decrease. In this research, a lake-level increasing in endorheic regions of Central Asia and South American Altiplano of the Andes is described. The lake investigation is related to its conditions during the LGM. The study also includes a lake catalogue clearly presenting the basin conditions at the LGM stage and nowadays. The data compilation partly consists of information from an earlier work of Mikhail Amosov, Lake-levels, Vegetation And Climate In Central Asia During The Last Glacial Maximum (EGU2014-3015). According to the investigation, a lake catalogue on 27 lakes showed that most of the water bodies had higher level. This feature could be mentioned for the biggest lakes of the Aral Sea, Lake Balkhash, Issyk-Kul etc. and for the small ones located in the mountains, such as Pamir, Tian-Shan and Tibet. Yet some lakes that are situated in Central Asian periphery (Lake Qinghai and lakes in Inner Mongolia) used to be lower than nowadays. Also, the lake-level increasing of Altiplano turned to be a significant feature during the LGM in accordance with the data of 5 lakes, such as Titicaca, Coipasa-Uyuni, Lejia, Miscanti and Santa-Maria. Most of the current endorheic basins at the LGM stage were filled with water due to abundant

  20. Effect of alloy type and surface conditioning on roughness and bond strength of metal brackets

    NARCIS (Netherlands)

    Nergiz, I.; Schmage, P.; Herrmann, W.; Ozcan, M.; Nergiz, [No Value

    2004-01-01

    The effect of 5 different surface conditioning methods on bonding of metal brackets to cast dental alloys was examined. The surface conditioning methods were fine (30-µm) or rough (125-µm) diamond bur, sandblasting (50-µm or 110-µm aluminum oxide [Al2O3]), and silica coating (30-µm silica). Fifty

  1. Analysis and modelling of surface Urban Heat Island in 20 Canadian cities under climate and land-cover change.

    Science.gov (United States)

    Gaur, Abhishek; Eichenbaum, Markus Kalev; Simonovic, Slobodan P

    2018-01-15

    Surface Urban Heat Island (SUHI) is an urban climate phenomenon that is expected to respond to future climate and land-use land-cover change. It is important to further our understanding of physical mechanisms that govern SUHI phenomenon to enhance our ability to model future SUHI characteristics under changing geophysical conditions. In this study, SUHI phenomenon is quantified and modelled at 20 cities distributed across Canada. By analyzing MODerate Resolution Imaging Spectroradiometer (MODIS) sensed surface temperature at the cities over 2002-2012, it is found that 16 out of 20 selected cities have experienced a positive SUHI phenomenon while 4 cities located in the prairies region and high elevation locations have experienced a negative SUHI phenomenon in the past. A statistically significant relationship between observed SUHI magnitude and city elevation is also recorded over the observational period. A Physical Scaling downscaling model is then validated and used to downscale future surface temperature projections from 3 GCMs and 2 extreme Representative Concentration Pathways in the urban and rural areas of the cities. Future changes in SUHI magnitudes between historical (2006-2015) and future timelines: 2030s (2026-2035), 2050s (2046-2055), and 2090s (2091-2100) are estimated. Analysis of future projected changes indicate that 15 (13) out of 20 cities can be expected to experience increases in SUHI magnitudes in future under RCP 2.6 (RCP 8.5). A statistically significant relationship between projected future SUHI change and current size of the cities is also obtained. The study highlights the role of city properties (i.e. its size, elevation, and surrounding land-cover) towards shaping their current and future SUHI characteristics. The results from this analysis will help decision-makers to manage Canadian cities more efficiently under rapidly changing geophysical and demographical conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. The Climate for Steel. Actions for, and conditions to, a Copenhagen climate agreement from the perspective of the EU steel sector

    International Nuclear Information System (INIS)

    Slingerland, S.; Werring, L.; De Bruijn, S.; Korteland, M.

    2009-02-01

    A position paper discussing the relationship between climate change policies and competitiveness in the global steel sector. Question is how the need for effective action to confront global climate change can be combined with a level playing field for competition in the global steel sector, taking into account the position of Corus Netherlands as a European steel producer. More specifically; what conditions in an international agreement could provide such a level playing field? Chapter 2 of this paper briefly outlines some essential characteristics of the global and European steel sector. Chapter 3 outlines the present status quo of the multilateral climate change negotiation process towards the December 2009 Copenhagen conference. Chapter 4 gives a view on climate and competitiveness for the EU steel sector. Chapter 5 finally provides conclusions and recommendations for provisions in an international agreement that could provide for a competitive level playing field in the steel sector

  3. Global agricultural land resources--a high resolution suitability evaluation and its perspectives until 2100 under climate change conditions.

    Directory of Open Access Journals (Sweden)

    Florian Zabel

    Full Text Available Changing natural conditions determine the land's suitability for agriculture. The growing demand for food, feed, fiber and bioenergy increases pressure on land and causes trade-offs between different uses of land and ecosystem services. Accordingly, an inventory is required on the changing potentially suitable areas for agriculture under changing climate conditions. We applied a fuzzy logic approach to compute global agricultural suitability to grow the 16 most important food and energy crops according to the climatic, soil and topographic conditions at a spatial resolution of 30 arc seconds. We present our results for current climate conditions (1981-2010, considering today's irrigated areas and separately investigate the suitability of densely forested as well as protected areas, in order to investigate their potentials for agriculture. The impact of climate change under SRES A1B conditions, as simulated by the global climate model ECHAM5, on agricultural suitability is shown by comparing the time-period 2071-2100 with 1981-2010. Our results show that climate change will expand suitable cropland by additionally 5.6 million km2, particularly in the Northern high latitudes (mainly in Canada, China and Russia. Most sensitive regions with decreasing suitability are found in the Global South, mainly in tropical regions, where also the suitability for multiple cropping decreases.

  4. Start-up of belt conveyors used for haulage of large lumps under difficult climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Drobny, J

    1979-01-01

    Investigations are discussed carried out by the Research and Development Center for Brown Coal in Most, Czechoslovakia into effects of climate, weather and mass of coal lumps on reliability of belt conveyors in surface mines. Dirt buildup on the driving drums reduces friction and increases belt sliding hazards. Belt wear increases. Driving drum diameter, increased by the buildup, negatively influences load distribution among the electric motors of the drive system. In extreme cases belt wear and irregular load distribution cause belt failures. Methods for buildup removal used in Czechoslovakia and methods for protection of the return side of a conveyor are described. Effects of large mass of coal lumps and ice buildup on large lumps on the risk of belt damage (cuts, punctures etc,) are discussed. Recommendations for design of coal transfer points are made. 2 refs.

  5. Impact of Future Emissions and Climate Change on Surface Ozone over China

    Science.gov (United States)

    Ma, C. T.; Westervelt, D. M.; Fiore, A. M.; Rieder, H. E.; Kinney, P.; Wang, S.; Correa, G. J. P.

    2017-12-01

    China's immense ambient air pollution problem and world-leading greenhouse gas emissions place it at the forefront of global efforts to address these related environmental concerns. Here, we analyze the impact of ECLIPSE (Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants) future emissions scenarios representative of current legislation (CLE) and maximum technically feasible emissions reductions (MFR) on surface ozone (O3) concentrations over China in the 2030s and 2050s, in the context of a changing climate. We use a suite of simulations performed with the NOAA Geophysical Fluid Dynamics Laboratory's AM3 global chemistry-climate model. To estimate the impact of climate change in isolation on Chinese air quality, we hold emissions of air pollutants including O3 precursors fixed at 2015 levels but allow climate (global sea surface temperatures and sea ice cover) to change according to decadal averages for the years 2026-2035 and 2046-2055 from a three-member ensemble of GFDL-CM3 simulations under the RCP8.5 high warming scenario. Evaluation of the present-day simulation (2015 CLE) with observations from 1497 chiefly urban air quality monitoring stations shows that simulated surface O3 is positively biased by 26 ppb on average over the domain of China. Previous studies, however, have shown that the modeled ozone response to changes in NOx emissions over the Eastern United States mirrors the magnitude and structure of observed changes in maximum daily average 8-hour (MDA8) O3 distributions. Therefore, we use the model's simulated changes for the 2030s and 2050s to project changes in policy-relevant MDA8 O3 concentrations. We find an overall increase in MDA8 O3 for CLE scenarios in which emissions of NOx precursors are projected to increase, and under MFR scenarios, an overall decrease, with the highest changes occurring in summertime for both 2030 and 2050 MFR. Under climate change alone, the model simulates a mean summertime decrease of 1.3 ppb

  6. Assessing the Impacts of Atmospheric Conditions under Climate Change on Air Quality Profile over Hong Kong

    Science.gov (United States)

    Hei Tong, Cheuk

    2017-04-01

    Small particulates can cause long term impairment to human health as they can penetrate deep and deposit on the wall of the respiratory system. Under the projected climate change as reported by literature, atmospheric stability, which has strong effects on vertical mixing of air pollutants and thus air quality Hong Kong, is also varying from near to far future. In addition to domestic emission, Hong Kong receives also significant concentration of cross-boundary particulates that their natures and movements are correlated with atmospheric condition. This study aims to study the relation of atmospheric conditions with air quality over Hong Kong. Past meteorological data is based on Modern Era Retrospective Analysis for Research and Applications (MERRA) reanalysis data. Radiosonde data provided from HKO are also adopted in testing and validating the data. Future meteorological data is simulated by the Weather Research and Forecasting Model (WRF), which dynamically downscaled the past and future climate under the A1B scenario simulated by ECHAM5/MPIOM. Air quality data is collected on one hand from the ground station data provided by Environment Protection Department, with selected stations revealing local emission and trans-boundary emission respectively. On the other hand, an Atmospheric Light Detection and Ranging (LiDAR), which operates using the radar principle to detect Rayleigh and Mie scattering from atmospheric gas and aerosols, has also been adopted to measure vertical aerosol profile, which has been observed tightly related to the high level meteorology. Data from scattered signals are collected, averaged or some episode selected for characteristic comparison with the atmospheric stability indices and other meteorological factors. The relation between atmospheric conditions and air quality is observed by statistical analysis, and statistical models are built based on the stability indices to project the changes in sulphur dioxide, ozone and particulate

  7. Adherence of platelets to in situ albumin-binding surfaces under flow conditions: role of surface-adsorbed albumin

    International Nuclear Information System (INIS)

    Guha Thakurta, Sanjukta; Miller, Robert; Subramanian, Anuradha

    2012-01-01

    Surfaces that preferentially bind human serum albumin (HSA) were generated by grafting albumin-binding linear peptide (LP1) onto silicon surfaces. The research aim was to evaluate the adsorption pattern of proteins and the adhesion of platelets from platelet-poor plasma and platelet-rich plasma, respectively, by albumin-binding surfaces under physiological shear rate (96 and 319 s −1 ) conditions. Bound proteins were quantified using enzyme-linked immunosorbent assays (ELISAs) and two-dimensional gel electrophoresis. A ratio of ∼1000:100:1 of adsorbed HSA, human immunoglobulin (HIgG) and human fibrinogen (HFib) was noted, respectively, on LP1-functionalized surfaces, and a ratio of ∼5:2:1 of the same was noted on control surfaces, as confirmed by ELISAs. The surface-adsorbed von Willebrand factor was undetectable by sensitive ELISAs. The amount of adhered platelets correlated with the ratio of adsorbed HSA/HFib. Platelet morphology was more rounded on LP1-functionalized surfaces when compared to control surfaces. The platelet adhesion response on albumin-binding surfaces can be explained by the reduction in the co-adsorption of other plasma proteins in a surface environment where there is an excess of albumin molecules, coupled with restrictions in the conformational transitions of other surface-adsorbed proteins into hemostatically active forms. (paper)

  8. Evaluating Thermal Comfort in a Naturally Conditioned Office in a Temperate Climate Zone

    Directory of Open Access Journals (Sweden)

    Andrés Gallardo

    2016-07-01

    Full Text Available This study aims to determine the optimal approach for evaluating thermal comfort in an office that uses natural ventilation as the main conditioning strategy; the office is located in Quito-Ecuador. The performance of the adaptive model included in CEN Standard EN15251 and the traditional PMV model are compared with reports of thermal environment satisfaction surveys presented simultaneously to all occupants of the office to determine which of the two comfort models is most suitable to evaluate the thermal environment. The results indicate that office occupants have developed some degree of adaptation to the climatic conditions of the city where the office is located (which only demands heating operation, and tend to accept and even prefer lower operative temperatures than those considered optimum by applying the PMV model. This is an indication that occupants of naturally conditioned buildings are usually able to match their comfort temperature to their normal environment. Therefore, the application of the adaptive model included in CEN Standard EN15251 seems like the optimal approach for evaluating thermal comfort in naturally conditioned buildings, because it takes into consideration the adaptive principle that indicates that if a change occurs such as to produce discomfort, people tend to react in ways which restore their comfort.

  9. A virtual climate library of surface temperature over North America for 1979–2015

    Science.gov (United States)

    Kravtsov, Sergey; Roebber, Paul; Brazauskas, Vytaras

    2017-01-01

    The most comprehensive continuous-coverage modern climatic data sets, known as reanalyses, come from combining state-of-the-art numerical weather prediction (NWP) models with diverse available observations. These reanalysis products estimate the path of climate evolution that actually happened, and their use in a probabilistic context—for example, to document trends in extreme events in response to climate change—is, therefore, limited. Free runs of NWP models without data assimilation can in principle be used for the latter purpose, but such simulations are computationally expensive and are prone to systematic biases. Here we produce a high-resolution, 100-member ensemble simulation of surface atmospheric temperature over North America for the 1979–2015 period using a comprehensive spatially extended non-stationary statistical model derived from the data based on the North American Regional Reanalysis. The surrogate climate realizations generated by this model are independent from, yet nearly statistically congruent with reality. This data set provides unique opportunities for the analysis of weather-related risk, with applications in agriculture, energy development, and protection of human life. PMID:29039842

  10. A virtual climate library of surface temperature over North America for 1979-2015

    Science.gov (United States)

    Kravtsov, Sergey; Roebber, Paul; Brazauskas, Vytaras

    2017-10-01

    The most comprehensive continuous-coverage modern climatic data sets, known as reanalyses, come from combining state-of-the-art numerical weather prediction (NWP) models with diverse available observations. These reanalysis products estimate the path of climate evolution that actually happened, and their use in a probabilistic context—for example, to document trends in extreme events in response to climate change—is, therefore, limited. Free runs of NWP models without data assimilation can in principle be used for the latter purpose, but such simulations are computationally expensive and are prone to systematic biases. Here we produce a high-resolution, 100-member ensemble simulation of surface atmospheric temperature over North America for the 1979-2015 period using a comprehensive spatially extended non-stationary statistical model derived from the data based on the North American Regional Reanalysis. The surrogate climate realizations generated by this model are independent from, yet nearly statistically congruent with reality. This data set provides unique opportunities for the analysis of weather-related risk, with applications in agriculture, energy development, and protection of human life.

