The biosphere as a driver of global atmospheric change

International Nuclear Information System (INIS)

Levine, J.S.

1991-01-01

The effects of the biosphere on the evolution of atmospheric oxygen and ozone, and the consequences of that development for global atmospheric change, are discussed. Attention is given to the impact of oxygen and ozone on atmospheric photolysis rates, the effect of oxygen on the biogenic production of nitrous oxide and nitric oxide, and the effects of the evolution of atmospheric oxygen on fires and biomass burning. The influence of the latter on atmospheric processes, particularly the production of methane, carbon dioxide, and carbon monoxide, is considered. 41 refs

Isotopic study of water exchange between atmosphere and biosphere at Changa Manga site in Pakistan

International Nuclear Information System (INIS)

Fazil, M.; Ali, M.; Latif, Z.; Butt, S.

2012-01-01

Study of water exchange between atmosphere and biosphere was initiated to understand the ties between these two spheres. Samples of leaves and stems of 23 woody plants along with soil from the surface and from the depth of 7 cm were collected from Changa Manga forest. Moisture content from these samples was extracted using the vacuum distillation method and analyzed for stable isotopes (/sup 18/O and /sup 2/H). Air moisture was also collected in the field. Isotopic data plotted long with the Local Meteoric Water Line (LMWL) indicates that /sup 18/O and /sup 2/H contents of moisture in the leaves of woody plants are higher than their respective stems. This behavior is due to the evaporative enrichment trend originating from the soil moisture in active root zone and also from the leaf surface. The stem samples did not show any significant variation in gamma /sup 18/O suggesting no significant evaporation from stems of big trees. Degree of enrichment of leave samples of woody plants indicated the species-specific effects in isotopes during transpiration. Pine and Eucalyptus leaves showed more variation in the isotopic contents as compared to other species. Temporal variations of /sup 18/O and /sup 2/H in the leaves indicated enriched isotopic values during hot and dry periods as compared to those during wet period (monsoon and winter rains) mainly due to higher transpiration rates at high temperature and low humidity. (orig./A.B.)

Insights from a network of long-term measurements of biosphere-atmospheric exchanges of water vapor and carbon dioxide in southern Arizona

Science.gov (United States)

Scott, R. L.; Barron-Gafford, G.; Biederman, J. A.

2016-12-01

Around one-third of Earth's land surface is classified as semiarid, and carbon dioxide exchange in these regions has been shown to be an important regulator of both the trend and interannual variability of the terrestrial carbon sink. Fifteen years ago, when we began making measurements of biosphere-atmospheric exchanges of energy, water vapor, and carbon dioxide using eddy covariance in southern Arizona USA, there was paucity of semiarid observations in flux networks like Ameriflux. We started by establishing riparian sites across a woody plant encroachment gradient to quantify the productivity and consumptive plant water use along a iconic and ecologically important desert river. Soon thereafter, we added semiarid grassland, shrubland, and savanna sites that do not have access to groundwater in order to better understand how water limitation and changes in vegetation structure affect ecosystem productivity. Here, we highlight the value of multiyear, multisite flux data for addressing regional to global scale problems associated with groundwater pumping, land cover change, drought, and climate change. For the riparian sites, we find that ecosystem water availability is altered by vegetation structure such that ecosystems with more deeply rooted trees have higher productivity but at a cost of greater groundwater use. For the non-riparian sites, precipitation strongly controls ecosystem water availability and the resultant productivity, but differences in ecosystem structure impact water use efficiency due to the partitioning of evapotranspiration into its component sources. Also, the productivity at sites with more grass, and less woody, plants responds more quickly to precipitation fluctuations including long-term drought conditions. In semiarid regions, variability in water and carbon fluxes is much larger than in more mesic climes. Across our riparian and non-riparian sites, access to more stable groundwater reserves reduces variability in water and carbon

Sensitivity study of land biosphere CO2 exchange through an atmospheric tracer transport model using satellite-derived vegetation index data

International Nuclear Information System (INIS)

Knorr, W.; Heimann, M.

1994-01-01

We develop a simple, globally uniform model of CO 2 exchange between the atmosphere and the terrestrial biosphere by coupling the model with a three-dimensional atmospheric tracer transport model using observed winds, and checking results against observed concentrations of CO 2 at various monitoring sites. CO 2 fluxes are derived from observed greenness using satellite-derived Global Vegetation Index data, combined with observations of temperature, radiation, and precipitation. We explore a range of CO 2 flux formulations together with some modifications of the modelled atmospheric transport. We find that while some formulations can be excluded, it cannot be decided whether or not to make CO 2 uptake and release dependent on water stress. It appears that the seasonality of net CO 2 fluxes in the tropics, which would be expected to be driven by water availability, is small and is therefore not visible in the seasonal cycle of atmospheric CO 2 . The latter is dominated largely by northern temperate and boreal vegetation, where seasonality is mostly temperature determined. We find some evidence that there is still considerable CO 2 release from soils during northern-hemisphere winter. An exponential air temperature dependence of soil release with a Q 10 of 1.5 is found to be most appropriate, with no cutoff at low freezing temperatures. This result is independent of the year from which observed winds were taken. This is remarkable insofar as year-to-year changes in modelled CO 2 concentrations caused by changes in the wind data clearly outweigh those caused by year-to-year variability in the climate and vegetation index data. (orig.)

SiB3 Modeled Global 1-degree Hourly Biosphere-Atmosphere Carbon Flux, 1998-2006

Data.gov (United States)

National Aeronautics and Space Administration — The Simple Biosphere Model, Version 3 (SiB3) was used to produce a global data set of hourly carbon fluxes between the atmosphere and the terrestrial biosphere for...

Quantifying regional changes in terrestrial carbon storage by extrapolation from local ecosystem models

Energy Technology Data Exchange (ETDEWEB)

King, A W

1991-12-31

A general procedure for quantifying regional carbon dynamics by spatial extrapolation of local ecosystem models is presented Monte Carlo simulation to calculate the expected value of one or more local models, explicitly integrating the spatial heterogeneity of variables that influence ecosystem carbon flux and storage. These variables are described by empirically derived probability distributions that are input to the Monte Carlo process. The procedure provides large-scale regional estimates based explicitly on information and understanding acquired at smaller and more accessible scales.Results are presented from an earlier application to seasonal atmosphere-biosphere CO{sub 2} exchange for circumpolar ``subarctic`` latitudes (64{degree}N-90{degree}N). Results suggest that, under certain climatic conditions, these high northern ecosystems could collectively release 0.2 Gt of carbon per year to the atmosphere. I interpret these results with respect to questions about global biospheric sinks for atmospheric CO{sub 2} .

Modern Microbial Ecosystems are a Key to Understanding Our Biosphere's Early Evolution and its Contributions To The Atmosphere and Rock Record

Science.gov (United States)

DesMarais, David J.; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

The survival of our early biosphere depended upon efficient coordination anion- diverse microbial populations. Microbial mats exhibit a 3.46-billion-year fossil record, thus they are the oldest known ecosystems. Photosynthetic microbial mats were key because, today, sunlight powers more than 99 percent of global primary productivity. Thus photosynthetic ecosystems have affected the atmosphere profoundly and have created the most pervasive, easily-detected fossils. Photosynthetic biospheres elsewhere will be most detectible via telescopes or spacecraft. As a part of the Astrobiology Institute, our Ames Microbial Ecosystems group examines the roles played by ecological processes in the early evolution of our biosphere, as recorded in geologic fossils and in the macromolecules of living cells: (1) We are defining the microbial mat microenvironment, which was an important milieu for early evolution. (2) We are comparing mats in contrasting environments to discern strategies of adaptation and diversification, traits that were key for long-term survival. (3) We have selected sites that mimic key environmental attributes of early Earth and thereby focus upon evolutionary adaptations to long-term changes in the global environment. (4) Our studies of gas exchange contribute to better estimates of biogenic gases in Earth's early atmosphere. This group therefore directly addresses the question: How have the Earth and its biosphere influenced each other over time Our studies strengthen the systematics for interpreting the microbial fossil record and thereby enhance astrobiological studies of martian samples. Our models of biogenic gas emissions will enhance models of atmospheres that might be detected on inhabited extrasolar planets. This work therefore also addresses the question: How can other biospheres be recogniZed" Our choice of field sites helps us explore Earth's evolving early environment. For example, modern mats that occupy thermal springs and certain freshwater

Effects on the atmosphere of a major nuclear exchange

International Nuclear Information System (INIS)

1985-01-01

The Committee on the Atmospheric Effects of Nuclear Explosions addressed the following charge: (1) determine the manner in which the atmosphere of the earth would be modified by a major exchange of nuclear weapons and, insofar as the current state of knowledge and understanding permits, give a quantitative description of the more important of the changes; and (2) recommend research and exploratory work appropriate to a better understanding of the question. Recent calculations by different investigators suggest that the climatic effects from a major nuclear exchange could be large in scale. Although there are enormous uncertainties involved in the calculations, the committee believes that long-term climatic effects with severe implications for the biosphere could occur, and these effects should be included in any analysis of the consequences of nuclear war. The estimates are necessarily rough and can only be used as a general indication of the seriousness of what might occur

Quantifying the influence of the terrestrial biosphere on glacial–interglacial climate dynamics

Directory of Open Access Journals (Sweden)

T. Davies-Barnard

2017-10-01

Full Text Available The terrestrial biosphere is thought to be a key component in the climatic variability seen in the palaeo-record. It has a direct impact on surface temperature through changes in surface albedo and evapotranspiration (so-called biogeophysical effects and, in addition, has an important indirect effect through changes in vegetation and soil carbon storage (biogeochemical effects and hence modulates the concentrations of greenhouse gases in the atmosphere. The biogeochemical and biogeophysical effects generally have opposite signs, meaning that the terrestrial biosphere could potentially have played only a very minor role in the dynamics of the glacial–interglacial cycles of the late Quaternary. Here we use a fully coupled dynamic atmosphere–ocean–vegetation general circulation model (GCM to generate a set of 62 equilibrium simulations spanning the last 120 kyr. The analysis of these simulations elucidates the relative importance of the biogeophysical versus biogeochemical terrestrial biosphere interactions with climate. We find that the biogeophysical effects of vegetation account for up to an additional −0.91 °C global mean cooling, with regional cooling as large as −5 °C, but with considerable variability across the glacial–interglacial cycle. By comparison, while opposite in sign, our model estimates of the biogeochemical impacts are substantially smaller in magnitude. Offline simulations show a maximum of +0.33 °C warming due to an increase of 25 ppm above our (pre-industrial baseline atmospheric CO2 mixing ratio. In contrast to shorter (century timescale projections of future terrestrial biosphere response where direct and indirect responses may at times cancel out, we find that the biogeophysical effects consistently and strongly dominate the biogeochemical effect over the inter-glacial cycle. On average across the period, the terrestrial biosphere has a −0.26 °C effect on temperature, with −0.58 °C at the

Toward Reducing Uncertainties in Biospheric Carbon Uptake in the American West: An Atmospheric Perspective

Science.gov (United States)

Lin, J. C.; Stephens, B. B.; Mallia, D.; Wu, D.; Jacobson, A. R.

2015-12-01

Despite the need for an understanding of terrestrial biospheric carbon fluxes to account for carbon cycle feedbacks and predict future CO2 concentrations, knowledge of such fluxes at the regional scale remains poor. This is particularly true in mountainous areas, where lack of observations combined with difficulties in their interpretation lead to significant uncertainties. Yet mountainous regions are also where significant forest cover and biomass are found—areas that have the potential to serve as carbon sinks. In particular, understanding carbon fluxes in the American West is of critical importance for the U.S. carbon budget, as the large area and biomass indicate potential for carbon sequestration. However, disturbances such as drought, insect outbreak, and wildfires in this region can introduce significant perturbations to the carbon cycle and thereby affect the amount of carbon sequestered by vegetation in the Rockies. To date, there have been few atmospheric CO2 observations in the American Rockies due to a combination of difficulties associated with logistics and interpretation of the measurements in the midst of complex terrain. Among the few sites are those associated with NCAR's Regional Atmospheric Continuous CO2 Network in the Rocky Mountains (Rocky RACCOON). As CO2 observations in mountainous areas increase in the future, it is imperative that they can be properly interpreted to yield information about biospheric carbon fluxes. In this paper, we will present CO2 observations from RACCOON, along with atmospheric simulations that attempt to extract information about biospheric carbon fluxes in the Western U.S. from these observations. We show that atmospheric models can significantly misinterpret the CO2 observations, leading to large errors in the retrieved biospheric fluxes, due to erroneous atmospheric flows. Recommendations for ways to minimize such errors and properly link the CO2 concentrations to biospheric fluxes are discussed.

Insights from a network of long-term measurements of biosphere-atmospheric exchanges of water vapor and carbon dioxide in a water-limited semiarid region

Science.gov (United States)

Scott, Russell; Biederman, Joel

2017-04-01

Around one-third of Earth's land surface is classified as semiarid, and carbon dioxide exchange in these regions has been shown to be an important regulator of both the trend and interannual variability of the terrestrial carbon sink. Fifteen years ago, when we began making measurements of biosphere-atmospheric exchanges of energy, water vapor, and carbon dioxide using eddy covariance in southern Arizona USA, there was paucity of semiarid observations in flux networks like AmeriFlux and EuroFlux. We started by establishing riparian sites across a woody plant encroachment gradient to quantify the productivity and consumptive plant water use along a iconic and ecologically important desert river. Soon thereafter, we added semiarid grassland, shrubland, and savanna sites that do not have access to groundwater in order to better understand how water limitation and changes in vegetation structure affect ecosystem productivity. Here, we highlight the value of multiyear, multisite flux data for addressing regional to global scale problems associated with groundwater pumping, land cover change, drought, and climate change. For the riparian sites, we find that ecosystem water availability is altered by vegetation structure such that ecosystems with more deeply rooted trees have higher productivity but at a cost of greater groundwater use. For the non-riparian sites, precipitation strongly controls ecosystem water availability and the resultant productivity, but differences in ecosystem structure impact water use efficiency due to the partitioning of evapotranspiration into its component sources. Also, the productivity at sites with more grass, and less woody, plants responds more quickly to precipitation fluctuations including long-term drought conditions. In semiarid regions, variability in water and carbon fluxes is much larger than in more mesic climes. Across our riparian and non-riparian sites, access to more stable groundwater reserves reduces variability in water and

Monitoring and modelling of biosphere/atmosphere exchange of gases and aerosols in Europe

Energy Technology Data Exchange (ETDEWEB)

Erisman, Jan Willem [Energy Research Centre of the Netherlands (ECN), P.O. Box 1, 1755 ZG Petten (Netherlands)]. E-mail: erisman@ecn.nl; Vermeulen, Alex [Energy Research Centre of the Netherlands (ECN), P.O. Box 1, 1755 ZG Petten (Netherlands); Hensen, Arjan [Energy Research Centre of the Netherlands (ECN), P.O. Box 1, 1755 ZG Petten (Netherlands); Flechard, Chris [Energy Research Centre of the Netherlands (ECN), P.O. Box 1, 1755 ZG Petten (Netherlands); Daemmgen, Ulrich [Federal Agricultural Research Centre, Institute of Agroecology, D-38116 Braunschweig, (Germany); Fowler, David [CEH, Bush Estate, Penicuik, Midlothian EH26 0QB (United Kingdom); Sutton, Mark [CEH, Bush Estate, Penicuik, Midlothian EH26 0QB (United Kingdom); Gruenhage, Ludger [Institute for Plant Ecology, Justus-Liebig-University, D-35392 Giessen (Germany); Tuovinen, Juha-Pekka [Finnish Meteorological Institute, FIN-00810 Helsinki (Finland)

2005-02-01

Monitoring and modelling of deposition of air pollutants is essential to develop and evaluate policies to abate the effects related to air pollution and to determine the losses of pollutants from the atmosphere. Techniques for monitoring wet deposition fluxes are widely applied. A recent intercomparison experiment, however, showed that the uncertainty in wet deposition is relatively high, up to 40%, apart from the fact that most samplers are biased because of a dry deposition contribution. Wet deposition amounts to about 80% of the total deposition in Europe with a range of 10-90% and uncertainty should therefore be decreased. During recent years the monitoring of dry deposition has become possible. Three sites have been operational for 5 years. The data are useful for model development, but also for model evaluation and monitoring of progress in policy. Data show a decline in SO{sub 2} dry deposition, whereas nitrogen deposition remained constant. Furthermore, surface affinities for pollutants changed leading to changes in deposition. Deposition models have been further developed and tested with dry deposition measurements and total deposition measurements on forests as derived from throughfall data. The comparison is reasonable given the measurement uncertainties. Progress in ozone surface exchange modelling and monitoring shows that stomatal uptake can be quantified with reasonable accuracy, but external surface uptake yields highest uncertainty. - Monitoring and modelling of the deposition of sulphur and nitrogen components and the exposure of ozone has gained much progress through the research within BIATEX.

ROLE OF LEAF SURFACE WATER IN THE BI-DIRECTIONAL AMMONIA EXCHANGE BETWEEN THE ATMOSPHERE AND TERRESTRIAL BIOSPHERE

Science.gov (United States)

A field experiment was conducted to study the ammonia exchange between plants and the atmosphere in a soybean field in Duplin County, North Carolina during the summer of 2002. Measurements indicate that the net canopy-scale ammonia exchange is bi-directional and has a significant...

Geosphere-Biosphere interface zone: the role of vegetation in water and element exchanges

International Nuclear Information System (INIS)

Vincke, C.

2007-01-01

The forest tree vegetation, because of its longevity and high evaporative capacity, has a great influence on the water cycling: it can transpire about 80% of the potential evapotranspiration (PET, mm) under high evaporative demand. The presence of a shallow water table increases the water's availability to root uptake from deep layers. In the scenario of a water table polluted with radionuclides, identifying the sources of water used by the forest vegetation (precipitation vs groundwater) is necessary to correctly predict the rhythm at which radionuclides will be absorbed by trees and further recycled into biosphere. This study aims at understanding and quantifying the forest vegetation and water table interactions. Through the soil-tree-atmosphere continuum, the water fluxes were monitored in parallel to the element cycle, the biomass compartments and the ecophysiological response of a Scots pine stand during 2005 growing season

Integrating Biodiversity into Biosphere-Atmosphere Interactions Using Individual-Based Models (IBM)

Science.gov (United States)

Wang, B.; Shugart, H. H., Jr.; Lerdau, M.

2017-12-01

A key component regulating complex, nonlinear, and dynamic biosphere-atmosphere interactions is the inherent diversity of biological systems. The model frameworks currently widely used, i.e., Plant Functional Type models) do not even begin to capture the metabolic and taxonomic diversity found in many terrestrial systems. We propose that a transition from PFT-based to individual-based modeling approaches (hereafter referred to as IBM) is essential for integrating biodiversity into research on biosphere-atmosphere interactions. The proposal emerges from our studying the interactions of forests with atmospheric processes in the context of climate change using an individual-based forest volatile organic compounds model, UVAFME-VOC. This individual-based model can explicitly simulate VOC emissions based on an explicit modelling of forest dynamics by computing the growth, death, and regeneration of each individual tree of different species and their competition for light, moisture, and nutrient, from which system-level VOC emissions are simulated by explicitly computing and summing up each individual's emissions. We found that elevated O3 significantly altered the forest dynamics by favoring species that are O3-resistant, which, meanwhile, are producers of isoprene. Such compositional changes, on the one hand, resulted in unsuppressed forest productivity and carbon stock because of the compensation by O3-resistant species. On the other hand, with more isoprene produced arising from increased producers, a possible positive feedback loop between tropospheric O3 and forest thereby emerged. We also found that climate warming will not always stimulate isoprene emissions because warming simultaneously reduces isoprene emissions by causing a decline in the abundance of isoprene-emitting species. These results suggest that species diversity is of great significance and that individual-based modelling strategies should be applied in studying biosphere-atmosphere interactions.

Back-exchange: a novel approach to quantifying oxygen diffusion and surface exchange in ambient atmospheres.

Science.gov (United States)

Cooper, Samuel J; Niania, Mathew; Hoffmann, Franca; Kilner, John A

2017-05-17

A novel two-step Isotopic Exchange (IE) technique has been developed to investigate the influence of oxygen containing components of ambient air (such as H 2 O and CO 2 ) on the effective surface exchange coefficient (k*) of a common mixed ionic electronic conductor material. The two step 'back-exchange' technique was used to introduce a tracer diffusion profile, which was subsequently measured using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). The isotopic fraction of oxygen in a dense sample as a function of distance from the surface, before and after the second exchange step, could then be used to determine the surface exchange coefficient in each atmosphere. A new analytical solution was found to the diffusion equation in a semi-infinite domain with a variable surface exchange boundary, for the special case where D* and k* are constant for all exchange steps. This solution validated the results of a numerical, Crank-Nicolson type finite-difference simulation, which was used to extract the parameters from the experimental data. When modelling electrodes, D* and k* are important input parameters, which significantly impact performance. In this study La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF6428) was investigated and it was found that the rate of exchange was increased by around 250% in ambient air compared to high purity oxygen at the same pO 2 . The three experiments performed in this study were used to validate the back-exchange approach and show its utility.

Exchange Processes at Geosphere-Biosphere Interface

International Nuclear Information System (INIS)

Worman, A.; Sjogren, B.; Dverstorp, B.; Xu, S.

2004-01-01

The radioecological models included in performance assessments to date by the Swedish nuclear industry for existing and planned nuclear waste repositories do not explicitly represent the transport of radionuclides from bedrock into the near-surface geological environment. It has been argued that bypassing the transition zone from the bedrock to the quarternary deposits and the biosphere (the geosphere-biosphere interface, GBI) leads to conservative estimates of estimated doses and risk. This study demonstrates that this may not always be true. The study is based on an integrated model representation of a release of radionuclides from a hypothetical repository, transport through the crystalline bedrock and the near-surface deposits to the biosphere. A three-dimensional flow model is developed, which has a fairly accurate description of both surface and groundwater hydrology and is coupled to radioecological models. The development has great significance for estimation of flow field at the repository level as well as for estimation of transport pathways and residence time distributions for radionuclides. The modelling approach is based on the characterisation of radionuclide residence times in the bedrock and the quaternary deposits, as well as the distribution of radionuclides in ecosystems. Simulation examples are presented to illustrate the relative importance of transport processes in the quaternary sediments and the hydraulic interaction between the bedrock, quaternary deposits and various ecosystems. The modelling results show that, in many cases, taking into account the biosphere-geosphere interface leads to a delay of radionuclide arrival to the biosphere. For other conditions, the more precise prediction of radionuclide ex-filtration locations in the biosphere can result in higher environmental concentrations compared with estimates based on diluting radionuclide in a large area. An improved representation of these processes will enhance our understanding of

The Biosphere.

Science.gov (United States)

Cloud, Preston

1983-01-01

Discusses the earth's biosphere, considering how the microbial, animal and plant life (which make up the biosphere) are sustained by the earth's lithosphere, hydrosphere, and atmosphere. Also considers how these three earth features have powerfully shaped the evolution of these organisms. (JN)

Assessing the Importance of Prior Biospheric Fluxes on Inverse Model Estimates of CO2

Science.gov (United States)

Philip, S.; Johnson, M. S.; Potter, C. S.; Genovese, V. B.

2017-12-01

Atmospheric mixing ratios of carbon dioxide (CO2) are largely controlled by anthropogenic emissions and biospheric sources/sinks. The processes controlling terrestrial biosphere-atmosphere carbon exchange are currently not fully understood, resulting in models having significant differences in the quantification of biospheric CO2 fluxes. Currently, atmospheric chemical transport models (CTM) and global climate models (GCM) use multiple different biospheric CO2 flux models resulting in large differences in simulating the global carbon cycle. The Orbiting Carbon Observatory 2 (OCO-2) satellite mission was designed to allow for the improved understanding of the processes involved in the exchange of carbon between terrestrial ecosystems and the atmosphere, and therefore allowing for more accurate assessment of the seasonal/inter-annual variability of CO2. OCO-2 provides much-needed CO2 observations in data-limited regions allowing for the evaluation of model simulations of greenhouse gases (GHG) and facilitating global/regional estimates of "top-down" CO2 fluxes. We conduct a 4-D Variation (4D-Var) data assimilation with the GEOS-Chem (Goddard Earth Observation System-Chemistry) CTM using 1) OCO-2 land nadir and land glint retrievals and 2) global in situ surface flask observations to constrain biospheric CO2 fluxes. We apply different state-of-the-science year-specific CO2 flux models (e.g., NASA-CASA (NASA-Carnegie Ames Stanford Approach), CASA-GFED (Global Fire Emissions Database), Simple Biosphere Model version 4 (SiB-4), and LPJ (Lund-Postdam-Jena)) to assess the impact of "a priori" flux predictions to "a posteriori" estimates. We will present the "top-down" CO2 flux estimates for the year 2015 using OCO-2 and in situ observations, and a complete indirect evaluation of the a priori and a posteriori flux estimates using independent in situ observations. We will also present our assessment of the variability of "top-down" CO2 flux estimates when using different

How Close Are We to the Temperature Tipping Point of the Biosphere?

Science.gov (United States)

Duffy, K. H.

2017-12-01

All biological processes accelerate rapidly with increasing temperature (Tinf); reaching a maximum rate (Tmax), after which they decline. However different biological processes may not be synchronised in their response to increasing temperatures resulting in major dis-equilibria of ecosystem processes. Particularly, the linked processes of photosynthesis and respiration have different curvature that is determined by their inherent sensitivity to temperature. Constraining the difference in temperature curves between photosynthesis and respiration allows us to quantify changes to global carbon metabolism and the land sink of carbon as a whole. During the last century the biosphere has acted as a sink of carbon from the atmosphere partly mitigating accumulation of CO2 derived from burning of fossil fuels Here we ask the following questions: As global temperature increases will photosynthesis and respiration become de-coupled and when? What is Tmax for the land sink, and where is current mean temperature range in regard to this important threshold? At what global and regional temperatures do we expect the biosphere to become a source of carbon to the atmosphere? To address these questions we used the recently released FLUXNET2015 dataset comprised of 212 eddy covariance flux tower sites which concurrently measure land-atmosphere carbon exchange along with micro-meteorological variables. Here, we illustrate our results for Tinf and Tmax of the land sink by biome and for the biosphere as a whole. Our results suggest that recent warming has already pushed us past the inflection point of photosynthesis, and that any additional warming will increase the cumulative annual dose of time spent past Tmax for the land sink. Even under moderate climate projections, we expect to see a slowing of the terrestrial carbon sink by as early as 2040.

Optimization of a prognostic biosphere model for terrestrial biomass and atmospheric CO2 variability

International Nuclear Information System (INIS)

Saito, M.; Ito, A.; Maksyutov, S.

2014-01-01

This study investigates the capacity of a prognostic biosphere model to simulate global variability in atmospheric CO 2 concentrations and vegetation carbon dynamics under current environmental conditions. Global data sets of atmospheric CO 2 concentrations, above-ground biomass (AGB), and net primary productivity (NPP) in terrestrial vegetation were assimilated into the biosphere model using an inverse modeling method combined with an atmospheric transport model. In this process, the optimal physiological parameters of the biosphere model were estimated by minimizing the misfit between observed and modeled values, and parameters were generated to characterize various biome types. Results obtained using the model with the optimized parameters correspond to the observed seasonal variations in CO 2 concentration and their annual amplitudes in both the Northern and Southern Hemispheres. In simulating the mean annual AGB and NPP, the model shows improvements in estimating the mean magnitudes and probability distributions for each biome, as compared with results obtained using prior simulation parameters. However, the model is less efficient in its simulation of AGB for forest type biomes. This misfit suggests that more accurate values of input parameters, specifically, grid mean AGB values and seasonal variabilities in physiological parameters, are required to improve the performance of the simulation model. (authors)

Exchange processes between a coniferous forest and the atmosphere

NARCIS (Netherlands)

Bosveld, F.C.

1999-01-01

This thesis deals with the research question: which processes are relevant in controlling the exchange fluxes between the forest and the atmosphere and how can this control be quantified? Answering this question is relevant for research in the fields of air pollution, weather and climate

Ecological research in the large-scale biosphere-atmosphere experiment in Amazonia: early results

NARCIS (Netherlands)

Keller, M.; Alencar, A.; Asner, G.P.; Braswell, B.; Bustamante, M.; Davidson, E.; Feldpausch, T.; Fernandes, E.; Goulden, M.; Kabat, P.; Kruijt, B.; Luizão, F.; Miller, S.; Markewitz, D.; Nobre, A.D.; Nobre, C.A.; Priante Filho, N.; Rocha, da H.; Silva Dias, P.; Randow, von C.; Vourlitis, G.L.

2004-01-01

The Large-scale Biosphere-Atmosphere Experiment in Amazonia (LBA) is a multinational, interdisciplinary research program led by Brazil. Ecological studies in LBA focus on how tropical forest conversion, regrowth, and selective logging influence carbon storage,. nutrient dynamics, trace gas fluxes,

TCCON Philippines: Towards Quantifying Atmospheric Carbon in Southeast Asia

Science.gov (United States)

Morino, I.; Velazco, V. A.; Uchino, O.; Schwandner, F. M.; Macatangay, R. C.; Nakatsuru, T.; Deutscher, N. M.; Belikov, D.; Maksyutov, S. S.; Oishi, Y.; Nakajima, T. Y.; Griffith, D. W. T.

2016-12-01

TCCON is dedicated to the precise measurements of greenhouse gases such as CO2 and CH4. TCCON measurements have been and are currently used extensively and globally for satellite validation, for comparison with atmospheric chemistry models and to study atmosphere-biosphere exchanges of carbon. With the global effort to cap greenhouse gas emissions, TCCON has taken on a vital role in validating satellite-based greenhouse gas data from past, current and future missions like Japanese GOSAT and GOSAT-2, NASA's OCO-2 and OCO-3, Chinese TanSat, and others. The lack of reliable validation data for the satellite-based greenhouse gas observing missions in the tropical regions is a common limitation in global carbon-cycle modeling studies that have a tropical component. The international CO2 modeling community has specified a requirement for "expansion of the CO2 observation network within the tropics" to reduce uncertainties in regional estimates of CO2 sources and sinks using atmospheric transport models. A TCCON site in the western tropical Pacific is a logical next step in obtaining additional knowledge that would greatly contribute to the understanding of the Earth's atmosphere and better constraining a major tropical region experiencing tremendous economic and population growth. Here, we present an assessment for a possible site in the Philippines where a new TCCON FTS will be installed. We also describe the newly constructed TCCON instrument intended for deployment to the Philippines and show a characterization of its performance and initial measurements at the NIES compound in Japan.

Air/surface exchange processes of mercury and their linkage to atmospheric pools

International Nuclear Information System (INIS)

Bahlmann, Enno; Ebinghaus, Ralf

2001-01-01

The atmospheric mercury cycle is strongly linked to the terrestrial, aquatic and biologic cycle of mercury via air/surface exchange processes. In order to quantify mercury fluxes from and to the atmosphere to predict local and regional source contributions the methods for flux measurements as well as the physicochemical factors controlling air/surface exchange processes must be assessed. We will describe methods for the determination of mercury and mercury species in ambient air which are basic for investigation of air/surface exchange processes. Further on we will describe approaches for studying the physicochemical factors controlling this processes by using a new laboratory flux measurement system. (author)

The response of the terrestrial biosphere to urbanization: land cover conversion, climate, and urban pollution

Directory of Open Access Journals (Sweden)

K. Trusilova

2008-11-01

Full Text Available Although urban areas occupy a relatively small fraction of land, they produce major disturbances of the carbon cycle through land use change, climate modification, and atmospheric pollution. In this study we quantify effects of urban areas on the carbon cycle in Europe. Among urbanization-driven environmental changes, which influence carbon sequestration in the terrestrial biosphere, we account for: (1 proportion of land covered by impervious materials, (2 local urban meteorological conditions, (3 urban high CO₂ concentrations, and (4 elevated atmospheric nitrogen deposition. We use the terrestrial ecosystem model BIOME-BGC to estimate fluxes of carbon exchange between the biosphere and the atmosphere in response to these urban factors.

We analysed four urbanization-driven changes individually, setting up our model in such a way that only one of the four was active at a time. From these model simulations we found that fertilization effects from the elevated CO₂ and the atmospheric nitrogen deposition made the strongest positive contributions to the carbon uptake (0.023 Pg C year⁻¹ and 0.039 Pg C year⁻¹, respectively, whereas, the impervious urban land and local urban meteorological conditions resulted in a reduction of carbon uptake (−0.005 Pg C year⁻¹ and −0.007 Pg C year⁻¹, respectively. The synergetic effect of the four urbanization-induced changes was an increase of the carbon sequestration in Europe of 0.058 Pg C year⁻¹.

Investigation of the influence of atmospheric stability and turbulence on land-atmosphere exchange

Science.gov (United States)

Osibanjo, O.; Holmes, H.

2015-12-01

Surface energy fluxes are exchanged between the surface of the earth and the atmosphere and impact weather, climate, and air quality. The radiation from the sun triggers the surface-atmosphere interaction during the day as heat is transmitted to the surface and the surface heats the air directly above generating wind (i.e., thermal turbulence) that transports heat, moisture, and momentum in the atmospheric boundary layer (ABL). This process is impacted by greenhouse gasses (i.e., water vapor, carbon dioxide and other trace gases) that absorb heat emitted by the earth's surface. The concentrations of atmospheric greenhouse gasses are increasing leading to changes in ABL dynamics as a result of the changing surface energy balance. The ABL processes are important to characterize because they are difficult to parameterize in global and regional scale atmospheric models. Empirical data can be collected using eddy covariance micrometeorological methods to measure turbulent fluxes (e.g., sensible heat, moisture, and CO2) and quantify the exchange between the surface and the atmosphere. The objective of this work is to calculate surface fluxes using observational data collected during one week in September 2014 from a monitoring site in Echo, Oregon. The site is located in the Columbia Basin with rolling terrain, irrigated farmland, and over 100 wind turbines. The 10m tower was placed in a small valley depression to isolate nighttime cold air pools. This work will present observations of momentum, sensible heat, moisture, and carbon dioxide fluxes from data collected at a sampling frequency of 10Hz at four heights. Atmospheric stability is determined using Monin-Obukov length and flux Richardson number, and the impact of stability on surface-atmosphere exchange is investigated. This work will provide a better understanding of surface fluxes and mixing, particularly during stable ABL periods, and the results can be used to compare with numerical models.

Soil-atmosphere trace gas exchange in semiarid and arid zones.

Science.gov (United States)

Galbally, Ian E; Kirstine, Wayne V; Meyer, C P Mick; Wang, Ying Ping

2008-01-01

A review is presented on trace gas exchange of CH4, CO, N2O, and NOx arising from agriculture and natural sources in the world's semiarid and arid zones due to soil processes. These gases are important contributors to the radiative forcing and the chemistry of the atmosphere. Quantitative information is summarized from the available studies. Between 5 and 40% of the global soil-atmosphere exchange for these gases (CH4, CO, N2O, and NOx) may occur in semiarid and arid zones, but for each of these gases there are fewer than a dozen studies to support the individual estimates, and these are from a limited number of locations. Significant differences in the biophysical and chemical processes controlling these trace gas exchanges are identified through the comparison of semiarid and arid zones with the moist temperate or wet/dry savanna land regions. Therefore, there is a poorly quantified understanding of the contribution of these regions to the global trace gas cycles and atmospheric chemistry. More importantly, there is a poor understanding of the feedback between these exchanges, global change, and regional land use and air pollution issues. A set of research issues is presented.

The exchange of acetaldehyde between plants and the atmosphere: Stable carbon isotope and flux measurements

Science.gov (United States)

Jardine, Kolby Jeremiah

The exchange of acetaldehyde between plant canopies and the atmosphere may significantly influence regional atmospheric chemistry and plant metabolism. While plants are known to both produce and consume acetaldehyde, the exchange of this compound with forested ecosystems is complicated by physical, biological, and chemical processes that range from being poorly understood to completely unknown. This precludes a quantitative understanding of acetaldehyde exchange rates between the atmosphere and the biosphere. In this study, the processes controlling the exchange of acetaldehyde with plant canopies was investigated using concentration, flux, and natural abundance 13C measurements of gas phase acetaldehyde from individual plants, soils, and entire ecosystems. Although previously only considered important in anoxic tissues, it was discovered that acetaldehyde is produced and consumed in leaves through ethanolic fermentation coupled to the pyruvate dehydrogenase bypass system under normal aerobic conditions. These coupled pathways determine the acetaldehyde compensation point, a major factor controlling its exchange with the atmosphere. Carbon isotope analysis suggests a new pathway for acetaldehyde production from plants under stress involving the peroxidation of membrane fatty acids. This pathway may be a major source of acetaldehyde to the atmosphere from plants under biotic and abiotic stresses. Plant stomata were found to be the dominant pathway for the exchange of acetaldehyde with the atmosphere with stomatal conductance influencing both emission and uptake fluxes. In addition, increasing temperature and solar radiation was found to increase the compensation point by increasing the rates of acetaldehyde production relative to consumption. Under ambient conditions, bare soil was neutral to the exchange of acetaldehyde while senescing and decaying leaves were found to be strong source of acetaldehyde to the atmosphere due to increased decomposition processes and

Biosphere II: engineering of manned, closed ecological systems.

Science.gov (United States)

Dempster, W F

1991-01-01

Space Biospheres and Ventures, a private, for-profit firm, has undertaken a major research and development project in the study of biospheres, with the objective of creating and producing biospheres. Biosphere II-scheduled for completion in March 1991-will be essentially isolated from the existing biosphere by a closed structure, composed of components derived from the existing biosphere. Like the biosphere of the Earth, Biosphere II will be essentially closed to exchanges of material or living organisms with the surrounding environment and open to energy and information exchanges. Also, like the biosphere of the Earth, Biosphere II will contain five kingdoms of life, a variety of ecosystems, plus humankind, culture, and technics. The system is designed to be complex, stable and evolving throughout its intended 100-year lifespan, rather than static. Biosphere II will cover approximately 1.3 hectare and contain 200,000 m3 in volume, with seven major biomes: tropical rainforest, tropical savannah, marsh, marine, desert, intensive agriculture, and human habitat. An interdisciplinary team of leading scientific, ecological, management, architectural, and engineering consultants have been contracted by Space Biospheres Ventures for the project. Potential applications for biospheric systems include scientific and ecological management research, refuges for endangered species, and life habitats for manned stations on spacecraft or other planets.

Decadal trends in the seasonal-cycle amplitude of terrestrial CO2 exchange resulting from the ensemble of terrestrial biosphere models

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Akihiko Ito

2016-05-01

Full Text Available The seasonal-cycle amplitude (SCA of the atmosphere–ecosystem carbon dioxide (CO2 exchange rate is a useful metric of the responsiveness of the terrestrial biosphere to environmental variations. It is unclear, however, what underlying mechanisms are responsible for the observed increasing trend of SCA in atmospheric CO2 concentration. Using output data from the Multi-scale Terrestrial Model Intercomparison Project (MsTMIP, we investigated how well the SCA of atmosphere–ecosystem CO2 exchange was simulated with 15 contemporary terrestrial ecosystem models during the period 1901–2010. Also, we made attempt to evaluate the contributions of potential mechanisms such as atmospheric CO2, climate, land-use, and nitrogen deposition, through factorial experiments using different combinations of forcing data. Under contemporary conditions, the simulated global-scale SCA of the cumulative net ecosystem carbon flux of most models was comparable in magnitude with the SCA of atmospheric CO2 concentrations. Results from factorial simulation experiments showed that elevated atmospheric CO2 exerted a strong influence on the seasonality amplification. When the model considered not only climate change but also land-use and atmospheric CO2 changes, the majority of the models showed amplification trends of the SCAs of photosynthesis, respiration, and net ecosystem production (+0.19 % to +0.50 % yr−1. In the case of land-use change, it was difficult to separate the contribution of agricultural management to SCA because of inadequacies in both the data and models. The simulated amplification of SCA was approximately consistent with the observational evidence of the SCA in atmospheric CO2 concentrations. Large inter-model differences remained, however, in the simulated global tendencies and spatial patterns of CO2 exchanges. Further studies are required to identify a consistent explanation for the simulated and observed amplification trends, including their

The Large-Scale Biosphere-Atmosphere Experiment in Amazonia: Analyzing Regional Land Use Change Effects.

Science.gov (United States)

Michael Keller; Maria Assunção Silva-Dias; Daniel C. Nepstad; Meinrat O. Andreae

2004-01-01

The Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) is a multi-disciplinary, multinational scientific project led by Brazil. LBA researchers seek to understand Amazonia in its global context especially with regard to regional and global climate. Current development activities in Amazonia including deforestation, logging, cattle ranching, and agriculture...

The legacy of Biosphere 2 for the study of biospherics and closed ecological systems.

Science.gov (United States)

Allen, J P; Nelson, M; Alling, A

2003-01-01

The unprecedented challenges of creating Biosphere 2, the world's first laboratory for biospherics, the study of global ecology and long-term closed ecological system dynamics, led to breakthrough developments in many fields, and a deeper understanding of the opportunities and difficulties of material closure. This paper will review accomplishments and challenges, citing some of the key research findings and publications that have resulted from the experiments in Biosphere 2. Engineering accomplishments included development of a technique for variable volume to deal with pressure differences between the facility and outside environment, developing methods of atmospheric leak detection and sealing, while achieving new standards of closure, with an annual atmospheric leakrate of less than 10%, or less than 300 ppm per day. This degree of closure permitted detailed tracking of carbon dioxide, oxygen, and trace gases such as nitrous oxide and ethylene over the seasonal variability of two years. Full closure also necessitated developing new approaches and technologies for complete air, water, and wastewater recycle and reuse within the facility. The development of a soil-based highly productive agricultural system was a first in closed ecological systems, and much was learned about managing a wide variety of crops using non-chemical means of pest and disease control. Closed ecological systems have different temporal biogeochemical cycling and ranges of atmospheric components because of their smaller reservoirs of air, water and soil, and higher concentration of biomass, and Biosphere 2 provided detailed examination and modeling of these accelerated cycles over a period of closure which measured in years. Medical research inside Biosphere 2 included the effects on humans of lowered oxygen: the discovery that human productivity can be maintained with good health with lowered atmospheric oxygen levels could lead to major economies on the design of space stations and

The legacy of biosphere 2 for the study of biospherics and closed ecological systems

Science.gov (United States)

Allen, J. P.; Nelson, M.; Alling, A.

The unprecedented challenges of creating Biosphere 2, the world's first laboratory for biospherics, the study of global ecology and long-term closed ecological system dynamics, led to breakthrough developments in many fields, and a deeper understanding of the opportunities and difficulties of material closure. This paper will review accomplishments and challenges, citing some of the key research findings and publications that have resulted from the experiments in Biosphere 2. Engineering accomplishments included development of a technique for variable volume to deal with pressure differences between the facility and outside environment, developing methods of atmospheric leak detection and sealing, while achieving new standards of closure, with an annual atmospheric leakrate of less than 10%, or less than 300 ppm per day. This degree of closure permitted detailed tracking of carbon dioxide, oxygen, and trice gases such as nitrous oxide and ethylene over the seasonal variability of two years. Full closure also necessitated developing new approaches and technologies for complete air, water, and wastewater recycle and reuse within the facility. The development of a soil-based highly productive agricultural system was a first in closed ecological systems, and much was learned about managing a wide variety of crops using non-chemical means of pest and disease control. Closed ecological systems have different temporal biogeochemical cycling and ranges of atmospheric components because of their smaller reservoirs of air, water and soil, and higher concentration of biomass, and Biosphere 2 provided detailed examination and modeling of these accelerated cycles over a period of closure which measured in years. Medical research inside Biosphere 2 included the effects on humans of lowered oxygen: the discovery that human productivity can be maintained with good health with lowered atmospheric oxygen levels could lead to major economies on the design of space stations and

Evolution of Earth-like Extrasolar Planetary Atmospheres: Assessing the Atmospheres and Biospheres of Early Earth Analog Planets with a Coupled Atmosphere Biogeochemical Model.

Science.gov (United States)

Gebauer, S; Grenfell, J L; Stock, J W; Lehmann, R; Godolt, M; von Paris, P; Rauer, H

2017-01-01

Understanding the evolution of Earth and potentially habitable Earth-like worlds is essential to fathom our origin in the Universe. The search for Earth-like planets in the habitable zone and investigation of their atmospheres with climate and photochemical models is a central focus in exoplanetary science. Taking the evolution of Earth as a reference for Earth-like planets, a central scientific goal is to understand what the interactions were between atmosphere, geology, and biology on early Earth. The Great Oxidation Event in Earth's history was certainly caused by their interplay, but the origin and controlling processes of this occurrence are not well understood, the study of which will require interdisciplinary, coupled models. In this work, we present results from our newly developed Coupled Atmosphere Biogeochemistry model in which atmospheric O 2 concentrations are fixed to values inferred by geological evidence. Applying a unique tool (Pathway Analysis Program), ours is the first quantitative analysis of catalytic cycles that governed O 2 in early Earth's atmosphere near the Great Oxidation Event. Complicated oxidation pathways play a key role in destroying O 2 , whereas in the upper atmosphere, most O 2 is formed abiotically via CO 2 photolysis. The O 2 bistability found by Goldblatt et al. ( 2006 ) is not observed in our calculations likely due to our detailed CH 4 oxidation scheme. We calculate increased CH 4 with increasing O 2 during the Great Oxidation Event. For a given atmospheric surface flux, different atmospheric states are possible; however, the net primary productivity of the biosphere that produces O 2 is unique. Mixing, CH 4 fluxes, ocean solubility, and mantle/crust properties strongly affect net primary productivity and surface O 2 fluxes. Regarding exoplanets, different "states" of O 2 could exist for similar biomass output. Strong geological activity could lead to false negatives for life (since our analysis suggests that reducing gases

Reconciling estimates of the contemporary North American carbon balance among terrestrial biosphere models, atmospheric inversions, and a new approach for estimating net ecosystem exchange from inventory-based data

Science.gov (United States)

Hayes, Daniel J.; Turner, David P.; Stinson, Graham; McGuire, A. David; Wei, Yaxing; West, Tristram O.; Heath, Linda S.; de Jong, Bernardus; McConkey, Brian G.; Birdsey, Richard A.; Kurz, Werner A.; Jacobson, Andrew R.; Huntzinger, Deborah N.; Pan, Yude; Post, W. Mac; Cook, Robert B.

2012-01-01

We develop an approach for estimating net ecosystem exchange (NEE) using inventory-based information over North America (NA) for a recent 7-year period (ca. 2000–2006). The approach notably retains information on the spatial distribution of NEE, or the vertical exchange between land and atmosphere of all non-fossil fuel sources and sinks of CO2, while accounting for lateral transfers of forest and crop products as well as their eventual emissions. The total NEE estimate of a -327 ± 252 TgC yr-1 sink for NA was driven primarily by CO2 uptake in the Forest Lands sector (-248 TgC yr-1), largely in the Northwest and Southeast regions of the US, and in the Crop Lands sector (-297 TgC yr-1), predominantly in the Midwest US states. These sinks are counteracted by the carbon source estimated for the Other Lands sector (+218 TgC yr-1), where much of the forest and crop products are assumed to be returned to the atmosphere (through livestock and human consumption). The ecosystems of Mexico are estimated to be a small net source (+18 TgC yr-1) due to land use change between 1993 and 2002. We compare these inventory-based estimates with results from a suite of terrestrial biosphere and atmospheric inversion models, where the mean continental-scale NEE estimate for each ensemble is -511 TgC yr-1 and -931 TgC yr-1, respectively. In the modeling approaches, all sectors, including Other Lands, were generally estimated to be a carbon sink, driven in part by assumed CO2 fertilization and/or lack of consideration of carbon sources from disturbances and product emissions. Additional fluxes not measured by the inventories, although highly uncertain, could add an additional -239 TgC yr-1 to the inventory-based NA sink estimate, thus suggesting some convergence with the modeling approaches.

Observations of atmosphere-biosphere exchange of total and speciated peroxynitrates: nitrogen fluxes and biogenic sources of peroxynitrates

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K.-E. Min

2012-10-01

Full Text Available Peroxynitrates are responsible for global scale transport of reactive nitrogen. Recent laboratory observations suggest that they may also play an important role in delivery of nutrients to plant canopies. We measured eddy covariance fluxes of total peroxynitrates (ΣPNs and three individual peroxynitrates (APNs ≡ PAN + PPN + MPAN over a ponderosa pine forest during the Biosphere Effects on AeRosols and Photochemistry EXperiment 2009 (BEARPEX 2009. Concentrations of these species were also measured at multiple heights above and within the canopy. While the above-canopy daytime concentrations are nearly identical for ΣPNs and APNs, we observed the downward flux of ΣPNs to be 30–60% slower than the flux of APNs. The vertical concentration gradients of ΣPNs and APNs vary with time of day and exhibit different temperature dependencies. These differences can be explained by the production of peroxynitrates other than PAN, PPN, and MPAN within the canopy (presumably as a consequence of biogenic VOC emissions and upward fluxes of these PN species. The impact of this implied peroxynitrate flux on the interpretation of NO_x fluxes and ecosystem N exchange is discussed.

Carbon-14 in the biosphere: Modeling and supporting research for the Canadian Nuclear Fuel Waste Management program

International Nuclear Information System (INIS)

Sheppard, S.C.; Amiro, B.D.; Sheppard, M.I.; Stephenson, M.; Zach, R.; Bird, G.A.

1994-01-01

Carbon-14 stands apart from most of the radionuclides present in nuclear fuel waste for several reasons. It has a relatively long radiological half-life and low retardation by granitic geological media so that 14 C is superceded only by 36 Cl and 129 I in potential release to the biosphere from unprocessed used fuel. In the biosphere, its importance continues because it is readily incorporated into the carbon compounds of life. Much of the behavior of 14 C in the biosphere can be conceptualized as isotopic exchange, where the 14 C mixes with 12 C from the biosphere. However, because of lack of data, the authors model the behavior of 14 C only partly as isotopic exchange, with most of the calculations relying on compartment transfer models. The authors experimental work has shown that soil-to-plant transfer may be dominated by the soil-atmosphere-plant pathway. Gaseous loss of 14 C from soils and lakes is significant. However, recalcitrant forms may persist in soils and sediments for long time periods. The impact of these forms is expected to be relatively low because their bioavailability is correspondingly low. Future research should be directed to support full modeling of 14 C as a series of isotopic exchange processes

Atmospheric dynamics and bioregenerative technologies in a soil-based ecological life support system: Initial results from biosphere 2

Science.gov (United States)

Nelson, M.; Dempster, W.; Alvarez-Romo, N.; MacCallum, T.

1994-11-01

Biosphere 2 is the first man-made, soil-based, bioregenerative life support system to be developed and tested. The utilization and amendment of local space resources, e.g. martian soil or lunar regolith, for agricultural and other purposes will be necesary if we are to minimize the requirement for Earth materials in the creation of long-term off-planet bases and habitations. Several of the roles soil plays in Biosphere 2 are 1) for air purification 2) as a key component in created wetland systems to recycle human and animal wastes and 3) as nutrient base for a sustainable agricultural cropping program. Initial results from the Biosphere 2 closure experiment are presented. These include the accelerated cycling rates due to small reservoir sizes, strong diurnal and seasonal fluxes in atmospheric CO2, an unexpected and continuing decline in atmospheric oxygen, overall maintenance of low levels of trace gases, recycling of waste waters through biological regeneration systems, and operation of an agriculture designed to provide diverse and nutritionally adequate diets for the crew members.

Atmospheric dynamics and bioregenerative technologies in a soil-based ecological life support system: initial results from Biosphere 2.

Science.gov (United States)

Nelson, M; Dempster, W; Alvarez-Romo, N; MacCallum, T

1994-11-01

Biosphere 2 is the first man-made, soil-based, bioregenerative life support system to be developed and tested. The utilization and amendment of local space resources, e.g. martian soil or lunar regolith, for agricultural and other purposes will be necessary if we are to minimize the requirement for Earth materials in the creation of long-term off-planet bases and habitations. Several of the roles soil plays in Biosphere 2 are 1) for air purification 2) as a key component in created wetland systems to recycle human and animal wastes and 3) as nutrient base for a sustainable agricultural cropping program. Initial results from the Biosphere 2 closure experiment are presented. These include the accelerated cycling rates due to small reservoir sizes, strong diurnal and seasonal fluxes in atmospheric CO2, an unexpected and continuing decline in atmospheric oxygen, overall maintenance of low levels of trace gases, recycling of waste waters through biological regeneration systems, and operation of an agriculture designed to provide diverse and nutritionally adequate diets for the crew members.

Projecting Soil Feedbacks to Atmospheric CO2 Following Erosion and Deposition on Centennial Timescales in Two Contrasting Forests: A Study of Critical Zone-Atmosphere Exchange

Science.gov (United States)

Billings, S. A.; Richter, D., Jr.; Ziegler, S. E.; Prestegaard, K. L.

2016-12-01

For almost 20 y there has been a growing recognition that erosion and associated lateral movement of SOC does not necessarily result in a net CO2 source from terrestrial sources to the atmosphere. Eroded SOC may undergo mineralization to CO2 at a more rapid pace than it would have in situ, but the eroding ecosystem continues to generate SOC at a potentially modified rate, and the eroding profile may also experience changing SOC mineralization rates. No one knows how these process rates may change upon erosion. Years ago, we introduced a model that computes the influence of erosion on biosphere-atmosphere CO2 exchange for any profile of interest. The model permits the user to test how assumptions of changing SOC production and mineralization can influence the degree to which erosion induces a net CO2 sink or source. Here we present an analogous model depicting how deposition of eroded SOC also can result in altered biosphere-atmosphere CO2 exchange. We employ both models to investigate how erosion and deposition in two contrasting forested regions may influence regional C budgets. Runoff-induced erosion in a boreal forest occurs at low rates, but removes C-rich, organic material; anthropogenically-enhanced erosion in a warm temperate forest removed both O- and mineral-rich A-horizons. Model runs (100 y) suggest that even though the great volume of mineral soil eroded from the temperate forest was relatively low-SOC, high erosion rates prompted greater potential for erosion to serve as a net CO2 sink compared to the boreal forest where C-rich material was lost but erosion rates remained low. The models further suggest that changes in SOC production and mineralization at eroding sites in both forest types are a greater influence on CO2 source or sink strength than analogous changes at depositional sites. The fate of eroded material and the influence of erosion and deposition on SOC dynamics remain knowledge gaps critical for projecting atmospheric CO2.

The Chemistry of Atmosphere-Forest Exchange (CAFE Model – Part 2: Application to BEARPEX-2007 observations

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G. M. Wolfe

2011-02-01

Full Text Available In a companion paper, we introduced the Chemistry of Atmosphere-Forest Exchange (CAFE model, a vertically-resolved 1-D chemical transport model designed to probe the details of near-surface reactive gas exchange. Here, we apply CAFE to noontime observations from the 2007 Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX-2007. In this work we evaluate the CAFE modeling approach, demonstrate the significance of in-canopy chemistry for forest-atmosphere exchange and identify key shortcomings in the current understanding of intra-canopy processes.

CAFE generally reproduces BEARPEX-2007 observations but requires an enhanced radical recycling mechanism to overcome a factor of 6 underestimate of hydroxyl (OH concentrations observed during a warm (~29 °C period. Modeled fluxes of acyl peroxy nitrates (APN are quite sensitive to gradients in chemical production and loss, demonstrating that chemistry may perturb forest-atmosphere exchange even when the chemical timescale is long relative to the canopy mixing timescale. The model underestimates peroxy acetyl nitrate (PAN fluxes by 50% and the exchange velocity by nearly a factor of three under warmer conditions, suggesting that near-surface APN sinks are underestimated relative to the sources. Nitric acid typically dominates gross dry N deposition at this site, though other reactive nitrogen (NO_y species can comprise up to 28% of the N deposition budget under cooler conditions. Upward NO₂ fluxes cause the net above-canopy NO_y flux to be ~30% lower than the gross depositional flux. CAFE under-predicts ozone fluxes and exchange velocities by ~20%. Large uncertainty in the parameterization of cuticular and ground deposition precludes conclusive attribution of non-stomatal fluxes to chemistry or surface uptake. Model-measurement comparisons of vertical concentration gradients for several emitted species suggests that the lower canopy airspace may be

Alternative biosphere modeling for safety assessment of HLW disposal taking account of geosphere-biosphere interface of marine environment

International Nuclear Information System (INIS)

Kato, Tomoko; Ishiguro, Katsuhiko; Naito, Morimasa; Ikeda, Takao; Little, Richard

2001-03-01

In the safety assessment of a high-level radioactive waste (HLW) disposal system, it is required to estimate radiological impacts on future human beings arising from potential radionuclide releases from a deep repository into the surface environment. In order to estimated the impacts, a biosphere model is developed by reasonably assuming radionuclide migration processes in the surface environment and relevant human lifestyles. It is important to modify the present biosphere models or to develop alternative biosphere models applying the biosphere models according to quality and quantify of the information acquired through the siting process for constructing the repository. In this study, alternative biosphere models were developed taking geosphere-biosphere interface of marine environment into account. Moreover, the flux to dose conversion factors calculated by these alternative biosphere models was compared with those by the present basic biosphere models. (author)

An improved land biosphere module for use in the DCESS Earth system model (version 1.1 with application to the last glacial termination

Directory of Open Access Journals (Sweden)

R. Eichinger

2017-09-01

Full Text Available Interactions between the land biosphere and the atmosphere play an important role for the Earth's carbon cycle and thus should be considered in studies of global carbon cycling and climate. Simple approaches are a useful first step in this direction but may not be applicable for certain climatic conditions. To improve the ability of the reduced-complexity Danish Center for Earth System Science (DCESS Earth system model DCESS to address cold climate conditions, we reformulated the model's land biosphere module by extending it to include three dynamically varying vegetation zones as well as a permafrost component. The vegetation zones are formulated by emulating the behaviour of a complex land biosphere model. We show that with the new module, the size and timing of carbon exchanges between atmosphere and land are represented more realistically in cooling and warming experiments. In particular, we use the new module to address carbon cycling and climate change across the last glacial transition. Within the constraints provided by various proxy data records, we tune the DCESS model to a Last Glacial Maximum state and then conduct transient sensitivity experiments across the transition under the application of explicit transition functions for high-latitude ocean exchange, atmospheric dust, and the land ice sheet extent. We compare simulated time evolutions of global mean temperature, pCO2, atmospheric and oceanic carbon isotopes as well as ocean dissolved oxygen concentrations with proxy data records. In this way we estimate the importance of different processes across the transition with emphasis on the role of land biosphere variations and show that carbon outgassing from permafrost and uptake of carbon by the land biosphere broadly compensate for each other during the temperature rise of the early last deglaciation.

Earth's early biosphere

Science.gov (United States)

Des Marais, D. J.

1998-01-01

Understanding our own early biosphere is essential to our search for life elsewhere, because life arose on Earth very early and rocky planets shared similar early histories. The biosphere arose before 3.8 Ga ago, was exclusively unicellular and was dominated by hyperthermophiles that utilized chemical sources of energy and employed a range of metabolic pathways for CO2 assimilation. Photosynthesis also arose very early. Oxygenic photosynthesis arose later but still prior to 2.7 Ga. The transition toward the modern global environment was paced by a decline in volcanic and hydrothermal activity. These developments allowed atmospheric O2 levels to increase. The O2 increase created new niches for aerobic life, most notably the more advanced Eukarya that eventually spawned the megascopic fauna and flora of our modern biosphere.

The terrestrial biosphere as a net source of greenhouse gases to the atmosphere.

Science.gov (United States)

Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M; Canadell, Josep G; Saikawa, Eri; Huntzinger, Deborah N; Gurney, Kevin R; Sitch, Stephen; Zhang, Bowen; Yang, Jia; Bousquet, Philippe; Bruhwiler, Lori; Chen, Guangsheng; Dlugokencky, Edward; Friedlingstein, Pierre; Melillo, Jerry; Pan, Shufen; Poulter, Benjamin; Prinn, Ronald; Saunois, Marielle; Schwalm, Christopher R; Wofsy, Steven C

2016-03-10

The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain. Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change.

Radiological risk assessment and biosphere modelling for radioactive waste disposal in Switzerland.

Science.gov (United States)

Brennwald, M S; van Dorp, F

2009-12-01

Long-term safety assessments for geological disposal of radioactive waste in Switzerland involve the demonstration that the annual radiation dose to humans due to the potential release of radionuclides from the waste repository into the biosphere will not exceed the regulatory limit of 0.1 mSv. Here, we describe the simple but robust approach used by Nagra (Swiss National Cooperative for the Disposal of Radioactive Waste) to quantify the dose to humans as a result to time-dependent release of radionuclides from the geosphere into the biosphere. The model calculates the concentrations of radionuclides in different terrestrial and aquatic compartments of the surface environment. The fluxes of water and solids within the environment are the drivers for the exchange of radionuclides between these compartments. The calculated radionuclide concentrations in the biosphere are then used to estimate the radiation doses to humans due to various exposure paths (e.g. ingestion of radionuclides via drinking water and food, inhalation of radionuclides, external irradiation from radionuclides in soils). In this paper we also discuss recent new achievements and planned future work.

Sensitivity properties of a biosphere model based on BATS and a statistical-dynamical climate model

Energy Technology Data Exchange (ETDEWEB)

Zhang, T. (Yale Univ., New Haven, CT (United States))

1994-06-01

A biosphere model based on the Biosphere-Atmosphere Transfer Scheme (BATS) and the Saltzman-Vernekar (SV) statistical-dynamical climate model is developed. Some equations of BATS are adopted either intact or with modifications, some are conceptually modified, and still others are replaced with equations of the SV model. The model is designed so that it can be run independently as long as the parameters related to the physiology and physiognomy of the vegetation, the atmospheric conditions, solar radiation, and soil conditions are given. With this stand-alone biosphere model, a series of sensitivity investigations, particularly the model sensitivity to fractional area of vegetation cover, soil surface water availability, and solar radiation for different types of vegetation, were conducted as a first step. These numerical experiments indicate that the presence of a vegetation cover greatly enhances the exchanges of momentum, water vapor, and energy between the atmosphere and the surface of the earth. An interesting result is that a dense and thick vegetation cover tends to serve as an environment conditioner or, more specifically, a thermostat and a humidistat, since the soil surface temperature, foliage temperature, and temperature and vapor pressure of air within the foliage are practically insensitive to variation of soil surface water availability and even solar radiation within a wide range. An attempt is also made to simulate the gradual deterioration of environment accompanying gradual degradation of a tropical forest to grasslands. Comparison with field data shows that this model can realistically simulate the land surface processes involving biospheric variations. 46 refs., 10 figs., 6 tabs.

High Precision Stable Isotope Measurements of Caribic Aircraft CO{sub 2} Samples: Global Distribution and Exchange with the Biosphere

Energy Technology Data Exchange (ETDEWEB)

Assonov, S. S. [Max Planck Institute for Chemistry, Mainz (Germany); Joint Research Centre, Institute for Reference Materials and Measurements (JRC-IRMM), European Commission, Geel (Belgium); Brenninkmeijer, C. A.M.; Schuck, T. J. [Max Planck Institute for Chemistry, Mainz (Germany); Taylor, P. [Joint Research Centre, Institute for Reference Materials and Measurements (JRC-IRMM), European Commission, Geel (Belgium)

2013-07-15

In 2007-2009 JRC-IRMM, in collaboration with the project CARIBIC (Civil Aircraft for Regular Investigation of the atmosphere Based on an Instrument Container, www.caribicatmospheric. com), conducted systematic measurements aimed to study the global distribution of CO{sub 2} isotopic composition. A large data set for the upper troposphere-lowermost stratosphere and free troposphere was obtained. For the first time it is demonstrated how CO{sub 2} isotope signals reflect global scale variability in air mass origin. Tight correlations observed arise either from stratosphere/troposphere mixing or from mixing of background air and air masses affected by CO{sub 2} sources and sinks, over long distances and throughout the seasons. The high quality {delta}{sup 18}O(CO{sub 2}) data prove to be a useful tracer reflecting long range CO{sub 2} transport and also CO{sub 2} exchange with land biosphere and soils. The data provide a benchmark for future comparisons and are available for modelling studies. (author)

The Legacy of Biosphere 2 for Biospherics and Closed Ecological System Research

Science.gov (United States)

Allen, J.; Alling, A.; Nelson, M.

The unprecedented challenges of creating Biosphere 2, the world's first laboratory for biospherics, the study of global ecology and long-term closed ecological system dynamics led to breakthrough developments in many fields, and a deeper understanding of the opportunities and difficulties of material closure. This paper will review these accomplishments and challenges, citing some of the key research accomplishments and publications which have resulted from the experiments in Biosphere 2. Engineering accomplishments included development of a technique for variable volume to deal with pressure differences between the facility and outside environment, developing methods of leak detection and sealing, and achieving new standards of closure, with an annual atmospheric leakrate of less than 10%, or less than 300 ppm per day. This degree of closure permitted detailed tracking of carbon dioxide, oxygen, and trace gases such as nitrous oxide and ethylene over the seasonal variability of two years. Full closure also necessitated developing new approaches and technologies for complete air, water, and wastewater recycle and reuse within the facility. The development of a soil-based highly productive agricultural system was a first in closed ecological systems, and much was learned about managing a wide variety of crops using non-chemical means of pest and disease control. Closed ecological systems have different temporal b ogeochemical cycling and ranges ofi atmospheric components because of their smaller reservoirs of air, water and soil, and higher concentration of biomass, and Biosphere 2 provided detailed examination and modeling of these accelerated cycles over a period of closure which measured in years. Medical research inside Biosphere 2 included the effects on humans of lowered oxygen: the discovery that human productivity can be maintained down to 15% oxygen could lead to major economies on the design of space stations and planetary/lunar settlements. The improved

The Middle Miocene climate as modelled in an atmosphere-ocean-biosphere model

Directory of Open Access Journals (Sweden)

M. Krapp

2011-11-01

Full Text Available We present simulations with a coupled atmosphere-ocean-biosphere model for the Middle Miocene 15 million years ago. The model is insofar more consistent than previous models because it captures the essential interactions between ocean and atmosphere and between atmosphere and vegetation. The Middle Miocene topography, which alters both large-scale ocean and atmospheric circulations, causes a global warming of 0.7 K compared to present day. Higher than present-day CO₂ levels of 480 and 720 ppm cause a global warming of 2.8 and 4.9 K. The associated water vapour feedback enhances the greenhouse effect which leads to a polar amplification of the warming. These results suggest that higher than present-day CO₂ levels are necessary to drive the warm Middle Miocene climate, also because the dynamic vegetation model simulates a denser vegetation which is in line with fossil records. However, we do not find a flatter than present-day equator-to-pole temperature gradient as has been suggested by marine and terrestrial proxies. Instead, a compensation between atmospheric and ocean heat transport counteracts the flattening of the temperature gradient. The acclaimed role of the large-scale ocean circulation in redistributing heat cannot be supported by our results. Including full ocean dynamics, therefore, does not solve the problem of the flat temperature gradient during the Middle Miocene.

Coupled carbon-water exchange of the Amazon rain forest. I. Model description, parameterization and sensitivity analysis

NARCIS (Netherlands)

Simon, E.; Meixner, F.X.; Ganzeveld, L.N.; Kesselmeier, J.

2005-01-01

Detailed one-dimensional multilayer biosphere-atmosphere models, also referred to as CANVEG models, are used for more than a decade to describe coupled water-carbon exchange between the terrestrial vegetation and the lower atmosphere. Within the present study, a modified CANVEG scheme is described.

The Biosphere International Peer Review

International Nuclear Information System (INIS)

Van Luik, Abraham

2002-01-01

Abe van Luik (US DOE- YM, USA), ended the presentation by giving feedback from the IAEA peer review on the biosphere modelling strategy developed by the DOE Yucca Mountain Site Characterisation Office (YMSCO). This review was based on available international standards and guidance. The peer review team was constituted of both experts from regulatory and waste management organisations and national advisory committees. The implementation of the review consisted of an examination of biosphere reports mainly regarding the modelling and question and answer exchanges. The final report was submitted in April 2000. It contained twenty-three recommendations within two broad classifications; one concerning the regulatory framework, the other one regarding the framework to increase stakeholders' confidence in modelling. The three main categories of recommendations were outlined, namely (i) the DOE' s Biosphere assessment Approach, (ii) the definition of the biosphere system, and (iii) the model development, data and results. Regarding in particular the treatment of the uncertainties in the biosphere, it was viewed as a key issue during the review and thus it will be re-evaluated in the future performance assessment. The summary highlighted most of the recommendations received are to be acted on, and are to be included in the License Application plan for biosphere modelling

Biosphere-Atmosphere Transfer Scheme (BATS) version le as coupled to the NCAR community climate model. Technical note. [NCAR (National Center for Atmospheric Research)

Energy Technology Data Exchange (ETDEWEB)

Dickinson, R.E.; Henderson-Sellers, A.; Kennedy, P.J.

1993-08-01

A comprehensive model of land-surface processes has been under development suitable for use with various National Center for Atmospheric Research (NCAR) General Circulation Models (GCMs). Special emphasis has been given to describing properly the role of vegetation in modifying the surface moisture and energy budgets. The result of these efforts has been incorporated into a boundary package, referred to as the Biosphere-Atmosphere Transfer Scheme (BATS). The current frozen version, BATS1e is a piece of software about four thousand lines of code that runs as an offline version or coupled to the Community Climate Model (CCM).

Collagen proteins exchange O with demineralisation and gelatinisation reagents and also with atmospheric moisture.

Science.gov (United States)

von Holstein, Isabella; von Tersch, Matthew; Coutu, Ashley N; Penkman, Kirsty E H; Makarewicz, Cheryl A; Collins, Matthew J

2018-01-23

The oxygen isotope composition of collagen proteins is a potential indicator of adult residential location, useful for provenancing in ecology, archaeology and forensics. In acidic solution, proteins can exchange O from carboxylic acid moieties with reagent O. This study investigated whether this exchange occurs during demineralisation and gelatinisation preparation of bone/ivory collagen. EDTA and HCl demineralisation or gelatinisation reagents were made up in waters with different δ 18 O values, and were used to extract collagen from four skeletal tissue samples. Aliquots of extracted collagen were exposed to two different atmospheric waters, at 120°C and ambient temperature, and subsequently dried in a vacuum oven at 40°C or by freeze drying. Sample δ 18 O values were measured by HT/EA pyrolysis-IRMS using a zero-blank autosampler. Collagen samples exchanged O with both reagent waters and atmospheric water, which altered sample δ 18 O values. Exchange with reagent waters occurred in all extraction methods, but was greater at lower pH. Damage to the collagen samples during extraction increased O exchange. The nature of exchange of O with atmospheric water depended on the temperature of exposure: kinetic fractionation of O was identified at 120°C but not at ambient temperature. Exchange was difficult to quantify due to high variability of δ 18 O value between experimental replicates. Studies of δ 18 O values in collagen proteins should avoid extraction methods using acid solutions. This article is protected by copyright. All rights reserved.

The CarbonTracker Data Assimilation System for CO2 and δ13C (CTDAS-C13 v1.0): retrieving information on land-atmosphere exchange processes

Science.gov (United States)

van der Velde, Ivar R.; Miller, John B.; van der Molen, Michiel K.; Tans, Pieter P.; Vaughn, Bruce H.; White, James W. C.; Schaefer, Kevin; Peters, Wouter

2018-01-01

To improve our understanding of the global carbon balance and its representation in terrestrial biosphere models, we present here a first dual-species application of the CarbonTracker Data Assimilation System (CTDAS). The system's modular design allows for assimilating multiple atmospheric trace gases simultaneously to infer exchange fluxes at the Earth surface. In the prototype discussed here, we interpret signals recorded in observed carbon dioxide (CO2) along with observed ratios of its stable isotopologues 13CO2/12CO2 (δ13C). The latter is in particular a valuable tracer to untangle CO2 exchange from land and oceans. Potentially, it can also be used as a proxy for continent-wide drought stress in plants, largely because the ratio of 13CO2 and 12CO2 molecules removed from the atmosphere by plants is dependent on moisture conditions.The dual-species CTDAS system varies the net exchange fluxes of both 13CO2 and CO2 in ocean and terrestrial biosphere models to create an ensemble of 13CO2 and CO2 fluxes that propagates through an atmospheric transport model. Based on differences between observed and simulated 13CO2 and CO2 mole fractions (and thus δ13C) our Bayesian minimization approach solves for weekly adjustments to both net fluxes and isotopic terrestrial discrimination that minimizes the difference between observed and estimated mole fractions.With this system, we are able to estimate changes in terrestrial δ13C exchange on seasonal and continental scales in the Northern Hemisphere where the observational network is most dense. Our results indicate a decrease in stomatal conductance on a continent-wide scale during a severe drought. These changes could only be detected after applying combined atmospheric CO2 and δ13C constraints as done in this work. The additional constraints on surface CO2 exchange from δ13C observations neither affected the estimated carbon fluxes nor compromised our ability to match observed CO2 variations. The prototype presented

Interannual variability in the oxygen isotopes of atmospheric CO2 driven by El Nino

NARCIS (Netherlands)

Welp, Lisa R.; Keeling, Ralph F.; Meijer, Harro A. J.; Bollenbacher, Alane F.; Piper, Stephen C.; Yoshimura, Kei; Francey, Roger J.; Allison, Colin E.; Wahlen, Martin

2011-01-01

The stable isotope ratios of atmospheric CO2 (O-18/O-16 and C-13/C-12) have been monitored since 1977 to improve our understanding of the global carbon cycle, because biosphere-atmosphere exchange fluxes affect the different atomic masses in a measurable way(1). Interpreting the O-18/O-16

Natural radium and radon tracers to quantify water exchange and movement in reservoirs

Science.gov (United States)

Smith, Christopher G.; Baskaran, Mark

2011-01-01

Radon and radium isotopes are routinely used to quantify exchange rates between different hydrologic reservoirs. Since their recognition as oceanic tracers in the 1960s, both radon and radium have been used to examine processes such as air-sea exchange, deep oceanic mixing, benthic inputs, and many others. Recently, the application of radon-222 and the radium-quartet (223,224,226,228Ra) as coastal tracers has seen a revelation with the growing interest in coastal groundwater dynamics. The enrichment of these isotopes in benthic fluids including groundwater makes both radium and radon ideal tracers of coastal benthic processes (e.g. submarine groundwater discharge). In this chapter we review traditional and recent advances in the application of radon and radium isotopes to understand mixing and exchange between various hydrologic reservoirs, specifically: (1) atmosphere and ocean, (2) deep and shallow oceanic water masses, (3) coastal groundwater/benthic pore waters and surface ocean, and (4) aquifer-lakes. While the isotopes themselves and their distribution in the environment provide qualitative information about the exchange processes, it is mixing/exchange and transport models for these isotopes that provide specific quantitative information about these processes. Brief introductions of these models and mixing parameters are provided for both historical and more recent studies.

Inhalation Exposure Input Parameters for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

M. Wasiolek

2006-06-05

This analysis is one of the technical reports that support the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), referred to in this report as the biosphere model. ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents development of input parameters for the biosphere model that are related to atmospheric mass loading and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for a Yucca Mountain repository. ''Inhalation Exposure Input Parameters for the Biosphere Model'' is one of five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the biosphere model is presented in Figure 1-1 (based on BSC 2006 [DIRS 176938]). This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and how this analysis report contributes to biosphere modeling. This analysis report defines and justifies values of atmospheric mass loading for the biosphere model. Mass loading is the total mass concentration of resuspended particles (e.g., dust, ash) in a volume of air. Mass loading values are used in the air submodel of the biosphere model to calculate concentrations of radionuclides in air inhaled by a receptor and concentrations in air surrounding crops. Concentrations in air to which the receptor is exposed are then used in the inhalation submodel to calculate the dose contribution to the receptor from inhalation of contaminated airborne particles. Concentrations in air surrounding plants are used in the plant submodel to calculate the concentrations of radionuclides in foodstuffs contributed from uptake by foliar interception. This

Inhalation Exposure Input Parameters for the Biosphere Model

International Nuclear Information System (INIS)

M. Wasiolek

2006-01-01

This analysis is one of the technical reports that support the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), referred to in this report as the biosphere model. ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents development of input parameters for the biosphere model that are related to atmospheric mass loading and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for a Yucca Mountain repository. ''Inhalation Exposure Input Parameters for the Biosphere Model'' is one of five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the biosphere model is presented in Figure 1-1 (based on BSC 2006 [DIRS 176938]). This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and how this analysis report contributes to biosphere modeling. This analysis report defines and justifies values of atmospheric mass loading for the biosphere model. Mass loading is the total mass concentration of resuspended particles (e.g., dust, ash) in a volume of air. Mass loading values are used in the air submodel of the biosphere model to calculate concentrations of radionuclides in air inhaled by a receptor and concentrations in air surrounding crops. Concentrations in air to which the receptor is exposed are then used in the inhalation submodel to calculate the dose contribution to the receptor from inhalation of contaminated airborne particles. Concentrations in air surrounding plants are used in the plant submodel to calculate the concentrations of radionuclides in foodstuffs contributed from uptake by foliar interception. This report is concerned primarily with the

Modeling seasonal changes of atmospheric carbon dioxide and carbon 13

International Nuclear Information System (INIS)

Gillette, D.A.; Box, E.O.