  11. Can phenological models predict tree phenology accurately under climate change conditions?

    Science.gov (United States)

    Chuine, Isabelle; Bonhomme, Marc; Legave, Jean Michel; García de Cortázar-Atauri, Inaki; Charrier, Guillaume; Lacointe, André; Améglio, Thierry

    2014-05-01

    The onset of the growing season of trees has been globally earlier by 2.3 days/decade during the last 50 years because of global warming and this trend is predicted to continue according to climate forecast. The effect of temperature on plant phenology is however not linear because temperature has a dual effect on bud development. On one hand, low temperatures are necessary to break bud dormancy, and on the other hand higher temperatures are necessary to promote bud cells growth afterwards. Increasing phenological changes in temperate woody species have strong impacts on forest trees distribution and productivity, as well as crops cultivation areas. Accurate predictions of trees phenology are therefore a prerequisite to understand and foresee the impacts of climate change on forests and agrosystems. Different process-based models have been developed in the last two decades to predict the date of budburst or flowering of woody species. They are two main families: (1) one-phase models which consider only the ecodormancy phase and make the assumption that endodormancy is always broken before adequate climatic conditions for cell growth occur; and (2) two-phase models which consider both the endodormancy and ecodormancy phases and predict a date of dormancy break which varies from year to year. So far, one-phase models have been able to predict accurately tree bud break and flowering under historical climate. However, because they do not consider what happens prior to ecodormancy, and especially the possible negative effect of winter temperature warming on dormancy break, it seems unlikely that they can provide accurate predictions in future climate conditions. It is indeed well known that a lack of low temperature results in abnormal pattern of bud break and development in temperate fruit trees. An accurate modelling of the dormancy break date has thus become a major issue in phenology modelling. Two-phases phenological models predict that global warming should delay

  12. Changes on the coastline of buenaventura bay (colombian pacific) and its relationship with the climatic conditions

    Science.gov (United States)

    Coca-Domínguez, Oswaldo; Ricaurte-Villota, Constanza; Andres Ordoñez, Silvio

    2016-04-01

    Some authors point out that the variability of a coastal system is the response of physical factors (climate, waves, currents, wind, etc.) or combination of some of them, for example long-term variations in the relationship between climate and supply of sedimentary material. For Colombian Pacific coast it has been said that the regimen of meso-tidal is one of the agents that contribute to changes in the morphology of the littoral zone. Between 2012-2015 was conducted a research in the mouth of Buenaventura Bay (Colombia Pacific coast), using two stations: Soldado point (southern point of the bay) and Bazan point (the northern point of the bay), for those stations the digital elevation model (DEM) was performed using a DGPS with technology GNSS the recent evolution of the coastline and changes in volume of sand from beaches for two scalar approaches were determined: annual and intra-annual. The use of ArcGIS 3D Analyst in the DEMs allowed to calculate the cubic area between the raised surfaces each month. Changes in the coastline were made using Digital Shoreline Analysis System (DSAS) an ARCGIS extension. We used zonal and meridional components of the wind data near the coast from WindSat, rainfall and sea level anomaly data from the database AVISO (Archiving, Validation and Interpretation of Satellite Oceanographic), and sea level pressure (SLP) from NCEP/NCAR (National Center for Environmental Prediction/ National Center for Atmospheric Research), in collaboration with the National Oceanic and Atmospheric Administration (NOAA). Finally, climatic variables were correlated with the rates of coastal erosion and changes in sand volume of the beaches, because wind and precipitation are some of the factors in sediment transport. The study showed erosion rates with negative values in 2014 and 2015 that represent loss of land, the intra-annual variability in September and October were the highest loss of land, this coincides with the values of the highest tides of the

  13. Land-Surface Characteristics and Climate in West Africa: Models’ Biases and Impacts of Historical Anthropogenically-Induced Deforestation

    Directory of Open Access Journals (Sweden)

    Souleymane Sy

    2017-10-01

    Full Text Available Land Use Land-Cover Change (LULCC, such as deforestation, affects the climate system and land-atmosphere interactions. Using simulations carried out within the LUCID (Land Use and Climate, IDentification of robust Impacts project framework, we first quantify the role of historical land-cover change induced by human activities on surface climate in West Africa. Focusing on two contrasted African regions, we find that climate responses of land-use changes are small but they are still statistically significant. In Western Sahel, a statistically significant near-surface atmospheric cooling and a decrease in water recycling are simulated in summer in response to LULCC. Over the Guinean zone, models simulate a significant decrease in precipitation and water recycling in autumn in response to LULCC. This signal is comparable in magnitude with the effect induced by the increase in greenhouse gases. Simulated climate changes due to historical LULCC could however be underestimated because: (i the prescribed LULCC can be underestimated in those regions; (ii the climate models underestimate the coupling strength between West African surface climate and leaf area index (LAI and (iii the lack of interactive LAI in some models. Finally, our study reveals indirect atmospheric processes triggered by LULCC. Over the Western Sahel, models reveal that a significant decrease in solar reflection tend to cool down the surface and thus counteract the atmospheric feedback. Conversely, over the Guinea zone, models reveal that the indirect atmospheric processes and turbulent heat fluxes dominate the climatic responses over the direct effects of LULCC.

  14. Climatic variability and trends in the surface waters of coastal British Columbia

    Science.gov (United States)

    Cummins, Patrick F.; Masson, Diane

    2014-01-01

    Multi-decadal records of monthly sea surface temperature (SST) and sea surface salinity (SSS) collected at a set of lighthouse stations are used to examine climatic variability and trends in the coastal waters of British Columbia. Particular attention is given to relations between the water property anomalies and variability in coastal freshwater discharge and alongshore wind stress. Within the Strait of Georgia, SSS anomalies are closely related to Fraser River discharge anomalies. Along the Pacific coast, anomalies in alongshore wind stress and freshwater runoff have the characteristics of white noise processes. A cross-correlation analysis demonstrates that SST and SSS variability along the open west coast is consistent with the response of a first-order autoregressive process driven by anomalous alongshore wind stress and coastal freshwater discharge, respectively. Thus climatic variability of SST and SSS along the Pacific coast of British Columbia occurs, in part, through the integration of noisy atmospheric forcing and coastal precipitation. Seasonal correlations show that SST is strongly related to wind stress during winter and fall. Conversely, SSS is relatively weakly related to the alongshore wind during spring, suggesting that variability in upwelling makes only a modest contribution to variability of SSS in the nearshore environment. Consistent with previous studies, secular trends indicate long-term warming and freshening of the coastal ocean at most stations. It is shown that long-term SST trends can be obscured by the pronounced climatic variability of these waters, requiring that time series extend for several decades to be reliably detected.

  15. Adaptation response surfaces from an ensemble of wheat projections under climate change in Europe

    Science.gov (United States)

    Ruiz-Ramos, Margarita; Ferrise, Roberto

    2016-04-01

    The uncertainty about climate change (CC) complicates impact adaptation and risk management evaluation at the regional level. Approaches for managing this uncertainty and for simulating and communicating climate change impacts and adaptation opportunities are required. Here we apply an ensemble of crop models for adapting rainfed winter wheat at Lleida (NE Spain), constructing adaptation response surfaces (ARS). Our methodology has been adapted from Pirttioja et al. (2015). Impact response surfaces (IRS) are plotted surfaces showing the response of an impact variable (here crop yield Y) to changes in two explanatory variables (here precipitation P and temperature T). By analyzing adaptation variables such as changes in crop yield (ΔY) when an adaptation option is simulated, these can be interpreted as the adaptation response to potential changes of P and T, i.e. ARS. To build these ARS, we explore the sensitivity of an ensemble of wheat models to changes in T and P. Baseline (1981-2010) T and P were modified using a delta change approach with changes in the seasonal patterns. Three levels of CO2 (representing future conditions until 2050) and two actual soil profiles are considered. Crop models were calibrated with field data from Abeledo et al. (2008) and Cartelle et al. (2006). Most promising adaptation options to be analyzed by the ARS approach are identified in a pilot stage with the models DSSAT4.5 and SiriusQuality v.2, subsequently simulating the selected adaptation combinations by the whole ensemble of 11 crop models. The adaptation options identified from pilot stage were: a cultivar with no vernalisation requirements, shortening or extending a 10 % the crop cycle of the standard cultivar, sowing 15 days earlier and 30 days later than the standard date, supplementary irrigation with 40 mm at flowering and full irrigation. These options and those of the standard cultivar and management resulted in 54 combinations and 450.000 runs per crop model. Our

  16. Potential Alternative Lower Global Warming Refrigerants for Air Conditioning in Hot Climates

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [ORNL; Shrestha, Som S [ORNL; Shen, Bo [ORNL

    2017-01-01

    The earth continues to see record increase in temperatures and extreme weather conditions that is largely driven by anthropogenic emissions of warming gases such as carbon dioxide and other more potent greenhouse gases such as refrigerants. The cooperation of 188 countries in the Conference of the Parties in Paris 2015 (COP21) resulted in an agreement aimed to achieve a legally binding and universal agreement on climate, with the aim of keeping global warming below 2 C. A global phasedown of hydrofluorocarbons (HFCs) can prevent 0.5 C of warming by 2100. However, most of the countries in hot climates are considered as developing countries and as such are still using R-22 (a Hydrochlorofluorocarbon (HCFC)) as the baseline refrigerant and are currently undergoing a phase-out of R-22 which is controlled by current Montreal Protocol to R-410A and other HFC based refrigerants. These HFCs have significantly high Global Warming Potential (GWP) and might not perform as well as R-22 at high ambient temperature conditions. In this paper we present recent results on evaluating the performance of alternative lower GWP refrigerants for R-22 and R-410A for small residential mini-split air conditioners and large commercial packaged units. Results showed that several of the alternatives would provide adequate replacement for R-22 with minor system modification. For the R-410A system, results showed that some of the alternatives were almost drop-in ready with benefit in efficiency and/or capacity. One of the most promising alternatives for R-22 mini-split unit is propane (R-290) as it offers higher efficiency; however it requires compressor and some other minor system modification to maintain capacity and minimize flammability risk. Between the R-410A alternatives, R-32 appears to have a competitive advantage; however at the cost of higher compressor discharge temperature. With respect to the hydrofluoroolefin (HFO) blends, there existed a tradeoff in performance and system design

  17. Performance Analysis of Air-to-Water Heat Pump in Latvian Climate Conditions

    Science.gov (United States)

    Kazjonovs, Janis; Sipkevics, Andrejs; Jakovics, Andris; Dancigs, Andris; Bajare, Diana; Dancigs, Leonards

    2014-12-01

    Strategy of the European Union in efficient energy usage demands to have a higher proportion of renewable energy in the energy market. Since heat pumps are considered to be one of the most efficient heating and cooling systems, they will play an important role in the energy consumption reduction in buildings aimed to meet the target of nearly zero energy buildings set out in the EU Directive 2010/31/EU. Unfortunately, the declared heat pump Coefficient of Performance (COP) corresponds to a certain outdoor temperature (+7 °C), therefore different climate conditions, building characteristics and settings result in different COP values during the year. The aim of this research is to investigate the Seasonal Performance factor (SPF) values of air-to-water heat pump which better characterize the effectiveness of heat pump in a longer selected period of time, especially during the winter season, in different types of residential buildings in Latvian climate conditions. Latvia has four pronounced seasons of near-equal length. Winter starts in mid-December and lasts until mid-March. Latvia is characterized by cold, maritime climate (duration of the average heating period being 203 days, the average outdoor air temperature during the heating period being 0.0 °C, the coldest five-day average temperature being -20.7 °C, the average annual air temperature being +6.2 °C, the daily average relative humidity being 79 %). The first part of this research consists of operational air-towater heat pump energy performance monitoring in different residential buildings during the winter season. The second part of the research takes place under natural conditions in an experimental construction stand which is located in an urban environment in Riga, Latvia. The inner area of this test stand, where air-to-water heat pump performance is analyzed, is 9 m2. The ceiling height is 3 m, all external wall constructions (U = 0.16 W/(m2K)) have ventilated facades. To calculate SPF, the

  18. Popular culture and the "new human condition": Catastrophe narratives and climate change

    Science.gov (United States)

    Bulfin, Ailise

    2017-09-01

    Striking popular culture images of burnt landscapes, tidal waves and ice-bound cities have the potential to dramatically and emotively convey the dangers of climate change. Given that a significant number of people derive a substantial proportion of their information on the threat of climate change, or the ;new human condition;, from popular culture works such as catastrophe movies, it is important that an investigation into the nature of the representations produced be embedded in the attempt to address the issue. What climate change-related messages may be encoded in popular films, television and novels, how are they being received, and what effects may they have? This article adopts the cultural studies perspective that popular culture gives us an important means by which to access the ;structures of feeling; that characterise a society at a particular historic juncture: the views held and emotional states experienced by significant amounts of people as evident in disparate forms of cultural production. It further adopts the related viewpoint that popular culture has an effect upon the society in which it is consumed, as well as reflecting that society's desires and concerns - although the nature of the effect may be difficult to quantify. From this position, the article puts forward a theory on the role of ecological catastrophe narratives in current popular culture, before going on to review existing critical work on ecologically-charged popular films and novels which attempts to assess their effects on their audiences. It also suggests areas for future research, such as the prevalent but little studied theme of natural and environmental disaster in late-Victorian science fiction writing. This latter area is of interest because it reveals the emergence of an ecological awareness or structure of feeling as early as the late-nineteenth century, and allows the relationship of this development to environmental policy making to be investigated because of the

  19. ClimoBase: Rouse Canadian Surface Observations of Weather, Climate, and Hydrological Variables, 1984-1998, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — ClimoBase is a collection of surface climate measurements collected in Northern Canada by Dr. Wayne Rouse between 1984 and 1998 in three locations: Churchill,...

  20. Experience in a Climate Microworld: Influence of Surface and Structure Learning, Problem Difficulty, and Decision Aids in Reducing Stock-Flow Misconceptions

    Directory of Open Access Journals (Sweden)

    Medha Kumar

    2018-03-01

    Full Text Available Research shows that people’s wait-and-see preferences for actions against climate change are a result of several factors, including cognitive misconceptions. The use of simulation tools could help reduce these misconceptions concerning Earth’s climate. However, it is still unclear whether the learning in these tools is of the problem’s surface features (dimensions of emissions and absorptions and cover-story used or of the problem’s structural features (how emissions and absorptions cause a change in CO2 concentration under different CO2 concentration scenarios. Also, little is known on how problem’s difficulty in these tools (the shape of CO2 concentration trajectory, as well as the use of these tools as a decision aid influences performance. The primary objective of this paper was to investigate how learning about Earth’s climate via simulation tools is influenced by problem’s surface and structural features, problem’s difficulty, and decision aids. In experiment 1, we tested the influence of problem’s surface and structural features in a simulation called Dynamic Climate Change Simulator (DCCS on subsequent performance in a paper-and-pencil Climate Stabilization (CS task (N = 100 across four between-subject conditions. In experiment 2, we tested the effects of problem’s difficulty in DCCS on subsequent performance in the CS task (N = 90 across three between-subject conditions. In experiment 3, we tested the influence of DCCS as a decision aid on subsequent performance in the CS task (N = 60 across two between-subject conditions. Results revealed a significant reduction in people’s misconceptions in the CS task after performing in DCCS compared to when performing in CS task in the absence of DCCS. The decrease in misconceptions in the CS task was similar for both problems’ surface and structural features, showing both structure and surface learning in DCCS. However, the proportion of misconceptions was similar across

  1. Detailed performance analysis of realistic solar photovoltaic systems at extensive climatic conditions

    International Nuclear Information System (INIS)

    Gupta, Ankit; Chauhan, Yogesh K.

    2016-01-01

    In recent years, solar energy has been considered as one of the principle renewable energy source for electric power generation. In this paper, single diode photovoltaic (PV) system and double/bypass diode based PV system are designed in MATLAB/Simulink environment based on their mathematical modeling and are validated with a commercially available solar panel. The novelty of the paper is to include the effect of climatic conditions i.e. variable irradiation level, wind speed, temperature, humidity level and dust accumulation in the modeling of both the PV systems to represent a realistic PV system. The comprehensive investigations are made on both the modeled PV systems. The obtained results show the satisfactory performance for realistic models of the PV system. Furthermore, an in depth comparative analysis is carried out for both PV systems. - Highlights: • Modeling of Single diode and Double diode PV systems in MATLAB/Simulink software. • Validation of designed PV systems with a commercially available PV panel. • Acquisition and employment of key climatic factors in modeling of the PV systems. • Evaluation of main model parameters of both the PV systems. • Detailed comparative assessment of both the modeled PV system parameters.

  2. Monitoring Thermal Performance of Hollow Bricks with Different Cavity Fillers in Difference Climate Conditions

    Science.gov (United States)

    Pavlík, Zbyšek; Jerman, Miloš; Fořt, Jan; Černý, Robert

    2015-03-01

    Hollow brick blocks have found widespread use in the building industry during the last decades. The increasing requirements to the thermal insulation properties of building envelopes given by the national standards in Europe led the brick producers to reduce the production of common solid bricks. Brick blocks with more or less complex systems of internal cavities replaced the traditional bricks and became dominant on the building ceramics market. However, contrary to the solid bricks where the thermal conductivity can easily be measured by standard methods, the complex geometry of hollow brick blocks makes the application of common techniques impossible. In this paper, a steady-state technique utilizing a system of two climatic chambers separated by a connecting tunnel for sample positioning is used for the determination of the thermal conductivity, thermal resistance, and thermal transmittance ( U value) of hollow bricks with the cavities filled by air, two different types of mineral wool, polystyrene balls, and foam polyurethane. The particular brick block is provided with the necessary temperature- and heat-flux sensors and thermally insulated in the tunnel. In the climatic chambers, different temperatures are set. After steady-state conditions are established in the measuring system, the effective thermal properties of the brick block are calculated using the measured data. Experimental results show that the best results are achieved with hydrophilic mineral wool as a cavity filler; the worst performance exhibits the brick block with air-filled cavities.

  3. Kinetically limited weathering at low denudation rates in semiarid climatic conditions

    Science.gov (United States)

    Schoonejans, Jérôme; Vanacker, Veerle; Opfergelt, Sophie; Ameijeiras-Mariño, Yolanda; Christl, Marcus

    2016-02-01

    Biogeochemical cycling within the Critical Zone depends on the interactions between minerals and fluids controlling chemical weathering and physical erosion rates. In this study, we explore the role of water availability in controlling soil chemical weathering in semiarid climatic conditions. Weathering rates and intensities were evaluated for nine soil profiles located on convex ridge crests of three mountain ranges in the Spanish Betic Cordillera. We combine a geochemical mass balance with 10Be cosmogenic nuclides to constrain chemical weathering intensities and long-term denudation rates. As such, this study presents new data on chemical weathering and 10Be-derived denudation for understudied semiarid climate systems. In the Betic Cordillera, chemical weathering intensities are relatively low (~5 to 30% of the total denudation of the soil) and negatively correlated with the magnitude of the water deficit in soils. Chemical mass losses are inversely related to denudation rates (14-109 mm/kyr) and positively to soil thickness (14-58 cm); these results are consistent with kinetic limitation of chemical weathering rates. A worldwide compilation of chemical weathering data suggests that soil water balance may regulate the coupling between chemical weathering and physical erosion by modulating soil solute fluxes. Therefore, future landscape evolution models that seek to link chemical weathering and physical erosion should include soil water flux as an essential driver of weathering.

  4. Productive and qualitative evaluation of onion cultivars under agro-climatic conditions of faisalabad

    International Nuclear Information System (INIS)

    Mushtaq, S.; Amjad, M.; Ziaf, K.; Cheema, K.L.

    2013-01-01

    Onion varieties are very specific in their photoperiod and vernalization requirements and therefore vary for yield, yield related traits and bolting in a specific agro-climate. Therefore, performance of nineteen onion varieties for these traits was evaluated at Vegetable Research Institute, Faisalabad. The maximum bolting percentage was recorded in Desi Red (46.67%) that indicates less vernalization requirement of this variety while it was the minimum in Faisal Red and VRIO-6 (13.33%). The cultivar Phulkara produced larger size bulbs (73.22 mm diameter) as well as highest yield (21.90 t ha/sup -1/) and bulb to neck diameter ratio (6.75). Similarly, minimum weight loss during curing was observed in Desi Red (4.64%), Pusa Red (4.76%) and Phulkara (4.83%), indicating higher dry matter contents while maximum weight loss (6%) was recorded in VRIO-6. Overall results revealed that both Phulkara and Desi Red are excellent for processing while Dark Red for cooking purpose under agro-climatic conditions of Faisalabad. (author)

  5. Cropland versus Gariga schrubland on soil organic carbon storage under Mediterranen climatic condition of Sicily

    Science.gov (United States)

    Novara, A.; Gristina, L.; Santoro, A.; Poma, I.

    2009-04-01

    Soil organic carbon (SOC) pool is the largest among the terrestrial pool and it plays a key role to mitigate climate change. The restoration of SOC pool represents a potential sink for atmospheric CO2. Land use is one of the most important factors controlling organic carbon content. The main land uses throughout the Mediterranean are croplands (olive, wheat and vineyards) and scrublands. The land abandonment or the reclamation of land is changing the cover of scrubland and cropland. This will change the carbon cycle. The aim of this work is determining the direction and magnitude of soil organic change associated with land use change under Mediterranean Climatic Conditions. Using both historic record and land cover crop maps we estimated the effect of land cover change on the stock carbon from 1972 to 2008 in Sicily. A system of paired plots was established on Mollic Gypsiric cambisol and Gypsiric cambisol on agriculture and rangeland land uses. The study sites were selected at the natural reserve "Grotta di S. Ninfa", in the West of Sicily. Soil samples (24) were taken at 20 and 40 cm depth, air dried and sieved at 2 mm. Dry aggregate size fractions selected were >1000 µm, 1000-500 µm, 500-250 µm, 250-63 µm, 63-25 µm and <25 µm. The results show that gariga increase the organic matter in soil, mainly on the organic horizon. Key worlds: Land use change, Soil organic Carbon , Mediterranean, aggregates, gariga, cropland.

  6. Sugarcane yield estimation for climatic conditions in the state of Goiás

    Directory of Open Access Journals (Sweden)

    Jordana Moura Caetano

    Full Text Available ABSTRACT Models that estimate potential and depleted crop yield according to climatic variable enable the crop planning and production quantification for a specific region. Therefore, the objective of this study was to compare methods to sugarcane yield estimates grown in the climatic condition in the central part of Goiás, Brazil. So, Agroecological Zone Method (ZAE and the model proposed by Scarpari (S were correlated with real data of sugarcane yield from an experimental area, located in Santo Antônio de Goiás, state of Goiás, Brazil. Data yield refer to the crops of 2008/2009 (sugarcane plant, 2009/2010, 2010/2011 and 2011/2012 (ratoon sugarcane. Yield rates were calculated as a function of atmospheric water demand and water deficit in the area under study. Real and estimated yields were adjusted in function of productivity loss due to cutting stage of sugarcane, using an average reduction in productivity observed in the experimental area and the average reduction in the state of Goiás. The results indicated that the ZAE method, considering the water deficit, displayed good yield estimates for cane-plant (d > 0.90. Water deficit decreased the yield rates (r = -0.8636; α = 0.05 while the thermal sum increased that rate for all evaluated harvests (r > 0.68; α = 0.05.

  7. CLIMATE CHANGE. Possible artifacts of data biases in the recent global surface warming hiatus.

    Science.gov (United States)

    Karl, Thomas R; Arguez, Anthony; Huang, Boyin; Lawrimore, Jay H; McMahon, James R; Menne, Matthew J; Peterson, Thomas C; Vose, Russell S; Zhang, Huai-Min

    2015-06-26

    Much study has been devoted to the possible causes of an apparent decrease in the upward trend of global surface temperatures since 1998, a phenomenon that has been dubbed the global warming "hiatus." Here, we present an updated global surface temperature analysis that reveals that global trends are higher than those reported by the Intergovernmental Panel on Climate Change, especially in recent decades, and that the central estimate for the rate of warming during the first 15 years of the 21st century is at least as great as the last half of the 20th century. These results do not support the notion of a "slowdown" in the increase of global surface temperature. Copyright © 2015, American Association for the Advancement of Science.

  8. Improvement in Simulation of Eurasian Winter Climate Variability with a Realistic Arctic Sea Ice Condition in an Atmospheric GCM

    Science.gov (United States)

    Lim, Young-Kwon; Ham, Yoo-Geun; Jeong, Jee-Hoon; Kug, Jong-Seong

    2012-01-01

    The present study investigates how much a realistic Arctic sea ice condition can contribute to improve simulation of the winter climate variation over the Eurasia region. Model experiments are set up using different sea ice boundary conditions over the past 24 years (i.e., 1988-2011). One is an atmospheric model inter-comparison (AMIP) type of run forced with observed sea-surface temperature (SST), sea ice, and greenhouse gases (referred to as Exp RSI), and the other is the same as Exp RSI except for the sea ice forcing, which is a repeating climatological annual cycle (referred to as Exp CSI). Results show that Exp RSI produces the observed dominant pattern of Eurasian winter temperatures and their interannual variation better than Exp CSI (correlation difference up to approx. 0.3). Exp RSI captures the observed strong relationship between the sea ice concentration near the Barents and Kara seas and the temperature anomaly across Eurasia, including northeastern Asia, which is not well captured in Exp CSI. Lagged atmospheric responses to sea ice retreat are examined using observations to understand atmospheric processes for the Eurasian cooling response including the Arctic temperature increase, sea-level pressure increase, upper-level jet weakening and cold air outbreak toward the mid-latitude. The reproducibility of these lagged responses by Exp RSI is also evaluated.

  9. Improvement in simulation of Eurasian winter climate variability with a realistic Arctic sea ice condition in an atmospheric GCM

    International Nuclear Information System (INIS)

    Lim, Young-Kwon; Ham, Yoo-Geun; Jeong, Jee-Hoon; Kug, Jong-Seong

    2012-01-01

    The present study investigates how much a realistic Arctic sea ice condition can contribute to improve simulation of the winter climate variation over the Eurasia region. Model experiments are set up using different sea ice boundary conditions over the past 24 years (i.e., 1988–2011). One is an atmospheric model inter-comparison (AMIP) type of run forced with observed sea-surface temperature (SST), sea ice, and greenhouse gases (referred to as Exp RSI), and the other is the same as Exp RSI except for the sea ice forcing, which is a repeating climatological annual cycle (referred to as Exp CSI). Results show that Exp RSI produces the observed dominant pattern of Eurasian winter temperatures and their interannual variation better than Exp CSI (correlation difference up to ∼0.3). Exp RSI captures the observed strong relationship between the sea ice concentration near the Barents and Kara seas and the temperature anomaly across Eurasia, including northeastern Asia, which is not well captured in Exp CSI. Lagged atmospheric responses to sea ice retreat are examined using observations to understand atmospheric processes for the Eurasian cooling response including the Arctic temperature increase, sea-level pressure increase, upper-level jet weakening and cold air outbreak toward the mid-latitude. The reproducibility of these lagged responses by Exp RSI is also evaluated. (letter)

  10. Climate

    International Nuclear Information System (INIS)

    Fellous, J.L.

    2005-02-01

    This book starts with a series of about 20 preconceived ideas about climate and climatic change and analyses each of them in the light of the present day knowledge. Using this approach, it makes a status of the reality of the climatic change, of its causes and of the measures to be implemented to limit its impacts and reduce its most harmful consequences. (J.S.)

  11. Mixed precipitation occurrences over southern Québec, Canada, under warmer climate conditions using a regional climate model

    Science.gov (United States)

    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.

  12. Climatic and environmental conditions favoring the crossing of the Carpathians by early Neolithic populations

    Science.gov (United States)

    Perşoiu, Ioana; Perşoiu, Aurel

    2015-04-01

    The study of the origin and spread of Neolithic has been the subject of heated debate since the early studies of Childe (1942). To what extent the dispersal process was influenced by environmental factors is still debated, one of the issues being whether climatic conditions influencing agricultural practices, could have influenced the dispersal route, "blocking" some of the Neolithic societies in front of ecological barriers. Data from Neolithic sites in SE Europe shows that a continuous stream of people and cultures flowed through the Danube's Iron Gates towards Central Europe, while in the eastern part of Europe this process was delayed, people and cultures "moving" around the Carpathians and crossing them with a delay of ca. 1000 years. One of the possible avenues for this crossing is the floodplain of Someşu Mic River (Transylvanian depression), home to the oldest (~8500 cal. BP) Neolithic settlement in Romania. In this paper, we review the climatic and environmental changes that affected the region at the time of Neolithic dispersal. Pollen and stable isotopes in cave ice indicate an early Holocene rapid warming during summer months, peaking around 7 ka cal. BP; and a delayed warming for autumn and winter months, peaking at 5 ka cal. BP, both followed by a continuous cooling trend towards the present. Someşu Mic River developed and maintained a narrow sinuous channel during the Holocene, with local development of meanders and anabranches, in response to both climatic and geologic controlling factors. Archaeological finds in the floodplain and the lower terraces suggest that human societies in the region responded in sensitive manner to these climatic and environmental changes. During warm and dry periods, with low fluvial activity, the number of settlements increased in the floodplain's perimeter, while during the short cold and humid periods, the number of settlements rapidly increased on the lower terraces and on the valley slopes, disappearing from the

  13. Life cycle of the potato golden cyst nematode (Globodera rostochiensis grown under climatic conditions in Belgrade

    Directory of Open Access Journals (Sweden)

    Bačić Jasmina

    2011-01-01

    Full Text Available The life cycle of a population of the quarantine nematode Globodera rostochiensis on the root of susceptible potato variety, Desiree, originating from an infected field (CC Ljubovija no. 413 on the mountain of Jagodnja in the district of Mačva, was studied under experimental conditions in Belgrade in 2002-2003. The golden cyst nematode completed one generation per year in the temperate climate of this region. In 2002, the life cycle lasted 29 days after the penetration of the second stage juveniles into the roots. An adverse effect of high soil temperatures above 25 °C was observed in 2003, influencing the development of the nematode and making the life cycle last two months longer.

  14. Effects of climate change on surface-water photochemistry: a review.

    Science.gov (United States)

    De Laurentiis, Elisa; Minella, Marco; Maurino, Valter; Minero, Claudio; Vione, Davide

    2014-10-01

    Information concerning the link between surface-water photochemistry and climate is presently very scarce as only a few studies have been dedicated to the subject. On the basis of the limited knowledge that is currently available, the present inferences can be made as follows: (1) Warming can cause enhanced leaching of ionic solutes from the catchments to surface waters, including cations and more biologically labile anions such as sulphate. Preferential sulphate biodegradation followed by removal as organic sulphides in sediment could increase alkalinity, favouring the generation of the carbonate radical, CO3 (·-). However, this phenomenon would be easily offset by fluctuations of the dissolved organic carbon (DOC), which is strongly anticorrelated with CO3 (·-). Therefore, obtaining insight into DOC evolution is a key issue in understanding the link between photochemistry and climate. (2) Climate change could exacerbate water scarcity in the dry season in some regions. Fluctuations in the water column could deeply alter photochemistry that is usually favoured in shallower waters. However, the way water is lost would strongly affect the prevailing photoinduced processes. Water outflow without important changes in solute concentration would mostly favour reactions induced by the hydroxyl and carbonate radicals (·OH and CO3 (·-)). In contrast, evaporative concentration would enhance reactions mediated by singlet oxygen ((1)O2) and by the triplet states of chromophoric dissolved organic matter ((3)CDOM*). (3) In a warmer climate, the summer stratification period of lakes would last longer, thereby enhancing photochemical reactions in the epilimnion but at the same time keeping the hypolimnion water in the dark for longer periods.

  15. Predicting Summer Dryness Under a Warmer Climate: Modeling Land Surface Processes in the Midwestern United States

    Science.gov (United States)

    Winter, J. M.; Eltahir, E. A.

    2009-12-01

    One of the most significant impacts of climate change is the potential alteration of local hydrologic cycles over agriculturally productive areas. As the world’s food supply continues to be taxed by its burgeoning population, a greater percentage of arable land will need to be utilized and land currently producing food must become more efficient. This study seeks to quantify the effects of climate change on soil moisture in the American Midwest. A series of 24-year numerical experiments were conducted to assess the ability of Regional Climate Model Version 3 coupled to Integrated Biosphere Simulator (RegCM3-IBIS) and Biosphere-Atmosphere Transfer Scheme 1e (RegCM3-BATS1e) to simulate the observed hydroclimatology of the midwestern United States. Model results were evaluated using NASA Surface Radiation Budget, NASA Earth Radiation Budget Experiment, Illinois State Water Survey, Climate Research Unit Time Series 2.1, Global Soil Moisture Data Bank, and regional-scale estimations of evapotranspiration. The response of RegCM3-IBIS and RegCM3-BATS1e to a surrogate climate change scenario, a warming of 3oC at the boundaries and doubling of CO2, was explored. Precipitation increased significantly during the spring and summer in both RegCM3-IBIS and RegCM3-BATS1e, leading to additional runoff. In contrast, enhancement of evapotranspiration and shortwave radiation were modest. Soil moisture remained relatively unchanged in RegCM3-IBIS, while RegCM3-BATS1e exhibited some fall and winter wetting.

  16. Flatfish recruitment response to decadal climatic variability and ocean conditions in the eastern Bering Sea

    Science.gov (United States)

    Wilderbuer, T. K.; Hollowed, A. B.; Ingraham, W. J.; Spencer, P. D.; Conners, M. E.; Bond, N. A.; Walters, G. E.

    2002-10-01

    This paper provides a retrospective analysis of the relationship of physical oceanography and biology and recruitment of three Eastern Bering Sea flatfish stocks: flathead sole ( Hippoglossoides elassodon), northern rock sole ( Lepidopsetta polyxystra), and arrowtooth flounder ( Atheresthes stomias) for the period 1978-1996. Temporal trends in flatfish production in the Eastern Bering Sea are consistent with the hypothesis that decadal scale climate variability influences marine survival during the early life history period. Density-dependence (spawning stock size) is statistically significant in a Ricker model of flatfish recruitment, which includes environmental terms. Wind-driven advection of flatfish larvae to favorable nursery grounds was also found to coincide with years of above-average recruitment through the use of an ocean surface current simulation model (OSCURS). Ocean forcing of Bristol Bay surface waters during springtime was mostly shoreward (eastward) during the 1980s and seaward (westerly) during the 1990s, corresponding with periods of good and poor recruitment. Distance from shore and water depth at the endpoint of 90-day drift periods (estimated time of settlement) were also found to correspond with flatfish productivity.