1986-01-01

A two-dimensional (latitude-altitude) model of atmospheric CO 2 and δ 13 C was constructed to simulate some features of seasonal carbon cycle fluctuations. The model simulates air-sea exchange, atmospheric diffusion, and fossil fuel carbon sources, which are functions of time and latitude. In addition, it uses biosphere-atmosphere fluxes of carbon that are based on global-scale biological models of vegetation growth and decay. Results of the model show fair agreement with observational results for CO 2 and δ 13 C seasonal fluctuations. Their model results have far northern fluctuations with smaller amplitudes than are observed. Analysis of sources of CO 2 change at given latitudes shows that, for far southern latitudes, southern hemisphere biospheric fluxes are dominant in affecting the seasonal CO 2 fluctuations. Long-term decrease of δ 13 C for the model is larger than for observations. This may be due to errors in the formulation for oceanic fluxes for 13 C in the model or to a net uptake of carbon by the biosphere

Atmospheric Composition Change: Climate-Chemistry Interactions

Science.gov (United States)

Isaksen, I.S.A.; Granier, C.; Myhre, G.; Bernsten, T. K.; Dalsoren, S. B.; Gauss, S.; Klimont, Z.; Benestad, R.; Bousquet, P.; Collins, W.;

The CarbonTracker Data Assimilation System for CO2 and δ13C (CTDAS-C13 v1.0: retrieving information on land–atmosphere exchange processes

Directory of Open Access Journals (Sweden)

I. R. van der Velde

2018-01-01

Full Text Available To improve our understanding of the global carbon balance and its representation in terrestrial biosphere models, we present here a first dual-species application of the CarbonTracker Data Assimilation System (CTDAS. The system's modular design allows for assimilating multiple atmospheric trace gases simultaneously to infer exchange fluxes at the Earth surface. In the prototype discussed here, we interpret signals recorded in observed carbon dioxide (CO2 along with observed ratios of its stable isotopologues 13CO2∕12CO2 (δ13C. The latter is in particular a valuable tracer to untangle CO2 exchange from land and oceans. Potentially, it can also be used as a proxy for continent-wide drought stress in plants, largely because the ratio of 13CO2 and 12CO2 molecules removed from the atmosphere by plants is dependent on moisture conditions.The dual-species CTDAS system varies the net exchange fluxes of both 13CO2 and CO2 in ocean and terrestrial biosphere models to create an ensemble of 13CO2 and CO2 fluxes that propagates through an atmospheric transport model. Based on differences between observed and simulated 13CO2 and CO2 mole fractions (and thus δ13C our Bayesian minimization approach solves for weekly adjustments to both net fluxes and isotopic terrestrial discrimination that minimizes the difference between observed and estimated mole fractions.With this system, we are able to estimate changes in terrestrial δ13C exchange on seasonal and continental scales in the Northern Hemisphere where the observational network is most dense. Our results indicate a decrease in stomatal conductance on a continent-wide scale during a severe drought. These changes could only be detected after applying combined atmospheric CO2 and δ13C constraints as done in this work. The additional constraints on surface CO2 exchange from δ13C observations neither affected the estimated carbon fluxes nor compromised our ability to match observed CO2 variations

Modelling the impact of soil Carbonic Anhydrase on the net ecosystem exchange of OCS at Harvard forest using the MuSICA model

Science.gov (United States)

Launois, Thomas; Ogée, Jérôme; Commane, Roisin; Wehr, Rchard; Meredith, Laura; Munger, Bill; Nelson, David; Saleska, Scott; Wofsy, Steve; Zahniser, Mark; Wingate, Lisa

2016-04-01

The exchange of CO2 between the terrestrial biosphere and the atmosphere is driven by photosynthetic uptake and respiratory loss, two fluxes currently estimated with considerable uncertainty at large scales. Model predictions indicate that these biosphere fluxes will be modified in the future as CO2 concentrations and temperatures increase; however, it still unclear to what extent. To address this challenge there is a need for better constraints on land surface model parameterisations. Additional atmospheric tracers of large-scale CO2 fluxes have been identified as potential candidates for this task. In particular carbonyl sulphide (OCS) has been proposed as a complementary tracer of gross photosynthesis over land, since OCS uptake by plants is dominated by carbonic anhydrase (CA) activity, an enzyme abundant in leaves that catalyses CO2 hydration during photosynthesis. However, although the mass budget at the ecosystem is dominated by the flux of OCS into leaves, some OCS is also exchanged between the atmosphere and the soil and this component of the budget requires constraining. In this study, we adapted the process-based isotope-enabled model MuSICA (Multi-layer Simulator of the Interactions between a vegetation Canopy and the Atmosphere) to include the transport, reaction, diffusion and production of OCS within a forested ecosystem. This model was combined with 3 years (2011-2013) of in situ measurements of OCS atmospheric concentration profiles and fluxes at the Harvard Forest (Massachussets, USA) to test hypotheses on the mechanisms responsible for CA-driven uptake by leaves and soils as well as possible OCS emissions during litter decomposition. Model simulations over the three years captured well the impact of diurnally and seasonally varying environmental conditions on the net ecosystem OCS flux. A sensitivity analysis on soil CA activity and soil OCS emission rates was also performed to quantify their impact on the vertical profiles of OCS inside the

Disruptive Event Biosphere Dose Conversion Factor Analysis

Energy Technology Data Exchange (ETDEWEB)

M. Wasiolek

2004-09-08

analysis was to develop the BDCFs for the volcanic ash exposure scenario and the dose factors for calculating inhalation doses during volcanic eruption (eruption phase of the volcanic event). For the volcanic ash exposure scenario, the mode of radionuclide release into the biosphere is a volcanic eruption through the repository with the resulting entrainment of contaminated waste in the tephra and the subsequent atmospheric transport and dispersion of contaminated material in the biosphere. The biosphere process model for this scenario uses the surface deposition of contaminated ash as the source of radionuclides in the biosphere. The initial atmospheric transport and dispersion of the ash as well as its subsequent redistribution by fluvial and aeolian processes are not addressed within the biosphere model. These processes influence the value of the source term that is calculated elsewhere and then combined with the BDCFs in the TSPA model to calculate expected dose to the receptor. Another objective of this analysis was to re-qualify the output of the previous revision (BSC 2003 [DIRS 163958]).

Disruptive Event Biosphere Dose Conversion Factor Analysis

International Nuclear Information System (INIS)

M. Wasiolek

2004-01-01

exposure scenario and the dose factors for calculating inhalation doses during volcanic eruption (eruption phase of the volcanic event). For the volcanic ash exposure scenario, the mode of radionuclide release into the biosphere is a volcanic eruption through the repository with the resulting entrainment of contaminated waste in the tephra and the subsequent atmospheric transport and dispersion of contaminated material in the biosphere. The biosphere process model for this scenario uses the surface deposition of contaminated ash as the source of radionuclides in the biosphere. The initial atmospheric transport and dispersion of the ash as well as its subsequent redistribution by fluvial and aeolian processes are not addressed within the biosphere model. These processes influence the value of the source term that is calculated elsewhere and then combined with the BDCFs in the TSPA model to calculate expected dose to the receptor. Another objective of this analysis was to re-qualify the output of the previous revision (BSC 2003 [DIRS 163958])

DISRUPTIVE EVENT BIOSPHERE DOSE CONVERSION FACTOR ANALYSIS

International Nuclear Information System (INIS)

M.A. Wasiolek

2005-01-01

ash exposure scenario and the dose factors for calculating inhalation doses during volcanic eruption (eruption phase of the volcanic event). For the volcanic ash exposure scenario, the mode of radionuclide release into the biosphere is a volcanic eruption through the repository with the resulting entrainment of contaminated waste in the tephra and the subsequent atmospheric transport and dispersion of contaminated material in the biosphere. The biosphere process model for this scenario uses the surface deposition of contaminated ash as the source of radionuclides in the biosphere. The initial atmospheric transport and dispersion of the ash as well as its subsequent redistribution by fluvial and aeolian processes are not addressed within the biosphere model. These processes influence the value of the source term that is calculated elsewhere and then combined with the BDCFs in the TSPA model to calculate expected dose to the receptor

Inter-annual variability of the atmospheric carbon dioxide concentrations as simulated with global terrestrial biosphere models and an atmospheric transport model

Energy Technology Data Exchange (ETDEWEB)

Fujita, Daisuke; Saeki, Tazu; Nakazawa, Takakiyo [Tohoku Univ., Sendai (Japan). Center for Atmospheric and Oceanic Studies; Ishizawa, Misa; Maksyutov, Shamil [Inst. for Global Change Research, Yokohama (Japan). Frontier Research System for Global Change; Thornton, Peter E. [National Center for Atmospheric Research, Boulder, CO (United States). Climate and Global Dynamics Div.

2003-04-01

Seasonal and inter-annual variations of atmospheric CO{sub 2} for the period from 1961 to 1997 have been simulated using a global tracer transport model driven by a new version of the Biome BioGeochemical Cycle model (Biome-BGC). Biome-BGC was forced by daily temperature and precipitation from the NCEP reanalysis dataset, and the calculated monthly-averaged CO{sub 2} fluxes were used as input to the global transport model. Results from an inter-comparison with the Carnegie-Ames-Stanford Approach model (CASA) and the Simulation model of Carbon CYCLE in Land Ecosystems (Sim-CYCLE) model are also reported. The phase of the seasonal cycle in the Northern Hemisphere was reproduced generally well by Biome-BGC, although the amplitude was smaller compared to the observations and to the other biosphere models. The CO{sub 2} time series simulated by Biome-BGC were compared to the global CO{sub 2} concentration anomalies from the observations at Mauna Loa and the South Pole. The modeled concentration anomalies matched the phase of the inter-annual variations in the atmospheric CO{sub 2} observations; however, the modeled amplitude was lower than the observed value in several cases. The result suggests that a significant part of the inter-annual variability in the global carbon cycle can be accounted for by the terrestrial biosphere models. Simulations performed with another climate-based model, Sim-CYCLE, produced a larger amplitude of inter-annual variability in atmospheric CO{sub 2}, making the amplitude closer to the observed range, but with a more visible phase mismatch in a number of time periods. This may indicate the need to increase the Biome-BGC model sensitivity to seasonal and inter-annual changes in temperature and precipitation.

Inter-annual variability of the atmospheric carbon dioxide concentrations as simulated with global terrestrial biosphere models and an atmospheric transport model

International Nuclear Information System (INIS)

Fujita, Daisuke; Saeki, Tazu; Nakazawa, Takakiyo; Ishizawa, Misa; Maksyutov, Shamil; Thornton, Peter E.

2003-01-01

Seasonal and inter-annual variations of atmospheric CO 2 for the period from 1961 to 1997 have been simulated using a global tracer transport model driven by a new version of the Biome BioGeochemical Cycle model (Biome-BGC). Biome-BGC was forced by daily temperature and precipitation from the NCEP reanalysis dataset, and the calculated monthly-averaged CO 2 fluxes were used as input to the global transport model. Results from an inter-comparison with the Carnegie-Ames-Stanford Approach model (CASA) and the Simulation model of Carbon CYCLE in Land Ecosystems (Sim-CYCLE) model are also reported. The phase of the seasonal cycle in the Northern Hemisphere was reproduced generally well by Biome-BGC, although the amplitude was smaller compared to the observations and to the other biosphere models. The CO 2 time series simulated by Biome-BGC were compared to the global CO 2 concentration anomalies from the observations at Mauna Loa and the South Pole. The modeled concentration anomalies matched the phase of the inter-annual variations in the atmospheric CO 2 observations; however, the modeled amplitude was lower than the observed value in several cases. The result suggests that a significant part of the inter-annual variability in the global carbon cycle can be accounted for by the terrestrial biosphere models. Simulations performed with another climate-based model, Sim-CYCLE, produced a larger amplitude of inter-annual variability in atmospheric CO 2 , making the amplitude closer to the observed range, but with a more visible phase mismatch in a number of time periods. This may indicate the need to increase the Biome-BGC model sensitivity to seasonal and inter-annual changes in temperature and precipitation

Development of atmosphere-soil-vegetation model for investigation of radioactive materials transport in terrestrial biosphere

International Nuclear Information System (INIS)

Katata, Genki; Nagai, Haruyasu; Zhang, Leiming; Held, Andreas; Serca, Dominique; Klemm, Otto

2010-01-01

In order to investigate the transport of radionuclides in the terrestrial biosphere we have developed a one-dimensional numerical model named SOLVEG that predicts the transfer of water, heat, and gaseous and particulate matters in atmosphere-soil-vegetation system. The SOLVEG represents atmosphere, soil, and vegetation as an aggregation of several layers. Basic equations used in the model are solved using the finite difference method. Most of predicted variables are interrelated with the source/sink terms of momentum, water, heat, gases, and particles based on mathematically described biophysical processes in atmosphere, soil and vegetation. The SOLVEG can estimate dry, wet and fog deposition of gaseous and particulate matters at each canopy layer. Performance tests of the SOLVEG with several observational sites were carried out. The SOLVEG predicted the observed temporal changes in water vapor, CO 2 , and ozone fluxes over vegetated surfaces. The SOLVEG also reproduced measured fluxes of fog droplets and of fine aerosols over the forest. (author)

Boreal forests and atmosphere - Biosphere exchange of carbon dioxide

Science.gov (United States)

D'Arrigo, Rosanne; Jacoby, Gordon C.; Fung, Inez Y.

1987-01-01

Two approaches to investigating the role of boreal forests in the global carbon cycle are presented. First, a tracer support model which incorporates the normalized-difference vegetation index obtained from advanced, very high resolution radiometer radiances was used to simulate the annual cycle of CO2 in the atmosphere. Results indicate that the seasonal growth of the combined boreal forests of North America and Eurasia accounts for about 50 percent of the mean seasonal CO2 amplitude recorded at Pt. Barrow, Alaska and about 30 percent of the more globally representative CO2 signal at Mauna Loa, Hawaii. Second, tree-ring width data from four boreal treeline sites in northern Canada were positively correlated with Pt. Barrow CO2 drawdown for the period 1971-1982. These results suggest that large-scale changes in the growth of boreal forests may be contributing to the observed increasing trend in CO2 amplitude. They further suggest that tree-ring data may be applicable as indices for CO2 uptake and remote sensing estimates of photosynthetic activity.

Biosphere-Atmosphere Exchange of NOx and O3 in Central Amazon

Science.gov (United States)

Wiedemann, K. T.; Swofsy, S. C.; Munger, J. W.; Saleska, S. R.; Rizzo, L. V.; Silva Campos, K.

2017-12-01

The primary source of atmospheric OH is the photolysis of O3 in the presence of water vapor. NOx gases are the main precursors of O3 and OH. In NOx-rich environments that have both high humidity and high solar radiation, OH concentrations are enhanced, making tropical forests dominant in global oxidation of long lived gases. The Amazon rain forest has a unique combination of vegetation with diverse characteristics, climate, and a dynamic land use, factors that altogether govern the emission and fate of trace gases, particle formation and atmospheric chemistry. Understanding the interactions among the mechanisms that govern local precursor emissions will lead to a better description of the local atmospheric chemistry and its global impacts. As part of the GoAmazon project, an array of complementary measurements was conducted in a research site in central Amazon, near Santarem (PA, Brazil), inside the Tapajos National Forest. The research site is surrounded by intact rain forest in a 6km radius, and a 45m canopy. The 67m tower was assembled in the site in 2001 for flux measurements (CO2 and H2O). In mid 2014 additional instrumentation were added, measuring NOx, O3, CH4, and SO2 fluxes and profiles. The low concentrations of SO2 (up to 0.1ppb during the peak of the dry season), and a small vertical gradient, suggest the predominance of biogenic sources. O3 show no significant seasonality between the daytime and nighttime vertical profiles, but occasional nighttime high concentrations for levels below canopy were observed. Hourly ozone fluxes suggest a production of O3 under canopy. NO soil emissions are indicated by concentrations in the ppb range for lower profile levels, decreasing to a few hundreds ppt above the canopy, and emission rates of NO from Amazonian soils may be higher than expected from earlier measurements. Daytime data indicate that not all of this NOx escapes to the atmosphere, however. Fluxes of NO average 133x109 molec cm-2 s-1, a factor of 4 higher

Applications of quantitative remote sensing to hydrology

NARCIS (Netherlands)

Su, Z.; Troch, P.A.A.

2003-01-01

In order to quantify the rates of the exchanges of energy and matter among hydrosphere, biosphere and atmosphere, quantitative description of land surface processes by means of measurements at different scales are essential. Quantitative remote sensing plays an important role in this respect. The

Disruptive Event Biosphere Dose Conversion Factor Analysis

Energy Technology Data Exchange (ETDEWEB)

M. A. Wasiolek

2003-07-21

This analysis report, ''Disruptive Event Biosphere Dose Conversion Factor Analysis'', is one of the technical reports containing documentation of the ERMYN (Environmental Radiation Model for Yucca Mountain Nevada) biosphere model for the geologic repository at Yucca Mountain, its input parameters, and the application of the model to perform the dose assessment for the repository. The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for the Yucca Mountain repository. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of the two reports that develop biosphere dose conversion factors (BDCFs), which are input parameters for the TSPA model. The ''Biosphere Model Report'' (BSC 2003 [DIRS 164186]) describes in detail the conceptual model as well as the mathematical model and lists its input parameters. Model input parameters are developed and described in detail in five analysis report (BSC 2003 [DIRS 160964], BSC 2003 [DIRS 160965], BSC 2003 [DIRS 160976], BSC 2003 [DIRS 161239], and BSC 2003 [DIRS 161241]). The objective of this analysis was to develop the BDCFs for the volcanic ash exposure scenario and the dose factors (DFs) for calculating inhalation doses during volcanic eruption (eruption phase of the volcanic event). The volcanic ash exposure scenario is hereafter referred to as the volcanic ash scenario. For the volcanic ash scenario, the mode of radionuclide release into the biosphere is a volcanic eruption through the repository with the resulting entrainment of contaminated waste in the tephra and the subsequent atmospheric transport and dispersion of contaminated material in

Disruptive Event Biosphere Dose Conversion Factor Analysis

International Nuclear Information System (INIS)

M. A. Wasiolek

2003-01-01

This analysis report, ''Disruptive Event Biosphere Dose Conversion Factor Analysis'', is one of the technical reports containing documentation of the ERMYN (Environmental Radiation Model for Yucca Mountain Nevada) biosphere model for the geologic repository at Yucca Mountain, its input parameters, and the application of the model to perform the dose assessment for the repository. The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for the Yucca Mountain repository. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of the two reports that develop biosphere dose conversion factors (BDCFs), which are input parameters for the TSPA model. The ''Biosphere Model Report'' (BSC 2003 [DIRS 164186]) describes in detail the conceptual model as well as the mathematical model and lists its input parameters. Model input parameters are developed and described in detail in five analysis report (BSC 2003 [DIRS 160964], BSC 2003 [DIRS 160965], BSC 2003 [DIRS 160976], BSC 2003 [DIRS 161239], and BSC 2003 [DIRS 161241]). The objective of this analysis was to develop the BDCFs for the volcanic ash exposure scenario and the dose factors (DFs) for calculating inhalation doses during volcanic eruption (eruption phase of the volcanic event). The volcanic ash exposure scenario is hereafter referred to as the volcanic ash scenario. For the volcanic ash scenario, the mode of radionuclide release into the biosphere is a volcanic eruption through the repository with the resulting entrainment of contaminated waste in the tephra and the subsequent atmospheric transport and dispersion of contaminated material in the biosphere. The biosphere process

A Biosphere Assessment: Influence due to Geosphere-Biosphere Interfaces

International Nuclear Information System (INIS)

Lee, Youn Myoung; Hwang, Yong Soo

2009-01-01

models it is necessary to treat properly all the relevant FEPs and scenarios associated with the organically coupled chain between the modeling schemes of groundwater flow and nuclide transport in the geosphere and biosphere. Since the first development of a biosphere assessment model and the implemented codes, ACBIO and ACBIO2, which has more complex modeling scheme than its predecessor, based on BIOMASS methodology by utilizing AMBER for the purpose of evaluating dose rate to individual due to the long-term release of nuclides from the HLW or LILW repositories, a couple of their successors have been further developed and finally migrated to GoldSim scheme which is more flexible to adopt complex nuclide behaviors between the geosphere and the biosphere than AMBER based ACBIOs and then currently is being implemented into a GoldSim total system performance assessment programs which is being developed for the total safety assessment of the radioactive waste repository. To show its practicability and usability as well as to see the importance of GBIs, a quantified influence of the biosphere assessment has been investigated for varying GBI schemes through this study. To this end, among a few other possibilities, two cases having a different GBI scheme, the first one of which is 'Aquifer-only' GBI and the other one is 'Allpossible GBIs', they have been evaluated and compared with each other. Two plots for the calculated results are represented where peak dose conversion factors only for farming exposure group due to 38 nuclides are shown. Which represents the case of 'Aquifer- GBI' only, some discrepancy is found for such selected nuclides as 79 Se and 135 Cs between the cases of 'existence of a well' through which groundwater in the aquifer is drawn for the farming usage. However, unlike the farming exposure group no other two exposure groups, freshwater exposure and marine water exposure groups, seem to be free from the same scheme. However, all the exposure groups are

Mechanistic insights on the responses of plant and ecosystem gas exchange to global environmental change: lessons from Biosphere 2.

Science.gov (United States)

Gonzalez-Meler, Miquel A; Rucks, Jessica S; Aubanell, Gerard

2014-09-01

Scaling up leaf processes to canopy/ecosystem level fluxes is critical for examining feedbacks between vegetation and climate. Collectively, studies from Biosphere 2 Laboratory have provided important insight of leaf-to-ecosystem investigations of multiple environmental parameters that were not before possible in enclosed or field studies. B2L has been a testing lab for the applicability of new technologies such as spectral approaches to detect spatial and temporal changes in photosynthesis within canopies, or for the development of cavity ring-down isotope applications for ecosystem evapotranspiration. Short and long term changes in atmospheric CO2, drought or temperature allowed for intensive investigation of the interactions between photosynthesis and leaf, soil and ecosystem respiration. Experiments conducted in the rainforest biome have provided some of the most comprehensive dataset to date on the effects of climate change variables on tropical ecosystems. Results from these studies have been later corroborated in natural rainforest ecosystems and have improved the predictive capabilities of models that now show increased resilience of tropics to climate change. Studies of temperature and CO2 effects on ecosystem respiration and its leaf and soil components have helped reconsider the use of simple first-order kinetics for characterizing respiration in models. The B2L also provided opportunities to quantify the rhizosphere priming effect, or establish the relationships between net primary productivity, atmospheric CO2 and isoprene emissions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

An overview of the rangelands atmosphere hydrosphere biosphere interaction study experiment in northeastern Asia (RAISE)

Science.gov (United States)

Sugita, Michiaki; Asanuma, Jun; Tsujimura, Maki; Mariko, Shigeru; Lu, Minjiao; Kimura, Fujio; Azzaya, Dolgorsuren; Adyasuren, Tsokhio

2007-01-01

SummaryIntensive observations, analysis and modeling within the framework of the rangelands atmosphere-hydrosphere-biosphere interaction study experiment in northeastern Asia (RAISE) project, have allowed investigations into the hydrologic cycle in the ecotone of forest-steppe, and its relation to atmosphere and ecosystem in the eastern part of Mongolia. In this region, changes in the climate have been reported and a market oriented economy was introduced recently, but their impact on the natural environment is still not well understood. In this RAISE special issue, the outcome is presented of the studies carried out by six groups within RAISE, namely: (1) Land-atmosphere interaction analysis, (2) ecosystem analysis and modeling, (3) hydrologic cycle analysis, (4) climatic modeling, (5) hydrologic modeling, and (6) integration. The results are organized in five relevant categories comprising (i) hydrologic cycle including precipitation, groundwater, and surface water, (ii) hydrologic cycle and ecosystem, (iii) surface-atmosphere interaction, (iv) effect of grazing activities on soils, plant ecosystem and surface fluxes, and (v) future prediction. Comparison with studies on rangelands in other parts of the world, and some future directions of studies still needed in this region are also summarized.

Potential changes in atmospheric chemistry in the decades ahead: Climate and biosphere interactions and feedbacks

Energy Technology Data Exchange (ETDEWEB)

Gaffney, J.S.; Marley, N.A.

1991-10-01

Atmospheric chemistry is a challenging area of research where much knowledge is needed if we are to continue to survive as a species. This paper outlines research needs in the decades ahead in this key area of scientific endeavor. Highlighted are areas of research that are likely to lead to climatic and biospheric impacts and have been given little attention in the past. In particular, the possible organic transformation chemistries that may lead to chemical and physical changes in tropospheric cloud chemistries are highlighted and emphasized as an area where research is needed in the future. 22 refs.

Studies of land-cover, land-use, and biophysical properties of vegetation in the Large Scale Biosphere Atmosphere experiment in Amazonia.

Science.gov (United States)

Dar A. Robertsa; Michael Keller; Joao Vianei Soares

2003-01-01

We summarize early research on land-cover, land-use, and biophysical properties of vegetation from the Large Scale Biosphere Atmosphere (LBA) experiment in Amazoˆnia. LBA is an international research program developed to evaluate regional function and to determine how land-use and climate modify biological, chemical and physical processes there. Remote sensing has...

Surface - atmosphere exchange of ammonia over grazed pasture

NARCIS (Netherlands)

Plantaz, M.A.H.G.

1998-01-01

This thesis deals with the exchange of ammonia between the atmosphere and grazed pasture in an area of intensive livestock breeding. The term exchange is used because gaseous ammonia can be taken up (dry deposition) as well as released (emission) by this type of surface.
Ammonia exchange

Ecological Controls on Land-Atmosphere Exchange

Science.gov (United States)

Goulden, M. L.; Litvak, M. E.; Winston, G.; Miller, S. D.; Read, E.; Elliot, R.

2002-12-01

We have been using long-term eddy covariance to investigate the patterns of energy and CO2 exchange between the atmosphere and a freshwater marsh in California, and also between the atmosphere and a series of boreal forest stands in Manitoba, Canada. Most researchers believe that ecological phenomenon, such as plant herbivore interactions and interspecific differences in plant life-history strategy, are relatively unimportant in determining the interannual and landscape patterns of Land-Atmosphere exchange. However, we have found that interactions between plants and herbivores exert a large control on the interannual patterns of energy and CO2 exchange in the freshwater marsh, and that interspecific differences in plant strategy are critical for understanding the landscape scale patterns of energy and CO2 exchange in the boreal forest. Despite a relatively constant climate and flooding regime at the California marsh, annual Carbon balance varied by 6 tC ha-1 or more from year to year. These deviations were caused in part by variation in herbivory by rodents and insects. Likewise, peak CO2 uptake by boreal forest stands recovering from fire differed less than expected, with a 4-year-old stand assimilating CO2 at rates comparable to that by middle aged stands, and faster than that by old stands. These patterns reflect differences in the life history strategies of the dominant plants, with the youngest stands dominated by fast growing ruderals, the middle aged stands dominated by fast growing competitive species, and the old stands dominated by slow growing stress tolerant species.

Diffusion-type model of the global carbon cycle for the estimation of dose to the world population from releases of carbon-14 to the atmosphere

International Nuclear Information System (INIS)

Killough, G.G.

1977-05-01

A nonlinear dynamic model of the exchange of carbon among the atmosphere, terrestrial biosphere, and ocean is described and applied to estimating the radiation dose to the world's population from the release of 14 C to the atmosphere from the nuclear power industry. A computer implementation of the model, written in the IBM Continuous System Modeling Program III (CSMP III) simulation language, is presented. The model treats the ocean as a diffusive medium with respect to vertical transport of carbon, and the nonlinear variation of CO 2 partial pressure with the total inorganic carbon concentration in surface waters is taken into account in calculating the transfer rate from ocean to atmosphere. Transfers between the atmosphere and terrestrial biosphere are represented by nonlinear equations which consider CO 2 fertilization and impose a constraint on the ultimate total carbon mass in the biosphere

North America's net terrestrial CO2 exchange with the atmosphere 1990-2009

Science.gov (United States)

King, A. W.; Andres, R. J.; Davis, K. J.; Hafer, M.; Hayes, D. J.; Huntzinger, D. N.; de Jong, B.; Kurz, W. A.; McGuire, A. D.; Vargas, R.; Wei, Y.; West, T. O.; Woodall, C. W.

2015-01-01

Scientific understanding of the global carbon cycle is required for developing national and international policy to mitigate fossil fuel CO2 emissions by managing terrestrial carbon uptake. Toward that understanding and as a contribution to the REgional Carbon Cycle Assessment and Processes (RECCAP) project, this paper provides a synthesis of net land-atmosphere CO2 exchange for North America (Canada, United States, and Mexico) over the period 1990-2009. Only CO2 is considered, not methane or other greenhouse gases. This synthesis is based on results from three different methods: atmospheric inversion, inventory-based methods and terrestrial biosphere modeling. All methods indicate that the North American land surface was a sink for atmospheric CO2, with a net transfer from atmosphere to land. Estimates ranged from -890 to -280 Tg C yr-1, where the mean of atmospheric inversion estimates forms the lower bound of that range (a larger land sink) and the inventory-based estimate using the production approach the upper (a smaller land sink). This relatively large range is due in part to differences in how the approaches represent trade, fire and other disturbances and which ecosystems they include. Integrating across estimates, "best" estimates (i.e., measures of central tendency) are -472 ± 281 Tg C yr-1 based on the mean and standard deviation of the distribution and -360 Tg C yr-1 (with an interquartile range of -496 to -337) based on the median. Considering both the fossil fuel emissions source and the land sink, our analysis shows that North America was, however, a net contributor to the growth of CO2 in the atmosphere in the late 20th and early 21st century. With North America's mean annual fossil fuel CO2 emissions for the period 1990-2009 equal to 1720 Tg C yr-1 and assuming the estimate of -472 Tg C yr-1 as an approximation of the true terrestrial CO2 sink, the continent's source : sink ratio for this time period was 1720:472, or nearly 4:1.

Sensitivity analysis of biospheric behaviour of radionuclides released from nuclear waste repositories

International Nuclear Information System (INIS)

Korhonen, R.; Savolainen, I.; Suolanen, V.

1985-01-01

Sensitivity studies of biospheric behaviour of radionuclides released from a planned spent nuclear fuel repository are performed. Sensitivity of radionuclide concentrations in biosphere and that of radiation doses to solubility of nuclides, to sedimentation rate and to intercompartmental water exchange are studied. Solubility has pronounced effect on the sedimentation on the local scale, and in general, sediment sinks were found to be of major importance in the biospheric behaviour of radionuclides. (author)

Land-Atmosphere Interactions in Cold Environments (LATICE): The role of Atmosphere - Biosphere - Cryosphere - Hydrosphere interactions in a changing climate

Science.gov (United States)

Burkhart, J. F.; Tallaksen, L. M.; Stordal, F.; Berntsen, T.; Westermann, S.; Kristjansson, J. E.; Etzelmuller, B.; Hagen, J. O.; Schuler, T.; Hamran, S. E.; Lande, T. S.; Bryn, A.

2015-12-01

Climate change is impacting the high latitudes more rapidly and significantly than any other region of the Earth because of feedback processes between the atmosphere and the underlying surface. A warmer climate has already led to thawing of permafrost, reducing snow cover and a longer growing season; changes, which in turn influence the atmospheric circulation and the hydrological cycle. Still, many studies rely on one-way coupling between the atmosphere and the land surface, thereby neglecting important interactions and feedbacks. The observation, understanding and prediction of such processes from local to regional and global scales, represent a major scientific challenge that requires multidisciplinary scientific effort. The successful integration of earth observations (remote and in-situ data) and model development requires a harmonized research effort between earth system scientists, modelers and the developers of technologies and sensors. LATICE, which is recognized as a priority research area by the Faculty of Mathematics and Natural Sciences at the University of Oslo, aims to advance the knowledge base concerning land atmosphere interactions and their role in controlling climate variability and climate change at high northern latitudes. The consortium consists of an interdisciplinary team of experts from the atmospheric and terrestrial (hydrosphere, cryosphere and biosphere) research groups, together with key expertise on earth observations and novel sensor technologies. LATICE addresses critical knowledge gaps in the current climate assessment capacity through: Improving parameterizations of processes in earth system models controlling the interactions and feedbacks between the land (snow, ice, permafrost, soil and vegetation) and the atmosphere at high latitudes, including the boreal, alpine and artic zone. Assessing the influence of climate and land cover changes on water and energy fluxes. Integrating remote earth observations with in-situ data and

"Biospheric medicine" as viewed from the two-year first closure of Biosphere 2.

Science.gov (United States)

Walford, R L; Bechtel, R; MacCallum, T; Paglia, D E; Weber, L J

1996-07-01

Biosphere 2 is a 3.15-acre, 7-million ft. enclosed ecological space near Tucson, AZ. It contains five wilderness and two domestic biomes (rain forest, savanna, desert, ocean, marsh; agricultural station, living quarters), an original introduction of 3,800 species (approximately 20% extinctions have occurred), and a large basement "technosphere." Sealed inside Biosphere 2 in September 1991, four women and four men, including two of the authors, maintained themselves and the various systems for 2 yr, the longest-sustained "isolated confined environment" period on record. MMPI psychological profile scores for Biosphere 2 crewmembers correlated closely with those reported for astronauts and shuttle applicants. Major medical problems encountered during the 2 yr included adaptation to a low-calorie (1800-2200 kcal.d-1 per person) but otherwise nutritionally adequate diet, with substantial weight loss (18% for men, 10% for women), and a declining oxygen atmosphere (down to 14.2%). Life in a miniworld such as Biosphere 2 may differ substantially from life in a space station or temporary planetary base. These differences include multiple, shifting, sometimes opposing post-launch objectives; complete self-sustenance with recycling of virtually all materials within a highly complex biologic system; retooling of some areas of practical medicine; an attention to "culture" as a social dynamic and how that may influence crew and leadership selection in a societal rather than a quasi-military community. Assuming that long-term planetary colonies must be largely self-sustaining (due to costs of supply over great distances), they must of necessity approach the condition of biospheres. Subject to chaos dynamic (nonlinear dynamic) perturbations, the behavior of complex biospheres will be inherently non-predictable--as opposed to the linear dynamic situation of most space missions--and will require of the inhabitants, including the medical team, a wide range of coping abilities. Under

Global patterns and controls of soil organic carbon dynamics as simulated by multiple terrestrial biosphere models: Current status and future directions.

Science.gov (United States)

Tian, Hanqin; Lu, Chaoqun; Yang, Jia; Banger, Kamaljit; Huntzinger, Deborah N; Schwalm, Christopher R; Michalak, Anna M; Cook, Robert; Ciais, Philippe; Hayes, Daniel; Huang, Maoyi; Ito, Akihiko; Jain, Atul K; Lei, Huimin; Mao, Jiafu; Pan, Shufen; Post, Wilfred M; Peng, Shushi; Poulter, Benjamin; Ren, Wei; Ricciuto, Daniel; Schaefer, Kevin; Shi, Xiaoying; Tao, Bo; Wang, Weile; Wei, Yaxing; Yang, Qichun; Zhang, Bowen; Zeng, Ning

2015-06-01

Soil is the largest organic carbon (C) pool of terrestrial ecosystems, and C loss from soil accounts for a large proportion of land-atmosphere C exchange. Therefore, a small change in soil organic C (SOC) can affect atmospheric carbon dioxide (CO 2 ) concentration and climate change. In the past decades, a wide variety of studies have been conducted to quantify global SOC stocks and soil C exchange with the atmosphere through site measurements, inventories, and empirical/process-based modeling. However, these estimates are highly uncertain, and identifying major driving forces controlling soil C dynamics remains a key research challenge. This study has compiled century-long (1901-2010) estimates of SOC storage and heterotrophic respiration (Rh) from 10 terrestrial biosphere models (TBMs) in the Multi-scale Synthesis and Terrestrial Model Intercomparison Project and two observation-based data sets. The 10 TBM ensemble shows that global SOC estimate ranges from 425 to 2111 Pg C (1 Pg = 10 15  g) with a median value of 1158 Pg C in 2010. The models estimate a broad range of Rh from 35 to 69 Pg C yr -1 with a median value of 51 Pg C yr -1 during 2001-2010. The largest uncertainty in SOC stocks exists in the 40-65°N latitude whereas the largest cross-model divergence in Rh are in the tropics. The modeled SOC change during 1901-2010 ranges from -70 Pg C to 86 Pg C, but in some models the SOC change has a different sign from the change of total C stock, implying very different contribution of vegetation and soil pools in determining the terrestrial C budget among models. The model ensemble-estimated mean residence time of SOC shows a reduction of 3.4 years over the past century, which accelerate C cycling through the land biosphere. All the models agreed that climate and land use changes decreased SOC stocks, while elevated atmospheric CO 2 and nitrogen deposition over intact ecosystems increased SOC stocks-even though the responses varied

Atmospheric Seasonality as an Exoplanet Biosignature

Science.gov (United States)

Olson, Stephanie L.; Schwieterman, Edward W.; Reinhard, Christopher T.; Ridgwell, Andy; Kane, Stephen R.; Meadows, Victoria S.; Lyons, Timothy W.

2018-05-01

Current investigations of exoplanet biosignatures have focused on static evidence of life, such as the presence of biogenic gases like O2 or CH4. However, the expected diversity of terrestrial planet atmospheres and the likelihood of both “false positives” and “false negatives” for conventional biosignatures motivate exploration of additional life detection strategies, including time-varying signals. Seasonal variation in atmospheric composition is a biologically modulated phenomenon on Earth that may occur elsewhere because it arises naturally from the interplay between the biosphere and time-variable insolation. The search for seasonality as a biosignature would avoid many assumptions about specific metabolisms and provide an opportunity to directly quantify biological fluxes—allowing us to characterize, rather than simply recognize, biospheres on exoplanets. Despite this potential, there have been no comprehensive studies of seasonality as an exoplanet biosignature. Here, we provide a foundation for further studies by reviewing both biological and abiological controls on the magnitude and detectability of seasonality of atmospheric CO2, CH4, O2, and O3 on Earth. We also consider an example of an inhabited world for which atmospheric seasonality may be the most notable expression of its biosphere. We show that life on a low O2 planet like the weakly oxygenated mid-Proterozoic Earth could be fingerprinted by seasonal variation in O3 as revealed in its UV Hartley–Huggins bands. This example highlights the need for UV capabilities in future direct-imaging telescope missions (e.g., LUVOIR/HabEx) and illustrates the diagnostic importance of studying temporal biosignatures for exoplanet life detection/characterization.