  17. Effects of lateral boundary condition resolution and update frequency on regional climate model predictions

    Science.gov (United States)

    Pankatz, Klaus; Kerkweg, Astrid

    2015-04-01

    The work presented is part of the joint project "DecReg" ("Regional decadal predictability") which is in turn part of the project "MiKlip" ("Decadal predictions"), an effort funded by the German Federal Ministry of Education and Research to improve decadal predictions on a global and regional scale. In MiKlip, one big question is if regional climate modeling shows "added value", i.e. to evaluate, if regional climate models (RCM) produce better results than the driving models. However, the scope of this study is to look more closely at the setup specific details of regional climate modeling. As regional models only simulate a small domain, they have to inherit information about the state of the atmosphere at their lateral boundaries from external data sets. There are many unresolved questions concerning the setup of lateral boundary conditions (LBC). External data sets come from global models or from global reanalysis data-sets. A temporal resolution of six hours is common for this kind of data. This is mainly due to the fact, that storage space is a limiting factor, especially for climate simulations. However, theoretically, the coupling frequency could be as high as the time step of the driving model. Meanwhile, it is unclear if a more frequent update of the LBCs has a significant effect on the climate in the domain of the RCM. The first study examines how the RCM reacts to a higher update frequency. The study is based on a 30 year time slice experiment for three update frequencies of the LBC, namely six hours, one hour and six minutes. The evaluation of means, standard deviations and statistics of the climate in the regional domain shows only small deviations, some statistically significant though, of 2m temperature, sea level pressure and precipitation. The second part of the first study assesses parameters linked to cyclone activity, which is affected by the LBC update frequency. Differences in track density and strength are found when comparing the simulations

  18. Ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bang Selsted, M

    2010-07-15

    Global change is a reality. Atmospheric CO{sub 2} levels are rising as well as mean global temperature and precipitation patterns are changing. These three environmental factors have separately and in combination effect on ecosystem processes. Terrestrial ecosystems hold large amounts of carbon, why understanding plant and soil responses to such changes are necessary, as ecosystems potentially can ameliorate or accelerate global change. To predict the feedback of ecosystems to the atmospheric CO{sub 2} concentrations experiments imitating global change effects are therefore an important tool. This work on ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions, shows that extended summer drought in combination with elevated temperature will ensure permanent dryer soil conditions, which decreases carbon turnover, while elevated atmospheric CO{sub 2} concentrations will increase carbon turnover. In the full future climate scenario, carbon turnover is over all expected to increase and the heathland to become a source of atmospheric CO{sub 2}. The methodology of static chamber CO{sub 2} flux measurements and applying the technology in a FACE (free air CO{sub 2} enrichment) facility is a challenge. Fluxes of CO{sub 2} from soil to atmosphere depend on a physical equilibrium between those two medias, why it is important to keep the CO{sub 2} gradient between soil and atmosphere unchanged during measurement. Uptake to plants via photosynthesis depends on a physiological process, which depends strongly on the atmospheric CO{sub 2} concentration. Photosynthesis and respiration run in parallel during measurements of net ecosystem exchange, and these measurements should therefore be performed with care to both the atmospheric CO{sub 2} concentration and the CO{sub 2} soil-atmosphere gradient. (author)

  19. Degradation and performance evaluation of PV module in desert climate conditions with estimate uncertainty in measuring

    Directory of Open Access Journals (Sweden)

    Fezzani Amor

    2017-01-01

    Full Text Available The performance of photovoltaic (PV module is affected by outdoor conditions. Outdoor testing consists installing a module, and collecting electrical performance data and climatic data over a certain period of time. It can also include the study of long-term performance under real work conditions. Tests are operated in URAER located in desert region of Ghardaïa (Algeria characterized by high irradiation and temperature levels. The degradation of PV module with temperature and time exposure to sunlight contributes significantly to the final output from the module, as the output reduces each year. This paper presents a comparative study of different methods to evaluate the degradation of PV module after a long term exposure of more than 12 years in desert region and calculates uncertainties in measuring. Firstly, this evaluation uses three methods: Visual inspection, data given by Solmetric PVA-600 Analyzer translated at Standard Test Condition (STC and based on the investigation results of the translation equations as ICE 60891. Secondly, the degradation rates calculated for all methods. Finally, a comparison between a degradation rates given by Solmetric PVA-600 analyzer, calculated by simulation model and calculated by two methods (ICE 60891 procedures 1, 2. We achieved a detailed uncertainty study in order to improve the procedure and measurement instrument.

  20. Present and future assessment of growing degree days over selected Greek areas with different climate conditions

    Science.gov (United States)

    Paparrizos, Spyridon; Matzarakis, Andreas

    2017-10-01

    The determination of heat requirements in the first developing phases of plants has been expressed as Growing Degree Days (GDD). The current study focuses on three selected study areas in Greece that are characterised by different climatic conditions due to their location and aims to assess the future variation and spatial distribution of Growing Degree Days (GDD) and how these can affect the main cultivations in the study areas. Future temperature data were obtained and analysed by the ENSEMBLES project. The analysis was performed for the future periods 2021-2050 and 2071-2100 with the A1B and B1 scenarios. Spatial distribution was performed using a combination of dynamical and statistical downscaling technique through ArcGIS 10.2.1. The results indicated that for all the future periods and scenarios, the GDD are expected to increase. Furthermore, the increase in the Sperchios River basin will be the highest, followed by the Ardas and the Geropotamos River basins. Moreover, the cultivation period will be shifted from April-October to April-September which will have social, economical and environmental benefits. Additionally, the spatial distribution indicated that in the upcoming years the existing cultivations can find favourable conditions and can be expanded in mountainous areas as well. On the other hand, due to the rough topography that exists in the study areas, the wide expansion of the existing cultivations into higher altitudes is unaffordable. Nevertheless, new more profitable cultivations can be introduced which can find propitious conditions in terms of GDD.

  1. Comparison and development of advanced dosimetric techniques to be used under extreme climatic conditions

    International Nuclear Information System (INIS)

    Madhvanath, U.

    1975-08-01

    The post-irradiation fading characteristics of various dosimeters in function of relative humidity of air during storage were tested in specially set up humidity boxes. The temperature and relative humidity were varied between 5deg-35degC and 40-90%, respectively. Fading was 70% and 80% at 2 and 6 days respectively, for Kodak Type 2 film under 28degC and 76% relative humidity. Under these conditions the corresponding values for NTA emulsions were 30% and 80% respectively. Agfa-Gevaert films proved to be less sensitive and gave 20% and 30%, respectively, for the mentioned intervals. When Kodak Type 2 film was sealed in polythene bags, fading was reduced considerably, to appr. 15% in 4 weeks. Alternate storage of exposed films in humid and dry conditions also reduced fading to the same extent. When NTA emulsions were double-sealed with desiccant inside fading was reduced to 10% in 15 days. CaSO 4 :Dy (DRP and Harshaw) showed only 7% fading in 3 months. LiF TLD-100 was more sensitive, 13% in 2 months. Gamma-irradiated Li-borate has faded up to 30% at extreme climatic conditions in 3 months but thermal neutron irradiated Li-borate was resistant against fading for this period

  2. Growing Season Conditions Mediate the Dependence of Aspen on Redistributed Snow Under Climate Change.

    Science.gov (United States)

    Soderquist, B.; Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Strand, E. K.

    2016-12-01

    Precipitation regimes in many semiarid ecosystems are becoming increasingly dominated by winter rainfall as a result of climate change. Across these regions, snowpack plays a vital role in the distribution and timing of soil moisture availability. Rising temperatures will result in a more uniform distribution of soil moisture, advanced spring phenology, and prolonged growing seasons. Productive and wide ranging tree species like aspen, Populus tremuloides, may experience increased vulnerability to drought and mortality resulting from both reduced snowpack and increased evaporative demand during the growing season. We simulated the net primary production (NPP) of aspen stands spanning the rain:snow transition zone in the Reynolds Creek Critical Zone Observatory (RCCZO) in southwest Idaho, USA. Within the RCCZO, the total amount of precipitation has remained unchanged over the past 50 years, however the percentage of the precipitation falling as snow has declined by approximately 4% per decade at mid-elevation sites. The biogeochemical process model Biome-BGC was used to simulate aspen NPP at three stands located directly below snowdrifts that provide melt water late into the spring. After adjusting precipitation inputs to account for the redistribution of snow, we assessed climate change impacts on future aspen productivity. Mid-century (2046-2065) aspen NPP was simulated using temperature projections from a multi-model average under high emission conditions using the Multivariate Adaptive Constructed Analogs (MACA) data set. While climate change simulations indicated over a 20% decrease in annual NPP for some years, NPP rates for other mid-century years remained relatively unchanged due to variations in growing season conditions. Mid-century years with the largest decreases in NPP typically showed increased spring transpiration rates resulting from earlier leaf flush combined with warmer spring conditions. During these years, the onset of drought stress occurred

  3. Stress and body condition are associated with climate and demography in Asian elephants.

    Science.gov (United States)

    Mumby, Hannah S; Mar, Khyne U; Thitaram, Chatchote; Courtiol, Alexandre; Towiboon, Patcharapa; Min-Oo, Zaw; Htut-Aung, Ye; Brown, Janine L; Lummaa, Virpi

    2015-01-01

    Establishing links between ecological variation, physiological markers of stress and demography is crucial for understanding how and why changes in environmental conditions affect population dynamics, and may also play a key role for conservation efforts of endangered species. However, detailed longitudinal studies of long-lived species are rarely available. We test how two markers of stress and body condition vary through the year and are associated with climatic conditions and large-scale mortality and fertility variation in the world's largest semi-captive population of Asian elephants employed in the timber industry in Myanmar. Glucocorticoid metabolites (used as a proxy for stress levels in 75 elephants) and body weight (used as a proxy for condition in 116 elephants) were monitored monthly across a typical monsoon cycle and compared with birth and death patterns of the entire elephant population over half a century (n = 2350). Our results show seasonal variation in both markers of stress and condition. In addition, this variation is correlated with population-level demographic variables. Weight is inversely correlated with population mortality rates 1 month later, and glucocorticoid metabolites are negatively associated with birth rates. Weight shows a highly positive correlation with rainfall 1 month earlier. Determining the factors associated with demography may be key to species conservation by providing information about the correlates of mortality and fertility patterns. The unsustainability of the studied captive population has meant that wild elephants have been captured and tamed for work. By elucidating the correlates of demography in captive elephants, our results offer management solutions that could reduce the pressure on the wild elephant population in Myanmar.

  4. Assessment of Environmental Flows under Human Intervention and Climate Change Conditions in a Mediterranean Watershed

    Science.gov (United States)

    Yilmaz, M. T.; Alp, E.; Aras, M.; Özaltın, A. M.; Sarıcan, Y.; Afsar, M.; Bulut, B.; Ersoy, E. N.; Karasu, İ. G.; Onen, A.

    2017-12-01

    Allocation of the river flow for ecosystems is very critical for sustainable management of ecosystems containing aquatic habitats in need of more water than other environments. Availability and allocation of water over such locations becomes more stressed as a result of the influence of human interventions (e.g., increased water use for irrigation) and the expected change in climate. This study investigates the current and future (until 2100) low-flow requirements over 10 subcatchments in a Mediterranean Watershed, in Turkey, using Tennant and hydrological low-flow methods. The future river flows are estimated using HBV model forced by climate projections obtained by HADGEM2, MPI-ESM-MR, and CNRM-CM5.1 models coupled with RegCM4.3 under RCP 4.5 and RCP 8.5 emission scenarios. Critical flows (i.e., Q10, Q25, Q50) are calculated using the best fit to commonly used distributions for the river flow data, while the decision between the selection of Q10, Q25, Q50 critical levels are made depending on the level of human interference made over the catchment. Total three low-flow requirement estimations are obtained over each subcatchment using the Tennant (two estimates for the low and high flow seasons for environmentally good conditions) and the hydrological low-flow methods. The highest estimate among these three methods is selected as the low-flow requirement of the subcatchment. The river flows over these 10 subcatchments range between 197hm3 and 1534hm3 while the drainage areas changing between 936 and 4505 km2. The final low-flow estimation (i.e., the highest among the three estimate) for the current conditions range between 94 hm3 and 715 hm3. The low-flow projection values between 2075 and 2099 are on average 39% lower than the 2016 values, while the steepest decline is expected between 2050 and 2074. The low flow and high flow season Tennant estimates dropped 22-25% while the hydrological method low-flow estimates dropped 32% from 2016 to 2075-2099 average, where

  5. Wear Behavior of Medium Carbon Steel with Biomimetic Surface Under Starved Lubricated Conditions

    Science.gov (United States)

    Zhang, Zhihui; Shao, Feixian; Liang, Yunhong; Lin, Pengyu; Tong, Xin; Ren, Luquan

    2017-07-01

    Friction and wear under starved lubrication condition are both key life-related factors for mechanical performance of many structural parts. In this paper, different surface morphologies on medium carbon steel were fabricated using laser, inspired by the surface coupling effect of biological system. The friction and sliding wear behaviors of biomimetic specimens (characterized by convex and concave units on the specimen surface) were studied under starved lubrication condition. The stress distribution on different sliding surfaces under sliding friction was studied using finite element method. The results showed that the tribological performance of studied surfaces under starved lubrication condition depended not only on the surface morphology but also on the structure of biomimetic units below surface (subsurface structure). The friction coefficient of biomimetic surface was effectively reduced by the concave unit depth, while the refined microstructure with higher hardness led to the much better wear resistance. In addition to lubricant reserving and wear debris trapping effect derived from the surface concave morphology, it was believed that the well-formed subsurface structure of biomimetic units could carry much heavy loads against tribopair, which enhanced the function of surface topography and resulted in complementary lubrication in the wear contact area. The uniform stress distribution on the entire biomimetic surface also played an important role in stabilizing the friction coefficient and reducing the wear cracks.

  6. Two new techniques for the remote evaluation of reactor steel condition - microscopic removal and surface examination

    International Nuclear Information System (INIS)

    Clayton, R.

    Much reactor inspection work involves an assessment of the condition of structural steel. This paper reviews two different techniques which provide information for such an assessment. The first - micro-sample removal (for the measurement of surface oxide thickness and chemical composition) - requires contact with the steel surface, whereas the second - a 'teach and learn' photographic technique (in which a special photogrammatic camera is used to obtain high-quality close-up photographs, to assess surface condition and corrosion growth) can obtain surface information on inaccessible components. (author)

  7. Modeling Surface Climate in US Cities Using Simple Biosphere Model Sib2

    Science.gov (United States)

    Zhang, Ping; Bounoua, Lahouari; Thome, Kurtis; Wolfe, Robert; Imhoff, Marc

    2015-01-01

    We combine Landsat- and the Moderate Resolution Imaging Spectroradiometer (MODIS)-based products in the Simple Biosphere model (SiB2) to assess the effects of urbanized land on the continental US (CONUS) surface climate. Using National Land Cover Database (NLCD) Impervious Surface Area (ISA), we define more than 300 urban settlements and their surrounding suburban and rural areas over the CONUS. The SiB2 modeled Gross Primary Production (GPP) over the CONUS of 7.10 PgC (1 PgC= 10(exp 15) grams of Carbon) is comparable to the MODIS improved GPP of 6.29 PgC. At state level, SiB2 GPP is highly correlated with MODIS GPP with a correlation coefficient of 0.94. An increasing horizontal GPP gradient is shown from the urban out to the rural area, with, on average, rural areas fixing 30% more GPP than urbans. Cities built in forested biomes have stronger UHI magnitude than those built in short vegetation with low biomass. Mediterranean climate cities have a stronger UHI in wet season than dry season. Our results also show that for urban areas built within forests, 39% of the precipitation is discharged as surface runoff during summer versus 23% in rural areas.

  8. A 10-days heatwave around flowering superimposed on climate change conditions significantly affects production of 22 barley accessions

    DEFF Research Database (Denmark)

    Ingvordsen, Cathrine Heinz; Lyngkjær, Michael F.; Peltonen-Sainio, Pirjo

    2015-01-01

    Extreme climate events as heatwaves, floods and storms cause acute changes in season variability influencing primary production and are very likely to increase in magnitude and/or frequency (IPCC, AR5, WGI). In the present study 22 primarily Nordic barley accessions were grown in four basic clima...... climate change conditions on numerous accessions in order to select appropriate genotypes for breeding future cultivars that can secure the primary production....

  9. Future Changes in Surface Runoff over Korea Projected by a Regional Climate Model under A1B Scenario

    Directory of Open Access Journals (Sweden)

    Ji-Woo Lee

    2014-01-01

    Full Text Available This study assesses future change of surface runoff due to climate change over Korea using a regional climate model (RCM, namely, the Global/Regional Integrated Model System (GRIMs, Regional Model Program (RMP. The RMP is forced by future climate scenario, namely, A1B of Intergovernmental Panel on Climate Change (IPCC Fourth Assessment Report (AR4. The RMP satisfactorily reproduces the observed seasonal mean and variation of surface runoff for the current climate simulation. The distribution of monsoonal precipitation-related runoff is adequately captured by the RMP. In the future (2040–2070 simulation, it is shown that the increasing trend of temperature has significant impacts on the intra-annual runoff variation. The variability of runoff is increased in summer; moreover, the strengthened possibility of extreme occurrence is detected in the future climate. This study indicates that future climate projection, including surface runoff and its variability over Korea, can be adequately addressed on the RMP testbed. Furthermore, this study reflects that global warming affects local hydrological cycle by changing major water budget components. This study adduces that the importance of runoff should not be overlooked in regional climate studies, and more elaborate presentation of fresh-water cycle is needed to close hydrological circulation in RCMs.