Sensitivity of the biosphere-atmosphere transfer scheme (BATS) to the inclusion of variable soil characteristics

Energy Technology Data Exchange (ETDEWEB)

Wilson, M.F.; Henderson-Sellers, A.; Dickinson, R.E.; Kennedy, P.J.

1987-03-01

The soils data of Wilson and Henderson-Sellers have been incorporated into the land-surface parameterization scheme of the NCAR Community Climate Model after Dickinson. A stand-alone version of this land-surface scheme, termed the Biosphere-Atmosphere Transfer Scheme (BATS), has been tested in a series of sensitivity experiments designed to assess the sensitivity of the scheme to the inclusion of variable soil characteristics. The cases investigated were for conditions designed to represent a low-latitude, evergreen forest; a low-latitude sand desert; a high-latitude coniferous forest; high-latitude tundra; and prairie grasslands, each for a specified time of year. The tundra included spring snowmelt and the grassland incorporated snow accumulation. The sensitivity experiments included varying the soil texture from a coarse texture typical of sand through a medium texture typical of loam to a fine texture typical of clay. The sensitivity of the formation to the specified total and upper soil column depth and the response to altering the parameterization of the soil albedo dependence upon soil wetness and snow-cover were also examined. The biosphere-atmosphere transfer scheme showed the greatest sensitivity to the soil texture variation, particularly to the associated variation in the hydraulic conductivity and diffusivity parameters. There was only a very small response to the change in the soil albedo dependence on wetness and, although the sensitivity to the snow-covered soil albedo via the response to roughness length/snowmasking depth was significant, the results were predictable. Soil moisture responses can also be initiated by changes in vegetation characteristics such as the stomatal resistance through changed canopy interaction which modify the radiation and water budgets of the soil surface.

Dose assessment considering evolution of the biosphere

International Nuclear Information System (INIS)

Karlsson, Sara; Bergstroem, Ulla

2002-01-01

Swedish Nuclear Fuel and Waste Management AB (SKB) is presently updating the safety assessment for SFR (Final repository for radioactive operational waste) in Sweden. The bio-spheric part of the analysis is performed by Studsvik Eco and Safety AB. According to the regulations the safety of the repository has to be accounted for different possible courses of the development of the biosphere. A number of studies have been carried out during the past years to investigate and document the biosphere in the area surrounding the repository. Modelling of shore-level displacement by land uplift, coastal water exchange and sedimentation have provided data for prediction of the evolution of the area. The prediction is done without considering a future change in climatic conditions. The results from this study show that accumulation of radionuclides in sediments is an important process to simulate when performing dose assessments covering biosphere evolution. The dose calculated for the first years of the period with agricultural use of the contaminated sediments may be severely underestimated in a scenario with large accumulation in coastal and lake stages. (LN)

The Geosphere - Biosphere international program and the global change

International Nuclear Information System (INIS)

Chanin, M.L.

1991-01-01

The objective of the Geosphere-Biosphere International Program (GBIP) is to achieve a correct approach of the various biogeochemical interactions between the different components of the environment (oceans, atmosphere, biosphere). The main themes are: study of the chemical regulation in the global atmosphere and influence of natural and anthropogenic processes on trace element cycles; influence of the oceanic biogeochemical processes on climates and their response to climatic changes; influence of soil utilization modification (especially coastal) on climates and ecosystems; interaction between vegetation and the water cycle; interaction between climatic changes, ecosystems and agricultural productivity; approaches to climate modelling. French component of the GBIP is presented [fr

Causes and timing of future biosphere extinctions

Directory of Open Access Journals (Sweden)

S. Franck

2006-01-01

Full Text Available We present a minimal model for the global carbon cycle of the Earth containing the reservoirs mantle, ocean floor, continental crust, biosphere, and the kerogen, as well as the combined ocean and atmosphere reservoir. The model is specified by introducing three different types of biosphere: procaryotes, eucaryotes, and complex multicellular life. During the entire existence of the biosphere procaryotes are always present. 2 Gyr ago eucaryotic life first appears. The emergence of complex multicellular life is connected with an explosive increase in biomass and a strong decrease in Cambrian global surface temperature at about 0.54 Gyr ago. In the long-term future the three types of biosphere will die out in reverse sequence of their appearance. We show that there is no evidence for an implosion-like extinction in contrast to the Cambrian explosion. In dependence of their temperature tolerance complex multicellular life and eucaryotes become extinct in about 0.8–1.2 Gyr and 1.3–1.5 Gyr, respectively. The ultimate life span of the biosphere is defined by the extinction of procaryotes in about 1.6 Gyr.

The water cycle in closed ecological systems: Perspectives from the Biosphere 2 and Laboratory Biosphere systems

Science.gov (United States)

Nelson, Mark; Dempster, W. F.; Allen, J. P.

2009-12-01

To achieve sustainable, healthy closed ecological systems requires solutions to challenges of closing the water cycle - recycling wastewater/irrigation water/soil medium leachate and evaporated water and supplying water of required quality as needed for different needs within the facility. Engineering Biosphere 2, the first multi-biome closed ecological system within a total airtight footprint of 12,700 m 2 with a combined volume of 200,000 m 3 with a total water capacity of some 6 × 10 6 L of water was especially challenging because it included human inhabitants, their agricultural and technical systems, as well as five analogue ecosystems ranging from rainforest to desert, freshwater ecologies to saltwater systems like mangrove and mini-ocean coral reef ecosystems. By contrast, the Laboratory Biosphere - a small (40 m 3 volume) soil-based plant growth facility with a footprint of 15 m 2 - is a very simplified system, but with similar challenges re salinity management and provision of water quality suitable for plant growth. In Biosphere 2, water needs included supplying potable water for people and domestic animals, irrigation water for a wide variety of food crops, and recycling and recovering soil nutrients from wastewater. In the wilderness biomes, providing adequately low salinity freshwater terrestrial ecosystems and maintaining appropriate salinity and pH in aquatic/marine ecosystems were challenges. The largest reservoirs in Biosphere 2 were the ocean/marsh with some 4 × 10 6 L, soil with 1 to 2 × 10 6 l, primary storage tank with 0 to 8 × 10 5 L and storage tanks for condensate and soil leachate collection and mixing tanks with a capacity of 1.6 × 10 5 L to supply irrigation for farm and wilderness ecosystems. Other reservoirs were far smaller - humidity in the atmosphere (2 × 10 3 L), streams in the rainforest and savannah, and seasonal pools in the desert were orders of magnitude smaller (8 × 10 4 L). Key technologies included condensation from

Reconciling estimates of the contemporary North American carbon balance among terrestrial biosphere models, atmospheric inversions, and a new approach for estimating net ecosystem exchange from inventory-based data

Science.gov (United States)

Daniel J. Hayes; David P. Turner; Graham Stinson; A. David Mcguire; Yaxing Wei; Tristram O. West; Linda S. Heath; Bernardus Dejong; Brian G. McConkey; Richard A. Birdsey; Werner A. Kurz; Andrew R. Jacobson; Deborah N. Huntzinger; Yude Pan; W. Mac Post; Robert B. Cook

2012-01-01

We develop an approach for estimating net ecosystem exchange (NEE) using inventory-based information over North America (NA) for a recent 7-year period (ca. 2000-2006). The approach notably retains information on the spatial distribution of NEE, or the vertical exchange between land and atmosphere of all non-fossil fuel sources and sinks of CO2,...

Methane Production and Transport within the Marsh Biome of Biosphere 2

Science.gov (United States)

Molnar, Jennifer; Goodridge, Kelven

1997-01-01

In recent decades, the concentration of methane in the earth's atmosphere increased 1-2% annually. It's rate of increases, combined with methane's effectiveness as a greenhouse gas, has led to an intensive research effort to determine the sources and sinks of the gas in the environment. Biosphere 2 offers a unique opportunity to contribute to the effort because it lacks a major photochemical sink present in the Earth's atmosphere. Researchers can therefore concentrate on biological processes involved in methane cycles. Wetlands are a large source of atmospheric methane, due to anoxic conditions in the sediments and the abundance of organic materials. In order to determine if these conditions in Biosphere 2 also promote methane production, this study looked for the fluxes of methane and methods of transport of the gas from from the water and sediments to the atmosphere in the Marsh Biome. Fluxes of methane from the sediments and waters were measured using static chambers, peepers, and leaf bags. Fluxes and vertical profiles of methane in the sediments show that substantial amounts of methane are being produced in the marsh and are being transported into the Biosphere 2 environment.

Inhalation Exposure Input Parameters for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

K. Rautenstrauch

2004-09-10

This analysis is one of 10 reports that support the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN) biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents development of input parameters for the biosphere model that are related to atmospheric mass loading and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for a Yucca Mountain repository. Inhalation Exposure Input Parameters for the Biosphere Model is one of five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the plan for development of the biosphere abstraction products for TSPA, as identified in the Technical Work Plan for Biosphere Modeling and Expert Support (BSC 2004 [DIRS 169573]). This analysis report defines and justifies values of mass loading for the biosphere model. Mass loading is the total mass concentration of resuspended particles (e.g., dust, ash) in a volume of air. Mass loading values are used in the air submodel of ERMYN to calculate concentrations of radionuclides in air inhaled by a receptor and concentrations in air surrounding crops. Concentrations in air to which the receptor is exposed are then used in the inhalation submodel to calculate the dose contribution to the receptor from inhalation of contaminated airborne particles. Concentrations in air surrounding plants are used in the plant submodel to calculate the concentrations of radionuclides in foodstuffs contributed from uptake by foliar interception.

Inhalation Exposure Input Parameters for the Biosphere Model

International Nuclear Information System (INIS)

K. Rautenstrauch

2004-01-01

This analysis is one of 10 reports that support the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN) biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents development of input parameters for the biosphere model that are related to atmospheric mass loading and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for a Yucca Mountain repository. Inhalation Exposure Input Parameters for the Biosphere Model is one of five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the plan for development of the biosphere abstraction products for TSPA, as identified in the Technical Work Plan for Biosphere Modeling and Expert Support (BSC 2004 [DIRS 169573]). This analysis report defines and justifies values of mass loading for the biosphere model. Mass loading is the total mass concentration of resuspended particles (e.g., dust, ash) in a volume of air. Mass loading values are used in the air submodel of ERMYN to calculate concentrations of radionuclides in air inhaled by a receptor and concentrations in air surrounding crops. Concentrations in air to which the receptor is exposed are then used in the inhalation submodel to calculate the dose contribution to the receptor from inhalation of contaminated airborne particles. Concentrations in air surrounding plants are used in the plant submodel to calculate the concentrations of radionuclides in foodstuffs contributed from uptake by foliar interception

Space Based Measurements for Atmospheric Carbon Dioxide: a New Tool for Monitoring Our Environment

Science.gov (United States)

Crisp, David

2015-01-01

Fossil fuel combustion, deforestation, and other human activities are now adding almost 40 billion tons of carbon dioxide (CO2) to the atmosphere each year. Interestingly, as these emissions have increased over time, natural "sinks" in land biosphere and oceans have absorbed roughly half of this CO2, reducing the rate of atmospheric buildup by a half. Measurements of the increasing acidity (pH) of seawater indicate that the ocean absorbs one quarter of this CO2. Another quarter is apparently being absorbed by the land biosphere, but the identity and location of these natural land CO2 "sinks" are still unknown. The existing ground-based greenhouse gas monitoring network provides an accurate record of the atmospheric buildup, but still does not have the spatial resolution or coverage needed to identify or quantify CO2 sources and sinks.

An Estimate of the Total DNA in the Biosphere.

Science.gov (United States)

Landenmark, Hanna K E; Forgan, Duncan H; Cockell, Charles S

2015-06-01

Modern whole-organism genome analysis, in combination with biomass estimates, allows us to estimate a lower bound on the total information content in the biosphere: 5.3 × 1031 (±3.6 × 1031) megabases (Mb) of DNA. Given conservative estimates regarding DNA transcription rates, this information content suggests biosphere processing speeds exceeding yottaNOPS values (1024 Nucleotide Operations Per Second). Although prokaryotes evolved at least 3 billion years before plants and animals, we find that the information content of prokaryotes is similar to plants and animals at the present day. This information-based approach offers a new way to quantify anthropogenic and natural processes in the biosphere and its information diversity over time.

WEB-DHM: A distributed biosphere hydrological model developed by coupling a simple biosphere scheme with a hillslope hydrological model

Science.gov (United States)

The coupling of land surface models and hydrological models potentially improves the land surface representation, benefiting both the streamflow prediction capabilities as well as providing improved estimates of water and energy fluxes into the atmosphere. In this study, the simple biosphere model 2...

Post-closure performance assessment treatment of the biosphere

Energy Technology Data Exchange (ETDEWEB)

Broderick, M A [UK Nirex Ltd., Harwell, Oxfordshire (United Kingdom); Egan, M J [AEA Technology, Risley, Cheshire (United Kingdom); Thorne, M C [Electrowatt, Horsham, Sussex (United Kingdom); Williams, J A [AEA Technology, Risley, Cheshire (United Kingdom)

1996-07-01

The Nirex strategy for radioactive waste disposal is based on a system of engineered and natural barriers, providing long-term isolation of the waste from those parts of the environment that are in contact with or readily available for use by humans (i.e. the biosphere). Even so, there remains the possibility that, on a timescale of thousands to tens of thousands of years, small quantities of poorly-sorbed, long-lived radionuclides may be released from the engineered disposal system, ultimately to emerge into the biosphere. Biosphere models are used in post-closure performance assessments to quantify the competing effects of dilution and accumulation processes on radionuclide concentrations in the accessible environment. Understanding biosphere processes and their time dependence is necessary not only to determine the radiological impact of possible future releases, but also to characterise the dynamics of transport in groundwater and the location, duration and extent of any such releases. Nirex is developing a new biosphere model for use in post-closure radiological assessments for the proposed Sellafield repository. A compartment modelling approach has been adopted, as in studies performed previously, but the system will be dynamic, allowing changes with time in both the properties of compartments and the transfers between compartments. The transport model considers both mass transport within the biosphere and the migration of radionuclides, thereby ensuring that a self-consistent description of the biosphere, in a spatially-extensive domain is maintained. The above approach is designed to link the assessment models used by the Nirex assessment team more closely into the Nirex biosphere research programme than has hitherto been possible with time-invariant assessment models. (author)

Post-closure performance assessment treatment of the biosphere

International Nuclear Information System (INIS)

Broderick, M.A.; Egan, M.J.; Thorne, M.C.; Williams, J.A.

1996-01-01

The Nirex strategy for radioactive waste disposal is based on a system of engineered and natural barriers, providing long-term isolation of the waste from those parts of the environment that are in contact with or readily available for use by humans (i.e. the biosphere). Even so, there remains the possibility that, on a timescale of thousands to tens of thousands of years, small quantities of poorly-sorbed, long-lived radionuclides may be released from the engineered disposal system, ultimately to emerge into the biosphere. Biosphere models are used in post-closure performance assessments to quantify the competing effects of dilution and accumulation processes on radionuclide concentrations in the accessible environment. Understanding biosphere processes and their time dependence is necessary not only to determine the radiological impact of possible future releases, but also to characterise the dynamics of transport in groundwater and the location, duration and extent of any such releases. Nirex is developing a new biosphere model for use in post-closure radiological assessments for the proposed Sellafield repository. A compartment modelling approach has been adopted, as in studies performed previously, but the system will be dynamic, allowing changes with time in both the properties of compartments and the transfers between compartments. The transport model considers both mass transport within the biosphere and the migration of radionuclides, thereby ensuring that a self-consistent description of the biosphere, in a spatially-extensive domain is maintained. The above approach is designed to link the assessment models used by the Nirex assessment team more closely into the Nirex biosphere research programme than has hitherto been possible with time-invariant assessment models. (author)

Contrasting carbon cycle responses of the tropical continents to the 2015-2016 El Niño.

Science.gov (United States)

Liu, Junjie; Bowman, Kevin W; Schimel, David S; Parazoo, Nicolas C; Jiang, Zhe; Lee, Meemong; Bloom, A Anthony; Wunch, Debra; Frankenberg, Christian; Sun, Ying; O'Dell, Christopher W; Gurney, Kevin R; Menemenlis, Dimitris; Gierach, Michelle; Crisp, David; Eldering, Annmarie

2017-10-13

The 2015-2016 El Niño led to historically high temperatures and low precipitation over the tropics, while the growth rate of atmospheric carbon dioxide (CO 2 ) was the largest on record. Here we quantify the response of tropical net biosphere exchange, gross primary production, biomass burning, and respiration to these climate anomalies by assimilating column CO 2 , solar-induced chlorophyll fluorescence, and carbon monoxide observations from multiple satellites. Relative to the 2011 La Niña, the pantropical biosphere released 2.5 ± 0.34 gigatons more carbon into the atmosphere in 2015, consisting of approximately even contributions from three tropical continents but dominated by diverse carbon exchange processes. The heterogeneity of the carbon-exchange processes indicated here challenges previous studies that suggested that a single dominant process determines carbon cycle interannual variability. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Russian biosphere reserves at the youth MAB-2017 Forum in Italy

Directory of Open Access Journals (Sweden)

Elena A. Shuyskaya

2018-02-01

Full Text Available Russia was represented by 9 participants from Biosphere Reserves at the MAB Youth Forum in Italy. The main question of the Forum was «How to involve the young in the work of biosphere reserves?» The debate resulted in a Declaration, elaborated by participants from around the world (282 delegates from 85 countries. Measures to improve scientific cooperation, data exchange in the sphere of educational tourism and administrative management, development of joint projects in environmental education were formulated. The article contains a number of recommendations for the network of biosphere reserves in Russia, based on Seville strategy and Lima Action Plan.

The nitrogen cycle: Atmosphere interactions

Science.gov (United States)

Levine, J. S.

1984-01-01

Atmospheric interactions involving the nitrogen species are varied and complex. These interactions include photochemical reactions, initiated by the absorption of solar photons and chemical kinetic reactions, which involve both homogeneous (gas-to-gas reactions) and heterogeneous (gas-to-particle) reactions. Another important atmospheric interaction is the production of nitrogen oxides by atmospheric lightning. The nitrogen cycle strongly couples the biosphere and atmosphere. Many nitrogen species are produced by biogenic processes. Once in the atmosphere nitrogen oxides are photochemically and chemically transformed to nitrates, which are returned to the biosphere via precipitation, dry deposition and aerosols to close the biosphere-atmosphere nitrogen cycle. The sources, sinks and photochemistry/chemistry of the nitrogen species; atmospheric nitrogen species; souces and sinks of nitrous oxide; sources; sinks and photochemistry/chemistry of ammonia; seasonal variation of the vertical distribution of ammonia in the troposphere; surface and atmospheric sources of the nitrogen species, and seasonal variation of ground level ammonia are summarized.

TransCom model simulations of hourly atmospheric CO2: Experimental overview and diurnal cycle results for 2002

NARCIS (Netherlands)

Law, R. M.; Peters, W.; RöDenbeck, C.; Aulagnier, C.; Baker, I.; Bergmann, D. J.; Bousquet, P.; Brandt, J.; Bruhwiler, L.; Cameron-Smith, P. J.; Christensen, J. H.; Delage, F.; Denning, A. S.; Fan, S.; Geels, C.; Houweling, S.; Imasu, R.; Karstens, U.; Kawa, S. R.; Kleist, J.; Krol, M. C.; Lin, S.-J.; Lokupitiya, R.; Maki, T.; Maksyutov, S.; Niwa, Y.; Onishi, R.; Parazoo, N.; Patra, P. K.; Pieterse, G.; Rivier, L.; Satoh, M.; Serrar, S.; Taguchi, S.; Takigawa, M.; Vautard, R.; Vermeulen, A. T.; Zhu, Z.

2008-01-01

A forward atmospheric transport modeling experiment has been coordinated by the TransCom group to investigate synoptic and diurnal variations in CO2. Model simulations were run for biospheric, fossil, and air-sea exchange of CO2 and for SF6 and radon for 2000-2003. Twenty-five models or model

Mesoscale modelling of atmospheric CO2 across Denmark

DEFF Research Database (Denmark)

Lansø, Anne Sofie

2016-01-01

of the simulated atmospheric CO2 across Denmark was, in particular, affected by the Danish terrestrial surface exchanges and its temporal variability. This study urges all future modelling studies of air–sea CO2 to include short-term variability in pCO2. To capture the full heterogeneity of the surface exchanges......It is scientifically well-established that the increase of atmospheric CO2 affects the entire globe and will lead to higher surface temperatures. Although anthropogenic CO2is emitted straight into the atmosphere, it does not all contribute to the existing atmospheric CO2 reservoir. Approximately 29......% is taken up by the global oceans, due to under-saturation of CO2 in the surface waters, while another 33 % is taken up by the terrestrial biosphere, via photosynthesis. In order to estimate the effects of increasing anthropogenic emissions of CO2 more accurately in the future, it is essential to understand...

Biospheric theory and report on overall Biosphere 2 design and performance.

Science.gov (United States)

Allen, J

1997-01-01

This article reviews the structural complexity of Biospheres as well as Vernadsky's two laws of biospherics generalized into laws of thermodynamics. The history of designing and building apparatuses to test biospheric hypothesis are summarized: Drs. Shepelev and Gitelson's experiments in Russia, and Space Biospheres Ventures' 10,974 ft3 Test Module and 3.15-acre Biosphere 2 systems. Critical parameters in building Biosphere 2 are outlined: species lists, state descriptors, ecosystems, key variables, closure, and the necessity of observer-managers. Some results of the 2-year Mission One experiment in Biosphere 2 are summarized: human health, light-CO2 coupling, food production, redundancy in maintenance. Change made to the Biosphere 2 system after the first 2-year mission and before the start-up of the second mission are listed. As well, the future of artificial biospheres is considered.

A Controlled Environment System For Measuring Plant-Atmosphere Gas Exchange

Science.gov (United States)

James M. Brown

1975-01-01

Describes an inexpensive, efficient system for measuring plant-atmosphere gas exchange. Designed to measure transpiration from potted tree seedlings, it is readily adaptable for measuring other gas exchanges or gas exchange by plant parts. Light level, air and root temperature can be precisely controlled at minimum cost.

LIMITS OF THE EARTH BIOSPHERE

Directory of Open Access Journals (Sweden)

Karel KUDRNA

2011-01-01

Full Text Available Evaluation of the state of CO2 accumulation in the atmosphere demands knowledge on possibilities of the biosphere – its photosynthetizing apparatus, conditions and limits of absorption. A decisive precondition is to determine relation of CO2 accumulation by photosynthesis in dependence on the water balance, especially on its control quantity – transpiration, which is stabilized by supporting of underground waters.

Gas exchange between the forest and the atmosphere

International Nuclear Information System (INIS)

Murphy, C.E. Jr.

1985-01-01

Forest gas exchange is discussed in terms of the processes that control the rate of exchange with the atmosphere. Examples are presented to show how vegetative uptake control is varied for gases with different characteristics. The prediction of uptake for large areas and over long periods of time is discussed in terms of quantitative models of the gas exchange processes. Finally, remote sensing is suggested as a means of obtaining the parameters needed to make the model predictions. 46 refs., 6 figs

Atmosphere-soil-vegetation model including CO2 exchange processes: SOLVEG2

International Nuclear Information System (INIS)

Nagai, Haruyasu

2004-11-01

A new atmosphere-soil-vegetation model named SOLVEG2 (SOLVEG version 2) was developed to study the heat, water, and CO 2 exchanges between the atmosphere and land-surface. The model consists of one-dimensional multilayer sub-models for the atmosphere, soil, and vegetation. It also includes sophisticated processes for solar and long-wave radiation transmission in vegetation canopy and CO 2 exchanges among the atmosphere, soil, and vegetation. Although the model usually simulates only vertical variation of variables in the surface-layer atmosphere, soil, and vegetation canopy by using meteorological data as top boundary conditions, it can be used by coupling with a three-dimensional atmosphere model. In this paper, details of SOLVEG2, which includes the function of coupling with atmosphere model MM5, are described. (author)

Biosphere-Atmosphere Exchange of NOx, CH4, and O3 in Central Amazon

Science.gov (United States)

Wiedemann, K. T.; Munger, J. W.; Wofsy, S. C.; Budney, J.; Rizzo, L. V.; Campos, K.; Rocha, H.; Freitas, H.

2016-12-01

Oxidation by OH is the dominant pathway for removing important trace gases such as CH4, CO, CH3Br, and HCFCs. The primary source of atmospheric OH is the photolysis of O3 in the presence of water vapor, and NOx are the main precursors of O3 and OH. Thus, in NOx-rich environments that have both high humidity and high solar radiation, OH concentrations are enhanced, and therefore, tropical forests dominate global oxidation of long-lived gases. The Amazon rain forest has a unique combination of vegetation with diverse characteristics, climate, and a dynamic land use, factors that altogether govern the emission and fate of trace-gases and control particle formation and atmospheric chemistry. Understanding the interactions among the mechanisms that govern local precursor emissions will lead to a better description of the local atmospheric chemistry, which have global impacts. As part of the GoAmazon project, an array of complementary measurements was conducted in a research site in central Amazon, southeast of Santarem (PA, Brazil), situated inside the Tapajos National Forest. The site where the measurements were taken is surrounded by intact rain forest in a 6 km radius, and a 45 m closed canopy. In the east side out of this radius (upwind), some settlements are distributed in a stripe along a road, which were cleared for agriculture and are sparsely populated. The 67 m tower was assembled in the site in 2001 for flux measurements (CO2 and H2O), and included CO in order to assess local and regional biomass burning. In mid 2014 additional instrumentation were added, measuring NOx, O3, CH4, and SO2 fluxes and profiles. The SO2 measurements (until early 2015) showed concentrations up to 0.1 ppb during the peak of the dry season, and a small vertical gradient, suggesting the predominance of biogenic sources. Preliminary results show no significant seasonality in the daytime and nighttime O3 vertical profiles. Occasionally, nighttime profiles showed high concentrations for

Technical Review of the Laboratory Biosphere Closed Ecological System Facility

Science.gov (United States)

Dempster, W.; van Thillo, M.; Alling, A.; Allen, J.; Silverstone, S.; Nelson, M.

The "Laboratory Biosphere", a new closed ecological system facility in Santa Fe, New Mexico (USA) has been constructed and became operational in May 2002. Built and operated by the Global Ecotechnics consortium (Biosphere Technologies and Biosphere Foundation with Biospheric Design Inc., and the Institute of Ecotechnics), the research apparatus for intensive crop growth, biogeochemical cycle dynamics and recycling of inedible crop biomass comprises a sealed cylindrical steel chamber and attached variable volume chamber (lung) to prevent pressures caused by the expansion and contraction of the contained air. The cylindrical growing chamber is 3.7m (12 feet) long and 3.7m (12 foot) diameter, giving an internal volume of 34 m3 (1200 ft 3 ). The two crop growth beds cover 5.5 m2, with a soil depth of 0.3m (12 inches), with 12 x 1000 watt high-pressure sodium lights capable of variable lighting of 40-70 mol per m2 per day. A small soil bed reactor in the chamber can be activated to help with metabolism of chamber trace gases. The volume of the attached variable volume chamber (lung) can range between 0-11 m3 (0-400 ft 3 ). Evapotranspired and soil leachate water are collected, combined and recycled to water the planting beds. Sampling ports enable testing of water quality of leachate, condensate and irrigation water. Visual inspection windows provide views of the entire interior and growing beds. The chamber is also outfitted with an airlock to minimize air exchange when people enter and work in the chamber. Continuous sensors include atmospheric CO2 and oxygen, temperature, humidity, soil moisture, light level and water levels in reservoirs. Both "sniffer" (air ports) and "sipper" (water ports) will enable collection of water or air samples for detailed analysis. This paper reports on the development of this new soil-based bioregenerative life support closed system apparatus and its technical challenges and capabilities.

Unifying Dynamic Prognostic Phenology, Heterogeneous Soil and Vegetation Fluxes, and Ecosystem Biomass and Carbon Stocks To Predict the Terrestrial Carbon Cycle and Land-Atmosphere Exchanges in the Simple Biosphere Model (SiB4)

Science.gov (United States)

Haynes, K. D.; Baker, I. T.; Denning, S.

2016-12-01

Future climate projections require process-based models that incorporate the mechanisms and feedbacks controlling the carbon cycle. Over the past three decades, land surface models have been key contributors to Earth system models, evolving from predicting latent (LE) and sensible (SH) heat fluxes to energy and water budgets, momentum transfer, and terrestrial carbon exchange and storage. This study presents the latest version of the Simple Biosphere Model (SiB4), which builds on a compilation of previous versions and adds a new mechanistic-based scheme that fully predicts the terrestrial carbon cycle. The main SiB4 updates can be summarized as follows: (i) Incorporation of carbon pools that use new respiration and transfer methods, (ii) Creation of a new dynamic phenology scheme that uses mechanistic-based seasonal stages, and (iii) Unification of carbon pools, phenology and disturbance to close the carbon cycle. SiB4 removes the dependence on satellite-based vegetation indices, and instead uses a single mathematical framework to prognose self-consistent land-atmosphere exchanges of carbon, water, energy, radiation, and momentum, as well as carbon storage. Since grasslands cover 30% of land and are highly seasonal, we investigated forty grass sites. Diurnal cycles of gross primary productivity (GPP), ecosystem respiration (RE), net ecosystem exchange (NEE), LE and SH have third-quartile root mean squared (RMS) errors less than 2.0 µmol m-2 s-1, 1.9 µmol m-2 s-1, 2.0 µmol m-2 s-1, 42 W m-2, and 78 W m-2, respectively. On the synoptic timeframe, all sites have significant LE correlation coefficients of non-seasonal daily data; and all but one have significant SH correlations. Mean seasonal cycles for leaf area index (LAI), GPP, RE, LE, and SH have third-quartile normalized RMS errors less than 32%, 25%, 28%, 16%, and 48%, respectively. On multi-year timescales, daily correlations of LAI, GPP, RE, and LE are all statistically significant, with third-quartile RMS

Quantifying tidally driven benthic oxygen exchange across permeable sediments

DEFF Research Database (Denmark)

McGinnis, Daniel F.; Sommer, Stefan; Lorke, Andreas

2014-01-01

Continental shelves are predominately (approximate to 70%) covered with permeable, sandy sediments. While identified as critical sites for intense oxygen, carbon, and nutrient turnover, constituent exchange across permeable sediments remains poorly quantified. The central North Sea largely consists...... of permeable sediments and has been identified as increasingly at risk for developing hypoxia. Therefore, we investigate the benthic O-2 exchange across the permeable North Sea sediments using a combination of in situ microprofiles, a benthic chamber, and aquatic eddy correlation. Tidal bottom currents drive...... the variable sediment O-2 penetration depth (from approximate to 3 to 8 mm) and the concurrent turbulence-driven 25-fold variation in the benthic sediment O-2 uptake. The O-2 flux and variability were reproduced using a simple 1-D model linking the benthic turbulence to the sediment pore water exchange...

TransCom model simulations of hourly atmospheric CO2: Experimental overview and diurnal cycle results for 2002

NARCIS (Netherlands)

Law, R. M.; Peters, W.; Roedenbeck, C.; Aulagnier, C.; Baker, I.; Bergmann, D. J.; Bousquet, P.; Brandt, J.; Bruhwiler, L.; Cameron-Smith, P. J.; Christensen, J. H.; Delage, F.; Denning, A. S.; Fan, S.; Geels, C.; Houweling, S.; Imasu, R.; Karstens, U.; Kawa, S. R.; Kleist, J.; Krol, M. C.; Lin, S. -J.; Lokupitiya, R.; Maki, T.; Maksyutov, S.; Niwa, Y.; Onishi, R.; Parazoo, N.; Patra, P. K.; Pieterse, G.; Rivier, L.; Satoh, M.; Serrar, S.; Taguchi, S.; Takigawa, M.; Vautard, R.; Vermeulen, A. T.; Zhu, Z.

2008-01-01

[1] A forward atmospheric transport modeling experiment has been coordinated by the TransCom group to investigate synoptic and diurnal variations in CO2. Model simulations were run for biospheric, fossil, and air-sea exchange of CO2 and for SF6 and radon for 2000-2003. Twenty-five models or model

Environmental transport and long-term exposure for tritium released in the biosphere

International Nuclear Information System (INIS)

Bergman, R.; Bergstroem, U.; Evans, S.

1979-01-01

Global cycling of tritium is studied with regard to long-term exposure and dose. Dose and dose commitment are calculated for releases at different latitudes to the troposphere, land and upper ocean layer, with particular regard to effects from release into recipients of intermediate size as, for example, the Baltic Sea. The global transport of tritium appears to be governed by first order kinetics. Compartment models based on linear differential equation systems, as used in this study, should therefore be adequate. The realism and applicability of ecological compartment models are analysed with respect to completeness of the systems of reservoirs and pathways as well as accuracy in assumed reservoir sizes and exchange rates. By introducing different biospheric reservoirs and transfer mechanisms, important carriers and recipients are identified for the analysis of tritium released to air, land and water. Terrestrial biota and groundwater are shown to be significant both with regard to reservoir sizes and influence on the land-troposphere and land-sea exchange of tritium. Model studies regarding the conversion of HT to HTO in different biospheric reservoirs indicate that an atmospheric release of HT may yield up to 1.7 times the dose commitment obtained after release of the same amount of tritium as HTO. The global collective dose commitment from a tropospheric release of tritium is 0.002-0.004 man.rem per Ci depending on the latitude at the release point. Release to the surface ocean layers gives a ten times lower collective dose. (author)

North America's net terrestrial CO2 exchange with the atmosphere 1990–2009

Science.gov (United States)

King, A.W.; Andres, R.J.; Davis, K.J.; Hafer, M.; Hayes, D.J.; Huntzinger, Deborah N.; de Jong, Bernardus; Kurz, W.A.; McGuire, A. David; Vargas, Rodrigo I.; Wei, Y.; West, Tristram O.; Woodall, Christopher W.

2015-01-01

Scientific understanding of the global carbon cycle is required for developing national and international policy to mitigate fossil fuel CO2 emissions by managing terrestrial carbon uptake. Toward that understanding and as a contribution to the REgional Carbon Cycle Assessment and Processes (RECCAP) project, this paper provides a synthesis of net land–atmosphere CO2 exchange for North America (Canada, United States, and Mexico) over the period 1990–2009. Only CO2 is considered, not methane or other greenhouse gases. This synthesis is based on results from three different methods: atmospheric inversion, inventory-based methods and terrestrial biosphere modeling. All methods indicate that the North American land surface was a sink for atmospheric CO2, with a net transfer from atmosphere to land. Estimates ranged from −890 to −280 Tg C yr−1, where the mean of atmospheric inversion estimates forms the lower bound of that range (a larger land sink) and the inventory-based estimate using the production approach the upper (a smaller land sink). This relatively large range is due in part to differences in how the approaches represent trade, fire and other disturbances and which ecosystems they include. Integrating across estimates, "best" estimates (i.e., measures of central tendency) are −472 ± 281 Tg C yr−1 based on the mean and standard deviation of the distribution and −360 Tg C yr−1 (with an interquartile range of −496 to −337) based on the median. Considering both the fossil fuel emissions source and the land sink, our analysis shows that North America was, however, a net contributor to the growth of CO2 in the atmosphere in the late 20th and early 21st century. With North America's mean annual fossil fuel CO2 emissions for the period 1990–2009 equal to 1720 Tg C yr−1 and assuming the estimate of −472 Tg C yr−1 as an approximation of the true terrestrial CO2 sink, the continent's source : sink ratio for this time period was

Atmospheric and biospheric effects of cosmic

International Nuclear Information System (INIS)

Cardenas, Rolando

2007-01-01

We briefly review and classify the action that different sources of cosmic radiations might have had on Earth climate and biosphere in the geological past and at present times. We present the action of both sparse explosive phenomena, like gamma-ray bursts and supernovae, and permanent ones like cosmic rays and ultraviolet radiation backgrounds. Very energetic cosmic radiation coming from explosions can deplete the ozone lawyer due to initial ionization reactions, while soft backgrounds might trigger low altitude cloud formation through certain microphysical amplification processes. We examine a hypothesis concerning the potential role of cosmic rays on present Global Climatic Change. We also present the potential of UV astronomy to probe some of above scenarios, and speak on the possibilities for the Cuban participation in the international mega-project World Space Observatory, a UV telescope to be launched in the period 2007-2009. (Author)

Predicted net efflux of radiocarbon from the ocean and increase in atmospheric radiocarbon content

Science.gov (United States)

Caldeira, Ken; Rau, Greg H.; Duffy, Philip B.

Prior to changes introduced by man, production of radiocarbon (14C) in the stratosphere nearly balanced the flux of 14C from the atmosphere to the ocean and land biosphere, which in turn nearly balanced radioactive decay in these 14C reservoirs. This balance has been altered by land-use changes, fossil-fuel burning, and atmospheric nuclear detonations. Here, we use a model of the global carbon cycle to quantify these radiocarbon fluxes and make predictions about their magnitude in the future. Atmospheric nuclear detonations increased atmospheric 14C content by about 80% by the mid-1960's. Since that time, the 14C content of the atmosphere has been diminishing as this bomb radiocarbon has been entering the oceans and terrestrial biosphere. However, we predict that atmospheric 14C content will reach a minimum and start to increase within the next few years if fossil-fuel burning continues according to a “business-as-usual” scenario, even though fossil fuels are devoid of 14C. This will happen because fossil-fuel carbon diminishes the net flux of 14C from the atmosphere to the oceans and land biosphere, forcing 14C to accumulate in the atmosphere. Furthermore, the net flux of both bomb and natural 14C into the ocean are predicted to continue to slow and then, in the middle of the next century, to reverse, so that there will be a net flux of 14C from the ocean to the atmosphere. The predicted reversal of net 14C fluxes into the ocean is a further example of human impacts on the global carbon cycle.

Biosphere Model Report

Energy Technology Data Exchange (ETDEWEB)

D. W. Wu

2003-07-16

The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), the TSPA-LA. The ERMYN model provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs), the reference biosphere, the human receptor, and assumptions (Section 6.2 and Section 6.3); (3) Building a mathematical model using the biosphere conceptual model and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN model compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an ERMYN implementation tool (model) based on the biosphere mathematical model using GoldSim stochastic simulation software (Sections 6.8 and 6.9); (7) Verifying the ERMYN model by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); and (8) Validating the ERMYN model by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7).