  10. Improving PAQ and comfort conditions in Spanish office buildings with passive climate control

    Energy Technology Data Exchange (ETDEWEB)

    Orosa, Jose A.; Baalina, A. [Departamento de Energia y P.M. Escuela Tecnica Superior de N. y M, Universidade da Coruna, Paseo de Ronda 51, P.C.:15011 A Coruna (Spain)

    2009-03-15

    Some researchers have demonstrated that passive moisture transfer between indoor air and hygroscopic structures has the potential to moderate variations of indoor air relative humidity and, thus, to improve comfort and PAQ [Simonson CJ, Salonvaara M, Ojalen T. The effect of structures on indoor humidity-possibility to improve comfort and perceived air quality. Indoor Air 2002; 12: 243-51; Simonson CJ, Salonvaara M, Ojalen T. Improving indoor climate and comfort with wooden structures. Espoo 2001. Technical Research Centre of Finland, VTT Publications 431.200p+app 91p]. The main objective of this study is to show the internal wall coating effect on indoor air conditions and, as a consequence of this, in comfort conditions and PAQ. In a previous paper [Orosa JA, Baalina A. Passive climate control in Spanish office buildings for long periods of time. Building and Environment 2008], we analysed the influence of permeable and impermeable materials on indoor air conditions, during the unoccupied period, in 25 office buildings in different seasons. Results obtained lead us to conclude that real coverings such as permeable, semi-permeable and impermeable types, present different behavioural patterns in indoor air conditions. Furthermore, we concluded that an absorbent structure will moderate relative humidity indoors. In this paper, we study this indoor relative humidity effect on local thermal discomfort, due to decreased respiratory cooling, and indoor ambience acceptability for the early hours of morning applying PD and Acc models [Toftum J, Jorgensen AS, Fanger PO. Upper limits for indoor air humidity to avoid uncomfortably humid skin. Energy and buildings 1998; 28: 1-13; Toftum J, Jorgensen AS, Fanger PO. Upper limits of air humidity for preventing warm respiratory discomfort. Energy and Buildings 1998; 28: 15-23] such as that proposed by Simonson et al. [The effect of structures on indoor humidity-possibility to improve comfort and perceived air quality. Indoor Air

  11. Study the flashover voltage for outdoor polymer insulators under desert climatic conditions

    Directory of Open Access Journals (Sweden)

    L.S. Nasrat

    2013-06-01

    Results showed that flashover voltage reaches to 38 kV for samples without filler and 47 kV for samples containing 50% of ATH filler in dry condition. A comparison between inorganic fillers under various environmental conditions showed higher flashover voltage values for samples containing ATH filler than that of samples containing H3BO3 and Mg(OH2 fillers at all filler concentrations. Flashover voltage increases 24% by adding ATH filler for polyester samples under sandstorm conditions. Also, in this study, the effects of sandstorm, ultra violet (UV radiation, mechanical strength (compressive and tensile strengths and thermal performance with respect to surface of the sample under test have been investigated in detail.

  12. Uncertainties in predicting rice yield by current crop models under a wide range of climatic conditions

    NARCIS (Netherlands)

    Li, T.; Hasegawa, T.; Yin, X.; Zhu, Y.; Boote, K.; Adam, M.; Bregaglio, S.; Buis, S.; Confalonieri, R.; Fumoto, T.; Gaydon, D.; Marcaida III, M.; Nakagawa, H.; Oriol, P.; Ruane, A.C.; Ruget, F.; Singh, B.; Singh, U.; Tang, L.; Yoshida, H.; Zhang, Z.; Bouman, B.

    2015-01-01

    Predicting rice (Oryza sativa) productivity under future climates is important for global food security. Ecophysiological crop models in combination with climate model outputs are commonly used in yield prediction, but uncertainties associated with crop models remain largely unquantified. We

  13. Influence of surface condition on the corrosion resistance of copper alloy condenser tubes in sea water

    Energy Technology Data Exchange (ETDEWEB)

    Sato, S; Nagata, K; Yamauchi, S

    1979-07-01

    Investigation was made on the influence of various surface conditions of aluminum brass tube. The corrosion behavior of aluminum brass tube, with nine kinds of surface conditions, was studied in stagnant 0.1N NaHCo/sub 3/ solution and flowing sea water (natural, Fe/sup + +/ containing and S/sup - -/ containing water). Surface treatments investigated contained bright annealing, special annealing to form carbon film, hot oxidizing and pickling. Anodic polarization measurements in 0.1N NaHCO/sub 3/ solution showed that the oxidized surface was superior and that the pickled surface was inferior. However, relation between these characteristics and corrosion resistance in sea water has not been established. Electrochemical characteristics in flowing sea water were dependent on the surface conditions in the very beginning of immersion time; nobler corrosion potential for the surface with carbon film, higher polarization resistance for the bright annealed and the oxidized surface, and faster decrease of polarization resistance in S/sup - -/ containing sea water for the pickled surface. However, these differences disappeared in the immersion time of only 2 to 7 days. It was revealed, by the statistical analysis on the corrosion depth in corrosion test in flowing sea water and in jet impingement test, that the corrosion behavior was not influenced by surface conditions, but was significantly influenced by quality of sea water and sponge ball cleaning. Sulfide ion of 0.05 ppm caused severe pitting corrosion, and sponge ball cleaning of 5 chances a week caused erosion corrosion. From above results, it was concluded that surface conditions of aluminum brass were not important to sea water corrosion, and that quality of sea water and operating condition such as sponge ball cleaning were more significant.

  14. The influence of land surface properties on Sahel climate. Part 1: Desertification

    Science.gov (United States)

    Xue, Yongkang; Shukla, Jagadish

    1993-01-01

    This is a general circulation model sensitivity study of the physical mechanisms of the effects of desertification on the Sahel drought. The model vegetation types were changed in the prescribed desertification area, which led to changes in the surface characteristics. The model was integrated for three months (June, July, August) with climatological surface conditions (control) and desertification conditions (anomaly) to examine the summer season response to the changed surface conditions. The control and anomaly experiments consisted of five pairs of integrations with different initial conditions and/or sea surface temperature boundary conditions. In the desertification experiment, the moisture flux convergence and rainfall were reduced in the test area and increased to the immediate south of this area. The simulated anomaly dipole pattern was similar to the observed African drought patterns in which the axis of the maximum rainfall shifts to the south. The circulation changes in the desertification experiment were consistent with those observed during sub-Saharan dry years. The tropical easterly jet was weaker and the African easterly jet was stronger than normal. Further, in agreement with the observations, the easterly wave disturbances were reduced in intensity but not in number. Descending motion dominated the desertification area. The surface energy budget and hydrological cycle were also changed substantially in the anomaly experiment.

  15. Anomalous winter climate conditions in the Pacific rim during recent El Nino Modoki and El Nino events

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Hengyi; Behera, Swadhin K. [Climate Variations Research Program, Frontier Research Center for Global Change/JAMSTEC, Yokohama (Japan); Yamagata, Toshio [Climate Variations Research Program, Frontier Research Center for Global Change/JAMSTEC, Yokohama (Japan)]|[University of Tokyo, Department of Earth and Planetary Science, Graduate School of Sciences, Tokyo (Japan)

    2009-04-15

    Present work compares impacts of El Nino Modoki and El Nino on anomalous climate in the Pacific rim during boreal winters of 1979-2005. El Nino Modoki (El Nino) is associated with tripole (dipole) patterns in anomalies of sea-surface temperature, precipitation, and upper-level divergent wind in the tropical Pacific, which are related to multiple 'boomerangs' of ocean-atmosphere conditions in the Pacific. Zonal and meridional extents of those 'boomerangs' reflect their independent influences, which are seen from lower latitudes in the west to higher latitudes in the east. In the central Pacific, more moisture is transported from the tropics to higher latitudes during El Nino Modoki owing to displacement of the wet 'boomerang' arms more poleward toward east. Discontinuities at outer 'boomerang' arms manifest intense interactions between tropical and subtropical/extratropical systems. The Pacific/North American pattern and related climate anomalies in North America found in earlier studies are modified in very different ways by the two phenomena. The seesaw with the dry north and the wet south in the western USA is more likely to occur during El Nino Modoki, while much of the western USA is wet during El Nino. The moisture to the southwestern USA is transported from the northward shifted ITCZ during El Nino Modoki, while it is carried by the storms traveling along the southerly shifted polar front jet during El Nino. The East Asian winter monsoon related anticyclone is over the South China Sea during El Nino Modoki as compared to its position over the Philippine Sea during El Nino, causing opposite precipitation anomalies in the southern East Asia between the two phenomena. (orig.)

  16. Using semi-variogram analysis for providing spatially distributed information on soil surface condition for land surface modeling

    Science.gov (United States)

    Croft, Holly; Anderson, Karen; Kuhn, Nikolaus J.

    2010-05-01

    The ability to quantitatively and spatially assess soil surface roughness is important in geomorphology and land degradation studies. Soils can experience rapid structural degradation in response to land cover changes, resulting in increased susceptibility to erosion and a loss of Soil Organic Matter (SOM). Changes in soil surface condition can also alter sediment detachment, transport and deposition processes, infiltration rates and surface runoff characteristics. Deriving spatially distributed quantitative information on soil surface condition for inclusion in hydrological and soil erosion models is therefore paramount. However, due to the time and resources involved in using traditional field sampling techniques, there is a lack of spatially distributed information on soil surface condition. Laser techniques can provide data for a rapid three dimensional representation of the soil surface at a fine spatial resolution. This provides the ability to capture changes at the soil surface associated with aggregate breakdown, flow routing, erosion and sediment re-distribution. Semi-variogram analysis of the laser data can be used to represent spatial dependence within the dataset; providing information about the spatial character of soil surface structure. This experiment details the ability of semi-variogram analysis to spatially describe changes in soil surface condition. Soil for three soil types (silt, silt loam and silty clay) was sieved to produce aggregates between 1 mm and 16 mm in size and placed evenly in sample trays (25 x 20 x 2 cm). Soil samples for each soil type were exposed to five different durations of artificial rainfall, to produce progressively structurally degraded soil states. A calibrated laser profiling instrument was used to measure surface roughness over a central 10 x 10 cm plot of each soil state, at 2 mm sample spacing. The laser data were analysed within a geostatistical framework, where semi-variogram analysis quantitatively represented

  17. Impact of groundwater capillary rises as lower boundary conditions for soil moisture in a land surface model

    Science.gov (United States)

    Vergnes, Jean-Pierre; Decharme, Bertrand; Habets, Florence

    2014-05-01

    Groundwater is a key component of the global hydrological cycle. It sustains base flow in humid climate while it receives seepage in arid region. Moreover, groundwater influences soil moisture through water capillary rise into the soil and potentially affects the energy and water budget between the land surface and the atmosphere. Despite its importance, most global climate models do not account for groundwater and their possible interaction with both the surface hydrology and the overlying atmosphere. This study assesses the impact of capillary rise from shallow groundwater on the simulated water budget over France. The groundwater scheme implemented in the Total Runoff Integrated Pathways (TRIP) river routing model in a previous study is coupled with the Interaction between Soil Biosphere Atmosphere (ISBA) land surface model. In this coupling, the simulated water table depth acts as the lower boundary condition for the soil moisture diffusivity equation. An original parameterization accounting for the subgrid elevation inside each grid cell is proposed in order to compute this fully-coupled soil lower boundary condition. Simulations are performed at high (1/12°) and low (0.5°) resolutions and evaluated over the 1989-2009 period. Compared to a free-drain experiment, upward capillary fluxes at the bottom of soil increase the mean annual evapotranspiration simulated over the aquifer domain by 3.12 % and 1.54 % at fine and low resolutions respectively. This process logically induces a decrease of the simulated recharge from ISBA to the aquifers and contributes to enhance the soil moisture memory. The simulated water table depths are then lowered, which induces a slight decrease of the simulated mean annual river discharges. However, the fully-coupled simulations compare well with river discharge and water table depth observations which confirms the relevance of the coupling formalism.

  18. A Snow Density Dataset for Improving Surface Boundary Conditions in Greenland Ice Sheet Firn Modeling

    DEFF Research Database (Denmark)

    S. Fausto, Robert; E. Box, Jason; Vandecrux, Baptiste Robert Marcel

    2018-01-01

    The surface snow density of glaciers and ice sheets is of fundamental importance in converting volume to mass in both altimetry and surface mass balance studies, yet it is often poorly constrained. Site-specific surface snow densities are typically derived from empirical relations based...... on temperature and wind speed. These parameterizations commonly calculate the average density of the top meter of snow, thereby systematically overestimating snow density at the actual surface. Therefore, constraining surface snow density to the top 0.1 m can improve boundary conditions in high-resolution firn......-evolution modeling. We have compiled an extensive dataset of 200 point measurements of surface snow density from firn cores and snow pits on the Greenland ice sheet. We find that surface snow density within 0.1 m of the surface has an average value of 315 kg m−3 with a standard deviation of 44 kg m−3, and has...

  19. Climate related trends and meteorological conditions in European Arctic region - Porsanger fjord, Norway

    Science.gov (United States)

    Cieszyńska, Agata; Stramska, Małgorzata

    2017-04-01

    Climate change has significant effect on the Arctic environment, where global trends are amplified. In this study, we have focused on the Porsanger fjord, located in European Arctic in the coastal region of the Barents Sea. We have analyzed climate related trends and meteorological condititions in the area of interest. Meteorological data included wind speed and direction, air temperature (AT) and precipitation from Era-Interim reanalysis (1986-2015) and local observations (1996-2015) from Lakselv (L, fjord's head area) and Honningsvaag (H - fjord's exit area). Our results confirm that this region is undergoing climate change related warming, which is indicated by rising air temperatures. Based on long-term reanalysis data, estimated trends for air temperature (AT) in Porsanger fjord are: 0.0536 °C year-1 at fjord's exit and 0.0428 °C year-1 at fjord's head. The results show that climate change does not seem to have a significant effect on long-term changes of wind speed and precipitation in the Porsanger fjord. Statistical analysis underlined significant spatial variability of meteorological conditions inside the fjord. For example, there are large differences in the annual cycle of AT with monthly mean January and July values of -8.4 and 12.6 °C in L and -2.5 and 10.1 °C in H. Dominant wind directions in Lakselv are S and SSE, while in Honningsvaag S and SSW directions prevail. Strong wind events (above 12 m s-1) are more frequent in H than in L. Annual cycle is characterized by stronger winds in winter and seasonality of wind direction. Precipitation for a given location can change by about 50% between years and varies spatially. Synoptic scale and within day variability are extremely intense in the area of interest. Air temperature and wind speed and direction can change dramatically in hours. In addition, regular patterns of the daily cycle of AT have different intensity in L and H. It is interesting to note that in spring/summer season, the daily cycle of

  20. On the initial condition problem of the time domain PMCHWT surface integral equation

    KAUST Repository

    Uysal, Ismail Enes; Bagci, Hakan; Ergin, A. Arif; Ulku, H. Arda

    2017-01-01

    Non-physical, linearly increasing and constant current components are induced in marching on-in-time solution of time domain surface integral equations when initial conditions on time derivatives of (unknown) equivalent currents are not enforced

  1. Modeling global residential sector energy demand for heating and air conditioning in the context of climate change

    International Nuclear Information System (INIS)

    Isaac, Morna; Vuuren, Detlef P. van

    2009-01-01

    In this article, we assess the potential development of energy use for future residential heating and air conditioning in the context of climate change. In a reference scenario, global energy demand for heating is projected to increase until 2030 and then stabilize. In contrast, energy demand for air conditioning is projected to increase rapidly over the whole 2000-2100 period, mostly driven by income growth. The associated CO 2 emissions for both heating and cooling increase from 0.8 Gt C in 2000 to 2.2 Gt C in 2100, i.e. about 12% of total CO 2 emissions from energy use (the strongest increase occurs in Asia). The net effect of climate change on global energy use and emissions is relatively small as decreases in heating are compensated for by increases in cooling. However, impacts on heating and cooling individually are considerable in this scenario, with heating energy demand decreased by 34% worldwide by 2100 as a result of climate change, and air-conditioning energy demand increased by 72%. At the regional scale considerable impacts can be seen, particularly in South Asia, where energy demand for residential air conditioning could increase by around 50% due to climate change, compared with the situation without climate change

  2. Topsoil moisture mapping using geostatistical techniques under different Mediterranean climatic conditions.

    Science.gov (United States)

    Martínez-Murillo, J F; Hueso-González, P; Ruiz-Sinoga, J D

    2017-10-01

    Soil mapping has been considered as an important factor in the widening of Soil Science and giving response to many different environmental questions. Geostatistical techniques, through kriging and co-kriging techniques, have made possible to improve the understanding of eco-geomorphologic variables, e.g., soil moisture. This study is focused on mapping of topsoil moisture using geostatistical techniques under different Mediterranean climatic conditions (humid, dry and semiarid) in three small watersheds and considering topography and soil properties as key factors. A Digital Elevation Model (DEM) with a resolution of 1×1m was derived from a topographical survey as well as soils were sampled to analyzed soil properties controlling topsoil moisture, which was measured during 4-years. Afterwards, some topography attributes were derived from the DEM, the soil properties analyzed in laboratory, and the topsoil moisture was modeled for the entire watersheds applying three geostatistical techniques: i) ordinary kriging; ii) co-kriging considering as co-variate topography attributes; and iii) co-kriging ta considering as co-variates topography attributes and gravel content. The results indicated topsoil moisture was more accurately mapped in the dry and semiarid watersheds when co-kriging procedure was performed. The study is a contribution to improve the efficiency and accuracy of studies about the Mediterranean eco-geomorphologic system and soil hydrology in field conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Climatic conditions as a risk factor in canine gastric dilatation-volvulus.