Biosphere Model Report

Energy Technology Data Exchange (ETDEWEB)

M. A. Wasiolek

2003-10-27

The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), the TSPA-LA. The ERMYN model provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs), the reference biosphere, the human receptor, and assumptions (Section 6.2 and Section 6.3); (3) Building a mathematical model using the biosphere conceptual model and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN model compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an ERMYN implementation tool (model) based on the biosphere mathematical model using GoldSim stochastic simulation software (Sections 6.8 and 6.9); (7) Verifying the ERMYN model by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); and (8) Validating the ERMYN model by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7).

Biosphere Model Report

International Nuclear Information System (INIS)

D. W. Wu

2003-01-01

The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), the TSPA-LA. The ERMYN model provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs), the reference biosphere, the human receptor, and assumptions (Section 6.2 and Section 6.3); (3) Building a mathematical model using the biosphere conceptual model and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN model compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an ERMYN implementation tool (model) based on the biosphere mathematical model using GoldSim stochastic simulation software (Sections 6.8 and 6.9); (7) Verifying the ERMYN model by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); and (8) Validating the ERMYN model by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7)

Efficient gas exchange between a boreal river and the atmosphere

Science.gov (United States)

Huotari, Jussi; Haapanala, Sami; Pumpanen, Jukka; Vesala, Timo; Ojala, Anne

2013-11-01

largest uncertainties in accurately resolving the role of rivers and streams in carbon cycling stem from difficulties in determining gas exchange between water and the atmosphere. So far, estimates for river-atmosphere gas exchange have lacked direct ecosystem-scale flux measurements not disturbing gas exchange across the air-water interface. We conducted the first direct riverine gas exchange measurements with eddy covariance in tandem with continuous surface water CO2 measurements in a large boreal river for 30 days. Our measured gas transfer velocity was, on average, 20.8 cm h-1, which is clearly higher than the model estimates based on river channel morphology and water velocity, whereas our floating chambers gave comparable values at 17.3 cm h-1. These results demonstrate that present estimates for riverine CO2 emissions are very likely too low. This result is also relevant to any other gases emitted, as their diffusive exchange rates are similarly proportional to gas transfer velocity.

Exchange Processes in the Atmospheric Boundary Layer Over Mountainous Terrain

Directory of Open Access Journals (Sweden)

Stefano Serafin

2018-03-01

Full Text Available The exchange of heat, momentum, and mass in the atmosphere over mountainous terrain is controlled by synoptic-scale dynamics, thermally driven mesoscale circulations, and turbulence. This article reviews the key challenges relevant to the understanding of exchange processes in the mountain boundary layer and outlines possible research priorities for the future. The review describes the limitations of the experimental study of turbulent exchange over complex terrain, the impact of slope and valley breezes on the structure of the convective boundary layer, and the role of intermittent mixing and wave–turbulence interaction in the stable boundary layer. The interplay between exchange processes at different spatial scales is discussed in depth, emphasizing the role of elevated and ground-based stable layers in controlling multi-scale interactions in the atmosphere over and near mountains. Implications of the current understanding of exchange processes over mountains towards the improvement of numerical weather prediction and climate models are discussed, considering in particular the representation of surface boundary conditions, the parameterization of sub-grid-scale exchange, and the development of stochastic perturbation schemes.

The life span of the biosphere revisited

Science.gov (United States)

Caldeira, Ken; Kasting, James F.

1992-01-01

How much longer the biosphere can survive on earth is reexamined using a more elaborate model than that of Lovelock and Whitfield (1982). The model includes a more accurate treatment of the greenhouse effect of CO2, a biologically mediated weathering parametrization, and the realization that C4 photosynthesis can persist to much lower concentrations of atmospheric CO2. It is found that a C4-plant-based biosphere could survive for at least another 0.9 Gyr to 1.5 Gyr after the present time, depending respectively on whether CO2 or temperature is the limiting factor. Within an additional 1 Gyr, earth may lose water to space, thereby following the path of Venus.

Biosphere Model Report

Energy Technology Data Exchange (ETDEWEB)

D.W. Wu; A.J. Smith

2004-11-08

The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), TSPA-LA. The ERMYN provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs) (Section 6.2), the reference biosphere (Section 6.1.1), the human receptor (Section 6.1.2), and approximations (Sections 6.3.1.4 and 6.3.2.4); (3) Building a mathematical model using the biosphere conceptual model (Section 6.3) and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an ERMYN implementation tool (model) based on the biosphere mathematical model using GoldSim stochastic simulation software (Sections 6.8 and 6.9); (7) Verifying the ERMYN by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); (8) Validating the ERMYN by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7).

Biosphere Model Report

International Nuclear Information System (INIS)

D.W. Wu; A.J. Smith

2004-01-01

The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), TSPA-LA. The ERMYN provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs) (Section 6.2), the reference biosphere (Section 6.1.1), the human receptor (Section 6.1.2), and approximations (Sections 6.3.1.4 and 6.3.2.4); (3) Building a mathematical model using the biosphere conceptual model (Section 6.3) and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an ERMYN implementation tool (model) based on the biosphere mathematical model using GoldSim stochastic simulation software (Sections 6.8 and 6.9); (7) Verifying the ERMYN by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); (8) Validating the ERMYN by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7)

Carbon-Water-Nitrogen relationships between lichens and the atmosphere: Tools to understand metabolism and ecosystem change

Directory of Open Access Journals (Sweden)

Cristina Máguas

2013-04-01

Full Text Available Due to the close linking between the biosphere and atmosphere, there are clear impacts of changes in climate, atmospheric deposition of nutrients/pollutants and land use (Global Changes on the terrestrial biosphere. Lichens, with a direct dependence on atmospheric conditions, are much more affected by their immediate microclimate than by the ecosystem’s prevailing macroclimate. In contrast to higher plants, poikilohydric organisms have different mechanisms of water and CO2 exchange. The application of stable isotopes to the understanding of the mechanisms that are fundamental to lichen gas exchange and water uptake is a promising tool for the evaluation of lichen response to environmental changes. Indeed, lichens have been shown to be influenced by a large number of natural and anthropogenic environmental factors, serving as ecological indicators. Thus, we may use these organisms to model the impact of key global change drivers, such as nitrogen deposition and biodiversity changes, at local scale. Particularly useful is the application of the Lichen Diversity Value (LDV in order to evaluate the impact of global drivers. Moreover, it has been shown that these indices, associated with main photobiont types, green-algae (LDVch or cyanobacteria (LDVcyh, and/or nitrophilous versus oligotrophic species, were good candidates as ecological indicators. Besides mapping with high spatial resolution the effects of climate alterations, lichen functional groups could also be used as an early-warning system in order to detect the first effects of climate change in ecosystems before sudden shifts occur on other components that may be less sensitive. Clearly, lichens possess the adequate traits to be used as powerful indicators of complex interactions between atmosphere and biosphere, and thus can generate potentially interesting models for global change drivers.

Experimental and Numerical Studies of Atmosphere Water Interactions

KAUST Repository

Bou-Zeid, Elie

2011-07-04

Understanding and quantifying the interaction of the atmosphere with underlying water surfaces is of great importance for a wide range of scientific fields such as water resources management, climate studies of ocean-atmosphere exchange, and regional weat

Exchange coupling in hybrid anisotropy magnetic multilayers quantified by vector magnetometry

Energy Technology Data Exchange (ETDEWEB)

Morrison, C., E-mail: C.Morrison.2@warwick.ac.uk; Miles, J. J.; Thomson, T. [School of Computer Science, University of Manchester, Manchester M13 9PL (United Kingdom); Anh Nguyen, T. N. [Materials Physics, School of ICT, KTH Royal Institute of Technology, Electrum 229, 164 40 Kista (Sweden); Spintronics Research Group, Laboratory for Nanotechnology (LNT), VNU-HCM, Ho Chi Minh City (Viet Nam); Fang, Y.; Dumas, R. K. [Department of Physics, University of Gothenburg, 412 96 Gothenburg (Sweden); Åkerman, J. [Materials Physics, School of ICT, KTH Royal Institute of Technology, Electrum 229, 164 40 Kista (Sweden); Department of Physics, University of Gothenburg, 412 96 Gothenburg (Sweden)

2015-05-07

Hybrid anisotropy thin film heterostructures, where layers with perpendicular and in-plane anisotropy are separated by a thin spacer, are novel materials for zero/low field spin torque oscillators and bit patterned media. Here, we report on magnetization reversal and exchange coupling in a archetypal Co/Pd (perpendicular)-NiFe (in-plane) hybrid anisotropy system studied using vector vibrating sample magnetometry. This technique allows us to quantify the magnetization reversal in each individual magnetic layer, and measure of the interlayer exchange as a function of non-magnetic spacer thickness. At large (>1 nm) spacer thicknesses Ruderman-Kittel-Kasuya-Yosida-like exchange dominates, with orange-peel coupling providing a significant contribution only for sub-nm spacer thickness.

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....

Emission and role of biogenic volatile organic compounds in biosphere

International Nuclear Information System (INIS)

Saleem, A.R.

2013-01-01

Plants are an essential part of the biosphere. Under the influence of climate change, plants respond in multiple ways within the ecosystem. One such way is the release of assimilated carbon back to the atmosphere in form of biogenic volatile organic compounds (BVOCs), which are produced by plants and are involved in plant growth, reproduction, defense and other . These compounds are emitted from vegetation into the atmosphere under different environmental situations. Plants produce an extensive range of BVOCs, including isoprenoids, sequisterpenes, aldehydes, alcohols and terpenes in different tissues above and below the ground. The emission rates vary with various environmental conditions and the plant growth stage in its life span.BVOCs are released under biotic and abiotic stress changes, like heat, drought, land-use changes, higher atmospheric CO concentrations, increased UV radiation and insect or disease attack. Plants emit BVOCs in atmosphere in order to avoid stress, and adapt to harsh circumstances. These compounds also have a significant role in plant-plant interaction, communication and competition. BVOCs have the ability to alter atmospheric chemistry; they readily react with atmospheric pollutant gases under high temperature and form tropospheric ozone, which is a potent air pollutant for global warming and disease occurrence. BVOCs may be a cause of photochemical smog and increase the stay of other GHGs in the atmosphere. Therefore, further study is required to assess the behavior of BVOCs in the biosphere as well as the atmosphere. (author)

Soil-related Input Parameters for the Biosphere Model

International Nuclear Information System (INIS)

A. J. Smith

2003-01-01

deposition and, as a direct consequence, radionuclide concentration in resuspended particulate matter in the atmosphere. The analysis was performed in accordance with the technical work plan for the biosphere modeling and expert support (TWP) (BSC 2003 [163602]). This analysis revises the previous one titled ''Evaluate Soil/Radionuclide Removal by Erosion and Leaching'' (CRWMS M and O 2001 [152517]). In REV 00 of this report, the data generated were fixed (i.e., taking no account of uncertainty and variability) values. This revision incorporates uncertainty and variability into the values for the bulk density, elemental partition coefficients, average annual loss of soil from erosion, resuspension enhancement factor, and field capacity water content

The first IGAC scientific conference: global atmospheric-biospheric chemistry. Book of abstracts

International Nuclear Information System (INIS)

1993-04-01

Various global/transfrontier air pollution problems are described. The causes of these problems are presented. The impact on ecology and biosphere are discussed. Special attention is given to the greenhouse causing agents

Quantifying hyporheic exchange dynamics in a highly regulated large river reach.

Energy Technology Data Exchange (ETDEWEB)

Hammond, Glenn Edward; Zhou, T; Huang, M; Hou, Z; Bao, J; Arntzen, E; Mackley, R; Harding, S; Titzler, S; Murray, C; Perkins, W; Chen, X; Stegen, J; Thorne, P; Zachara, J

2017-03-01

Hyporheic exchange is an important mechanism taking place in riverbanks and riverbed sediments, where river water and shallow groundwater mix and interact with each other. The direction, magnitude, and residence time of the hyporheic flux that penetrates the river bed are critical for biogeochemical processes such as carbon and nitrogen cycling, and biodegradation of organic contaminants. Many approaches including field measurements and numerical methods have been developed to quantify the hyporheic exchanges in relatively small rivers. However, the spatial and temporal distributions of hyporheic exchanges in a large, regulated river reach remain less explored due to the large spatial domains, complexity of geomorphologic features and subsurface properties, and the great pressure gradient variations at the riverbed created by dam operations.

Use of the method of biosphere compatibility for the assessment of environmental protection methods

Science.gov (United States)

Vorobyov, Sergey

2018-01-01

The article is devoted to the question of using the indicator of biosphere compatibility for assessing the effectiveness of environmental protection methods. The indicator of biosphere compatibility was proposed by the vice-president of RAASN (Russian Academy of Architecture and Building Sciences), Doctor of Technical Sciences, Professor V.I. Ilyichev. This indicator is allows not only qualitatively but also quantitatively to assess the degree of development of urban urban areas, from the standpoint of preserving the biosphere in urban ecosystems while realizing the city’s main functions. The integral indicator of biosphere compatibility is allows us to assess not only the current ecological situation in the territory under consideration, but also to plan the forecast of its changes for building the new construction projects, or for reconstructing existing ones. The indicator of biosphere compatibility, which is a mathematical expression of the tripartite balance (technosphere, biosphere and population of this area), is allows us to quantify the degree of effectiveness of different method of protecting the environment for choose the most effective for these conditions.

Application of Biosphere Compatibility Indicator for Assessment of the Effectiveness of Environmental Protection Methods

Science.gov (United States)

Bakaeva, N. V.; Vorobyov, S. A.; Chernyaeva, I. V.

2017-11-01

The article is devoted to the issue of using the biosphere compatibility indicator to assess the effectiveness of environmental protection methods. The indicator biosphere compatibility was proposed by the vice-president of RAASN (Russian Academy of Architecture and Building Sciences), Doctor of Technical Sciences, Professor V.I. Ilyichev. This indicator allows one to assess not only qualitatively but also quantitatively the degree of urban areas development from the standpoint of preserving the biosphere in urban ecosystems while performing the city’s main functions. The integral biosphere compatibility indicator allows us to assess not only the current ecological situation in the territory under consideration but also to plan the forecast of its changes for the new construction projects implementation or for the reconstruction of the existing ones. The biosphere compatibility indicator, which is a mathematical expression of the tripartite balance (technosphere, biosphere and population of this area), allows us to quantify the effectiveness degree of different methods for environment protection to choose the most effective one under these conditions.

Estimation of Global 1km-grid Terrestrial Carbon Exchange Part II: Evaluations and Applications

Science.gov (United States)

Murakami, K.; Sasai, T.; Kato, S.; Niwa, Y.; Saito, M.; Takagi, H.; Matsunaga, T.; Hiraki, K.; Maksyutov, S. S.; Yokota, T.

2015-12-01

Global terrestrial carbon cycle largely depends on a spatial pattern in land cover type, which is heterogeneously-distributed over regional and global scales. Many studies have been trying to reveal distribution of carbon exchanges between terrestrial ecosystems and atmosphere for understanding global carbon cycle dynamics by using terrestrial biosphere models, satellite data, inventory data, and so on. However, most studies remained within several tens of kilometers grid spatial resolution, and the results have not been enough to understand the detailed pattern of carbon exchanges based on ecological community and to evaluate the carbon stocks by forest ecosystems in each countries. Improving the sophistication of spatial resolution is obviously necessary to enhance the accuracy of carbon exchanges. Moreover, the improvement may contribute to global warming awareness, policy makers and other social activities. We show global terrestrial carbon exchanges (net ecosystem production, net primary production, and gross primary production) with 1km-grid resolution. The methodology for these estimations are shown in the 2015 AGU FM poster "Estimation of Global 1km-grid Terrestrial Carbon Exchange Part I: Developing Inputs and Modelling". In this study, we evaluated the carbon exchanges in various regions with other approaches. We used the satellite-driven biosphere model (BEAMS) as our estimations, GOSAT L4A CO2 flux data, NEP retrieved by NICAM and CarbonTracer2013 flux data, for period from Jun 2001 to Dec 2012. The temporal patterns for this period were indicated similar trends between BEAMS, GOSAT, NICAM, and CT2013 in many sub-continental regions. Then, we estimated the terrestrial carbon exchanges in each countries, and could indicated the temporal patterns of the exchanges in large carbon stock regions.Global terrestrial carbon cycle largely depends on a spatial pattern of land cover type, which is heterogeneously-distributed over regional and global scales. Many

Estimation of Global 1km-grid Terrestrial Carbon Exchange Part I: Developing Inputs and Modelling

Science.gov (United States)

Sasai, T.; Murakami, K.; Kato, S.; Matsunaga, T.; Saigusa, N.; Hiraki, K.

2015-12-01

Global terrestrial carbon cycle largely depends on a spatial pattern in land cover type, which is heterogeneously-distributed over regional and global scales. However, most studies, which aimed at the estimation of carbon exchanges between ecosystem and atmosphere, remained within several tens of kilometers grid spatial resolution, and the results have not been enough to understand the detailed pattern of carbon exchanges based on ecological community. Improving the sophistication of spatial resolution is obviously necessary to enhance the accuracy of carbon exchanges. Moreover, the improvement may contribute to global warming awareness, policy makers and other social activities. In this study, we show global terrestrial carbon exchanges (net ecosystem production, net primary production, and gross primary production) with 1km-grid resolution. As methodology for computing the exchanges, we 1) developed a global 1km-grid climate and satellite dataset based on the approach in Setoyama and Sasai (2013); 2) used the satellite-driven biosphere model (Biosphere model integrating Eco-physiological And Mechanistic approaches using Satellite data: BEAMS) (Sasai et al., 2005, 2007, 2011); 3) simulated the carbon exchanges by using the new dataset and BEAMS by the use of a supercomputer that includes 1280 CPU and 320 GPGPU cores (GOSAT RCF of NIES). As a result, we could develop a global uniform system for realistically estimating terrestrial carbon exchange, and evaluate net ecosystem production in each community level; leading to obtain highly detailed understanding of terrestrial carbon exchanges.

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

The role of vegetation dynamics in the control of atmospheric CO{sub 2} content

Energy Technology Data Exchange (ETDEWEB)

Sitch, Stephen

2000-04-01

This thesis contains a description of the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM) and its application to infer the role of vegetation dynamics on atmospheric CO{sub 2} content at different time-scales. The model combines vegetation dynamics and biogeochemistry in a modular framework. Individual modules describe ecosystems processes, including vegetation resource competition and production, tissue turnover, growth, fire and mortality, soil and litter biogeochemistry, including the effects of CO{sub 2} on these processes. The model simulates realistic post-disturbance succession in different environments. Seasonal exchange of H{sub 2}O and CO{sub 2} between the terrestrial biosphere and the atmosphere is modelled in reasonable agreement with observation. Global estimates of carbon stocks in soil, litter and vegetation are within their acceptable ranges and the model captures the present-day patterns in vegetation. Fire return intervals are simulated correctly in most regions. Results emphasise the important role of the terrestrial biosphere in both the seasonal cycle and in the inter-annual variability in the growth rate of atmospheric CO{sub 2}. LPJ successfully reproduced both the amplitude and phase of the seasonal cycle of atmospheric CO{sub 2} content as measured at a global network of monitoring stations. The model predicted a small net terrestrial biosphere uptake of CO{sub 2} during the 1980s with a strong CO{sub 2} fertilisation effect, which enhances plant production, reduced by the effects of climate and land use change. Historical land use change and CO{sub 2} fertilisation have been the dominant, albeit opposing factors governing the response of the terrestrial biosphere with respect to carbon storage during the 20th century. LPJ is run using one future climate and atmospheric CO{sub 2} scenario until 2200. Enhanced production due to the CO{sub 2} fertilisation effect eventually reaches an asymptote, and consequently the ability of

Biosphere science news roundup. The Center for Biospheric Education and Research

Science.gov (United States)

Cotten, J H

1994-01-01

The Center for Biospheric Education and Research (CBER) is an exciting and truly unique addition to The Huntsville-Madison County Botanical Garden. The mission of CBER is to increase the knowledge and understanding of closed ecological life support systems, including both natural and man-made biospheres. Its primary emphasis will be on the Earth biosphere with particular attention to the role of plants in maintaining a balanced environment. Secondary emphasis will be on the space station and lunar habitation biospheres, both of which employ plants for environmental control, food, and aesthetics. CBER will serve as a catalyst providing both a forum and a facility for research, education, and display of methodologies and technologies relevant to the creation and maintenance of such biospheric systems.

Charge Exchange Reaction in Dopant-Assisted Atmospheric Pressure Chemical Ionization and Atmospheric Pressure Photoionization.

Science.gov (United States)

Vaikkinen, Anu; Kauppila, Tiina J; Kostiainen, Risto

2016-08-01

The efficiencies of charge exchange reaction in dopant-assisted atmospheric pressure chemical ionization (DA-APCI) and dopant-assisted atmospheric pressure photoionization (DA-APPI) mass spectrometry (MS) were compared by flow injection analysis. Fourteen individual compounds and a commercial mixture of 16 polycyclic aromatic hydrocarbons were chosen as model analytes to cover a wide range of polarities, gas-phase ionization energies, and proton affinities. Chlorobenzene was used as the dopant, and methanol/water (80/20) as the solvent. In both techniques, analytes formed the same ions (radical cations, protonated molecules, and/or fragments). However, in DA-APCI, the relative efficiency of charge exchange versus proton transfer was lower than in DA-APPI. This is suggested to be because in DA-APCI both dopant and solvent clusters can be ionized, and the formed reagent ions can react with the analytes via competing charge exchange and proton transfer reactions. In DA-APPI, on the other hand, the main reagents are dopant-derived radical cations, which favor ionization of analytes via charge exchange. The efficiency of charge exchange in both DA-APPI and DA-APCI was shown to depend heavily on the solvent flow rate, with best efficiency seen at lowest flow rates studied (0.05 and 0.1 mL/min). Both DA-APCI and DA-APPI showed the radical cation of chlorobenzene at 0.05-0.1 mL/min flow rate, but at increasing flow rate, the abundance of chlorobenzene M(+.) decreased and reagent ion populations deriving from different gas-phase chemistry were recorded. The formation of these reagent ions explains the decreasing ionization efficiency and the differences in charge exchange between the techniques. Graphical Abstract ᅟ.

Divided-evolution-based pulse scheme for quantifying exchange processes in proteins: powerful complement to relaxation dispersion experiments.

Science.gov (United States)

Bouvignies, Guillaume; Hansen, D Flemming; Vallurupalli, Pramodh; Kay, Lewis E

2011-02-16

A method for quantifying millisecond time scale exchange in proteins is presented based on scaling the rate of chemical exchange using a 2D (15)N, (1)H(N) experiment in which (15)N dwell times are separated by short spin-echo pulse trains. Unlike the popular Carr-Purcell-Meiboom-Gill (CPMG) experiment where the effects of a radio frequency field on measured transverse relaxation rates are quantified, the new approach measures peak positions in spectra that shift as the effective exchange time regime is varied. The utility of the method is established through an analysis of data recorded on an exchanging protein-ligand system for which the exchange parameters have been accurately determined using alternative approaches. Computations establish that a combined analysis of CPMG and peak shift profiles extends the time scale that can be studied to include exchanging systems with highly skewed populations and exchange rates as slow as 20 s(-1).

Constraints on a potential aerial biosphere on Venus: I. Cosmic rays

Science.gov (United States)

Dartnell, Lewis R.; Nordheim, Tom Andre; Patel, Manish R.; Mason, Jonathon P.; Coates, Andrew J.; Jones, Geraint H.

2015-09-01

While the present-day surface of Venus is certainly incompatible with terrestrial biology, the planet may have possessed oceans in the past and provided conditions suitable for the origin of life. Venusian life may persist today high in the atmosphere where the temperature and pH regime is tolerable to terrestrial extremophile microbes: an aerial habitable zone. Here we argue that on the basis of the combined biological hazard of high temperature and high acidity this habitable zone lies between 51 km (65 °C) and 62 km (-20 °C) altitude. Compared to Earth, this potential venusian biosphere may be exposed to substantially more comic ionising radiation: Venus has no protective magnetic field, orbits closer to the Sun, and the entire habitable region lies high in the atmosphere - if this narrow band is sterilised there is no reservoir of deeper life that can recolonise afterwards. Here we model the propagation of particle radiation through the venusian atmosphere, considering both the background flux of high-energy galactic cosmic rays and the transient but exceptionally high-fluence bursts of extreme solar particle events (SPE), such as the Carrington Event of 1859 and that inferred for AD 775. We calculate the altitude profiles of both energy deposition into the atmosphere and the absorbed radiation dose to assess this astrophysical threat to the potential high-altitude venusian biosphere. We find that at the top of the habitable zone (62 km altitude; 190 g/cm2 shielding depth) the radiation dose from the modelled Carrington Event with a hard spectrum (matched to the February 1956 SPE) is over 18,000 times higher than the background from GCR, and 50,000 times higher for the modelled 775 AD event. However, even though the flux of ionising radiation can be sterilizing high in the atmosphere, the total dose delivered at the top of the habitable zone by a worst-case SPE like the 775 AD event is 0.09 Gy, which is not likely to present a significant survival challenge

On-line stable isotope measurements during plant and soil gas exchange

International Nuclear Information System (INIS)

Yakir, D.

2001-01-01

Recent techniques for on-line stable isotope measurements during plant and soil exchange of CO 2 and/or water vapor are briefly reviewed. For CO 2 , these techniques provide means for on-line measurements of isotopic discrimination during CO 2 exchange by leaves in the laboratory and in the field, of isotopic discrimination during soil respiration and during soil-atmosphere CO 2 exchange, and of isotopic discrimination in O 2 during plant respiration. For water vapor, these techniques provide means to measure oxygen isotopic composition of water vapor during leaf transpiration and for the analysis of sub microliter condensed water vapor samples. Most of these techniques involve on-line sampling of CO 2 and water vapor from a dynamic, intact soil or plant system. In the laboratory, these systems also allow on-line isotopic analysis by continuous-flow isotope ratio mass spectrometry. The information obtained with these on-line techniques is becoming increasingly valuable, and often critical, for ecophysiologial research and in the study of biosphere-atmosphere interactions. (author)

Oxygen isotope anomaly in tropospheric CO2 and implications for CO2 residence time in the atmosphere and gross primary productivity.

Science.gov (United States)

Liang, Mao-Chang; Mahata, Sasadhar; Laskar, Amzad H; Thiemens, Mark H; Newman, Sally

2017-10-13

The abundance variations of near surface atmospheric CO 2 isotopologues (primarily 16 O 12 C 16 O, 16 O 13 C 16 O, 17 O 12 C 16 O, and 18 O 12 C 16 O) represent an integrated signal from anthropogenic/biogeochemical processes, including fossil fuel burning, biospheric photosynthesis and respiration, hydrospheric isotope exchange with water, and stratospheric photochemistry. Oxygen isotopes, in particular, are affected by the carbon and water cycles. Being a useful tracer that directly probes governing processes in CO 2 biogeochemical cycles, Δ 17 O (=ln(1 + δ 17 O) - 0.516 × ln(1 + δ 18 O)) provides an alternative constraint on the strengths of the associated cycles involving CO 2 . Here, we analyze Δ 17 O data from four places (Taipei, Taiwan; South China Sea; La Jolla, United States; Jerusalem, Israel) in the northern hemisphere (with a total of 455 measurements) and find a rather narrow range (0.326 ± 0.005‰). A conservative estimate places a lower limit of 345 ± 70 PgC year -1 on the cycling flux between the terrestrial biosphere and atmosphere and infers a residence time of CO 2 of 1.9 ± 0.3 years (upper limit) in the atmosphere. A Monte Carlo simulation that takes various plant uptake scenarios into account yields a terrestrial gross primary productivity of 120 ± 30 PgC year -1 and soil invasion of 110 ± 30 PgC year -1 , providing a quantitative assessment utilizing the oxygen isotope anomaly for quantifying CO 2 cycling.

Biomass Burning: The Cycling of Gases and Particulates from the Biosphere to the Atmosphere

Science.gov (United States)

Levine, J. S.

2003-12-01

Biomass burning is both a process of geochemical cycling of gases and particulates from the biosphere to the atmosphere and a process of global change. In the preface to the book, One Earth, One Future: Our Changing Global Environment (National Academy of Sciences, 1990), Dr. Frank Press, the President of the National Academy of Sciences, writes: "Human activities are transforming the global environment, and these global changes have many faces: ozone depletion, tropical deforestation, acid deposition, and increased atmospheric concentrations of gases that trap heat and may warm the global climate."It is interesting to note that all four global change "faces" identified by Dr. Press have a common thread - they are all caused by biomass burning.Biomass burning or vegetation burning is the burning of living and dead vegetation and includes human-initiated burning and natural lightning-induced burning. The bulk of the world's biomass burning occurs in the tropics - in the tropical forests of South America and Southeast Asia and in the savannasof Africa and South America. The majority of the biomass burning, primarily in the tropics (perhaps as much as 90%), is believed to be human initiated for land clearing and land-use change. Natural fires triggered by atmospheric lightning only accounts for ˜10% of all fires (Andreae, 1991). As will be discussed, a significant amount of biomass burning occurs in the boreal forests of Russia, Canada, and Alaska.Biomass burning is a significant source of gases and particulates to the regional and global atmosphere (Crutzen et al., 1979; Seiler and Crutzen, 1980; Crutzen and Andreae, 1990; Levine et al., 1995). Its burning is truly a multidiscipline subject, encompassing the following areas: fire ecology, fire measurements, fire modeling, fire combustion, remote sensing, fire combustion gaseous and particulate emissions, the atmospheric transport of these emissions, and the chemical and climatic impacts of these emissions. Recently

Impact of atmospheric and terrestrial CO2 feedbacks on fertilization-induced marine carbon uptake

Science.gov (United States)

Oschlies, A.

2009-08-01

The sensitivity of oceanic CO2 uptake to alterations in the marine biological carbon pump, such as brought about by natural or purposeful ocean fertilization, has repeatedly been investigated by studies employing numerical biogeochemical ocean models. It is shown here that the results of such ocean-centered studies are very sensitive to the assumption made about the response of the carbon reservoirs on the atmospheric side of the sea surface. Assumptions made include prescribed atmospheric pCO2, an interactive atmospheric CO2 pool exchanging carbon with the ocean but not with the terrestrial biosphere, and an interactive atmosphere that exchanges carbon with both oceanic and terrestrial carbon pools. The impact of these assumptions on simulated annual to millennial oceanic carbon uptake is investigated for a hypothetical increase in the C:N ratio of the biological pump and for an idealized enhancement of phytoplankton growth. Compared to simulations with interactive atmosphere, using prescribed atmospheric pCO2 overestimates the sensitivity of the oceanic CO2 uptake to changes in the biological pump, by about 2%, 25%, 100%, and >500% on annual, decadal, centennial, and millennial timescales, respectively. The smaller efficiency of the oceanic carbon uptake under an interactive atmosphere is due to the back flux of CO2 that occurs when atmospheric CO2 is reduced. Adding an interactive terrestrial carbon pool to the atmosphere-ocean model system has a small effect on annual timescales, but increases the simulated fertilization-induced oceanic carbon uptake by about 4%, 50%, and 100% on decadal, centennial, and millennial timescales, respectively, for pCO2 sensitivities of the terrestrial carbon storage in the middle range of the C4MIP models (Friedlingstein et al., 2006). For such sensitivities, a substantial fraction of oceanic carbon uptake induced by natural or purposeful ocean fertilization originates, on timescales longer than decades, not from the atmosphere

Multiple greenhouse-gas feedbacks from the land biosphere under future climate change scenarios

NARCIS (Netherlands)

Stocker, B.D.; Roth, R.; Joos, F.; Spahni, R.; Steinacher, M.; Zaehle, S.; Bouwman, L.; Xu, R.; Prentice, I.C.

2013-01-01

Atmospheric concentrations of the three important greenhouse gases (GHGs) CO2, CH4 and N2O are mediated by processes in the terrestrial biosphere that are sensitive to climate and CO2. This leads to feedbacks between climate and land and has contributed to the sharp rise in atmospheric

Understanding Microbial Contributions to Planetary Atmosphere

Science.gov (United States)

DesMarais, David J.

2000-01-01

Should our search of distant, extrasolar planetary atmospheres encounter evidence of life, that evidence will most likely be the gaseous products of microorganisms. Our biosphere was exclusively microbial for over 80 percent of its history and, even today, microbes strongly influence atmospheric composition. Life's greatest environmental impact arises from its capacity for harvesting energy and creating organic matter. Microorganisms catalyze the equilibration of C, S and transition metal species at temperatures where such reactions can be very slow in the absence of life. Sunlight has been harvested through photosynthesis to create enormous energy reservoirs that exist in the form of coexisting reservoirs of reduced, organic C and S stored in Earth's crust, and highly oxidized species (oxygen, sulfate and ferric iron) stored in the crust, oceans and atmosphere. Our civilization taps that storehouse of energy by burning fossil fuels. As astrobiologists, we identify the chemical consequences of distant biospheres as expressed in the atmospheres of their planets. Our approach must recognize that planets, biospheres and atmospheres evolve and change. For example, a tectonically more active early Earth hosted a thermophilic, non-photosynthetic biosphere and a mildly reducing, carbon dioxide-rich and oxygen-poor atmosphere. Microorganisms acquired energy by consuming hydrogen and sulfide and producing a broad array of reduced C and S gases, most notably, methane. Later, diverse types of bacterial photosynthesis developed that enhanced productivity but were incapable of splitting water to produce oxygen. Later, but still prior to 2.6 billion years ago, oxygenic photosynthesis developed. We can expect to encounter distant biospheres that represent various stages of evolution and that coexist with atmospheres ranging from mildly reducing to oxidizing compositions. Accordinaly, we must be prepared to interpret a broad range of atmospheric compositions, all containing

Atmospheric pressure photo ionization hydrogen/deuterium exchange mass spectrometry--a method to differentiate isomers by mass spectrometry.

Science.gov (United States)

Ahmed, Arif; Kim, Sunghwan

2013-12-01

In this report, a method for in-source hydrogen/deuterium (H/D) exchange at atmospheric pressure is reported. The method was named atmospheric pressure photo ionization hydrogen/deuterium exchange mass spectrometry (APPI HDX MS). H/D exchange was performed by mixing samples dissolved in toluene with CH3OD solvent and analyzing the mixture using atmospheric pressure photo ionization mass spectrometry (APPI-MS). The APPI HDX spectra obtained with contact times between the analyte solution and methanol-OD (CH3OD) of atmospheric pressure. H/D exchange can be performed in any laboratory with a mass spectrometer and a commercial APPI source. Using this method, multiple H/D exchanges of aromatic hydrogen and/or H/D exchange of active hydrogen were observed. These results demonstrated that H/D exchange can be used to distinguish between isomers containing primary, secondary, and tertiary amines, as well as pyridine and pyrrole functional groups.

Characterizing biospheric carbon balance using CO2 observations from the OCO-2 satellite

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S. M. Miller

2018-05-01

Full Text Available NASA's Orbiting Carbon Observatory 2 (OCO-2 satellite launched in summer of 2014. Its observations could allow scientists to constrain CO2 fluxes across regions or continents that were previously difficult to monitor. This study explores an initial step toward that goal; we evaluate the extent to which current OCO-2 observations can detect patterns in biospheric CO2 fluxes and constrain monthly CO2 budgets. Our goal is to guide top-down, inverse modeling studies and identify areas for future improvement. We find that uncertainties and biases in the individual OCO-2 observations are comparable to the atmospheric signal from biospheric fluxes, particularly during Northern Hemisphere winter when biospheric fluxes are small. A series of top-down experiments indicate how these errors affect our ability to constrain monthly biospheric CO2 budgets. We are able to constrain budgets for between two and four global regions using OCO-2 observations, depending on the month, and we can constrain CO2 budgets at the regional level (i.e., smaller than seven global biomes in only a handful of cases (16 % of all regions and months. The potential of the OCO-2 observations, however, is greater than these results might imply. A set of synthetic data experiments suggests that retrieval errors have a salient effect. Advances in retrieval algorithms and to a lesser extent atmospheric transport modeling will improve the results. In the interim, top-down studies that use current satellite observations are best-equipped to constrain the biospheric carbon balance across only continental or hemispheric regions.

Atmospheric CO2 Observations Reveal Strong Correlation Between Regional Net Biospheric Carbon Uptake and Solar-Induced Chlorophyll Fluorescence

Science.gov (United States)

Shiga, Yoichi P.; Tadić, Jovan M.; Qiu, Xuemei; Yadav, Vineet; Andrews, Arlyn E.; Berry, Joseph A.; Michalak, Anna M.

2018-01-01

Recent studies have shown the promise of remotely sensed solar-induced chlorophyll fluorescence (SIF) in informing terrestrial carbon exchange, but analyses have been limited to either plot level ( 1 km2) or hemispheric/global ( 108 km2) scales due to the lack of a direct measure of carbon exchange at intermediate scales. Here we use a network of atmospheric CO2 observations over North America to explore the value of SIF for informing net ecosystem exchange (NEE) at regional scales. We find that SIF explains space-time NEE patterns at regional ( 100 km2) scales better than a variety of other vegetation and climate indicators. We further show that incorporating SIF into an atmospheric inversion leads to a spatial redistribution of NEE estimates over North America, with more uptake attributed to agricultural regions and less to needleleaf forests. Our results highlight the synergy of ground-based and spaceborne carbon cycle observations.

Modeling the global society-biosphere-climate system : Part 2: Computed scenarios

NARCIS (Netherlands)

Alcamo, J.; Van Den Born, G.J.; Bouwman, A.F.; De Haan, B.J.; Klein Goldewijk, K.; Klepper, O.; Krabec, J.; Leemans, R.; Olivier, J.G.J.; Toet, A.M.C.; De Vries, H.J.M.; Van Der Woerd, H.J.

1994-01-01

This paper presents scenarios computed with IMAGE 2.0, an integrated model of the global environment and climate change. Results are presented for selected aspects of the society-biosphere-climate system including primary energy consumption, emissions of various greenhouse gases, atmospheric

Patterns of new versus recycled primary production in the terrestrial biosphere

Science.gov (United States)

Nitrogen (N) and phosphorus (P) availability regulate plant productivity throughout the terrestrial biosphere, influencing the patterns and magnitude of net primary production (NPP) by land plants both now and into the future. These nutrients enter ecosystems via geologic and atmospheric pathways, a...

Olkiluoto biosphere description 2006

International Nuclear Information System (INIS)

Haapanen, R.; Aro, L.; Ilvesniemi, H.; Kareinen, T.; Kirkkala, T.; Mykrae, S.; Turkki, H.; Lahdenperae, A.-M.; Ikonen, A.T.K.

2007-02-01

This report summarises the current knowledge of the biosphere of Olkiluoto, and it is the first Biosphere Description Report. The elements considered were climate, topography, land use, overburden, terrestrial vegetation and fauna and sea flora, fauna and water. The principal aim was to present a synthesis of the present state (now to 2020) and the main features of past evolution of the biosphere at the site using currently available data. The lack of site specific parameters and their importance was discussed. Conceptual ecosystem models are presented for land and sea. Currently available data made it possible to calculate the biomass of the terrestrial vegetation and further convert it to carbon. In the case of terrestrial animals, preliminary figures are given for moose alone due to lack of sitespecific data. For the same reason, the sea ecosystem model was not quantified within this work. The ecosystems on Olkiluoto do not deviate from the surrounding areas. Since mires are few on Olkiluoto, forests are the most important land ecosystem. However, coastal areas are the transition zones between land and sea, and also potential sites for deep groundwater discharge. The major interest concerning aquatic ecosystems was laid on four future lakes potentially developing from the sea due to the land up-lift. Current sea sediments near Olkiluoto are future land areas, and thus very important. Spatially, the forest ecosystems of Olkiluoto are now most comprehensively covered, while the temporal coverage is highest in sea ecosystems. Lack of data is greatest in terrestrial fauna and sea sediments. During this work, the system boundaries were crossed and the use of data over disciplines was started. The data were mostly in agreement, but some discrepancies were detected. To solve these, and to supplement the existing data, some recommendations were given. (orig.)

Biosphere 2: a prototype project for a permanent and evolving life system for Mars base.

Science.gov (United States)

Nelson, M; Allen, J P; Dempster, W F

1992-01-01

As part of the ground-based preparation for creating long-term life systems needed for space habitation and settlement, Space Biospheres Ventures (SBV) is undertaking the Biosphere 2 project near Oracle, Arizona. Biosphere 2, currently under construction, is scheduled to commence its operations in 1991 with a two-year closure period with a crew of eight people. Biosphere 2 is a facility which will be essentialy materially-closed to exchange with the outside environment. It is open to information and energy flow. Biosphere 2 is designed to achieve a complex life-support system by the integration of seven areas or "biomes"--rainforest, savannah, desert, marsh, ocean, intensive agriculture and human habitat. Unique bioregenerative technologies, such as soil bed reactors for air purification, aquatic waste processing systems, real-time analytic systems and complex computer monitoring and control systems are being developed for the Biosphere 2 project. Its operation should afford valuable insight into the functioning of complex life systems necessary for long-term habitation in space. It will serve as an experimental ground-based prototype and testbed for the stable, permanent life systems needed for human exploration of Mars.

Multiple greenhouse-gas feedbacks from the land biosphere under future climate change scenarios

Science.gov (United States)

Stocker, Benjamin D.; Roth, Raphael; Joos, Fortunat; Spahni, Renato; Steinacher, Marco; Zaehle, Soenke; Bouwman, Lex; Xu-Ri; Prentice, Iain Colin

2013-07-01

Atmospheric concentrations of the three important greenhouse gases (GHGs) CO2, CH4 and N2O are mediated by processes in the terrestrial biosphere that are sensitive to climate and CO2. This leads to feedbacks between climate and land and has contributed to the sharp rise in atmospheric GHG concentrations since pre-industrial times. Here, we apply a process-based model to reproduce the historical atmospheric N2O and CH4 budgets within their uncertainties and apply future scenarios for climate, land-use change and reactive nitrogen (Nr) inputs to investigate future GHG emissions and their feedbacks with climate in a consistent and comprehensive framework. Results suggest that in a business-as-usual scenario, terrestrial N2O and CH4 emissions increase by 80 and 45%, respectively, and the land becomes a net source of C by AD 2100. N2O and CH4 feedbacks imply an additional warming of 0.4-0.5°C by AD 2300; on top of 0.8-1.0°C caused by terrestrial carbon cycle and Albedo feedbacks. The land biosphere represents an increasingly positive feedback to anthropogenic climate change and amplifies equilibrium climate sensitivity by 22-27%. Strong mitigation limits the increase of terrestrial GHG emissions and prevents the land biosphere from acting as an increasingly strong amplifier to anthropogenic climate change.

Biosphere Model Report, Errata 1

Energy Technology Data Exchange (ETDEWEB)

M. Wasolek

2003-09-18

The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), the TSPA-LA. The ERMYN model provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs), the reference biosphere, the human receptor, and assumptions (Section 6.2 and Section 6.3); (3) Building a mathematical model using the biosphere conceptual model and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN model compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an ERMYN implementation tool (model) based on the biosphere mathematical model using GoldSim stochastic simulation software (Sections 6.8 and 6.9); (7) Verifying the ERMYN model by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); (8) Validating the ERMYN model by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7).

Biosphere Model Report, Errata 1

International Nuclear Information System (INIS)

Wasolek, M.

2003-01-01

The purpose of this report is to document the biosphere model, the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), which describes radionuclide transport processes in the biosphere and associated human exposure that may arise as the result of radionuclide release from the geologic repository at Yucca Mountain. The biosphere model is one of the process models that support the Yucca Mountain Project (YMP) Total System Performance Assessment (TSPA) for the license application (LA), the TSPA-LA. The ERMYN model provides the capability of performing human radiation dose assessments. This report documents the biosphere model, which includes: (1) Describing the reference biosphere, human receptor, exposure scenarios, and primary radionuclides for each exposure scenario (Section 6.1); (2) Developing a biosphere conceptual model using site-specific features, events, and processes (FEPs), the reference biosphere, the human receptor, and assumptions (Section 6.2 and Section 6.3); (3) Building a mathematical model using the biosphere conceptual model and published biosphere models (Sections 6.4 and 6.5); (4) Summarizing input parameters for the mathematical model, including the uncertainty associated with input values (Section 6.6); (5) Identifying improvements in the ERMYN model compared with the model used in previous biosphere modeling (Section 6.7); (6) Constructing an ERMYN implementation tool (model) based on the biosphere mathematical model using GoldSim stochastic simulation software (Sections 6.8 and 6.9); (7) Verifying the ERMYN model by comparing output from the software with hand calculations to ensure that the GoldSim implementation is correct (Section 6.10); (8) Validating the ERMYN model by corroborating it with published biosphere models; comparing conceptual models, mathematical models, and numerical results (Section 7)

Quantifying NMR relaxation correlation and exchange in articular cartilage with time domain analysis

Science.gov (United States)

Mailhiot, Sarah E.; Zong, Fangrong; Maneval, James E.; June, Ronald K.; Galvosas, Petrik; Seymour, Joseph D.

2018-02-01

Measured nuclear magnetic resonance (NMR) transverse relaxation data in articular cartilage has been shown to be multi-exponential and correlated to the health of the tissue. The observed relaxation rates are dependent on experimental parameters such as solvent, data acquisition methods, data analysis methods, and alignment to the magnetic field. In this study, we show that diffusive exchange occurs in porcine articular cartilage and impacts the observed relaxation rates in T1-T2 correlation experiments. By using time domain analysis of T2-T2 exchange spectroscopy, the diffusive exchange time can be quantified by measurements that use a single mixing time. Measured characteristic times for exchange are commensurate with T1 in this material and so impacts the observed T1 behavior. The approach used here allows for reliable quantification of NMR relaxation behavior in cartilage in the presence of diffusive fluid exchange between two environments.

Evaluation of Features, Events, and Processes (FEP) for the Biosphere Model

International Nuclear Information System (INIS)

J. J. Tappen

2003-01-01

The purpose of this revision of ''Evaluation of the Applicability of Biosphere-Related Features, Events, and Processes (FEPs)'' (BSC 2001) is to document the screening analysis of biosphere-related primary FEPs, as identified in ''The Development of Information Catalogued in REV00 of the YMP FEP Database'' (Freeze et al. 2001), in accordance with the requirements of the final U.S. Nuclear Regulatory Commission (NRC) regulations at 10 CFR Part 63. This database is referred to as the Yucca Mountain Project (YMP) FEP Database throughout this document. Those biosphere-related primary FEPs that are screened as applicable will be used to develop the conceptual model portion of the biosphere model, which will in turn be used to develop the mathematical model portion of the biosphere model. As part of this revision, any reference to the screening guidance or criteria provided either by Dyer (1999) or by the proposed NRC regulations at 64 FR 8640 has been removed. The title of this revision has been changed to more accurately reflect the purpose of the analyses. In addition, this revision will address Item Numbers 19, 20, 21, 25, and 26 from Attachment 2 of ''U.S. Nuclear Regulatory Commission/U.S. Department of Energy Technical Exchange and Management Meeting on Total System Performance Assessment and Integration (August 6 through 10, 2001)'' (Reamer 2001). This Scientific Analysis Report (SAR) does not support the current revision to the YMP FEP Database (Freeze et al. 2001). Subsequent to the release of the YMP FEP Database (Freeze et al. 2001), a series of reviews was conducted on both the FEP processes used to support Total System Performance Assessment for Site Recommendation and to develop the YMP FEP Database. In response to observations and comments from these reviews, particularly the NRC/DOE TSPA Technical Exchange in August 2001 (Reamer 2001), several Key Technical Issue (KTI) Agreements were developed. ''The Enhanced Plan for Features, Events and Processes

Evaluation of Features, Events, and Processes (FEP) for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

J. J. Tappen

2003-02-16

The purpose of this revision of ''Evaluation of the Applicability of Biosphere-Related Features, Events, and Processes (FEPs)'' (BSC 2001) is to document the screening analysis of biosphere-related primary FEPs, as identified in ''The Development of Information Catalogued in REV00 of the YMP FEP Database'' (Freeze et al. 2001), in accordance with the requirements of the final U.S. Nuclear Regulatory Commission (NRC) regulations at 10 CFR Part 63. This database is referred to as the Yucca Mountain Project (YMP) FEP Database throughout this document. Those biosphere-related primary FEPs that are screened as applicable will be used to develop the conceptual model portion of the biosphere model, which will in turn be used to develop the mathematical model portion of the biosphere model. As part of this revision, any reference to the screening guidance or criteria provided either by Dyer (1999) or by the proposed NRC regulations at 64 FR 8640 has been removed. The title of this revision has been changed to more accurately reflect the purpose of the analyses. In addition, this revision will address Item Numbers 19, 20, 21, 25, and 26 from Attachment 2 of ''U.S. Nuclear Regulatory Commission/U.S. Department of Energy Technical Exchange and Management Meeting on Total System Performance Assessment and Integration (August 6 through 10, 2001)'' (Reamer 2001). This Scientific Analysis Report (SAR) does not support the current revision to the YMP FEP Database (Freeze et al. 2001). Subsequent to the release of the YMP FEP Database (Freeze et al. 2001), a series of reviews was conducted on both the FEP processes used to support Total System Performance Assessment for Site Recommendation and to develop the YMP FEP Database. In response to observations and comments from these reviews, particularly the NRC/DOE TSPA Technical Exchange in August 2001 (Reamer 2001), several Key Technical Issue (KTI) Agreements were developed

Compiled records of carbon isotopes in atmospheric CO2 for historical simulations in CMIP6

Directory of Open Access Journals (Sweden)

H. Graven

2017-12-01

Full Text Available The isotopic composition of carbon (Δ14C and δ13C in atmospheric CO2 and in oceanic and terrestrial carbon reservoirs is influenced by anthropogenic emissions and by natural carbon exchanges, which can respond to and drive changes in climate. Simulations of 14C and 13C in the ocean and terrestrial components of Earth system models (ESMs present opportunities for model evaluation and for investigation of carbon cycling, including anthropogenic CO2 emissions and uptake. The use of carbon isotopes in novel evaluation of the ESMs' component ocean and terrestrial biosphere models and in new analyses of historical changes may improve predictions of future changes in the carbon cycle and climate system. We compile existing data to produce records of Δ14C and δ13C in atmospheric CO2 for the historical period 1850–2015. The primary motivation for this compilation is to provide the atmospheric boundary condition for historical simulations in the Coupled Model Intercomparison Project 6 (CMIP6 for models simulating carbon isotopes in the ocean or terrestrial biosphere. The data may also be useful for other carbon cycle modelling activities.

Compiled records of carbon isotopes in atmospheric CO2 for historical simulations in CMIP6

Science.gov (United States)

Graven, Heather; Allison, Colin E.; Etheridge, David M.; Hammer, Samuel; Keeling, Ralph F.; Levin, Ingeborg; Meijer, Harro A. J.; Rubino, Mauro; Tans, Pieter P.; Trudinger, Cathy M.; Vaughn, Bruce H.; White, James W. C.

2017-12-01

The isotopic composition of carbon (Δ14C and δ13C) in atmospheric CO2 and in oceanic and terrestrial carbon reservoirs is influenced by anthropogenic emissions and by natural carbon exchanges, which can respond to and drive changes in climate. Simulations of 14C and 13C in the ocean and terrestrial components of Earth system models (ESMs) present opportunities for model evaluation and for investigation of carbon cycling, including anthropogenic CO2 emissions and uptake. The use of carbon isotopes in novel evaluation of the ESMs' component ocean and terrestrial biosphere models and in new analyses of historical changes may improve predictions of future changes in the carbon cycle and climate system. We compile existing data to produce records of Δ14C and δ13C in atmospheric CO2 for the historical period 1850-2015. The primary motivation for this compilation is to provide the atmospheric boundary condition for historical simulations in the Coupled Model Intercomparison Project 6 (CMIP6) for models simulating carbon isotopes in the ocean or terrestrial biosphere. The data may also be useful for other carbon cycle modelling activities.

The Biosphere as a Living System. On Peculiarities of the Evolutionary Process on the Biosphere Level

Directory of Open Access Journals (Sweden)

Alexej Yablokov

2016-10-01

sovereign (“suprime” living system. The main functional feature of the biosphere is almost a vicious turnover of the matters; a phytomass becomes zoomass and mikrobiomass, and after their dying off both become a nekromass (mineral mass. Photosynthesis transforms of mineral mass again into a phytomass. This turnover of matter based on the division of all living organisms on the producers (autotrophs, of consumers (heterotrophs, and decomposers (reducents. Before the Anthropocene the degree of closure of the turnover of matter in the Earth’ ecosystem have reached, apparently, extreme values in 90–99%. This was due to more efficient utilization of waste of each of the trophic level, thanks to the growth of a biodiversity. During evolution of the biosphere intensity of turnover of chemical elements on the planet grew. The turnover rate in warm-blooded animals hundreds times higher than in cold-blooded ones. Although most of the biomass is turn into nekromass, a small portion turn into the propaguls (seeds, spores, eggs, etc., transferred by the arrow of time and providing the self-renewal of ecosystems. Its nonlinearity was essential feature of evolution of the biosphere – the periods of smooth development were replaced accelerated (including under the influence of the astrophysical factors. Maintenance of life on the planet was the main functional imperative of the biosphere at all stages of its evolution to an Anthropocene. A "memory" of the biosphere (the results of its evolution as in the form of the morphological and functional differentiation of biosystems, as soon as in forms of biogenous changes of a lithosphere, hydrosphere and atmosphere canalizes occurring in the biosphere subsequent changes. This a "memory" allows to multiply successful evolutionary discoveries (which are, in fact, the technologies of survival of ecosystems, and resulted of the emergence of more and more complex forms of life. The basis of the matter turnover is the trophic chain (transfer

Biosphere of the earth as a life-support system (LSS) for mankind

Science.gov (United States)

Pechurkin, Nickolay

As a component of biosphere the mankind became the most powerful and active link recently. Exponential growth of human population number and of some technological indicators of its development becomes menacing for steady (stationary or close-to-stationary) functioning of biosphere as single whole. Anyway, we should be able to estimate quantitatively limits of pos-sible anthropogenic impact on functional parameters of biosphere. Considering biosphere as a natural LSS, we can receive the helpful information for working out and creation of artificial LSS of various types. Big biotic cycle induced with flows of a solar energy, is a basis of func-tioning of biosphere and its basic cells -ecosystems. In comparison with the majority natural ecosystems, the biosphere has very high factor of closure of substance circulation, especially limiting biogenic elements: nitrogen and phosphorus. Voluntarily or not, the mankind interferes in big biotic cycle and modifies it. For example, extracting mineral fertilizers for cultivation of agricultural crops, we return in circulation lost before substances, type nitric, potassic, phos-phoric salts. Burning fossils of organic carbon (oil, gas, coal), we raise concentration of carbon dioxide in atmosphere. The melting of a permafrost connected with activity of mankind, is capable to lead to excretion of other greenhouse gases, in particular, methane. It's possible to summarize briefly the main functional properties of the biosphere: Integrity, Closure, Substance cycling, Steady state, Energy dependence. These properties of the biosphere, as a LSS, ensure potentially everlasting life under the conditions of a limited quantity of substrate suitable for the life on the planet. But the selfish mankind is able to destroy harmonic adjustment of this unique natural mechanism

Climate change and the biosphere option: moving to a sustainable future

International Nuclear Information System (INIS)

Layzell, D.B.; Mitchell, H.M.

1999-01-01

Human activities resulting in greenhouse gas (GHG) emissions have been implicated as the primary factor forcing climate change. This evidence led to a landmark international agreement in Kyoto, (1997) committing the developed countries of the world to reductions in GHG emissions. In Canada, fossil fuel use over the past few centuries has released about 5200 Mt C into the atmosphere. An equivalent amount has probably been added as a result of deforestation and agricultural practice in this country. If we can manage our biosphere better and return even a fraction of the lost biosphere C, we can make a significant contribution to reducing Canada's current annual GHG emission. In the process, plants ( including trees) will trap the sun's energy and build an energy-rich biomass that we can learn to utilize as an energy, chemical and material resource for the future. In doing so, we will relieve the escalating demand for fossil fuels. The BIOCAP Network will be a multidisciplinary group of university, government and industry researchers dedicated to exploring the scientific, technological and policy implications of this 'biosphere option'. Canada's 'biosphere option' for GHG management is both a national opportunity and a global responsibility

Recent Discoveries and Future Challenges in Atmospheric Organic Chemistry.

Science.gov (United States)

Glasius, Marianne; Goldstein, Allen H

2016-03-15

Earth's atmosphere contains a multitude of organic compounds, which differ by orders of magnitude regarding fundamental properties such as volatility, reactivity, and propensity to form cloud droplets, affecting their impact on global climate and human health. Despite recent major research efforts and advances, there are still substantial gaps in understanding of atmospheric organic chemistry, hampering efforts to understand, model, and mitigate environmental problems such as aerosol formation in both polluted urban and more pristine regions. The analytical toolbox available for chemists to study atmospheric organic components has expanded considerably during the past decade, opening new windows into speciation, time resolution and detection of reactive and semivolatile compounds at low concentrations. This has provided unprecedented opportunities, but also unveiled new scientific challenges. Specific groundbreaking examples include the role of epoxides in aerosol formation especially from isoprene, the importance of highly oxidized, reactive organics in air-surface processes (whether atmosphere-biosphere exchange or aerosols), as well as the extent of interactions of anthropogenic and biogenic emissions and the resulting impact on atmospheric organic chemistry.

Environmental Consequences of an Emerging Biosphere

Science.gov (United States)

DesMarais, David J.

2003-01-01

It seems feasible to detect biological signatures ("biosignatures") in other planetary systems using the tools of astronomy. There are at least two types of biosignatures; spectral and/or polarization features created by biological products, and electromagnetic signals created by technology. The latter example of a biosignature requires SETI-like searches. This presentation addresses only spectral signatures of biological products and properties of habitable planets. Spectral biosignatures are indeed promising targets for near-term exploration. They can arise from organic constituents (e.g., vegetation) and/or inorganic products (e.g., atmospheric O2). Features originating from a planet's surface are likely to be localized in specific regions, whereas gaseous biosignatures can become globally distributed by atmospheric circulation. Biosignatures should be most abundant within environments that are, or once were, habitable. We currently believe that habitable environments necessarily provide Liquid water and biochemically useful energy. However, we do not yet fully comprehend the diversity of features that might arise within these environments that are non-biological in origin, yet mimic biosignatures. For example, atmospheres reflect the events leading to their origins as well as a host of ongoing planetary processes that might include biological activity. We are persuaded that abundant atmospheric oxygen in an environment with abundant liquid water constitutes definitive evidence of life. However, our own early biosphere thrived for more than a billion years in the absence of abundant atmospheric oxygen. The production of other, more reduced, gaseous biomarkers of "young" and/or anaerobic biospheres has not been systematically studied. Biological gas production is strongly controlled by the structure and function of microbial ecosystems. Investigations of microbial ecosystems that are close analogs of ancient communities offer multiple benefits. Such studies can

Multiple greenhouse gas feedbacks from the land biosphere under future climate change scenarios

Science.gov (United States)

Stocker, Benjamin; Roth, Raphael; Joos, Fortunat; Spahni, Renato; Steinacher, Marco; Zaehle, Soenke; Bouwman, Lex; Xu-Ri, Xu-Ri; Prentice, Colin

2013-04-01

Atmospheric concentrations of the three important greenhouse gases (GHG) CO2, CH4, and N2O are mediated by processes in the terrestrial biosphere. The sensitivity of terrestrial GHG emissions to climate and CO2 contributed to the sharp rise in atmospheric GHG concentrations since preindustrial times and leads to multiple feedbacks between the terrestrial biosphere and the climate system. The strength of these feedbacks is determined by (i) the sensitivity of terrestrial GHG emissions to climate and CO2 and (ii) the greenhouse warming potential of the respective gas. Here, we quantify feedbacks from CO2, CH4, N2O, and land surface albedo in a consistent and comprehensive framework based on a large set of simulations conducted with an Earth System Model of Intermediate Complexity. The modeled sensitivities of CH4 and N2O emissions are tested, demonstrating that independent data for non-land (anthropogenic, oceanic, etc.) GHG emissions, combined with simulated emissions from natural and agricultural land reproduces historical atmospheric budgets within their uncertainties. 21st-century scenarios for climate, land use change and reactive nitrogen inputs (Nr) are applied to investigate future GHG emissions. Results suggest that in a business-as-usual scenario, terrestrial N2O emissions increase from 9.0 by today to 9.8-11.1 (RCP 2.6) and 14.2-17.0 TgN2O-N/yr by 2100 (RCP 8.5). Without anthropogenic Nr inputs, the amplification is reduced by 24-32%. Soil CH4 emissions increase from 221 at present to 228-245 in RCP 2.6 and to 303-343 TgCH4/yr in RCP 8.5, and the land becomes a net source of C by 2100 AD. Feedbacks from land imply an additional warming of 1.3-1.5°C by 2300 in RCP 8.5, 0.4-0.5°C of which are due to N2O and CH4. The combined effect of multiple GHGs and albedo represents an increasingly positive total feedback to anthropogenic climate change with positive individual feedbacks from CH4, N2O, and albedo outweighing the diminishing negative feedback from CO2

Optimal determination of the parameters controlling biospheric CO{sub 2} fluxes over Europe using eddy covariance fluxes and satellite NDVI measurements

Energy Technology Data Exchange (ETDEWEB)

Aalto, Tuula [Finnish Meteorological Inst., Helsinki (Finland). Air Quality Research; Ciais, Philippe; Moulin, Cyril [UMR CEA-CNRS, Gif-sur-Yvette (France). Laboratoire des Sciences du Climat et de l' Environnement; Chevillard, Anne [CEA, Fontenay-aux-Roses (France). DPRE/SERGD/LEIRPA

2004-04-01

Ecosystem CO{sub 2} flux measurements using the eddy covariance method were compared with the biospheric CO{sub 2} exchange estimates of a regional scale atmospheric model. The model described the seasonal patterns quite well, but underestimated the amplitude of the fluxes, especially at the northern sites. Two model parameters, photosynthetic efficiency for light use and Q{sub 10} for soil respiration, were re-evaluated on a diurnal and seasonal basis using the results from flux measurements. In most cases the photosynthetic efficiency was higher than the earlier estimate. The resulting flux was very sensitive to the value of photosynthetic efficiency, while changes in Q{sub 10} did not have a significant effect.

Biosphere Process Model Report

Energy Technology Data Exchange (ETDEWEB)

J. Schmitt

2000-05-25

To evaluate the postclosure performance of a potential monitored geologic repository at Yucca Mountain, a Total System Performance Assessment (TSPA) will be conducted. Nine Process Model Reports (PMRs), including this document, are being developed to summarize the technical basis for each of the process models supporting the TSPA model. These reports cover the following areas: (1) Integrated Site Model; (2) Unsaturated Zone Flow and Transport; (3) Near Field Environment; (4) Engineered Barrier System Degradation, Flow, and Transport; (5) Waste Package Degradation; (6) Waste Form Degradation; (7) Saturated Zone Flow and Transport; (8) Biosphere; and (9) Disruptive Events. Analysis/Model Reports (AMRs) contain the more detailed technical information used to support TSPA and the PMRs. The AMRs consists of data, analyses, models, software, and supporting documentation that will be used to defend the applicability of each process model for evaluating the postclosure performance of the potential Yucca Mountain repository system. This documentation will ensure the traceability of information from its source through its ultimate use in the TSPA-Site Recommendation (SR) and in the National Environmental Policy Act (NEPA) analysis processes. The objective of the Biosphere PMR is to summarize (1) the development of the biosphere model, and (2) the Biosphere Dose Conversion Factors (BDCFs) developed for use in TSPA. The Biosphere PMR does not present or summarize estimates of potential radiation doses to human receptors. Dose calculations are performed as part of TSPA and will be presented in the TSPA documentation. The biosphere model is a component of the process to evaluate postclosure repository performance and regulatory compliance for a potential monitored geologic repository at Yucca Mountain, Nevada. The biosphere model describes those exposure pathways in the biosphere by which radionuclides released from a potential repository could reach a human receptor

Biosphere Process Model Report

International Nuclear Information System (INIS)

Schmitt, J.

2000-01-01

To evaluate the postclosure performance of a potential monitored geologic repository at Yucca Mountain, a Total System Performance Assessment (TSPA) will be conducted. Nine Process Model Reports (PMRs), including this document, are being developed to summarize the technical basis for each of the process models supporting the TSPA model. These reports cover the following areas: (1) Integrated Site Model; (2) Unsaturated Zone Flow and Transport; (3) Near Field Environment; (4) Engineered Barrier System Degradation, Flow, and Transport; (5) Waste Package Degradation; (6) Waste Form Degradation; (7) Saturated Zone Flow and Transport; (8) Biosphere; and (9) Disruptive Events. Analysis/Model Reports (AMRs) contain the more detailed technical information used to support TSPA and the PMRs. The AMRs consists of data, analyses, models, software, and supporting documentation that will be used to defend the applicability of each process model for evaluating the postclosure performance of the potential Yucca Mountain repository system. This documentation will ensure the traceability of information from its source through its ultimate use in the TSPA-Site Recommendation (SR) and in the National Environmental Policy Act (NEPA) analysis processes. The objective of the Biosphere PMR is to summarize (1) the development of the biosphere model, and (2) the Biosphere Dose Conversion Factors (BDCFs) developed for use in TSPA. The Biosphere PMR does not present or summarize estimates of potential radiation doses to human receptors. Dose calculations are performed as part of TSPA and will be presented in the TSPA documentation. The biosphere model is a component of the process to evaluate postclosure repository performance and regulatory compliance for a potential monitored geologic repository at Yucca Mountain, Nevada. The biosphere model describes those exposure pathways in the biosphere by which radionuclides released from a potential repository could reach a human receptor

Application of the Biosphere Assessment Methodology to the ENRESA, 1997 Performance and Safety Assessment

International Nuclear Information System (INIS)

Pinedo, P.; Simon, I.; Aguero, A.

1998-01-01

For several years CIEMAT has been developing for ENRESA knowledge and tools to support the modelling of the migration and accumulation of radionuclides within the biosphere once those radionuclides are released or reach one or more parts of the biosphere (atmosphere, water bodies or soils). The model development also includes evaluation of radiological impacts arising from the resulting distribution of radionuclides in the biosphere. In 1996, a Methodology to analyse the biosphere in this context proposed to ENRESA. The level of development of the different aspects proposed within the Methodology was quite heterogeneous and, while aspects of radionuclide transport modelling were already well developed in theoretical and practical terms, other aspects like the procedure for conceptual model development and the description of biosphere system representatives of the long term needed further developments. At present, the International Atomic Energy Agency (IAEA) Programme on Biosphere Modelling and Assessment (BIOMASS) in collaboration with several national organizations, ENRESA and CIEMAT among them, is working to complete and augment the Reference Biosphere Methodology and to produce some practical descriptions of Reference Systems. The overall purpose of this document is to apply the Methodology, taking account of on-going developments in biosphere modelling, to the last performance assessment (PA) exercise made by ENRESA (ENRESA, 1997), using from it the general and particular information about the assessment context, radionuclide information, geosphere and geobiosphere interface data. There are three particular objectives to this work: (a) to determine the practicability of the Methodology in an application to a realistic assessment situation, (b) To compare and contrast previous biosphere modelling in HLW PA and, (c) to test software development related with data management and modelling. (Author) 42 refs

Fine modeling of energy exchanges between buildings and urban atmosphere

International Nuclear Information System (INIS)

Daviau-Pellegrin, Noelie

2016-01-01

This thesis work is about the effect of buildings on the urban atmosphere and more precisely the energetic exchanges that take place between these two systems. In order to model more finely the thermal effects of buildings on the atmospheric flows in simulations run under the CFD software Code-Saturne, we proceed to couple this tool with the building model BuildSysPro. This library is run under Dymola and can generate matrices describing the building thermal properties that can be used outside this software. In order to carry out the coupling, we use these matrices in a code that allows the building thermal calculations and the CFD to exchange their results. After a review about the physical phenomena and the existing models, we explain the interactions between the atmosphere and the urban elements, especially buildings. The latter can impact the air flows dynamically, as they act as obstacles, and thermally, through their surface temperatures. At first, we analyse the data obtained from the measurement campaign EM2PAU that we use in order to validate the coupled model. EM2PAU was carried out in Nantes in 2011 and represents a canyon street with two rows of four containers. Its distinctive feature lies in the simultaneous measurements of the air and wall temperatures as well as the wind speeds with anemometers located on a 10 m-high mast for the reference wind and on six locations in the canyon. This aims for studying the thermal influence of buildings on the air flows. Then the numerical simulations of the air flows in EM2PAU is carried out with different methods that allow us to calculate or impose the surface temperature we use for each of the container walls. The first method consists in imposing their temperatures from the measurements. For each wall, we set the temperature to the surface temperature that was measured during the EM2PAU campaign. The second method involves imposing the outdoor air temperature that was measured at a given time to all the

Developments in radiological assessment and biosphere modelling studies to support radioactive waste disposal in Spain

Energy Technology Data Exchange (ETDEWEB)

Perez-Sanchez, D. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas - CIEMAT (Spain); Thorne, M. [Mike Thorne and Associates Limited (United States)

2014-07-01

Long-term safety assessments for the disposal of radioactive waste in Spain involve the demonstration that annual radiation doses to humans due to potential releases of radionuclides from the waste disposal facility into the biosphere will satisfy the regulatory criteria. For several years, CIEMAT has been developing, for ENRESA, a conceptual approach and tool to support modelling of the migration and accumulation of radionuclides within environmental media once those radionuclides have been released to some component of the biosphere (atmosphere, water bodies or soils). The CIEMAT modelling approach calculates the concentrations of radionuclides in different components of the biosphere and then the calculated radionuclide concentrations are used to estimate the radiation doses to humans due to various exposure paths. In this paper, we not only describe the methodology and modelling approach, we also describe recent developments of that approach to better quantify the resultant doses to humans. First, we present recent developments in the mathematical model for the behaviour of {sup 79}Se and {sup 238}U-series radionuclides in soils and their uptake by plants, taking into account seasonal variations in soil hydrology in Spain. Initial studies with the model that are reported here demonstrate that it is a powerful tool for exploring the behaviour of redox-sensitive radionuclides and {sup 238}U decay chain members in soil-plant systems under different hydrological regimes. In particular, it permits studies of the degree to which secular equilibrium assumptions are appropriate when modelling the {sup 238}U decay chain. Further studies are currently being undertaken examining sensitivities of model results to input parameter values and also applying the model to sites contaminated with {sup 238}U-series radionuclides. It is anticipated that results from these studies will also be reported. A particular interest in biosphere safety assessment is how environmental

Biosphere 2: A prototype project for a permanent and evolving life system for Mars base

Science.gov (United States)

Nelson, Mark; Allen, John P.; Dempster, William F.

As part of the ground-based preparation for creating long-term life systems needed for space habitation and settlement, Space Biopsheres Ventures (SBV) is undertaking the Biosphere 2 project near Oracle, Arizona. Biosphere 2, currently under construction, is scheduled to commence its operations in 1991 with a two-year closure period with a crew of eight people. Biosphere 2 is a facility which will be essentially materially-closed to exchange with the outside environment. It is open to information and energy flow. Biosphere 2 is designed to achieve a complex life-support system by the integration of seven areas or ``biomes'' - rainforest, savannah, desert, marsh, ocean, intensive agriculture and human habitat. Unique bioregenerative technologies, such as soil bed reactors for air purification, aquatic waste processing systems, real-time analytic systems and complex computer monitoring and control systems are being developed for the Biosphere 2 project. Its operation should afford valuable insight into the functioning of complex life systems necessary for long-term habitation in space. It will serve as an experimental ground-based prototype and testbed for the stable, permanent life systems needed for human exploration of Mars.

Site and Regional Data for Biosphere Assessment BSA-2009 Supplement to Olkiluoto Biosphere Description 2009

International Nuclear Information System (INIS)

Aro, L.; Haapanen, R.; Puhakka, L.; Hjerpe, T.; Kirkkala, T.; Koivunen, S.; Lahdenperae, A.-M.; Salo, T.; Ikonen, A.T.K.; Helin, J.

2010-06-01

The safety case for a spent nuclear fuel repository at Olkiluoto includes a computational safety assessment. A site-specific biosphere assessment is an integral part of them both. In 2009 an assessment was conducted to demonstrate preparedness to apply for construction license to the repository in 2012. As a part of the biosphere assessment, the present conditions at the site are described in Olkiluoto biosphere description report for an analogue of the future conditions being simulated in the safety assessment. This report is a supplement to the biosphere description report of 2009 and documents the site and regional data used in the biosphere assessment 'BSA-2009' with respective rationales. (orig.)

Earth's Early Biosphere and the Biogeochemical Carbon Cycle

Science.gov (United States)

DesMarais, David

2004-01-01

Our biosphere has altered the global environment principally by influencing the chemistry of those elements most important for life, e g., C, N, S, O, P and transition metals (e.g., Fe and Mn). The coupling of oxygenic photosynthesis with the burial in sediments of photosynthetic organic matter, and with the escape of H2 to space, has increased the state of oxidation of the Oceans and atmosphere. It has also created highly reduced conditions within sedimentary rocks that have also extensively affected the geochemistry of several elements. The decline of volcanism during Earth's history reduced the flow of reduced chemical species that reacted with photosynthetically produced O2. The long-term net accumulation of photosynthetic O2 via biogeochemical processes has profoundly influenced our atmosphere and biosphere, as evidenced by the O2 levels required for algae, multicellular life and certain modem aerobic bacteria to exist. When our biosphere developed photosynthesis, it tapped into an energy resource that was much larger than the energy available from oxidation-reduction reactions associated with weathering and hydrothermal activity. Today, hydrothermal sources deliver globally (0.13-1.1)x10(exp l2) mol yr(sup -1) of reduced S, Fe(2+), Mn(2+), H2 and CH4; this is estimated to sustain at most about (0.2-2)xl0(exp 12)mol C yr(sup -1) of organic carbon production by chemautotrophic microorganisms. In contrast, global photosynthetic productivity is estimated to be 9000x10(exp 12) mol C yr(sup -1). Thus, even though global thermal fluxes were greater in the distant geologic past than today, the onset of oxygenic photosynthesis probably increased global organic productivity by some two or more orders of magnitude. This enormous productivity materialized principally because oxygenic photosynthesizers unleashed a virtually unlimited supply of reduced H that forever freed life from its sole dependence upon abiotic sources of reducing power such as hydrothermal emanations

FLUXNET: A new tool to study the temporal and spatial variability of ecosystem-scale carbon dioxide, water vapor, and energy flux densities

DEFF Research Database (Denmark)

Baldocchi, D.; Falge, E.; Gu, L.

2001-01-01

FLUXNET is a global network of micrometeorological flux measurement site's that measure the exchanges of carbon dioxide, water vapor, and energy between the biosphere and atmosphere. At present over 140 sites are operating on a long-term and continuous basis. Vegetation under study includes...... of annual ecosystem carbon and water balances, to quantify the response of stand-scale carbon dioxide and water vapor flux densities to controlling biotic and abiotic factors, and to validate a hierarchy of soil-plant-atmosphere trace gas exchange models. Findings so far include 1) net CO2 exchange......, it provides infrastructure for compiling, archiving, and distributing carbon, water, and energy flux measurement, and meteorological, plant, and soil data to the science community. (Data and site information are available online at the FLUXNET Web site, http://www-eosdis.oml.gov/FLUXNTET/.) Second...

Biosphere reserves: Attributes for success.

Science.gov (United States)

Van Cuong, Chu; Dart, Peter; Hockings, Marc

2017-03-01

Biosphere reserves established under the UNESCO Man and the Biosphere Program aim to harmonise biodiversity conservation and sustainable development. Concerns over the extent to which the reserve network was living up to this ideal led to the development of a new strategy in 1995 (the Seville Strategy) to enhance the operation of the network of reserves. An evaluation of effectiveness of management of the biosphere reserve network was called for as part of this strategy. Expert opinion was assembled through a Delphi Process to identify successful and less successful reserves and investigate common factors influencing success or failure. Ninety biosphere reserves including sixty successful and thirty less successful reserves in 42 countries across all five Man and the Biosphere Program regions were identified. Most successful sites are the post-Seville generation while the majority of unsuccessful sites are pre-Seville that are managed as national parks and have not been amended to conform to the characteristics that are meant to define a biosphere reserve. Stakeholder participation and collaboration, governance, finance and resources, management, and awareness and communication are the most influential factors in the success or failure of the biosphere reserves. For success, the biosphere reserve concept needs to be clearly understood and applied through landscape zoning. Designated reserves then need a management system with inclusive good governance, strong participation and collaboration, adequate finance and human resource allocation and stable and responsible management and implementation. All rather obvious but it is difficult to achieve without commitment to the biosphere reserve concept by the governance authorities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analysis specifications for the CC3 biosphere model BIOTRAC

International Nuclear Information System (INIS)

Szekely, J.G.; Wojciechowski, L.C.; Stephens, M.E.; Halliday, H.A.