    Science.gov (United States)

    Dennler, R; Koch, D; Hassig, M; Howard, J; Montavon, P M

    2005-01-01

    Canine acute gastric dilatation-volvulus (GDV) is a life-threatening condition of multifactorial origin. The risk of developing GDV is influenced by a variety of factors, including breed, age, gender, temperament, diet and management. A relationship between seasonal variations and the frequency of GDV has been previously documented although no association was found with any specific climatic event. Variables in weather conditions within a defined geographic region were investigated in a retrospective study of 287 client-owned dogs diagnosed with GDV between 1992 and 1999. Monthly incidences were evaluated and differences in atmospheric temperature, humidity and pressure between days in which GDV cases were observed and days in which no case was presented were examined. Although temperature was significantly associated with the occurrence of GDV, the difference in temperatures between days with and days without GDV cases was so small that it is unlikely to be of clinical relevance. Moreover, no significant association was found between GDV occurrence and atmospheric pressure or humidity, and a seasonal variation in GDV incidence was not observed.

  4. Analyses of phase change materials’ efficiency in warm-summer humid continental climate conditions

    Science.gov (United States)

    Ratnieks, J.; Gendelis, S.; Jakovics, A.; Bajare, D.

    2017-10-01

    The usage of phase change materials (PCMs) is a way to store excess energy produced during the hot time of the day and release it during the night thereby reducing the overheating problem. While, in Latvian climate conditions overheating is not a big issue in traditional buildings since it happens only a couple of weeks per year air conditioners must still be installed to maintain thermal comfort. The need for cooling in recently built office buildings with large window area can increase significantly. It is therefore of great interest if the thermal comfort conditions can be maintained by PCMs alone or with reduced maximum power of installed cooling systems. Our initial studies show that if the test building is well-insulated (necessary to reduce heat loss in winter), phase change material is not able to solidify fast enough during the relatively short night time. To further investigate the problem various experimental setups with two different phase change materials were installed in test buildings. Experimental results are compared with numerical modelling made in software COMSOL Multiphysics. The effectiveness of PCM using different situations is widely analysed.

  5. Global vegetation-fire pattern under different land use and climate conditions

    Science.gov (United States)

    Thonicke, K.; Poulter, B.; Heyder, U.; Gumpenberger, M.; Cramer, W.

    2008-12-01

    Fire is a process of global significance in the Earth System influencing vegetation dynamics, biogeochemical cycling and biophysical feedbacks. Naturally ignited wildfires have long history in the Earth System. Humans have been using fire to shape the landscape for their purposes for many millenia, sometimes influencing the status of the vegetation remarkably as for example in Mediterranean-type ecosystems. Processes and drivers describing fire danger, ignitions, fire spread and effects are relatively well-known for many fire-prone ecosystems. Modeling these has a long tradition in fire-affected regions to predict fire risk and behavior for fire-fighting purposes. On the other hand, the global vegetation community realized the importance of disturbances to be recognized in their global vegetation models with fire being globally most important and so-far best studied. First attempts to simulate fire globally considered a minimal set of drivers, whereas recent developments attempt to consider each fire process separately. The process-based fire model SPITFIRE (SPread and InTensity of FIRE) simulates these processes embedded in the LPJ DGVM. Uncertainties still arise from missing measurements for some parameters in less-studied fire regimes, or from broad PFT classifications which subsume different fire-ecological adaptations and tolerances. Some earth observation data sets as well as fire emission models help to evaluate seasonality and spatial distribution of simulated fire ignitions, area burnt and fire emissions within SPITFIRE. Deforestation fires are a major source of carbon released to the atmosphere in the tropics; in the Amazon basin it is the second-largest contributor to Brazils GHG emissions. How ongoing deforestation affects fire regimes, forest stability and biogeochemical cycling in the Amazon basin under present climate conditions will be presented. Relative importance of fire vs. climate and land use change is analyzed. Emissions resulting from

  6. An ensemble prediction approach to weekly Dengue cases forecasting based on climatic and terrain conditions

    Directory of Open Access Journals (Sweden)

    Sougata Deb

    2017-11-01

    Full Text Available Introduction: Dengue fever has been one of the most concerning endemic diseases of recent times. Every year, 50-100 million people get infected by the dengue virus across the world. Historically, it has been most prevalent in Southeast Asia and the Pacific Islands. In recent years, frequent dengue epidemics have started occurring in Latin America as well. This study focused on assessing the impact of different short and long-term lagged climatic predictors on dengue cases. Additionally, it assessed the impact of building an ensemble model using multiple time series and regression models, in improving prediction accuracy. Materials and Methods: Experimental data were based on two Latin American cities, viz. San Juan (Puerto Rico and Iquitos (Peru. Due to weather and geographic differences, San Juan recorded higher dengue incidences than Iquitos. Using lagged cross-correlations, this study confirmed the impact of temperature and vegetation on the number of dengue cases for both cities, though in varied degrees and time lags. An ensemble of multiple predictive models using an elaborate set of derived predictors was built and validated. Results: The proposed ensemble prediction achieved a mean absolute error of 21.55, 4.26 points lower than the 25.81 obtained by a standard negative binomial model. Changes in climatic conditions and urbanization were found to be strong predictors as established empirically in other researches. Some of the predictors were new and informative, which have not been explored in any other relevant studies yet. Discussion and Conclusions: Two original contributions were made in this research. Firstly, a focused and extensive feature engineering aligned with the mosquito lifecycle. Secondly, a novel covariate pattern-matching based prediction approach using past time series trend of the predictor variables. Increased accuracy of the proposed model over the benchmark model proved the appropriateness of the analytical approach

  7. Combined installation of electric and heat supply for climatic conditions of Iraq

    Science.gov (United States)

    Kaisi, Osama Al; Sidenkov, D. V.

    2017-11-01

    Electricity, heating and cooling are the three main components that make up the energy consumption base in residential, commercial and public buildings around the world. Demand for energy and fuel costs are constantly growing. Combined cooling, heating and power generation or trigeneration can be a promising solution to such a problem, providing an efficient, reliable, flexible, competitive and less harmful alternative to existing heat and cold supply systems. In this paper, scheme of the tri-generation plant on non-aqueous working substances is considered as an installation of a locally centralized electro-heat and cold supply of a typical residential house in a hot climate. The scheme of the combined installation of electro-heat (cold) supply consisted of the vapor power plant and heat pump system on low-boiling working substance for local consumers under the climatic conditions of Iraq is presented. The possibility of using different working substances in the thermodynamic cycles of these units, which will provide better efficiency of such tri-generation systems is shown. The calculations of steam turbine cycles and heat pump part on the selected working substances are conducted. It is proposed to use heat exchangers of plate type as the main exchangers in the combined processing. The developed method of thermal-hydraulic calculation of heat exchangers implemented in MathCad, which allows to evaluate the efficiency of plants of this type using the ε - NTU method. For the selected working substances of the steam part the optimal temperature of heat supply to the steam generator is determined. The results of thermodynamic and technical-economic analysis of the application of various working substances in the “organic” Rankine cycle of the steam turbine unit and the heat pump system of the heat and cold supply system are presented.

  8. Impact of Climate Conditions on Occupational Health and Related Economic Losses: A New Feature of Global and Urban Health in the Context of Climate Change.

    Science.gov (United States)

    Kjellstrom, Tord

    2016-03-01

    One feature of climate change is the increasing heat exposure in many workplaces where efficient cooling systems cannot be applied. Excessive heat exposure is a particular problem for working people because of the internal heat production when muscle work is carried out. The physiological basis for severe heat stroke, other clinical effects, and heat exhaustion is well known. One feature of this health effect of excessive workplace heat exposure is reduced work capacity, and new research has started to quantify this effect in the context of climate change. Current climate conditions in tropical and subtropical parts of the world are already so hot during the hot seasons that occupational health effects occur and work capacity for many working people is affected. The Hothaps-Soft database and software andClimateCHIP.orgwebsite make it possible to rapidly produce estimates of local heat conditions and trends. The results can be mapped to depict the spatial distribution of workplace heat stress. In South-East Asia as much as 15% to 20% of annual work hours may already be lost in heat-exposed jobs, and this may double by 2050 as global climate change progresses. By combining heat exposure data and estimates of the economic consequences, the vulnerability of many low- and middle-income countries is evident. The annual cost of reduced labor productivity at country level already in 2030 can be several percent of GDP, which means billions of US dollars even for medium-size countries. The results provide new arguments for effective climate change adaptation and mitigation policies and preventive actions in all countries. © 2015 APJPH.

  9. Effect of operational conditions of electroerosion machining on the surface microgeometry parameters of steels and alloys

    International Nuclear Information System (INIS)

    Foteev, N.K.

    1976-01-01

    Studies the influence of pulse duration and a series of operating conditions of a ShGI-40-440 spark-machining generator on changes in the basic surface microgeometry characteristics of components of stainless steel 1Kh18N10T, steel St 45 and hard alloy T14K8. The microgeometry characteristics of spark-machined surfaces differ significantly from the corresponding characteristics of surfaces machined by cutting and vibro-rolling

  10. Effects of Seasonal Land Surface Conditions on Hydrometeorological Dynamics in South-western North America

    Science.gov (United States)

    2015-09-21

    rain gauges to measure precipitation , and 1 internal mini-flume to measure runoff . 9 Fig. 8. Processed fluxes measured at the two eddy...SECURITY CLASSIFICATION OF: Arid and semiarid landscapes in regions with seasonal precipitation experience dramatic changes that alter land surface...semiarid landscapes in regions with seasonal precipitation experience dramatic changes that alter land surface conditions, including soil moisture

  11. Colonization by Cladosporium spp. of painted metal surfaces associated with heating and air conditioning systems

    Science.gov (United States)

    Ahearn, D. G.; Simmons, R. B.; Switzer, K. F.; Ajello, L.; Pierson, D. L.

    1991-01-01

    Cladosporium cladosporioides and C. hebarum colonized painted metal surfaces of covering panels and register vents of heating, air conditioning and ventilation systems. Hyphae penetrated the paint film and developed characteristic conidiophores and conidia. The colonies were tightly appressed to the metal surface and conidia were not readily detectable via standard air sampling procedures.

  12. Adhesion of resin composites to biomaterials in dentistry : an evaluation of surface conditioning methods

    NARCIS (Netherlands)

    Özcan, Mutlu

    2003-01-01

    Since previous investigations revealed that most clinical failures in adhesively luted ceramic restorations initiate from the cementation or internal surfaces, the study presented in Chapter II evaluated the effect of three different surface conditioning methods on the bond strength of a Bis-GMA

  13. Clear-Sky Longwave Irradiance at the Earth's Surface--Evaluation of Climate Models.

    Science.gov (United States)

    Garratt, J. R.

    2001-04-01

    An evaluation of the clear-sky longwave irradiance at the earth's surface (LI) simulated in climate models and in satellite-based global datasets is presented. Algorithm-based estimates of LI, derived from global observations of column water vapor and surface (or screen air) temperature, serve as proxy `observations.' All datasets capture the broad zonal variation and seasonal behavior in LI, mainly because the behavior in column water vapor and temperature is reproduced well. Over oceans, the dependence of annual and monthly mean irradiance upon sea surface temperature (SST) closely resembles the observed behavior of column water with SST. In particular, the observed hemispheric difference in the summer minus winter column water dependence on SST is found in all models, though with varying seasonal amplitudes. The analogous behavior in the summer minus winter LI is seen in all datasets. Over land, all models have a more highly scattered dependence of LI upon surface temperature compared with the situation over the oceans. This is related to a much weaker dependence of model column water on the screen-air temperature at both monthly and annual timescales, as observed. The ability of climate models to simulate realistic LI fields depends as much on the quality of model water vapor and temperature fields as on the quality of the longwave radiation codes. In a comparison of models with observations, root-mean-square gridpoint differences in mean monthly column water and temperature are 4-6 mm (5-8 mm) and 0.5-2 K (3-4 K), respectively, over large regions of ocean (land), consistent with the intermodel differences in LI of 5-13 W m2 (15-28 W m2).

  14. Impact of urban WWTP and CSO fluxes on river peak flow extremes under current and future climate conditions.

    Science.gov (United States)

    Keupers, Ingrid; Willems, Patrick

    2013-01-01

    The impact of urban water fluxes on the river system outflow of the Grote Nete catchment (Belgium) was studied. First the impact of the Waste Water Treatment Plant (WWTP) and the Combined Sewer Overflow (CSO) outflows on the river system for the current climatic conditions was determined by simulating the urban fluxes as point sources in a detailed, hydrodynamic river model. Comparison was made of the simulation results on peak flow extremes with and without the urban point sources. In a second step, the impact of climate change scenarios on the urban fluxes and the consequent impacts on the river flow extremes were studied. It is shown that the change in the 10-year return period hourly peak flow discharge due to climate change (-14% to +45%) was in the same order of magnitude as the change due to the urban fluxes (+5%) in current climate conditions. Different climate change scenarios do not change the impact of the urban fluxes much except for the climate scenario that involves a strong increase in rainfall extremes in summer. This scenario leads to a strong increase of the impact of the urban fluxes on the river system.

  15. Assessing the relationship between surface urban heat islands and landscape patterns across climatic zones in China.

    Science.gov (United States)

    Yang, Qiquan; Huang, Xin; Li, Jiayi

    2017-08-24

    The urban heat island (UHI) effect exerts a great influence on the Earth's environment and human health and has been the subject of considerable attention. Landscape patterns are among the most important factors relevant to surface UHIs (SUHIs); however, the relationship between SUHIs and landscape patterns is poorly understood over large areas. In this study, the surface UHI intensity (SUHII) is defined as the temperature difference between urban and suburban areas, and the landscape patterns are quantified by the urban-suburban differences in several typical landscape metrics (ΔLMs). Temperature and land-cover classification datasets based on satellite observations were applied to analyze the relationship between SUHII and ΔLMs in 332 cities/city agglomerations distributed in different climatic zones of China. The results indicate that SUHII and its correlations with ΔLMs are profoundly influenced by seasonal, diurnal, and climatic factors. The impacts of different land-cover types on SUHIs are different, and the landscape patterns of the built-up and vegetation (including forest, grassland, and cultivated land) classes have the most significant effects on SUHIs. The results of this study will help us to gain a deeper understanding of the relationship between the SUHI effect and landscape patterns.

  16. Climate applications for NOAA 1/4° Daily Optimum Interpolation Sea Surface Temperature

    Science.gov (United States)

    Boyer, T.; Banzon, P. V. F.; Liu, G.; Saha, K.; Wilson, C.; Stachniewicz, J. S.

    2015-12-01

    Few sea surface temperature (SST) datasets from satellites have the long temporal span needed for climate studies. The NOAA Daily Optimum Interpolation Sea Surface Temperature (DOISST) on a 1/4° grid, produced at National Centers for Environmental Information, is based primarily on SSTs from the Advanced Very High Resolution Radiometer (AVHRR), available from 1981 to the present. AVHRR data can contain biases, particularly when aerosols are present. Over the three decade span, the largest departure of AVHRR SSTs from buoy temperatures occurred during the Mt Pinatubo and El Chichon eruptions. Therefore, in DOISST, AVHRR SSTs are bias-adjusted to match in situ SSTs prior to interpolation. This produces a consistent time series of complete SST fields that is suitable for modelling and investigating local climate phenomena like El Nino or the Pacific warm blob in a long term context. Because many biological processes and animal distributions are temperature dependent, there are also many ecological uses of DOISST (e.g., coral bleaching thermal stress, fish and marine mammal distributions), thereby providing insights into resource management in a changing ocean. The advantages and limitations of using DOISST for different applications will be discussed.

  17. Tensile bond strength of metal bracket bonding to glazed ceramic surfaces with different surface conditionings.

    Science.gov (United States)

    Akhoundi, Ms Ahmad; Kamel, M Rahmati; Hashemi, Sh Mahmood; Imani, M

    2011-01-01

    The objective of this study was to compare the tensile bond strength of metal brackets bonding to glazed ceramic surfaces using three various surface treatments. Forty two glazed ceramic disks were assigned to three groups. In the first and second groups the specimens were etched with 9.5% hydrofluoric acid (HFA). Subsequently in first group, ceramic primer and adhesive were applied, but in second group a bonding agent alone was used. In third group, specimens were treated with 35% phosphoric acid followed by ceramic primer and adhesive application. Brackets were bonded with light cure composites. The specimens were stored in distilled water in the room temperature for 24 hours and thermocycled 500 times between 5°C and 55°C. The universal testing machine was used to test the tensile bond strength and the adhesive remenant index scores between three groups was evaluated. The data were subjected to one-way ANOVA, Tukey and Kruskal-Wallis tests respectively. The tensile bond strength was 3.69±0.52 MPa forfirst group, 2.69±0.91 MPa for second group and 3.60±0.41 MPa for third group. Group II specimens showed tensile strength values significantly different from other groups (Ptensile bond strength.