1994-12-01

AECL Research is assessing a concept for disposing of Canada's nuclear fuel waste in a vault deep in plutonic rock of the Canadian Shield. A computer program called the Systems Variability Analysis Code (SYVAC) has been developed as an analytical tool for the postclosure (long-term) assessment of the concept. SYVAC3, the third generation of the code, is an executive program that directs repeated simulation of the disposal system to take into account parameter variation. For the postclosure assessment, the system model, CC3 (Canadian Concept, generation 3), was developed to describe a hypothetical disposal system that includes a disposal vault, the local geosphere and the biosphere in the vicinity of any discharge zones. BIOTRAC (BIOsphere TRansport And Consequences) is the biosphere model in the CC3 system model. The specifications for BIOTRAC, which were developed over a period of seven years, were subjected to numerous walkthrough examinations by the Biosphere Model Working Group to ensure that the intent of the model developers would be correctly specified for transformation into FORTRAN code. The FORTRAN version of BIOTRAC was written from interim versions of these specifications. Improvements to the code are based on revised versions of these specifications. The specifications consist of a data dictionary; sets of synopses, data flow diagrams and mini specs for the component models of BIOTRAC (surface water, soil, atmosphere, and food chain and dose); and supporting calculations (interface to the geosphere, consequences, and mass balance). (author). 20 refs., tabs., figs

Methodology for biosphere analysis in high level waste disposal. Application to the Mediterranean system

International Nuclear Information System (INIS)

Pinedo, P.; Simon, I.; Aguero, A.; Cancio, D.

2000-01-01

For several years CIEMAT has been developing for ENRESA a conceptual approach and tools to support the modelling of the migration and accumulation of radionuclides within the biosphere once those radionuclides are released or reach one or more parts of the biosphere (atmosphere, water bodies or soils). The model development also includes evaluation of radiological impacts arising from the resulting distribution of radionuclides in the biosphere. At the time when the methodology was proposed, the level of development of the different aspects proposed within it was quite heterogeneous and, while aspects of radionuclide transport modelling were already well developed in theoretical and practical terms, other aspects, like the procedure for conceptual model development and the description of biosphere systems representatives of the long term needed further developments. The developments have been performed in parallel to international projects, within which there were and are an active participation, mainly, the BIOphere Models Validation Study (BIOMOVS II) international Project, within which it was developed the so called Reference Biosphere Methodology and, the International Atomic Energy Agency (IAEA) Programme on BIOsphere Modelling and ASSessment methods (BIOMASS), that is under development at present. The methodology been made takes account of these international developments. The purpose of the work summarised herein is the application of the methodology to the 1997 performance assessment (PA) exercise made by ENRESA, using from it the general and particular information about the assessment context, the source term, and the geo-biosphere interface data. (author)

Ecosystem-Atmosphere Exchange of Carbon, Water and Energy over a Mixed Deciduous Forest in the Midwest

Energy Technology Data Exchange (ETDEWEB)

Danilo Dragoni; Hans Peter Schmid; C.S.B. Grimmond; J.C. Randolph; J.R. White

2012-12-17

During the project period we continued to conduct long-term (multi-year) measurements, analysis, and modeling of energy and mass exchange in and over a deciduous forest in the Midwestern United States, to enhance the understanding of soil-vegetation-atmosphere exchange of carbon. At the time when this report was prepared, results from nine years of measurements (1998 - 2006) of above canopy CO2 and energy fluxes at the AmeriFlux site in the Morgan-Monroe State Forest, Indiana, USA (see Table 1), were available on the Fluxnet database, and the hourly CO2 fluxes for 2007 are presented here (see Figure 1). The annual sequestration of atmospheric carbon by the forest is determined to be between 240 and 420 g C m-2 a-1 for the first ten years. These estimates are based on eddy covariance measurements above the forest, with a gap-filling scheme based on soil temperature and photosynthetically active radiation. Data gaps result from missing data or measurements that were rejected in qua)lity control (e.g., during calm nights). Complementary measurements of ecological variables (i.e. inventory method), provided an alternative method to quantify net carbon uptake by the forest, partition carbon allocation in each ecosystem components, and reduce uncertainty on annual net ecosystem productivity (NEP). Biometric datasets are available on the Fluxnext database since 1998 (with the exclusion of 2006). Analysis for year 2007 is under completion.

Post-closure biosphere assessment modelling: comparison of complex and more stylised approaches.

Science.gov (United States)

Walke, Russell C; Kirchner, Gerald; Xu, Shulan; Dverstorp, Björn

2015-10-01

Geological disposal facilities are the preferred option for high-level radioactive waste, due to their potential to provide isolation from the surface environment (biosphere) on very long timescales. Assessments need to strike a balance between stylised models and more complex approaches that draw more extensively on site-specific information. This paper explores the relative merits of complex versus more stylised biosphere models in the context of a site-specific assessment. The more complex biosphere modelling approach was developed by the Swedish Nuclear Fuel and Waste Management Co (SKB) for the Formark candidate site for a spent nuclear fuel repository in Sweden. SKB's approach is built on a landscape development model, whereby radionuclide releases to distinct hydrological basins/sub-catchments (termed 'objects') are represented as they evolve through land rise and climate change. Each of seventeen of these objects is represented with more than 80 site specific parameters, with about 22 that are time-dependent and result in over 5000 input values per object. The more stylised biosphere models developed for this study represent releases to individual ecosystems without environmental change and include the most plausible transport processes. In the context of regulatory review of the landscape modelling approach adopted in the SR-Site assessment in Sweden, the more stylised representation has helped to build understanding in the more complex modelling approaches by providing bounding results, checking the reasonableness of the more complex modelling, highlighting uncertainties introduced through conceptual assumptions and helping to quantify the conservatisms involved. The more stylised biosphere models are also shown capable of reproducing the results of more complex approaches. A major recommendation is that biosphere assessments need to justify the degree of complexity in modelling approaches as well as simplifying and conservative assumptions. In light of

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)

Interannual Variability In the Atmospheric CO2 Rectification Over Boreal Forests Based On A Coupled Ecosystem-Atmosphere Model

Science.gov (United States)

Chen, B.; Chen, J. M.; Worthy, D.

2004-05-01

Ecosystem CO2 exchange and the planetary boundary layer (PBL) are correlated diurnally and seasonally. The simulation of this atmospheric rectifier effect is important in understanding the global CO2 distribution pattern. A 12-year (1990-1996, 1999-2003), continuous CO2 measurement record from Fraserdale, Ontario (located ~150 km north of Timmons), along with a coupled Vertical Diffusion Scheme (VDS) and ecosystem model (Boreal Ecosystem Productivity Simulator, BEPS), is used to investigate the interannual variability in this effect over a boreal forest region. The coupled model performed well in simulating CO2 vertical diffusion processes. Simulated annual atmospheric rectifier effects, (including seasonal and diurnal), quantified as the variation in the mean CO2 concentration from the surface to the top of the PBL, varied from 2.8 to 4.1 ppm, even though the modeled seasonal variations in the PBL depth were similar throughout the 12-year period. The differences in the interannual rectifier effect primarily resulted from changes in the biospheric CO2 uptake and heterotrophic respiration. Correlations in the year-to year variations of the CO2 rectification were found with mean annual air temperatures, simulated gross primary productivity (GPP) and heterotrophic respiration (Rh) (r2=0.5, 0.46, 0.42, respectively). A small increasing trend in the CO2 rectification was also observed. The year-to-year variation in the vertical distribution of the monthly mean CO2 mixing ratios (reflecting differences in the diurnal rectifier effect) was related to interannual climate variability, however, the seasonal rectifier effects were found to be more sensitive to climate variability than the diurnal rectifier effects.

Methodology for the biosphere evaluation during the RRAA management. Application for the Mediterranean system

International Nuclear Information System (INIS)

Pinedo, P.; Simon, I.; Aguero, A.

1998-01-01

For several years CIEMAT has been developing for ENRESA knowledge and tools to support the modelling of the migration and accumulation of radionuclides within the biosphere once those radionuclides are released or reach one or more parts of the biosphere (atmosphere, water impacts arising from the resulting distribution of radionuclides in the biosphere. In 1996, a Methodology to analyse the biosphere in the context of high level waste repositories was proposed to ENRESA, where the issues mentioned above were considered and treated. The level of development of the different aspects proposed within the Methodology was quite heterogeneous and, while aspects of radionuclide transport modelling were already well developed in theoretical and practical terms, other aspects like the procedure for conceptual model development using the RES matrix and the description of biosphere systems representatives of the long term needed further developments. These own methodological developments have been developed in parallel with similar international developments within which there were and are an active participation, the BIOMOVS II international Project, finalized in 1996 and where it was developed the so called Reference Biosphere Methodology and, the International Atomic Energy Agency (IAEA) Programme on Biosphere Modelling and Assessment (BIOMASS), that is developed at present in collaboration with several national organizations, ENRESA and CIEMAT among them. The work described here takes account of these international developments. The overall purpose of this work is to apply the Methodology, to the last performance assessment (PA) exercise made by ENRESA, using form it the general and particular information about the assessment context, the source term, and the geo-biosphere interface data. (Author) 6 refs

Radon gas-exchange rate through the interface sea atmosphere in the coast

International Nuclear Information System (INIS)

Duenas, C.; Fernandez, M.C.; Perez Martinez, M.

1985-01-01

The Rn gas exchange velocity through the interface sea atmosphere has been estimated. Our measurements have been made in a sampler station located in Malaga bay, obtaining a mean value of 0.45 m/d. The corresponding magnitude of the thickness of boundary layer is 316μ. Experimental results are discussed. No clear relationship can be found between the gas exchange rate and wind speed. (author)

It's the Biosphere, Stupid!

OpenAIRE

Cairns, John

2007-01-01

The biosphere is humankind s life support system and the source of the resources that drive exponential growth. Without the biospheric life support system functioning in a way that is favorable to humans, humankind could face extinctions.

Deciduous birch canopy as unexpected contributor to stand level atmospheric reactivity in boreal forests

Science.gov (United States)

Bäck, Jaana; Taipale, Ditte; Aalto, Juho

2017-04-01

senescence in addition to prevailing temperature and light conditions. With these improvements and inputs to the 1D biosphere-atmosphere model SOSAA (model to Simulate Organic vapours, Sulphuric Acid and Aerosols), we showed that the contribution of Silver birch to stand scale atmospheric reactivity may exceed the ones from conifers, and therefore specific land use and species distribution patterns should be accounted for in biosphere-atmosphere models describing the surface-atmosphere exchange of reactive gases.

Partitioning net ecosystem carbon exchange into net assimilation and respiration using 13CO2 measurements: A cost-effective sampling strategy

Science.gov (United States)

OgéE, J.; Peylin, P.; Ciais, P.; Bariac, T.; Brunet, Y.; Berbigier, P.; Roche, C.; Richard, P.; Bardoux, G.; Bonnefond, J.-M.

2003-06-01

The current emphasis on global climate studies has led the scientific community to set up a number of sites for measuring the long-term biosphere-atmosphere net CO2 exchange (net ecosystem exchange, NEE). Partitioning this flux into its elementary components, net assimilation (FA), and respiration (FR), remains necessary in order to get a better understanding of biosphere functioning and design better surface exchange models. Noting that FR and FA have different isotopic signatures, we evaluate the potential of isotopic 13CO2 measurements in the air (combined with CO2 flux and concentration measurements) to partition NEE into FR and FA on a routine basis. The study is conducted at a temperate coniferous forest where intensive isotopic measurements in air, soil, and biomass were performed in summer 1997. The multilayer soil-vegetation-atmosphere transfer model MuSICA is adapted to compute 13CO2 flux and concentration profiles. Using MuSICA as a "perfect" simulator and taking advantage of the very dense spatiotemporal resolution of the isotopic data set (341 flasks over a 24-hour period) enable us to test each hypothesis and estimate the performance of the method. The partitioning works better in midafternoon when isotopic disequilibrium is strong. With only 15 flasks, i.e., two 13CO2 nighttime profiles (to estimate the isotopic signature of FR) and five daytime measurements (to perform the partitioning) we get mean daily estimates of FR and FA that agree with the model within 15-20%. However, knowledge of the mesophyll conductance seems crucial and may be a limitation to the method.

The Earth's Biosphere

Science.gov (United States)

2002-01-01

In the last five years, scientists have been able to monitor our changing planet in ways never before possible. The Sea-viewing Wide Field-of-View Sensor (SeaWiFS), aboard the OrbView-2 satellite, has given researchers an unprecedented view of the biological engine that drives life on Earth-the countless forms of plants that cover the land and fill the oceans. 'There is no question the Earth is changing. SeaWiFS has enabled us, for the first time, to monitor the biological consequences of that change-to see how the things we do, as well as natural variability, affect the Earth's ability to support life,' said Gene Carl Feldman, SeaWiFS project manager at NASA's Goddard Space Flight Center, Greenbelt, Md. SeaWiFS data, based on continuous daily global observations, have helped scientists make a more accurate assessment of the oceans' role in the global carbon cycle. The data provide a key parameter in a number of ecological and environmental studies as well as global climate-change modeling. The images of the Earth's changing land, ocean and atmosphere from SeaWiFS have documented many previously unrecognized phenomena. The image above shows the global biosphere from June 2002 measured by SeaWiFS. Data in the oceans is chlorophyll concentration, a measure of the amount of phytoplankton (microscopic plants) living in the ocean. On land SeaWiFS measures Normalized Difference Vegetation Index, an indication of the density of plant growth. For more information and images, read: SeaWiFS Sensor Marks Five Years Documenting Earth'S Dynamic Biosphere Image courtesy SeaWiFS project and copyright Orbimage.

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

DEFF Research Database (Denmark)

Selsted, Merete Bang

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 CO2 concentrations experiments imitating global change effects are therefore an important tool. This work....... Fluxes of CO2 from soil to atmosphere depend on a physical equilibrium between those two medias, why it is important to keep the CO2 gradient between soil and atmosphere unchanged during measurement. Uptake to plants via photosynthesis depends on a physiological process, which depends strongly...... 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....

On the uncertainty of phenological responses to climate change, and implications for a terrestrial biosphere model

Directory of Open Access Journals (Sweden)

M. Migliavacca

2012-06-01

Full Text Available Phenology, the timing of recurring life cycle events, controls numerous land surface feedbacks to the climate system through the regulation of exchanges of carbon, water and energy between the biosphere and atmosphere.

Terrestrial biosphere models, however, are known to have systematic errors in the simulation of spring phenology, which potentially could propagate to uncertainty in modeled responses to future climate change. Here, we used the Harvard Forest phenology record to investigate and characterize sources of uncertainty in predicting phenology, and the subsequent impacts on model forecasts of carbon and water cycling. Using a model-data fusion approach, we combined information from 20 yr of phenological observations of 11 North American woody species, with 12 leaf bud-burst models that varied in complexity.

Akaike's Information Criterion indicated support for spring warming models with photoperiod limitations and, to a lesser extent, models that included chilling requirements.

We assessed three different sources of uncertainty in phenological forecasts: parameter uncertainty, model uncertainty, and driver uncertainty. The latter was characterized running the models to 2099 using 2 different IPCC climate scenarios (A1fi vs. B1, i.e. high CO₂ emissions vs. low CO₂ emissions scenario. Parameter uncertainty was the smallest (average 95% Confidence Interval – CI: 2.4 days century⁻¹ for scenario B1 and 4.5 days century⁻¹ for A1fi, whereas driver uncertainty was the largest (up to 8.4 days century⁻¹ in the simulated trends. The uncertainty related to model structure is also large and the predicted bud-burst trends as well as the shape of the smoothed projections varied among models (±7.7 days century⁻¹ for A1fi, ±3.6 days century⁻¹ for B1. The forecast sensitivity of bud-burst to temperature (i.e. days bud-burst advanced per

Anthropogenic transformation of the terrestrial biosphere.

Science.gov (United States)

Ellis, Erle C

2011-03-13

Human populations and their use of land have transformed most of the terrestrial biosphere into anthropogenic biomes (anthromes), causing a variety of novel ecological patterns and processes to emerge. To assess whether human populations and their use of land have directly altered the terrestrial biosphere sufficiently to indicate that the Earth system has entered a new geological epoch, spatially explicit global estimates of human populations and their use of land were analysed across the Holocene for their potential to induce irreversible novel transformation of the terrestrial biosphere. Human alteration of the terrestrial biosphere has been significant for more than 8000 years. However, only in the past century has the majority of the terrestrial biosphere been transformed into intensively used anthromes with predominantly novel anthropogenic ecological processes. At present, even were human populations to decline substantially or use of land become far more efficient, the current global extent, duration, type and intensity of human transformation of ecosystems have already irreversibly altered the terrestrial biosphere at levels sufficient to leave an unambiguous geological record differing substantially from that of the Holocene or any prior epoch. It remains to be seen whether the anthropogenic biosphere will be sustained and continue to evolve.

Influence of the soil-atmosphere exchange on the hydric profile induced in soil-structure system

Directory of Open Access Journals (Sweden)

A. Al Qadad

2012-06-01

Full Text Available Soil-atmosphere exchange leads to a moisture change in the soil. This can cause major damage to engineering structures due to the soil expansion and shrinkage. The soil-atmosphere exchange is related to several parameters, in particular the soil characteristics and climate conditions. The presence of an engineering structure causes a variation of the hydraulic profile in the soil, which can lead to heterogeneous soil movement and consequently to structural damage. This paper presents a coupled numerical model based on the consideration of both water flow in unsaturated soils and soil-atmosphere exchange. After the validation of the model, the paper presents its use for the analysis of the influence of the presence of structures on moisture change induced under climatic conditions recorded in a semi-arid region. Analysis shows that the presence of the structure leads to important change in the moisture distribution, in particular in the vicinity of the structure.

HTO deposition by vapor exchange between atmosphere and soil

International Nuclear Information System (INIS)

Bunnenberg, C.

1989-01-01

HTO deposition to soils occurs by vapor exchange between atmosphere and soil-air, when the concentration gradient is directed downwards, and it is principally independent from simultaneous transport of H 2 O. In relatively dry top soil, which is frequently the case, as it tries to attain equilibrium with the air humidity, HTO diffuses into deeper soil driven by the same mechanisms that caused the deposition process. The resulting HTO profile is depending on the atmospheric supply and the soil physical conditions, and it is the source for further tritium pathways, namely root uptake by plants and reemission from soil back into the ground-level air. Simulation experiments with soil columns exposed to HTO labeled atmospheres have proved the theoretical expectation that under certain boundary conditions the HTO profile can be described by an error function. The key parameter is the effective diffusion coefficient, which in turn is a function of the sorption characteristics of the particular soil. (orig.) [de

A factorial assessment of the sensitivity of the BATS land-surface parameterization scheme. [BATS (Biosphere-Atmosphere Transfer Scheme)

Energy Technology Data Exchange (ETDEWEB)

Henderson-Sellers, A. (Macquarie Univ., North Ryde, New South Wales (Australia))

1993-02-01

Land-surface schemes developed for incorporation into global climate models include parameterizations that are not yet fully validated and depend upon the specification of a large (20-50) number of ecological and soil parameters, the values of which are not yet well known. There are two methods of investigating the sensitivity of a land-surface scheme to prescribed values: simple one-at-a-time changes or factorial experiments. Factorial experiments offer information about interactions between parameters and are thus a more powerful tool. Here the results of a suite of factorial experiments are reported. These are designed (i) to illustrate the usefulness of this methodology and (ii) to identify factors important to the performance of complex land-surface schemes. The Biosphere-Atmosphere Transfer Scheme (BATS) is used and its sensitivity is considered (a) to prescribed ecological and soil parameters and (b) to atmospheric forcing used in the off-line tests undertaken. Results indicate that the most important atmospheric forcings are mean monthly temperature and the interaction between mean monthly temperature and total monthly precipitation, although fractional cloudiness and other parameters are also important. The most important ecological parameters are vegetation roughness length, soil porosity, and a factor describing the sensitivity of the stomatal resistance of vegetation to the amount of photosynthetically active solar radiation and, to a lesser extent, soil and vegetation albedos. Two-factor interactions including vegetation roughness length are more important than many of the 23 specified single factors. The results of factorial sensitivity experiments such as these could form the basis for intercomparison of land-surface parameterization schemes and for field experiments and satellite-based observation programs aimed at improving evaluation of important parameters.

Biosphere modeling for HLW disposal in Japan

International Nuclear Information System (INIS)

Naito, Morimasa

2001-01-01

Concept of Reference Biosphere is defined by 'the set of assumptions and hypotheses that is necessary to provide a consistent basis for calculations of the radiological impact arising from long-term releases of repository-derived radionuclides into the biosphere'. Geological environment and biosphere interface (GBI) is the place having the high probability of introduction of radioactive nuclides to biosphere by groundwater. Reference biosphere methodology, GBI, basic models, assessment context, assumptions concerning the surface environment for the biosphere assessment, nuclides migration process, interaction matrix showing radionuclide transport pathways for biosphere modeling, conceptual model for exposure modes and pathways for each exposure group in the biosphere assessment are explained. Response of the biosphere assessment model is steady, unit flux input (1 Bq/y) of different nuclides (farming exposure group). The dose per unit input of agriculture group is 1 to 3 figures larger than that of other two fisheries groups in the case of river and coastal environment except Po-210. We can calculate easily the dose by determining the dose conversion factors derived from different GBI models. Comparison of flux to dose conversion factors derived from different GBI models is effective to know the properties of each model, process and importance of data. (S.Y.)

Exchange of NO2 between spruces and the atmosphere is dominated by deposition

Science.gov (United States)

Breuninger, C.; Meixner, F. X.; Kesselmeier, J.

2009-04-01

The chemical budget of troposheric ozone is largely determined by the concentration of NOx (NO and NO2), which is in remote areas related to biological activities of soils and vegetation. The atmospheric concentration of NO2 is strongly influenced by the bi-directional exchange between the atmosphere and plants. The exchange depends on stomatal compensations points in close relation to the NO2 concentrations in ambient air. It is accepted that NO2 uptake by plants represents a large NO2 sink, but the magnitude is still unidentified. A better knowledge of compensation point values for the bi-directional NO2 exchange is a matter of recent discussions, as accurate estimates would help to reliably classify vegetation types. In close relation to our previous studies of Betula pendula, Fagus sylvatica, Quercus ilex und Pinus sylvestris we investigated a further representative of conifers, Picea abies, under field and laboratory conditions. The measurements were part of the DFG joined project EGER (ExchanGE processes in mountainous Regions). We used dynamic chambers and a sensitive and highly specific NO-NO2-Analysator. CO¬2 and H2O exchange were measured simultaneously to assess physiological comparative parameters such as photosynthesis, transpiration and stomatal conductance. Additionally O3 concentrations were recorded, to detect and estimate chemical reactions within the chamber. During the measurements the NO2 exchange was obviously dominated by deposition and depended on stomatal conductance.

Seven years of recent European net terrestrial carbon dioxide exchange constrained by atmospheric observations

NARCIS (Netherlands)

Peters, W.; Krol, M. C.; van der Werf, G. R.; Houweling, S.; Jones, C. D.; Hughes, J.; Schaefer, K.; Masarie, K. A.; Jacobson, A. R.; Miller, J. B.; Cho, C. H.; Ramonet, M.; Schmidt, M.; Ciattaglia, L.; Apadula, F.; Heltai, D.; Meinhardt, F.; di Sarra, A. G.; Piacentino, S.; Sferlazzo, D.; Aalto, T.; Hatakka, J.; StröM, J.; Haszpra, L.; Meijer, H. A J; van Der Laan, S.; Neubert, R. E M; Jordan, A.; Rodó, X.; Morguí, J. A.; Vermeulen, A. T.; Popa, Maria Elena; Rozanski, K.; Zimnoch, M.; Manning, A. C.; Leuenberger, M.; Uglietti, C.; Dolman, A. J.; Ciais, P.; Heimann, M.; Tans, P.

2010-01-01

We present an estimate of net ecosystem exchange (NEE) of CO2 in Europe for the years 2001-2007. It is derived with a data assimilation that uses a large set of atmospheric CO2 mole fraction observations (∼70 000) to guide relatively simple descriptions of terrestrial and oceanic net exchange, while

Seven years of recent European net terrestrial carbon dioxide exchange constrained by atmospheric observations

NARCIS (Netherlands)

Peters, W.; Krol, M.C.; Werf, van der G.R.; Houweling, S.; Jones, C.D.; Hughes, J.; Schaefer, K.; Masarie, K.A.

2010-01-01

We present an estimate of net ecosystem exchange (NEE) of CO2 in Europe for the years 2001–2007. It is derived with a data assimilation that uses a large set of atmospheric CO2 mole fraction observations (~70 000) to guide relatively simple descriptions of terrestrial and oceanic net exchange, while

Biosphere2 and Earthbuzz

Science.gov (United States)

Washburne, J. C.

2009-12-01

In an attempt to reach a broader audience, Biosphere 2, near Tucson, AZ, is participating in a network of science centers thanks to new funding through the Science Museum of Minnesota (SMM) and the National Center for Earth System Dynamics (NCED). Each of these centers will be tied together through an Earthbuzz kiosk, basically a networked web site that allows visitors to learn more about the work of leading local scientists in a very personal and captivating format. Content is currently being developed by Biosphere 2 researchers, staff, and graduate students that range from a public question and answer forum called “Scientist on the Spot” to science blogs by Biosphere 2 Fellows. It is hoped that this project will help educate the public about the Anthropocene, that is, the current geologic period that is so greatly affected by humankind’s impact on the health of the planet. Biosphere 2 provides a unique location to engage the public in this conversation for several reasons. First, no other destination on Earth gives the public such a physical immersion into what climate change might mean as does Biosphere 2. On the regular walking tour, visitors are guided through scaled down versions of an African savannah, a semi-arid thorn scrub, a coastal fog desert and a tropical rainforest. Digital displays of temperature and humidity confirm what your body is feeling - conditions ranging from desert aridity to tropical humidity. As one passes through the biomes of Biosphere 2, climate change is a whole body experience. Second, Biosphere 2 is also an active ecological research site - part of a unique network of sites run by the University of Arizona that allow scientists to study ecosystem processes across a range of scales - from microscopic root studies to studies encompassing large watersheds. In particular, a group of researchers is studying why large stands of pinion-juniper forests across the southwest have died in recent years. Biosphere2’s role in this

Measurements of gaseous mercury exchanges at the sediment-water, water-atmosphere and sediment-atmosphere interfaces of a tidal environment (Arcachon Bay, France).

Science.gov (United States)

Bouchet, Sylvain; Tessier, Emmanuel; Monperrus, Mathilde; Bridou, Romain; Clavier, Jacques; Thouzeau, Gerard; Amouroux, David

2011-05-01

The elemental mercury evasion from non-impacted natural areas is of significant importance in the global Hg cycle due to their large spatial coverage. Intertidal areas represent a dynamic environment promoting the transformations of Hg species and their subsequent redistribution. A major challenge remains in providing reliable data on Hg species variability and fluxes under typical transient tidal conditions found in such environment. Field experiments were thus carried out to allow the assessment and comparison of the magnitude of the gaseous Hg fluxes at the three interfaces, sediment-water, sediment-atmosphere and water-atmosphere of a mesotidal temperate lagoon (Arcachon Bay, Aquitaine, France) over three distinct seasonal conditions. The fluxes between the sediment-water and the sediment-atmosphere interfaces were directly evaluated with field flux chambers, respectively static or dynamic. Water-atmosphere fluxes were evaluated from ambient concentrations using a gas exchange model. The fluxes at the sediment-water interface ranged from -5.0 to 5.1 ng m(-2) h(-1) and appeared mainly controlled by diffusion. The occurrence of macrophytic covers (i.e.Zostera noltii sp.) enhanced the fluxes under light radiations. The first direct measurements of sediment-atmosphere fluxes are reported here. The exchanges were more intense and variable than the two other interfaces, ranging between -78 and 40 ng m(-2) h(-1) and were mostly driven by the overlying atmospheric Hg concentrations and superficial sediment temperature. The exchanges between the water column and the atmosphere, computed as a function of wind speed and gaseous mercury saturation ranged from 0.4 to 14.5 ng m(-2) h(-1). The flux intensities recorded over the intertidal sediments periodically exposed to the atmosphere were roughly 2 to 3 times higher than the fluxes of the other interfaces. The evasion of elemental mercury from emerged intertidal sediments is probably a significant pathway for Hg evasion in

Global observations and modeling of atmosphere-surface exchange of elemental mercury: a critical review

Science.gov (United States)

Zhu, Wei; Lin, Che-Jen; Wang, Xun; Sommar, Jonas; Fu, Xuewu; Feng, Xinbin

2016-04-01

Reliable quantification of air-surface fluxes of elemental Hg vapor (Hg0) is crucial for understanding mercury (Hg) global biogeochemical cycles. There have been extensive measurements and modeling efforts devoted to estimating the exchange fluxes between the atmosphere and various surfaces (e.g., soil, canopies, water, snow, etc.) in the past three decades. However, large uncertainties remain due to the complexity of Hg0 bidirectional exchange, limitations of flux quantification techniques and challenges in model parameterization. In this study, we provide a critical review on the state of science in the atmosphere-surface exchange of Hg0. Specifically, the advancement of flux quantification techniques, mechanisms in driving the air-surface Hg exchange and modeling efforts are presented. Due to the semi-volatile nature of Hg0 and redox transformation of Hg in environmental media, Hg deposition and evasion are influenced by multiple environmental variables including seasonality, vegetative coverage and its life cycle, temperature, light, moisture, atmospheric turbulence and the presence of reactants (e.g., O3, radicals, etc.). However, the effects of these processes on flux have not been fundamentally and quantitatively determined, which limits the accuracy of flux modeling. We compile an up-to-date global observational flux database and discuss the implication of flux data on the global Hg budget. Mean Hg0 fluxes obtained by micrometeorological measurements do not appear to be significantly greater than the fluxes measured by dynamic flux chamber methods over unpolluted surfaces (p = 0.16, one-tailed, Mann-Whitney U test). The spatiotemporal coverage of existing Hg0 flux measurements is highly heterogeneous with large data gaps existing in multiple continents (Africa, South Asia, Middle East, South America and Australia). The magnitude of the evasion flux is strongly enhanced by human activities, particularly at contaminated sites. Hg0 flux observations in East

Chapter 2. Radionuclides in the biosphere

International Nuclear Information System (INIS)

Toelgyessy, J.; Harangozo, M.

2000-01-01

This is a chapter of textbook of radioecology for university students. In this chapter authors deal with role of radionuclides in the biosphere. Chapter consists of next parts: (1) Natural radionuclides in biosphere; (2) Man-made radionuclides in the biosphere; (3) Ecologically important radionuclides; (4) Natural background; (5) Radiotoxicity and (6) Paths of transfer of radionuclides from the source to human

[Characteristics of mercury exchange flux between soil and atmosphere under the snow retention and snow melting control].

Science.gov (United States)

Zhang, Gang; Wang, Ning; Ai, Jian-Chao; Zhang, Lei; Yang, Jing; Liu, Zi-Qi

2013-02-01

Jiapigou gold mine, located in the upper Songhua River, was once the largest mine in China due to gold output, where gold extraction with algamation was widely applied to extract gold resulting in severe mercury pollution to ambient environmental medium. In order to study the characteristics of mercury exchange flux between soil (snow) and atmosphere under the snow retention and snow melting control, sampling sites were selected in equal distances along the slope which is situated in the typical hill-valley terrain unit. Mercury exchange flux between soil (snow) and atmosphere was determined with the method of dynamic flux chamber and in all sampling sites the atmosphere concentration from 0 to 150 cm near to the earth in the vertical direction was measured. Furthermore, the impact factors including synchronous meteorology, the surface characteristics under the snow retention and snow melting control and the mercury concentration in vertical direction were also investigated. The results are as follows: During the period of snow retention and melting the air mercury tends to gather towards valley bottom along the slope and an obvious deposit tendency process was found from air to the earth's surface under the control of thermal inversion due to the underlying surface of cold source (snow surface). However, during the period of snow melting, mercury exchange flux between the soil and atmosphere on the surface of the earth with the snow being melted demonstrates alternative deposit and release processes. As for the earth with snow covered, the deposit level of mercury exchange flux between soil and atmosphere is lower than that during the period of snow retention. The relationship between mercury exchange flux and impact factors shows that in snow retention there is a remarkable negative linear correlation between mercury exchange flux and air mercury concentration as well as between the former and the air temperature. In addition, in snow melting mercury exchange

Biomedical program at Space Biospheres Ventures

Science.gov (United States)

Walford, Roy

1990-01-01

There are many similarities and some important differences between potential health problems of Biosphere 2 and those of which might be anticipated for a space station or a major outpost on Mars. The demands of time, expense, and equipment would not readily allow medical evacuation from deep space for a serious illness or major trauma, whereas personnel can easily be evacuated from Biosphere 2 if necessary. Treatment facilities can be somewhat less inclusive, since distance would not compel the undertaking of heroic measures or highly complicated surgical procedures on site, and with personnel not fully trained for these procedures. The similarities are given between medical requirements of Biosphere 2 and the complex closed ecological systems of biospheres in space or on Mars. The major problems common to all these would seem to be trauma, infection, and toxicity. It is planned that minor and moderate degrees of trauma, including debridement and suturing of wounds, x ray study of fractures, will be done within Biosphere 2. Bacteriologic and fungal infections, and possibly allergies to pollen or spores are expected to be the commonest medical problem within Biosphere 2.

Quantifying the effect of nighttime interactions between roots and canopy physiology and their control of water and carbon cycling on feedbacks between soil moisture and terrestrial climatology under variable environmental conditions

Energy Technology Data Exchange (ETDEWEB)

Domec, Jean-Christophe [North Carolina State Univ., Raleigh, NC (United States); Palmroth, Sari [Duke Univ., Durham, NC (United States); Oren, Ram [Duke Univ., Durham, NC (United States); Swenson, Jennifer [Duke Univ., Durham, NC (United States); King, John S. [North Carolina State Univ., Raleigh, NC (United States); Noormets, Asko [North Carolina State Univ., Raleigh, NC (United States)

2016-04-01

The primary objective of this project is to characterize and quantify how the temporal variability of hydraulic redistribution (HR) and its physiological regulation in unmanaged and complex forests is affecting current water and carbon exchange and predict how future climate scenarios will affect these relationships and potentially feed back to the climate. Specifically, a detailed study of ecosystem water uptake and carbon exchange in relation to root functioning was proposed in order to quantify the mechanisms controlling temporal variability of soil moisture dynamic and HR in three active AmeriFlux sites, and to use published data of two other inactive AmeriFlux sites. Furthermore, data collected by our research group at the Duke Free Air CO2 enrichment (FACE) site was also being utilized to further improve our ability to forecast future environmental impacts of elevated CO2 concentration on soil moisture dynamic and its effect on carbon sequestration and terrestrial climatology. The overarching objective being to forecast, using a soil:plant:atmosphere model coupled with a biosphere:atmosphere model, the impact of root functioning on land surface climatology. By comparing unmanaged sites to plantations, we also proposed to determine the effect of land use change on terrestrial carbon sequestration and climatology through its effect on soil moisture dynamic and HR. Our simulations of HR by roots indicated that in some systems HR is an important mechanism that buffers soil water deficit, affects energy and carbon cycling; thus having significant implications for seasonal climate. HR maintained roots alive and below 70% loss of conductivity and our simulations also showed that the increased vapor pressure deficit at night under future conditions was sufficient to drive significant nighttime transpiration at all sites, which reduced HR. This predicted reduction in HR under future climate conditions played an important regulatory role in land atmosphere interactions

Work in support of biosphere assessments for solid radioactive waste disposal. 2. biosphere FEP list and biosphere modelling

Energy Technology Data Exchange (ETDEWEB)

Egan, M J; Maul, P R; Watkins, B M; Venter, A [QuantiSci Ltd., Henley-on-Thames (United Kingdom)

2001-10-01

In order to assist SSI in its reappraisal of the SFR safety case, QuantiSci has been appointed to develop a systematic framework within which to conduct the review of SKB's post-closure performance assessment (PA). The biosphere FEP list presented here was developed for use as reference material in conducting the review. SSI wishes to develop an independent PA capability for a time-dependent biosphere in preparation for the examination of the revised SFR safety case. This report documents the model development that has been undertaken by QuantiSci using the Amber computer code.

Work in support of biosphere assessments for solid radioactive waste disposal. 2. biosphere FEP list and biosphere modelling

International Nuclear Information System (INIS)

Egan, M.J.; Maul, P.R.; Watkins, B.M.; Venter, A.

2001-10-01

In order to assist SSI in its reappraisal of the SFR safety case, QuantiSci has been appointed to develop a systematic framework within which to conduct the review of SKB's post-closure performance assessment (PA). The biosphere FEP list presented here was developed for use as reference material in conducting the review. SSI wishes to develop an independent PA capability for a time-dependent biosphere in preparation for the examination of the revised SFR safety case. This report documents the model development that has been undertaken by QuantiSci using the Amber computer code

Composition of atmospheric precipitation. I. Sampling technique. Use of ion exchange resins

Energy Technology Data Exchange (ETDEWEB)

Egner, H; Eriksson, E; Emanuelsson, A

1947-01-01

In order to investigate the composition of atmospheric precipitations in Sweden, a technique using ion exchange resins has been developed. The possibilities of nitrate reduction, and ammonia losses, when the precipitation is collected in zinc gauges is stressed. Glass funnels are used, and they are effectively protected from bird droppings. The ion exchange resins so far available are quite serviceable but show some deficiencies as to stability, and activity in alkaline solutions. New resins, which are not yet available, seem to offer definite advantages.

Atmospheric 14C changes resulting from fossil fuel CO2 release and cosmic ray flux variability

International Nuclear Information System (INIS)

Stuiver, M.; Quay, P.D.

1981-01-01

A high-precision tree-ring record of the atmospheric 14 C levels between 1820 and 1954 is presented. Good agreement is obtained between measured and model calculated 19th and 20th century atmospheric δ 14 C levels when both fossil fuel CO 2 release and predicted natural variations in 14 C production are taken into account. The best fit is obtained by using a box-diffusion model with an oceanic eddy diffusion coefficient of 3 cm 2 /s, a CO 2 atmosphere-ocean gas exchange rate of 21 moles msup(-2) yrsup(-1) and biospheric residence time of 60 years. For trees in the state of Washington the measured 1949-1951 atmospheric δ 14 C level was 20.0 +- 1.2per mille below the 1855-1864 level. Model calculations indicate that in 1950 industrial CO 2 emissions are responsible for at least 85% of the δ 14 C decline, whereas natural variability accounts for the remaining 15%. (orig.)