  18. An explanation for the different climate sensitivities of land and ocean surfaces based on the diurnal cycle

    Directory of Open Access Journals (Sweden)

    A. Kleidon

    2017-09-01

    Full Text Available Observations and climate model simulations consistently show a higher climate sensitivity of land surfaces compared to ocean surfaces. Here we show that this difference in temperature sensitivity can be explained by the different means by which the diurnal variation in solar radiation is buffered. While ocean surfaces buffer the diurnal variations by heat storage changes below the surface, land surfaces buffer it mostly by heat storage changes above the surface in the lower atmosphere that are reflected in the diurnal growth of a convective boundary layer. Storage changes below the surface allow the ocean surface–atmosphere system to maintain turbulent fluxes over day and night, while the land surface–atmosphere system maintains turbulent fluxes only during the daytime hours, when the surface is heated by absorption of solar radiation. This shorter duration of turbulent fluxes on land results in a greater sensitivity of the land surface–atmosphere system to changes in the greenhouse forcing because nighttime temperatures are shaped by radiative exchange only, which are more sensitive to changes in greenhouse forcing. We use a simple, analytic energy balance model of the surface–atmosphere system in which turbulent fluxes are constrained by the maximum power limit to estimate the effects of these different means to buffer the diurnal cycle on the resulting temperature sensitivities. The model predicts that land surfaces have a 50 % greater climate sensitivity than ocean surfaces, and that the nighttime temperatures on land increase about twice as much as daytime temperatures because of the absence of turbulent fluxes at night. Both predictions compare very well with observations and CMIP5 climate model simulations. Hence, the greater climate sensitivity of land surfaces can be explained by its buffering of diurnal variations in solar radiation in the lower atmosphere.

  19. Are antimicrobial defences in bird eggs related to climatic conditions associated with risk of trans-shell microbial infection?

    Science.gov (United States)

    Horrocks, Nicholas Pc; Hine, Kathryn; Hegemann, Arne; Ndithia, Henry K; Shobrak, Mohammed; Ostrowski, Stéphane; Williams, Joseph B; Matson, Kevin D; Tieleman, B Irene

    2014-01-01

    All bird eggs are exposed to microbes in the environment, which if transmitted to the developing embryo, could cause hatching failure. However, the risk of trans-shell infection varies with environmental conditions and is higher for eggs laid in wetter environments. This might relate to generally higher microbial abundances and diversity in more humid environments, including on the surface of eggshells, as well as the need for moisture to facilitate microbial penetration of the eggshell. To protect against microbial infection, the albumen of avian eggs contains antimicrobial proteins, including lysozyme and ovotransferrin. We tested whether lysozyme and ovotransferrin activities varied in eggs of larks (Alaudidae) living along an arid-mesic gradient of environmental aridity, which we used as a proxy for risk of trans-shell infection. Contrary to expectations, lysozyme activity was highest in eggs from hotter, more arid locations, where we predicted the risk of trans-shell infection would be lower. Ovotransferrin concentrations did not vary with climatic factors. Temperature was a much better predictor of antimicrobial protein activity than precipitation, a result inconsistent with studies stressing the importance of moisture for trans-shell infection. Our study raises interesting questions about the links between temperature and lysozyme activity in eggs, but we find no support for the hypothesis that antimicrobial protein deposition is higher in eggs laid in wetter environments.

  20. Differential effects of air conditioning type on residential endotoxin levels in a semi-arid climate.

    Science.gov (United States)

    Johnston, J D; Kruman, B A; Nelson, M C; Merrill, R M; Graul, R J; Hoybjerg, T G; Tuttle, S C; Myers, S J; Cook, R B; Weber, K S

    2017-09-01

    Residential endotoxin exposure is associated with protective and pathogenic health outcomes. Evaporative coolers, an energy-efficient type of air conditioner used in dry climates, are a potential source of indoor endotoxins; however, this association is largely unstudied. We collected settled dust biannually from four locations in homes with evaporative coolers (n=18) and central air conditioners (n=22) in Utah County, Utah (USA), during winter (Jan-Apr) and summer (Aug-Sept), 2014. Dust samples (n=281) were analyzed by the Limulus amebocyte lysate test. Housing factors were measured by survey, and indoor temperature and relative humidity measures were collected during both seasons. Endotoxin concentrations (EU/mg) were significantly higher in homes with evaporative coolers from mattress and bedroom floor samples during both seasons. Endotoxin surface loads (EU/m 2 ) were significantly higher in homes with evaporative coolers from mattress and bedroom floor samples during both seasons and in upholstered furniture during winter. For the nine significant season-by-location comparisons, EU/mg and EU/m 2 were approximately three to six times greater in homes using evaporative coolers. A plausible explanation for these findings is that evaporative coolers serve as a reservoir and distribution system for Gram-negative bacteria or their cell wall components in homes. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Characterizing Pavement Surface Distress Conditions with Hyper-Spatial Resolution Natural Color Aerial Photography

    Directory of Open Access Journals (Sweden)

    Su Zhang

    2016-05-01

    Full Text Available Roadway pavement surface distress information is critical for effective pavement asset management, and subsequently, transportation management agencies at all levels (i.e., federal, state, and local dedicate a large amount of time and money to routinely evaluate pavement surface distress conditions as the core of their asset management programs. However, currently adopted ground-based evaluation methods for pavement surface conditions have many disadvantages, like being time-consuming and expensive. Aircraft-based evaluation methods, although getting more attention, have not been used for any operational evaluation programs yet because the acquired images lack the spatial resolution to resolve finer scale pavement surface distresses. Hyper-spatial resolution natural color aerial photography (HSR-AP provides a potential method for collecting pavement surface distress information that can supplement or substitute for currently adopted evaluation methods. Using roadway pavement sections located in the State of New Mexico as an example, this research explored the utility of aerial triangulation (AT technique and HSR-AP acquired from a low-altitude and low-cost small-unmanned aircraft system (S-UAS, in this case a tethered helium weather balloon, to permit characterization of detailed pavement surface distress conditions. The Wilcoxon Signed Rank test, Mann-Whitney U test, and visual comparison were used to compare detailed pavement surface distress rates measured from HSR-AP derived products (orthophotos and digital surface models generated from AT with reference distress rates manually collected on the ground using standard protocols. The results reveal that S-UAS based hyper-spatial resolution imaging and AT techniques can provide detailed and reliable primary observations suitable for characterizing detailed pavement surface distress conditions comparable to the ground-based manual measurement, which lays the foundation for the future application

  2. Growing season boundary layer climate and surface exchanges in a subarctic lichen woodland

    Science.gov (United States)

    Fitzjarrald, David R.; Moore, Kathleen E.

    1994-01-01

    Between June and August 1990, observations were made at two surface micrometeorological towers near Schefferville Quebec (54 deg 52 min N, 66 deg 40.5 min W), one in a fen and one in the subarctic lichen woodland, and at four surface climatological stations. Data from these surface stations were supplemented by regular radiosonde launches. Supporting measurements of radiative components and soil temperatures allowed heat and moisture balances to be obtained at two sites. The overall surface meteorological experiment design and results of micrometeorological observations made on a 30-m tower in the lichen woodland are presented here. Seasonal variation in the heat and water vapor transport characteristics illustrate the marked effect of the late summer climatological shift in air mass type. During the first half of the summer, average valley sidewalls only 100 m high are sufficient to channel winds along the valley in the entire convective boundary layer. Channeling effects at the surface, known for some time at the long-term climate station in Schefferville, are observed both at ridge top and in the valley, possibly the response of the flow to the NW-SE orientation of valleys in the region. Diurnal surface temperature amplitude at ridge top (approximately equal to 10 C) was found to be half that observed in the valley. Relatively large differences in precipitation among these stations and the climatological station at Schefferville airport were observed and attributed to the local topography. Eddy correlation observations of the heat, moisture and momentum transports were obtained from a 30-m tower above a sparse (approximately equal to 616 stems/ha) black spruce lichen woodland. Properties of the turbulent surface boundary layer agree well with previous wind tunnel studies over idealized rough surfaces. Daytime Bowen ratios of 2.5-3 are larger than those reported in previous studies. Surface layer flux data quality was assessed by looking at the surface layer heat

  3. Evaluation of Surface Characteristics and Shear Bond Strength of Metal Brackets Bonded to Two Different Porcelain Systems (Feldspathic/IPS-Empress-2 treated with Different Surface Conditioning Methods

    Directory of Open Access Journals (Sweden)

    Amal S Nair

    2012-01-01

    Conclusion: Surface conditioning with Co-Jet sand which produced silicatization resulted in a favorable bond strength in both feldspathic and IPS-Empress-2 ceramic surfaces. It was shown that it produced the least surface roughness among all the other surface conditioning groups.

  4. Surface energy balances of three general circulation models: Current climate and response to increasing atmospheric CO2

    International Nuclear Information System (INIS)

    Gutowski, W.J.; Gutzler, D.S.; Portman, D.; Wang, W.C.

    1988-04-01

    The surface energy balance simulated by state-of-the-art general circulation models at GFDL, GISS and NCAR for climates with current levels of atmospheric CO 2 concentration (control climate) and with twice the current levels. The work is part of an effort sponsored by the US Department of Energy to assess climate simulations produced by these models. The surface energy balance enables us to diagnose differences between models in surface temperature climatology and sensitivity to doubling CO 2 in terms of the processes that control surface temperature. Our analysis compares the simulated balances by averaging the fields of interest over a hierarchy of spatial domains ranging from the entire globe down to regions a few hundred kilometers across

  5. Research on Land Surface Thermal-Hydrologic Exchange in Southern China under Future Climate and Land Cover Scenarios

    Directory of Open Access Journals (Sweden)

    Jianwu Yan

    2013-01-01

    Full Text Available Climate change inevitably leads to changes in hydrothermal circulation. However, thermal-hydrologic exchanging caused by land cover change has also undergone ineligible changes. Therefore, studying the comprehensive effects of climate and land cover changes on land surface water and heat exchanges enables us to well understand the formation mechanism of regional climate and predict climate change with fewer uncertainties. This study investigated the land surface thermal-hydrologic exchange across southern China for the next 40 years using a land surface model (ecosystem-atmosphere simulation scheme (EASS. Our findings are summarized as follows. (i Spatiotemporal variation patterns of sensible heat flux (H and evapotranspiration (ET under the land cover scenarios (A2a or B2a and climate change scenario (A1B are unanimous. (ii Both H and ET take on a single peak pattern, and the peak occurs in June or July. (iii Based on the regional interannual variability analysis, H displays a downward trend (10% and ET presents an increasing trend (15%. (iv The annual average H and ET would, respectively, increase and decrease by about 10% when woodland converts to the cultivated land. Through this study, we recognize that land surface water and heat exchanges are affected greatly by the future climate change as well as land cover change.

  6. Tensile Bond Strength of Metal Bracket Bonding to Glazed Ceramic Surfaces With Different Surface Conditionings

    Directory of Open Access Journals (Sweden)

    M. Imani

    2011-12-01

    Full Text Available Objective: The objective of this study was to compare the tensile bond strength of metal brackets bonding to glazed ceramic surfaces using three various surface treatments.Materials and Methods: Forty two glazed ceramic disks were assigned to three groups. In the first and second groups the specimens were etched with 9.5% hydrofluoric acid (HFA. Subsequently in first group, ceramic primer and adhesive were applied, but in second group a bonding agent alone was used. In third group, specimens were treated with 35% phosphoric acid followed by ceramic primerand adhesive application. Brackets were bonded with light cure composites. The specimens were stored in distilled water in the room temperature for 24 hours and thermocycled 500 times between 5°C and 55°C. The universal testing machine was used to test the tensile bond strength and the adhesive remenant index scores between three groups was evaluated. The data were subjected to one-way ANOVA, Tukey and Kruskal-Wallis tests respectively.Results: The tensile bond strength was 3.69±0.52 MPa forfirst group, 2.69±0.91 MPa for second group and 3.60±0.41 MPa for third group. Group II specimens showed tensile strength values significantly different from other groups (P<0.01.Conclusion: In spite of limitations in laboratory studies it may be concluded that in application of Scotch bond multipurpose plus adhesive, phosphoric acid can be used instead of HFA for bonding brackets to the glazed ceramic restorations with enough tensile bond strength.

  7. Integrated analysis of present and future responses of precipitation over selected Greek areas with different climate conditions

    Science.gov (United States)

    Paparrizos, Spyridon; Maris, Fotios; Matzarakis, Andreas

    2016-03-01

    The assessment of future precipitation variations prevailing in an area is essential for the research regarding climate and climate change. The current paper focuses on 3 selected areas in Greece that present different climatic characteristics due to their location and aims to assess and compare the future variation of annual and seasonal precipitation. Future precipitation data from the ENSEMBLES anthropogenic climate-change (ACC) global simulations and the Climate version of the Local Model (CLM) were obtained and analyzed. The climate simulations were performed for the future periods 2021-2050 and 2071-2100 under the A1B and B1 scenarios. Mann-Kendall test was applied to investigate possible trends. Spatial distribution of precipitation was performed using a combination of dynamic and statistical downscaling techniques and Kriging method within ArcGIS 10.2.1. The results indicated that for both scenarios, reference periods and study areas, precipitation is expected to be critically decreased. Additionally, Mann-Kendall test application showed a strong downward trend for every study area. Furthermore, the decrease in precipitation for the Ardas River basin characterized by the continental climate will be tempered, while in the Sperchios River basin it will be smoother due to the influence of some minor climatic variations in the basins' springs in the highlands where milder conditions occur. Precipitation decrease in the Geropotamos River basin which is characterized by Mediterranean climate will be more vigorous. B1 scenario appeared more optimistic for the Ardas and Sperchios River basins, while in the Geropotamos River basin, both applied scenarios brought similar results, in terms of future precipitation response.

  8. Climate Change and water resources: Scenarios of low-flow conditions in the Upper Danube River Basin

    International Nuclear Information System (INIS)

    Mauser, W; Marke, T; Stoeber, S

    2008-01-01

    Global Climate Change will have regional impacts on the water resources and will force water resources managers and farmers to adapt. Both low-flow and its duration are critical hydrological parameters, which strongly influence the state of aquatic ecosystems as well as power production, reservoir management and industry. Impacts of future climate change is analysed using scenarios for the change of meteorological drivers and regional hydrological simulation models. The project GLOWA-Danube (www.glowa-danube.de) develops integrative modelling techniques combining process knowledge from both natural and social sciences to examine the sustainability of regional water systems as well as water management alternatives in the Upper Danube watershed (A = 77000 km 2 ). Special emphasis is given to changes in low-flow condition. DANUBIA describes the regional water cycle both physical and spatially distributed. It consists of a collection of tightly coupled models, which strictly preserve energy and matter and are not calibrated to maximise their overall predictive abilities. The paper demonstrates that DANUBIA can reproduce the daily discharge for the time period from 1971-2003 with a Nash-Suttcliffe coefficient of 0.84 (gauge Achleiten). Based on a statistical climate simulator 12 realisations of the IPCC A1B climate scenario were used to investigate impacts of climate change during the simulation period of 2011-2060. The change in discharge and frequency of occurrences of low-flow in the watershed for the scenario ensemble were analysed for the outlet gauge. The analysis shows that strong changes were simulated in the frequency of occurrences of low-flow conditions. The changing climate gradually reduces a 50-years NM7Q discharge of today to less than half of its discharge in the year 2060. These results clearly indicate that the expected climate change will strongly alter the low-flow conditions in the Upper Danube watershed.

  9. Influence of surface conditions in nucleate boiling--the concept of bubble flux density

    International Nuclear Information System (INIS)

    Shoukri, M.; Judd, R.L.

    1978-01-01

    A study of the influence of surface conditions in nucleate pool boiling is presented. The surface conditions are represented by the number and distribution of the active nucleation sites as well as the size and size distribution of the cavities that constitute the nucleation sites. The heat transfer rate during nucleate boiling is shown to be influenced by the surface condition through its effect on the number and distribution of the active nucleation sites as well as the frequency of bubble departure from each of these different size cavities. The concept of bubble flux density, which is a function of both the active site density and frequency of bubble departure, is introduced. A method of evaluating the bubble flux density is proposed and a uniform correlation between the boiling heat flux and the bubble flux density is found to exist for a particular solid-liquid combination irrespective of the surface finish within the region of isolated bubbles

  10. A missing piece of the puzzle in climate change hotspots: Near-surface turbulent interactions controlling ET-soil moisture coupling in semiarid areas

    Science.gov (United States)

    Haghighi, Erfan; Gianotti, Daniel J.; Rigden, Angela J.; Salvucci, Guido D.; Kirchner, James W.; Entekhabi, Dara

    2017-04-01

    Being located in the transitional zone between dry and wet climate areas, semiarid ecosystems (and their associated ecohydrological processes) play a critical role in controlling climate change and global warming. Land evapotranspiration (ET), which is a central process in the climate system and a nexus of the water, energy and carbon cycles, typically accounts for up to 95% of the water budget in semiarid areas. Thus, the manner in which ET is partitioned into soil evaporation and plant transpiration in these settings is of practical importance for water and carbon cycling and their feedbacks to the climate system. ET (and its partitioning) in these regions is primarily controlled by surface soil moisture which varies episodically under stochastic precipitation inputs. Important as the ET-soil moisture relationship is, it remains empirical, and physical mechanisms governing its nature and dynamics are underexplored. Thus, the objective of this study is twofold: (1) to provide observational evidence for the influence of surface cover conditions on ET-soil moisture coupling in semiarid regions using soil moisture data from NASA's SMAP satellite mission combined with independent observationally based ET estimates, and (2) to develop a relatively simple mechanistic modeling platform improving our physical understanding of interactions between micro and macroscale processes controlling ET and its partitioning in partially vegetated areas. To this end, we invoked concepts from recent progress in mechanistic modeling of turbulent energy flux exchange in bluff-rough regions, and developed a physically based ET model that explicitly accounts for how vegetation-induced turbulence in the near-surface region influences soil drying and thus ET rates and dynamics. Model predictions revealed nonlinearities in the strength of the ET-soil moisture relationship (i.e., ∂ET/∂θ) as vegetation cover fraction increases, accounted for by the nonlinearity of surface

  11. Factors affecting projected Arctic surface shortwave heating and albedo change in coupled climate models.

    Science.gov (United States)

    Holland, Marika M; Landrum, Laura

    2015-07-13

    We use a large ensemble of simulations from the Community Earth System Model to quantify simulated changes in the twentieth and twenty-first century Arctic surface shortwave heating associated with changing incoming solar radiation and changing ice conditions. For increases in shortwave absorption associated with albedo reductions, the relative influence of changing sea ice surface properties and changing sea ice areal coverage is assessed. Changes in the surface sea ice properties are associated with an earlier melt season onset, a longer snow-free season and enhanced surface ponding. Because many of these changes occur during peak solar insolation, they have a considerable influence on Arctic surface shortwave heating that is comparable to the influence of ice area loss in the early twenty-first century. As ice area loss continues through the twenty-first century, it overwhelms the influence of changes in the sea ice surface state, and is responsible for a majority of the net shortwave increases by the mid-twenty-first century. A comparison with the Arctic surface albedo and shortwave heating in CMIP5 models indicates a large spread in projected twenty-first century change. This is in part related to different ice loss rates among the models and different representations of the late twentieth century ice albedo and associated sea ice surface state. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  12. Directed International Technological Change and Climate Policy: New Methods for Identifying Robust Policies Under Conditions of Deep Uncertainty

    Science.gov (United States)

    Molina-Perez, Edmundo

    : climate change, elasticity of substitution between renewable and fossil energy and three different sources of technological uncertainty (i.e. R&D returns, innovation propensity and technological transferability). The performance of eight different GCF and non-GCF based policy regimes is evaluated in light of various end-of-century climate policy targets. Then I combine traditional scenario discovery data mining methods (Bryant and Lempert, 2010) with high dimensional stacking methods (Suzuki, Stem and Manzocchi, 2015; Taylor et al., 2006; LeBlanc, Ward and Wittels, 1990) to quantitatively characterize the conditions under which it is possible to stabilize greenhouse gas emissions and keep temperature rise below 2°C before the end of the century. Finally, I describe a method by which it is possible to combine the results of scenario discovery with high-dimensional stacking to construct a dynamic architecture of low cost technological cooperation. This dynamic architecture consists of adaptive pathways (Kwakkel, Haasnoot and Walker, 2014; Haasnoot et al., 2013) which begin with carbon taxation across both regions as a critical near term action. Then in subsequent phases different forms of cooperation are triggered depending on the unfolding climate and technological conditions. I show that there is no single policy regime that dominates over the entire uncertainty space. Instead I find that it is possible to combine these different architectures into a dynamic framework for technological cooperation across regions that can be adapted to unfolding climate and technological conditions which can lead to a greater rate of success and to lower costs in meeting the end-of-century climate change objectives agreed at the 2015 Paris Conference of the Parties. Keywords: international technological change, emerging nations, climate change, technological uncertainties, Green Climate Fund.

  13. Large Scale Skill in Regional Climate Modeling and the Lateral Boundary Condition Scheme

    Science.gov (United States)

    Veljović, K.; Rajković, B.; Mesinger, F.

    2009-04-01

    Several points are made concerning the somewhat controversial issue of regional climate modeling: should a regional climate model (RCM) be expected to maintain the large scale skill of the driver global model that is supplying its lateral boundary condition (LBC)? Given that this is normally desired, is it able to do so without help via the fairly popular large scale nudging? Specifically, without such nudging, will the RCM kinetic energy necessarily decrease with time compared to that of the driver model or analysis data as suggested by a study using the Regional Atmospheric Modeling System (RAMS)? Finally, can the lateral boundary condition scheme make a difference: is the almost universally used but somewhat costly relaxation scheme necessary for a desirable RCM performance? Experiments are made to explore these questions running the Eta model in two versions differing in the lateral boundary scheme used. One of these schemes is the traditional relaxation scheme, and the other the Eta model scheme in which information is used at the outermost boundary only, and not all variables are prescribed at the outflow boundary. Forecast lateral boundary conditions are used, and results are verified against the analyses. Thus, skill of the two RCM forecasts can be and is compared not only against each other but also against that of the driver global forecast. A novel verification method is used in the manner of customary precipitation verification in that forecast spatial wind speed distribution is verified against analyses by calculating bias adjusted equitable threat scores and bias scores for wind speeds greater than chosen wind speed thresholds. In this way, focusing on a high wind speed value in the upper troposphere, verification of large scale features we suggest can be done in a manner that may be more physically meaningful than verifications via spectral decomposition that are a standard RCM verification method. The results we have at this point are somewhat

  14. Isotopic evidence for climatic conditions in Southeast Asia at the last glacial maximum

    International Nuclear Information System (INIS)

    Aggarwal, P.K.; Gibson, J.J.; Kulkarni, K.M.; Froehlich, K.

    2002-01-01

    Stable isotope composition of dated groundwater archives from the Philippines, Vietnam, Thailand and Bangladesh trace changes in monsoon conditions, primarily rainout processes between the Last Glacial Maximum (LGM) and present day in southeast Asia. Today, isotope-climate relations are well established by the IAEA/WMO Global Network of Isotopes in Precipitation survey which reveals more depleted δ 18 O and δ 2 H for the Pacific Ocean monsoon regime than for the Indian Ocean monsoon regime, primarily due to proximal ocean sources and subdued continental moisture recycling for the latter region. Groundwater archives, reflecting past isotopic composition of precipitation, strongly suggest that this distinction was preserved or slightly enhanced at the time of the LGM, despite an apparent weakening of the summer monsoon and associated rainout processes. Overall, precipitation and moisture recycling, and enhanced continental effects are inferred to be the primary controls on δ 18 O signals in groundwater in southeast Asia. Comparison of groundwater isotope signatures and an ECHAM4 model simulation of the isotopic distribution in precipitation at 21ka reveal similar patterns, but the impacts of increased air mass contributions from high latitudes and reduced Eurasian moisture recycling at the LGM are shown to be potentially greater for the Pacific region than predicted by the model. (author)

  15. Response of tomato cultivars to different organic fertilizers under agro-climatic conditions of mingora, Swat

    International Nuclear Information System (INIS)

    Yousafzai, S.K.; Khan, S.M.; Khan, J.; Khan, S.A.; Hussain, I.; Naz, I.

    2016-01-01

    An experiment was conducted at Agricultural Research Institute (ARI) Mingora, Swat during 2013 to study the effect of different organic fertilizers of tomato cultivars under the agro-climatic conditions of Mingora, Swat. The experiment was conducted in randomized complete block design with split plot arrangements having four treatments with three replications. Almost all the traits showed significant differences for organic fertilizers and varieties, while their interactions had a varied response. The analyzed data showed that poultry manure gave maximum yield (24.65 t ha/sup -1/), followed by FYM (24.38 t ha/sup -1/) and mushroom compost (24.11 t ha/sup -1/ ) while minimum was recorded in plots where no organic fertilizer was used. The results revealed that cultivar, Rio Grand showed maximum number of plant survival percentage (98.33 percent), days to flowering (40.73), number of flowers plant/sup -1/ (6.23), number of fruit plant (25.67), fruit 3 weight (8.84 kg), number of leaves plant/sup -1/ (83.66), fruit size (64.70 cm/sup 3/) and total yield (25.67 t ha/sup -1/ ) in Farm Yard Manure (FYM). Considering the overall performance, it was found that the tomato cultivar Rio Grand was promising for yield and other characters where FYM was applied. (author)

  16. Experimental investigation on a coupled solar still under desert climatic conditions

    International Nuclear Information System (INIS)

    Boukar, M.; Harmim, A.

    2000-01-01

    Distillation of water is energy intensive, and the use of solar energy for this purpose has been quite well developed and applied in many places. The performance of a simple basin greenhouse-type solar still coupled to a flat plate collector is experimentally investigated. The Saharan sites of Algeria enjoys bright sunshine and dry weather during most part of year. The objective of the work is to improve the performances of a simple single basin solar still, we test the distillation system in winter, under desert climatic conditions, to improve the quality and increase the quantity of distilled water, by using a solar collector for increasing the brine temperature, enhancing the evaporation process of a simple solar still and improving distillate collection process. Experiments have been conducted in Adrar, Algerian desert town (27 degree 18' N, latitude, 0 degree 17' W longitude). The daily still productivity in winter period varies from 4.5 l/m 2 /day to 5.3 l/m 2 /day with variation of water level from 1.5 cm to 3.5 cm. (Author)

  17. Alpha-amylase activity in wheat flour and breadmaking properties in relation to different climatic conditions

    Directory of Open Access Journals (Sweden)

    Rakita Slađana M.

    2015-01-01

    Full Text Available The aim of the present paper was to evaluate the influence of different climatic conditions on the activity of alpha-amylase in wheat samples and bread quality parameters. Three wheat varieties grown in three different localities in three years were chosen for this study. Commonly used methods for estimation of alpha-amylase activity in wheat grain were employed. The obtained results indicated that harvest year 2013, which was characterized with the excessive amount of rainfall, exhibited the highest level of alpha-amylase activity and the lowest values of the peak viscosity. The lowest alpha-amylase level and the highest peak viscosity and FN value were observed for samples harvested in 2012 which was characterized with the greatest number of days with an average daily temperature above 30 and 35°C. In addition, a decrease in Mixolab parameter torque C3 and specific bread loaf volume, as well as increase in the breakdown torque (C3-C4 of samples harvested in 2013 were observed, which could be attributed to rainy weather influencing increase in alpha-amylase activity. It is found that specific bread loaf volume of wheat samples is highest in 2012. Moreover, a negative correlation between alpha-amylase activity and specific bread volume for all the samples grown in three years was determined.

  18. Nitrogen effects on growth and development of sunflower hybrids under agro-climatic conditions of malonate

    International Nuclear Information System (INIS)

    Nasim, W.; Ahmad, A.; Wajid, A.; Muhammad, D.

    2011-01-01

    The effect of nitrogen (N) on growth, development, yield and yield components of different sunflower (Helianthus annuus L.) hybrids was evaluated under agro-climatic conditions of Multan during spring 2008 and 2009. The experiment was laid out in a randomized complete block design with split plot arrangement having three replications, keeping cultivars in the main plots and N levels in the subplots. The net plot size was 4.2 m x 5 m. The results showed that, with increasing N rates, there was increment in the biomass, yield and yield components while the oil contents were adversely affected. However, there was high seed yield in 2008 as compared to 2009. Among sunflower hybrids, Hysun-38 gave more yield as compared to other sunflower hybrids (Hysun-33, Pioneer 64A93), while in case of N levels, 180 kg ha/sup -1/ provided higher yield than other N rates (0, 60, 120, 240 kg ha/sup -1/) in both years of study especially during 2008. (author)

  19. Wheat breadmaking properties in dependance on wheat enzymes status and climate conditions.

    Science.gov (United States)

    Tomić, Jelena; Torbica, Aleksandra; Popović, Ljiljana; Hristov, Nikola; Nikolovski, Branislava

    2016-05-15

    The objective of this study was to evaluate albumins profile, proteolytic and amylolytic activity level and baking performance of wheat varieties grown in two production years with different climate conditions (2011 and 2012) in four locations. The results of ANOVA showed that variety, location, production year, and their interactions all had significant effects on all tested wheat quality parameters. The enzymatic activity and specific bread volume were mainly influenced by the variety. The samples from 2012 production year, had the lower values of albumin content, proteolytic and amylolytic activity, and bread specific volume. The correlation analysis, performed for 2011 production year, showed that albumin fraction (15-30 kDa) and proteolytic activity were negatively correlated with bread specific volume indicating the role of this fraction on lowering the crucial bread quality parameter. In 2012 production year, albumin fractions (5-15 kDa; 50-65 kDa) showed the most correlations, especially with parameters of bread quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Energy-Efficient Supermarket Heating, Ventilation, and Air Conditioning in Humid Climates in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Clark, J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-03-01

    Supermarkets are energy-intensive buildings that consume the greatest amount of electricity per square foot of building of any building type in the United States and represent 5% of total U.S. commercial building primary energy use (EIA 2005). Refrigeration and heating, ventilation, and air-conditioning (HVAC) systems are responsible for a large proportion of supermarkets’ total energy use. These two systems sometimes work together and sometimes compete, but the performance of one system always affects the performance of the other. To better understand these challenges and opportunities, the Commercial Buildings team at the National Renewable Energy Laboratory investigated several of the most promising strategies for providing energy-efficient HVAC for supermarkets and quantified the resulting energy use and costs using detailed simulations. This research effort was conducted on behalf of the U.S. Department of Energy (DOE) Commercial Building Partnerships (CBP) (Baechler et al. 2012; Parrish et al. 2013; Antonopoulos et al. 2014; Hirsch et al. 2014). The goal of CBP was to reduce energy use in the commercial building sector by creating, testing, and validating design concepts on the pathway to net zero energy commercial buildings. Several CBP partners owned or operated buildings containing supermarkets and were interested in optimizing the energy efficiency of supermarket HVAC systems in hot-humid climates. These partners included Walmart, Target, Whole Foods Market, SUPERVALU, and the Defense Commissary Agency.

  1. Composition of Myrtus communis L. Essential Oils as Affected by Climatic Conditions

    Directory of Open Access Journals (Sweden)

    Paula Pereira

    2016-12-01

    Full Text Available Myrtus Communis L. (Myrtaceae family, commonly known as myrtle, possesses a set of qualities that make it very interesting for the pharmaceutical, nutraceutical and cosmetic industries. In this work, myrtle was studied over a period of three years (2006-2008, encompassing the main stages of the development cycle of the plant. The influence of climatic conditions, such as temperature and rainfall, on the chemical composition and yield of the essential oils obtained from leaves and berries was studied. The leaves and berries essential oils were obtained by Clevenger distillation and analysed by GC and GC-MS. The results show that the major components were limonene+1,8-cineole, myrtenyl acetate, α-pinene and linalool. Over the three year period of study, a decrease in the composition of the most volatile compounds (α-pinene and limonene+1,8-cineole was observed, the reverse being found for linalool and myrtenyl acetate. The highest value for the yield of the leaves’ essential oils was observed in the third year (0.64%, w/w, whereas that same year the lowest yield (0.07%, w/w of fruit was observed. These results were likely due to an atypically high record for rainfall in April and May of that year. The highest value of the berry essential oils (0.14%, w/w was obtained in the second year.

  2. Understanding surface-water availability in the Central Valley as a means to projecting future groundwater storage with climate variability

    Science.gov (United States)

    Goodrich, J. P.; Cayan, D. R.

    2017-12-01

    California's Central Valley (CV) relies heavily on diverted surface water and groundwater pumping to supply irrigated agriculture. However, understanding the spatiotemporal character of water availability in the CV is difficult because of the number of individual farms and local, state, and federal agencies involved in using and managing water. Here we use the Central Valley Hydrologic Model (CVHM), developed by the USGS, to understand the relationships between climatic variability, surface water inputs, and resulting groundwater use over the historical period 1970-2013. We analyzed monthly surface water diversion data from >500 CV locations. Principle components analyses were applied to drivers const