Planetary fertility during the past 400 ka based on the triple isotope composition of atmospheric oxygen in trapped gases from the Vostok ice core

Science.gov (United States)

Blunier, T.; Bender, M. L.; Barnett, B.; von Fisher, J. C.

2012-04-01

The productivity of the biosphere leaves its imprint on the isotopic composition of atmospheric oxygen. Ultimately atmospheric oxygen, through photosynthesis, originates from seawater. Fractionations during the passage from seawater to atmospheric O2 and during respiration are mass dependent, affecting δ17O about half as much as δ18O. An "anomalous" (also termed mass independent) fractionation process changes δ17O about 1.7 times as much as δ18O during isotope exchange between O2 and CO2 in the stratosphere. The relative rates of biological O2 production and stratospheric processing determine the relationship between δ17O and δ18O of O2 in the atmosphere. Variations of this relationship thus allow us to estimate changes in the rate of mass dependent O2 production by photosynthesis versus the rate of mass independent O2-CO2 exchange in the stratosphere. However, the analysis of the 17O anomaly is complicated because each hydrological and biological process influencing δ17O and δ18O fractionates 17O and 18O in slightly different proportions. In this study we present oxygen data covering the last 400 kyr from the Vostok ice core. We reconstruct oxygen productivities from the triple isotope composition of atmospheric oxygen with a box model. Our steady state model for the oxygen cycle takes into account fractionation during photosynthesis and respiration of the land and ocean biosphere as well as fractionation when oxygen passes through the stratosphere. We consider changes of fractionation factors linked to climate variations taking into account the span of estimates of the main factors affecting our calculations. We find that ocean oxygen productivity was likely elevated relative to modern during glacials. However, this increase probably did not fully compensate for a reduction in land ocean productivity resulting in a slight reduction in total oxygen production during glacials.

Biosphere 2: The True Story.

Science.gov (United States)

O'Keeffe, Michael

1992-01-01

Discusses the history and current developments of the Biosphere 2 Project, a prototype for enclosed self-sustaining structures for space colonization built in the Arizona Desert. Biosphere 2 was created to educate and provide solutions to environmental problems and revenue from research. (MCO)

Impact of land use change on the land atmosphere carbon flux of South and South East Asia: A Synthesis of Dynamic Vegetation Model Results

Science.gov (United States)

Cervarich, M.; Shu, S.; Jain, A. K.; Poulter, B.; Stocker, B.; Arneth, A.; Viovy, N.; Kato, E.; Wiltshire, A.; Koven, C.; Sitch, S.; Zeng, N.; Friedlingstein, P.

2015-12-01

Understanding our present day carbon cycle and possible solutions to recent increases in atmospheric carbon dioxide is dependent upon quantifying the terrestrial carbon budget. Currently, global land cover and land use change is estimated to emit 0.9 PgC yr-1 compared to emissions due to fossil fuel combustion and cement production of 8.4 PgC yr-1. South and Southeast Asia (India, Nepal, Bhutan, Bangladesh, Burma, Thailand, Laos, Vietnam, Cambodia, Malaysia, Philippines, Indonesia, Pakistan, Myanmar, and Singapore) is a region of rapid land cover and land use change due to the continuous development of agriculture, deforestation, reforestation, afforestation, and the increased demand of land for people to live. In this study, we synthesize outputs of nine models participated in Global Carbon Budget Project to identify the carbon budget of South and southeast Asia, diagnose the contribution of land cover and land use change to carbon emissions and assess areas of uncertainty in the suite of models. Uncertainty is determined using the standard deviation and the coefficient of variation of net ecosystem exchange and its component parts. Results show the region's terrestrial biosphere was a source of carbon emissions from the 1980 to the early 1990s. During the same time period, land cover and land use change increasingly contributed to carbon emission. In the most recent two decades, the region became a carbon sink since emission due to land cover land use changes. Spatially, the greatest total emissions occurred in the tropical forest of Southeast Asia. Additionally, this is the subregion with the greatest uncertainty and greatest biomass. Model uncertainty is shown to be proportional to total biomass. The atmospheric impacts of ENSO are shown to suppress the net biosphere productivity in South and Southeast Asia leading to years of increased carbon emissions.

Preindustrial nitrous oxide emissions from the land biosphere estimated by using a global biogeochemistry model

Science.gov (United States)

Xu, Rongting; Tian, Hanqin; Lu, Chaoqun; Pan, Shufen; Chen, Jian; Yang, Jia; Zhang, Bowen

2017-07-01

To accurately assess how increased global nitrous oxide (N2O) emission has affected the climate system requires a robust estimation of the preindustrial N2O emissions since only the difference between current and preindustrial emissions represents net drivers of anthropogenic climate change. However, large uncertainty exists in previous estimates of preindustrial N2O emissions from the land biosphere, while preindustrial N2O emissions on the finer scales, such as regional, biome, or sector scales, have not been well quantified yet. In this study, we applied a process-based Dynamic Land Ecosystem Model (DLEM) to estimate the magnitude and spatial patterns of preindustrial N2O fluxes at the biome, continental, and global level as driven by multiple environmental factors. Uncertainties associated with key parameters were also evaluated. Our study indicates that the mean of the preindustrial N2O emission was approximately 6.20 Tg N yr-1, with an uncertainty range of 4.76 to 8.13 Tg N yr-1. The estimated N2O emission varied significantly at spatial and biome levels. South America, Africa, and Southern Asia accounted for 34.12, 23.85, and 18.93 %, respectively, together contributing 76.90 % of global total emission. The tropics were identified as the major source of N2O released into the atmosphere, accounting for 64.66 % of the total emission. Our multi-scale estimates provide a robust reference for assessing the climate forcing of anthropogenic N2O emission from the land biosphere

Preindustrial nitrous oxide emissions from the land biosphere estimated by using a global biogeochemistry model

Directory of Open Access Journals (Sweden)

R. Xu

2017-07-01

Full Text Available To accurately assess how increased global nitrous oxide (N2O emission has affected the climate system requires a robust estimation of the preindustrial N2O emissions since only the difference between current and preindustrial emissions represents net drivers of anthropogenic climate change. However, large uncertainty exists in previous estimates of preindustrial N2O emissions from the land biosphere, while preindustrial N2O emissions on the finer scales, such as regional, biome, or sector scales, have not been well quantified yet. In this study, we applied a process-based Dynamic Land Ecosystem Model (DLEM to estimate the magnitude and spatial patterns of preindustrial N2O fluxes at the biome, continental, and global level as driven by multiple environmental factors. Uncertainties associated with key parameters were also evaluated. Our study indicates that the mean of the preindustrial N2O emission was approximately 6.20 Tg N yr−1, with an uncertainty range of 4.76 to 8.13 Tg N yr−1. The estimated N2O emission varied significantly at spatial and biome levels. South America, Africa, and Southern Asia accounted for 34.12, 23.85, and 18.93 %, respectively, together contributing 76.90 % of global total emission. The tropics were identified as the major source of N2O released into the atmosphere, accounting for 64.66 % of the total emission. Our multi-scale estimates provide a robust reference for assessing the climate forcing of anthropogenic N2O emission from the land biosphere

Environmental Transport Input Parameters for the Biosphere Model

International Nuclear Information System (INIS)

M. Wasiolek

2004-01-01

This analysis report is one of the technical reports documenting the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment for the license application (TSPA-LA) for the geologic repository at Yucca Mountain. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows relationships among the reports developed for biosphere modeling and biosphere abstraction products for the TSPA-LA, as identified in the ''Technical Work Plan for Biosphere Modeling and Expert Support'' (BSC 2004 [DIRS 169573]) (TWP). This figure provides an understanding of how this report contributes to biosphere modeling in support of the license application (LA). This report is one of the five reports that develop input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the conceptual model and the mathematical model. The input parameter reports, shown to the right of the Biosphere Model Report in Figure 1-1, contain detailed description of the model input parameters. The output of this report is used as direct input in the ''Nominal Performance Biosphere Dose Conversion Factor Analysis'' and in the ''Disruptive Event Biosphere Dose Conversion Factor Analysis'' that calculate the values of biosphere dose conversion factors (BDCFs) for the groundwater and volcanic ash exposure scenarios, respectively. The purpose of this analysis was to develop biosphere model parameter values related to radionuclide transport and accumulation in the environment. These parameters support calculations of radionuclide concentrations in the environmental media (e.g., soil, crops, animal products, and air) resulting from a given radionuclide concentration at the source of contamination (i.e., either in groundwater or in volcanic ash). The analysis was performed in accordance with the TWP (BSC 2004 [DIRS 169573])

Environmental Transport Input Parameters for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

M. Wasiolek

2004-09-10

This analysis report is one of the technical reports documenting the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment for the license application (TSPA-LA) for the geologic repository at Yucca Mountain. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows relationships among the reports developed for biosphere modeling and biosphere abstraction products for the TSPA-LA, as identified in the ''Technical Work Plan for Biosphere Modeling and Expert Support'' (BSC 2004 [DIRS 169573]) (TWP). This figure provides an understanding of how this report contributes to biosphere modeling in support of the license application (LA). This report is one of the five reports that develop input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the conceptual model and the mathematical model. The input parameter reports, shown to the right of the Biosphere Model Report in Figure 1-1, contain detailed description of the model input parameters. The output of this report is used as direct input in the ''Nominal Performance Biosphere Dose Conversion Factor Analysis'' and in the ''Disruptive Event Biosphere Dose Conversion Factor Analysis'' that calculate the values of biosphere dose conversion factors (BDCFs) for the groundwater and volcanic ash exposure scenarios, respectively. The purpose of this analysis was to develop biosphere model parameter values related to radionuclide transport and accumulation in the environment. These parameters support calculations of radionuclide concentrations in the environmental media (e.g., soil, crops, animal products, and air) resulting from a given radionuclide concentration at the source of contamination (i.e., either in groundwater or in volcanic ash). The analysis

Characteristics of the Receptor for the Biosphere Model

International Nuclear Information System (INIS)

Wasiolek, M.A.; Rautenstrauch, K.R.

2003-01-01

This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the geologic repository at Yucca Mountain. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows relationships among the products (i.e., analysis and model reports) developed for biosphere modeling and biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (TWP) (BSC 2003). Some documents identified in Figure 1-1 may be under development and not available at the time this report is issued. This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and access to the listed documents is not required to understand the contents of this report. This report is one of the reports that develop input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2003), describes the conceptual model as well as the mathematical model and its input parameters. The purpose of this analysis report is to define values for biosphere model parameters that are related to the dietary, lifestyle, and dosimetric characteristics of the receptor. The biosphere model, consistent with the licensing rule at 10 CFR Part 63, uses a hypothetical person called the reasonably maximally exposed individual (RMEI) to represent the potentially exposed population. The parameters that define the RMEI are based on the behaviors and characteristics of the Amargosa Valley population, consistent with the requirements of 10 CFR 63.312. Amargosa Valley is the community, located in the direction of the projected groundwater flow path, where most of the farming in the area occurs. The parameter values developed in this report support the

Work in support of biosphere assessments for solid radioactive waste disposal. 2. biosphere FEP list and biosphere modelling

Energy Technology Data Exchange (ETDEWEB)

Egan, M.J.; Maul, P.R.; Watkins, B.M.; Venter, A. [QuantiSci Ltd., Henley-on-Thames (United Kingdom)

2001-10-01

In order to assist SSI in its reappraisal of the SFR safety case, QuantiSci has been appointed to develop a systematic framework within which to conduct the review of SKB's post-closure performance assessment (PA). The biosphere FEP list presented here was developed for use as reference material in conducting the review. SSI wishes to develop an independent PA capability for a time-dependent biosphere in preparation for the examination of the revised SFR safety case. This report documents the model development that has been undertaken by QuantiSci using the Amber computer code.

Exchange processes at geosphere-biosphere interface. Current SKB approach and example of coupled hydrological-ecological approach

International Nuclear Information System (INIS)

Woerman, Anders

2003-09-01

The design of the repository for final disposal of spent nuclear fuel proposed by SKB is based on a multi-barrier system, in which the geosphere and biosphere are the utmost barrier surrounding the engineer barriers. This report briefly reviews the current approach taken by SKB to account for hydrological and ecological processes at the geosphere-biosphere interface (GBI) and their future plans in this area. A simple analysis was performed to shift the focus of performance assessment involving geosphere-biosphere interface modelling from the very simplistic assumption that the quaternary sediments are bypassed to one in which a more detailed model for sub-surface flows is included. This study indicated that, for many assumed ecosystem descriptions, the presence of the GBI leads to lower maximum doses to individual humans compared to a case when the GBI is neglected. This effect is due to the additional 'barrier' offered by the GBI. The main exposure pathways were assumed to occur through the food web. However, particularly the leakage on land through the stream-network and lakes can lead to higher doses due to ecosystem interaction with arable land. A scenario that gives particularly long duration of doses occurs due to land rise and with the transformation of the former bay and lake bed sediments into agricultural land. This effect is due to the significant retention or accumulation in aquatic sediment, which causes high activities to build up with time. Particularly, in combination with changing conditions in climate, humans life-style or geographic conditions (land rise, deforestation,etc.) doses to individual humans can be large

Exploring global carbon turnover and radiocarbon cycling in terrestrial biosphere models

Science.gov (United States)

Graven, H. D.; Warren, H.

2017-12-01

The uptake of carbon into terrestrial ecosystems through net primary productivity (NPP) and the turnover of that carbon through various pathways are the fundamental drivers of changing carbon stocks on land, in addition to human-induced and natural disturbances. Terrestrial biosphere models use different formulations for carbon uptake and release, resulting in a range of values in NPP of 40-70 PgC/yr and biomass turnover times of about 25-40 years for the preindustrial period in current-generation models from CMIP5. Biases in carbon uptake and turnover impact simulated carbon uptake and storage in the historical period and later in the century under changing climate and CO2 concentration, however evaluating global-scale NPP and carbon turnover is challenging. Scaling up of plot-scale measurements involves uncertainty due to the large heterogeneity across ecosystems and biomass types, some of which are not well-observed. We are developing the modelling of radiocarbon in terrestrial biosphere models, with a particular focus on decadal 14C dynamics after the nuclear weapons testing in the 1950s-60s, including the impact of carbon flux trends and variability on 14C cycling. We use an estimate of the total inventory of excess 14C in the biosphere constructed by Naegler and Levin (2009) using a 14C budget approach incorporating estimates of total 14C produced by the weapons tests and atmospheric and oceanic 14C observations. By simulating radiocarbon in simple biosphere box models using carbon fluxes from the CMIP5 models, we find that carbon turnover is too rapid in many of the simple models - the models appear to take up too much 14C and release it too quickly. Therefore many CMIP5 models may also simulate carbon turnover that is too rapid. A caveat is that the simple box models we use may not adequately represent carbon dynamics in the full-scale models. Explicit simulation of radiocarbon in terrestrial biosphere models would allow more robust evaluation of biosphere

The biomass theme 1 project: Reference biospheres

International Nuclear Information System (INIS)

Crossland, I.; Torres-Vidal, C.

2000-01-01

The long-term safety of a facility for the disposal of long-lived radioactive waste would principally depend upon a combination of engineered and natural barriers which would ensure that the radioactivity was prevented from reaching the biosphere. To assess radiological safety over extended timescales requires the construction of 'assessment biospheres'. A possibility is the development of 'Reference Biospheres', a series of stylised, internationally-agreed assessment biospheres that could be used to support post-closure assessments in a wide variety of situations. Current activities in this subject area are described. (author)

Nonlinear dynamics of global atmospheric and earth system processes

Science.gov (United States)

Zhang, Taiping; Verbitsky, Mikhail; Saltzman, Barry; Mann, Michael E.; Park, Jeffrey; Lall, Upmanu

1995-01-01

During the grant period, the authors continued ongoing studies aimed at enhancing their understanding of the operation of the atmosphere as a complex nonlinear system interacting with the hydrosphere, biosphere, and cryosphere in response to external radiative forcing. Five papers were completed with support from the grant, representing contributions in three main areas of study: (1) theoretical studies of the interactive atmospheric response to changed biospheric boundary conditions measurable from satellites; (2) statistical-observational studies of global-scale temperature variability on interannual to century time scales; and (3) dynamics of long-term earth system changes associated with ice sheet surges.

Remote sensing of the biosphere

Science.gov (United States)

1986-01-01

The current state of understanding of the biosphere is reviewed, the major scientific issues to be addressed are discussed, and techniques, existing and in need of development, for the science are evaluated. It is primarily concerned with developing the scientific capabilities of remote sensing for advancing the subject. The global nature of the scientific objectives requires the use of space-based techniques. The capability to look at the Earth as a whole was developed only recently. The space program has provided the technology to study the entire Earth from artificial satellites, and thus is a primary force in approaches to planetary biology. Space technology has also permitted comparative studies of planetary atmospheres and surfaces. These studies coupled with the growing awareness of the effects that life has on the entire Earth, are opening new lines of inquiry in science.

Interaction between Hydrosphere and Biosphere: Challenges and Opportunities

Science.gov (United States)

Kumar, P.; Sivapalan, M.

2007-12-01

Vegetated terrestrial ecosystems and the overlying atmosphere are dynamically linked though the continuous transfer of mass, energy and momentum. The hydrologic variability interacts with the vegetation at time scales ranging from hours to days to inter-annual and decadal. The existing distribution of ecosystems is a result of evolutionary selections in response to environmental constraints which are themselves modified as terrestrial systems evolve until reaching a dynamic equilibrium. However this balance is changing, often rapidly, in response to anthropogenic influences such as climate change, land use/land cover change, and urban and agricultural expansions. Evidence suggests that vegetation response is adaptive in that they alter their survival strategies in response to environmental change, for example, through development of deep rooting and using hydraulic redistribution to better utilize the available moisture in the deeper soil layers. Yet little is known on how this impacts the hydrologic cycle and its variability. Active and adaptive control of vegetation and atmospheric flow moves soil-moisture that is no longer constrained by watershed boundaries. How do the atmospheric and terrestrial moisture, and vegetation interact to produce the observed variability in the water cycle and how does/will this variability change in response to the anthropogenic influences? What are the ecological consequences of this change? These broad questions lie at the heart of understanding the interaction between the hydrosphere and biosphere. Some specific questions to address are: · How does biosphere mediate the interaction between long time scale sub-surface hydrology and short time scale atmospheric hydrologic cycle? · How has this interaction given rise to the observed self-organized patterns of ecosystems and how do these ecosystems sustain the hydrologic regime needed for their own sustenance? · How are the dynamic regimes of ecohydrologic interactions affected by

Estimating Carbon Stocks and Atmospheric Exchange of Depressional Marshes on the Central Florida Landscape

Science.gov (United States)

Benscoter, B.; McClellan, M. D.; Benavides, V.; Harshbarger, D.; Comas, X.

2014-12-01

Depressional marshes are ubiquitous throughout central and south Florida. Often distributed within a matrix of sandy pine flatwoods and hammocks, these wetlands have a seasonally variable water table, alternating between inundation and complete drydown. Though these landforms are typically small individually, they comprise a substantial component of the landscape and provide vital habitat for an array of flora and fauna. Given their fluctuating hydrology, conditions for soil and plant carbon (C) exchange mechanisms can vary greatly both spatially and temporally. In this study, we are developing a C budget for depressional marsh landforms by assessing ecosystem carbon exchange along an ecotone gradient and quantifying belowground C stocks using non-invasive geophysical methods (ground penetrating radar, GPR) at the Disney Wilderness Preserve (DWP) in Kissimmee, FL, USA. Using a series of closed chambers transecting the marsh from the center outward into the surrounding flatwoods, we are quantifying the effects of seasonal water table change on the magnitude of C exchange. Three dimensional GPR surveys were used to quantify peat layer thickness, and were constrained with direct core sampling to verify subsurface lithology and to assess peat C content. Using the relationship between landform surface area and belowground C volume, we assessed the cumulative C storage in depressional marshes across the DWP landscape. In conjunction with a nearby eddy covariance tower and seasonal hydrologic data, these response functions will help to evaluate the contribution of these small but widespread landscape features on regional C cycling.

Characteristics of the Receptor for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

M.A. Wasiolek; K.R. Rautenstrauch

2003-06-27

This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the geologic repository at Yucca Mountain. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows relationships among the products (i.e., analysis and model reports) developed for biosphere modeling and biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (TWP) (BSC 2003). Some documents identified in Figure 1-1 may be under development and not available at the time this report is issued. This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and access to the listed documents is not required to understand the contents of this report. This report is one of the reports that develop input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2003), describes the conceptual model as well as the mathematical model and its input parameters. The purpose of this analysis report is to define values for biosphere model parameters that are related to the dietary, lifestyle, and dosimetric characteristics of the receptor. The biosphere model, consistent with the licensing rule at 10 CFR Part 63, uses a hypothetical person called the reasonably maximally exposed individual (RMEI) to represent the potentially exposed population. The parameters that define the RMEI are based on the behaviors and characteristics of the Amargosa Valley population, consistent with the requirements of 10 CFR 63.312. Amargosa Valley is the community, located in the direction of the projected groundwater flow path, where most of the farming in the area occurs. The parameter values

Proceedings of the international symposium: Transfer of radionuclides in biosphere. Prediction and assessment

International Nuclear Information System (INIS)

Amano, Hikaru

2003-09-01

The International Symposium : Transfer of Radionuclides in Biosphere - Prediction and Assessment was held at Mito on the 18th and 19th of December 2002. This International Symposium was organized by the Interchange Committee on Radionuclide Transfer in Soil Ecosphere. This project is the 3rd Phase Crossover Research, which is engaged in cooperation with five organizations: Japan Atomic Energy Research Institute (JAERI), Meteorological Research Institute (MRI), National Institute of Radiological Sciences (NIRS), RIKEN (Institute of Physical and Chemical Research) and Institute for Environmental Sciences (IES). The main objective of this symposium is to discuss and exchange recent findings and ideas in the area of the behavior and transfer of radionuclides in biosphere. One of the important topics in this symposium is to discuss a suitable transfer model and transfer parameters which may be adapted for Southeast Asian countries including Japan, as environmental conditions and foodstuffs in this region are significantly different from those in Europe and North America. It will be hoped that the predictions of the consequences of the release of radionuclides in the terrestrial environment will be improved through exchange of views and new results. The symposium consisted of 12 invited lectures and 44 poster presentations. The 117 participants attended the symposium, including 19 foreigners coming from 12 countries. (author)

Out of Thin Air: Microbial Utilization of Atmospheric Gaseous Organics in the Surface Ocean

KAUST Repository

Arrieta, J M; Duarte, Carlos M.; Sala, M. Montserrat; Dachs, Jordi

2016-01-01

Volatile and semi-volatile gas-phase organic carbon (GOC) is a largely neglected component of the global carbon cycle, with poorly resolved pools and fluxes of natural and anthropogenic GOC in the biosphere. Substantial amounts of atmospheric GOC are exchanged with the surface ocean, and subsequent utilization of specific GOC compounds by surface ocean microbial communities has been demonstrated. Yet, the final fate of the bulk of the atmospheric GOC entering the surface ocean is unknown. Our data show experimental evidence of efficient use of atmospheric GOC by marine prokaryotes at different locations in the NE Subtropical Atlantic, the Arctic Ocean and the Mediterranean Sea. We estimate that between 2 and 27% of the prokaryotic carbon demand was supported by GOC with a major fraction of GOC inputs being consumed within the mixed layer. The role of the atmosphere as a key vector of organic carbon subsidizing marine microbial metabolism is a novel link yet to be incorporated into the microbial ecology of the surface ocean as well as into the global carbon budget.

Out of Thin Air: Microbial Utilization of Atmospheric Gaseous Organics in the Surface Ocean.

Science.gov (United States)

Arrieta, Jesús M; Duarte, Carlos M; Sala, M Montserrat; Dachs, Jordi

2015-01-01

Volatile and semi-volatile gas-phase organic carbon (GOC) is a largely neglected component of the global carbon cycle, with poorly resolved pools and fluxes of natural and anthropogenic GOC in the biosphere. Substantial amounts of atmospheric GOC are exchanged with the surface ocean, and subsequent utilization of specific GOC compounds by surface ocean microbial communities has been demonstrated. Yet, the final fate of the bulk of the atmospheric GOC entering the surface ocean is unknown. Our data show experimental evidence of efficient use of atmospheric GOC by marine prokaryotes at different locations in the NE Subtropical Atlantic, the Arctic Ocean and the Mediterranean Sea. We estimate that between 2 and 27% of the prokaryotic carbon demand was supported by GOC with a major fraction of GOC inputs being consumed within the mixed layer. The role of the atmosphere as a key vector of organic carbon subsidizing marine microbial metabolism is a novel link yet to be incorporated into the microbial ecology of the surface ocean as well as into the global carbon budget.

Out of thin air: Microbial utilization of atmospheric gaseous organics in the surface ocean

Directory of Open Access Journals (Sweden)

Jesus M Arrieta

2016-01-01

Full Text Available Volatile and semi-volatile gas-phase organic carbon (GOC is a largely neglected component of the global carbon cycle, with poorly resolved pools and fluxes of natural and anthropogenic GOC in the biosphere. Substantial amounts of atmospheric GOC are exchanged with the surface ocean, and subsequent utilization of specific GOC compounds by surface ocean microbial communities has been demonstrated. Yet, the final fate of the bulk of the atmospheric GOC entering the surface ocean is unknown. Our data show experimental evidence of efficient use of atmospheric GOC by marine prokaryotes at different locations in the NE Subtropical Atlantic, the Arctic Ocean and the Mediterranean Sea. We estimate that between 2 to 27% of the prokaryotic carbon demand was supported by GOC with a major fraction of GOC inputs being consumed within the mixed layer. The role of the atmosphere as a key vector of organic carbon subsidising marine microbial metabolism is a novel link yet to be incorporated into the microbial ecology of the surface ocean as well as into the global carbon budget.

Out of Thin Air: Microbial Utilization of Atmospheric Gaseous Organics in the Surface Ocean

KAUST Repository

Arrieta, Jesus

2016-01-20

Volatile and semi-volatile gas-phase organic carbon (GOC) is a largely neglected component of the global carbon cycle, with poorly resolved pools and fluxes of natural and anthropogenic GOC in the biosphere. Substantial amounts of atmospheric GOC are exchanged with the surface ocean, and subsequent utilization of specific GOC compounds by surface ocean microbial communities has been demonstrated. Yet, the final fate of the bulk of the atmospheric GOC entering the surface ocean is unknown. Our data show experimental evidence of efficient use of atmospheric GOC by marine prokaryotes at different locations in the NE Subtropical Atlantic, the Arctic Ocean and the Mediterranean Sea. We estimate that between 2 and 27% of the prokaryotic carbon demand was supported by GOC with a major fraction of GOC inputs being consumed within the mixed layer. The role of the atmosphere as a key vector of organic carbon subsidizing marine microbial metabolism is a novel link yet to be incorporated into the microbial ecology of the surface ocean as well as into the global carbon budget.

Biosphere models for deep waste disposal

International Nuclear Information System (INIS)

Olyslaegers, G.

2005-01-01

The management of the radioactive waste requires the implementation of disposal systems that ensure an adequate degree of isolation of the radioactivity from man and the environment. Because there are still a lot of uncertainties and a lack of consensus with respect to the importance of the exposure pathways of man, a project BioMoSA (Biosphere Models for Safety Assessment) was elaborated in the Fifth Framework Programme of EURATOM). It aimed at improving the scientific basis for the application of biosphere models in the framework of long-term safety studies for radioactive waste disposal facilities. The section radiological evaluations of SCK-CEN took part in the BioMoSA project. n the BioMoSA project, the reference biosphere methodology developed in the IAEA programme BIOMASS (Biosphere Modelling and Assessment methods) is implemented). We used this methodology in order to increase the transparency of biosphere modelling; t evaluate the importance of the different radionuclides and pathways, and to enhance public confidence in the assessment of potential radiological dose to population groups far into the future. Five European locations, covering a wide range of environmental and agricultural conditions are described and characterised. Each participant developed a specific biosphere model for their site. In order to achieve a consistency in this model derivation, a staged approach has been followed. Successively the biosphere is described and conceptual, mathematical and numerical models are constructed. For each of the locations site-specific parameters are selected. In the project, we had the specific task to make a comparison between the model results generated by the different participants. Results from these studies are presented and discussed

The past, present and future supernova threat to Earth's biosphere

Science.gov (United States)

Beech, Martin

2011-12-01

A brief review of the threat posed to Earth's biosphere via near-by supernova detonations is presented. The expected radiation dosage, cosmic ray flux and expanding blast wave collision effects are considered, and it is argued that a typical supernova must be closer than ˜10-pc before any appreciable and potentially harmful atmosphere/biosphere effects are likely to occur. In contrast, the critical distance for Gamma-ray bursts is of order 1-kpc. In spite of the high energy effects potentially involved, the geological record provides no clear-cut evidence for any historic supernova induced mass extinctions and/or strong climate change episodes. This, however, is mostly a reflection of their being numerous possible (terrestrial and astronomical) forcing mechanisms acting upon the biosphere and the difficulty of distinguishing between competing scenarios. Key to resolving this situation, it is suggested, is the development of supernova specific extinction and climate change linked ecological models. Moving to the future, we estimate that over the remaining lifetime of the biosphere (˜2 Gyr) the Earth might experience 1 GRB and 20 supernova detonations within their respective harmful threat ranges. There are currently at least 12 potential pre-supernova systems within 1-kpc of the Sun. Of these systems IK Pegasi is the closest Type Ia pre-supernova candidate and Betelgeuse is the closest potential Type II supernova candidate. We review in some detail the past, present and future behavior of these two systems. Developing a detailed evolutionary model we find that IK Pegasi will likely not detonate until some 1.9 billion years hence, and that it affords absolutely no threat to Earth's biosphere. Betelgeuse is the closest, reasonably well understood, pre-supernova candidate to the Sun at the present epoch, and may undergo detonation any time within the next several million years. The stand-off distance of Betelgeuse at the time of its detonation is estimated to fall

Transport of radionuclides in the biosphere

International Nuclear Information System (INIS)

Bundi, A.

1983-10-01

The dispersion of radionuclides in the biosphere and their uptake by man via various nutritional pathways is studied using a compartment model. The sample environment is the area of the lower Limmat and Aare valleys. General considerations of the compartmental description of the biosphere are made. The problem of the description of surface features, in particular soil, sediment and water, is studied in detail using the code BIOPATH. This study is intended to be an example of how a model of the biosphere could be constructed. It is shown that this is a reasonable model to calculate the spreading of radionuclides in the biosphere and that it indicates the relative significance of individual compartments, pathways and radionuclides. Calculated values of dose committment, however, should not be used as reference data for safety analyses. (Auth.)

Exchange of carbonyl sulfide (OCS) between soils and atmosphere under various CO2 concentrations

Science.gov (United States)

Bunk, Rüdiger; Behrendt, Thomas; Yi, Zhigang; Andreae, Meinrat O.; Kesselmeier, Jürgen

2017-06-01

A new continuous integrated cavity output spectroscopy analyzer and an automated soil chamber system were used to investigate the exchange processes of carbonyl sulfide (OCS) between soils and the atmosphere under laboratory conditions. The exchange patterns of OCS between soils and the atmosphere were found to be highly dependent on soil moisture and ambient CO2 concentration. With increasing soil moisture, OCS exchange ranged from emission under dry conditions to an uptake within an optimum moisture range, followed again by emission at high soil moisture. Elevated CO2 was found to have a significant impact on the exchange rate and direction as tested with several soils. There is a clear tendency toward a release of OCS at higher CO2 levels (up to 7600 ppm), which are typical for the upper few centimeters within soils. At high soil moisture, the release of OCS increased sharply. Measurements after chloroform vapor application show that there is a biotic component to the observed OCS exchange. Furthermore, soil treatment with the fungi inhibitor nystatin showed that fungi might be the dominant OCS consumers in the soils we examined. We discuss the influence of soil moisture and elevated CO2 on the OCS exchange as a change in the activity of microbial communities. Physical factors such as diffusivity that are governed by soil moisture also play a role. Comparing KM values of the enzymes to projected soil water CO2 concentrations showed that competitive inhibition is unlikely for carbonic anhydrase and PEPCO but might occur for RubisCO at higher CO2 concentrations.

Exchange processes at geosphere-biosphere interface. Current SKB approach and example of coupled hydrological-ecological approach

Energy Technology Data Exchange (ETDEWEB)

Woerman, Anders [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Biometry and Technology

2003-09-01

The design of the repository for final disposal of spent nuclear fuel proposed by SKB is based on a multi-barrier system, in which the geosphere and biosphere are the utmost barrier surrounding the engineer barriers. This report briefly reviews the current approach taken by SKB to account for hydrological and ecological processes at the geosphere-biosphere interface (GBI) and their future plans in this area. A simple analysis was performed to shift the focus of performance assessment involving geosphere-biosphere interface modelling from the very simplistic assumption that the quaternary sediments are bypassed to one in which a more detailed model for sub-surface flows is included. This study indicated that, for many assumed ecosystem descriptions, the presence of the GBI leads to lower maximum doses to individual humans compared to a case when the GBI is neglected. This effect is due to the additional 'barrier' offered by the GBI. The main exposure pathways were assumed to occur through the food web. However, particularly the leakage on land through the stream-network and lakes can lead to higher doses due to ecosystem interaction with arable land. A scenario that gives particularly long duration of doses occurs due to land rise and with the transformation of the former bay and lake bed sediments into agricultural land. This effect is due to the significant retention or accumulation in aquatic sediment, which causes high activities to build up with time. Particularly, in combination with changing conditions in climate, humans life-style or geographic conditions (land rise, deforestation,etc.) doses to individual humans can be large.

Impact of Sundarban mangrove biosphere on the carbon dioxide and methane mixing ratios at the NE Coast of Bay of Bengal, India

International Nuclear Information System (INIS)

Mukhopadhyay, S.K.; Biswas, H.; De, T.K.; Jana, T.K.; Sen, B.K.; Sen, S.

2002-01-01

Diurnal and seasonal variations in carbon dioxide and methane fluxes between Sundarban biosphere and atmosphere were measured using micrometeorological method during 1998-2000. Study of the diurnal variation of micrometeorological conditions in the atmosphere was found to be necessary to determine the duration of neutral stability when flux estimation was reliable. Neutral stability of the atmosphere occurred in the limited micrometeorological conditions, when friction velocity ranged between 0.360 and 0.383ms -1 . The value of drag coefficient (1.62-20.6) x 10 3 obtained at variable wind speed could be deemed specific for this particular surface. 58.2% drop of carbon dioxide and 63.4% drop of methane in the atmosphere at 1m height were observed during day time, between dawn and early evening. Diurnal variations in methane and carbon dioxide mixing ratios showed a positive correlation with Richardson's number (Ri). This environment acted as a net source for carbon dioxide and methane. The mixing ratios of methane were found to vary between 1.42 and 2.07ppmv, and that of carbon dioxide, between 324.3 and 528.7ppmv during the study period. The biosphere-atmosphere flux of carbon dioxide ranged between - 3.29 and 34.4mgm -2 s -1 , and that of methane, between - 4.53 and 8.88μgm -2 s -1 . The overall annual estimate of carbon dioxide and methane fluxes from this ecosystem to atmosphere were estimated to be 694Tgyr -1 and 184Ggyr -1 , respectively. Considerable variations in mixing ratios of carbon dioxide and methane at the NE coast of Bay of Bengal were observed due to the seasonal variations of their fluxes from the biosphere to the atmosphere. The composition was inferred by fitting model prediction to measurements. (Author)

Plant Uptake of Atmospheric Carbonyl Sulfide in Coast Redwood Forests

Science.gov (United States)

Campbell, J. E.; Whelan, M. E.; Berry, J. A.; Hilton, T. W.; Zumkehr, A.; Stinecipher, J.; Lu, Y.; Kornfeld, A.; Seibt, U.; Dawson, T. E.; Montzka, S. A.; Baker, I. T.; Kulkarni, S.; Wang, Y.; Herndon, S. C.; Zahniser, M. S.; Commane, R.; Loik, M. E.

2017-12-01

The future resilience of coast redwoods (Sequoia sempervirens) is now of critical concern due to the detection of a 33% decline in California coastal fog over the 20th century. However, ecosystem-scale measurements of photosynthesis and stomatal conductance are challenging in coast redwood forests, making it difficult to anticipate the impacts of future changes in fog. To address this methodological problem, we explore coastal variations in atmospheric carbonyl sulfide (COS or OCS), which could potentially be used as a tracer of these ecosystem processes. We conducted atmospheric flask campaigns in coast redwood sites, sampling at surface heights and in the canopy ( 70 m), at the University of California Landels-Hill Big Creek Reserve and Big Basin State Park. We simulated COS atmosphere-biosphere exchange with a high-resolution 3-D model to interpret these data. Flask measurements indicated a persistent daytime drawdown between the coast and the downwind forest (45 ± 6 ppt COS) that is consistent with the expected relationship between COS plant uptake, stomatal conductance, and gross primary production. Other sources and sinks of COS that could introduce noise to the COS tracer technique (soils, anthropogenic activity, nocturnal plant uptake, and surface hydrolysis on leaves) are likely to be small relative to daytime COS plant uptake. These results suggest that COS measurements may be useful for making ecosystem-scale estimates of carbon, water, and energy exchange in coast redwood forests.

Lignocellulose deconstruction in the biosphere

Energy Technology Data Exchange (ETDEWEB)

Bomble, Yannick J.; Lin, Chien-Yuan; Amore, Antonella; Wei, Hui; Holwerda, Evert K.; Ciesielski, Peter N.; Donohoe, Bryon S.; Decker, Stephen R.; Lynd, Lee R.; Himmel, Michael E.

2017-12-01

Microorganisms have evolved different and yet complementary mechanisms to degrade biomass in the biosphere. The chemical biology of lignocellulose deconstruction is a complex and intricate process that appears to vary in response to specific ecosystems. These microorganisms rely on simple to complex arrangements of glycoside hydrolases to conduct most of these polysaccharide depolymerization reactions and also, as discovered more recently, oxidative mechanisms via lytic polysaccharide monooxygenases or non-enzymatic Fenton reactions which are used to enhance deconstruction. It is now clear that these deconstruction mechanisms are often more efficient in the presence of the microorganisms. In general, a major fraction of the total plant biomass deconstruction in the biosphere results from the action of various microorganisms, primarily aerobic bacteria and fungi, as well as a variety of anaerobic bacteria. Beyond carbon recycling, specialized microorganisms interact with plants to manage nitrogen in the biosphere. Understanding the interplay between these organisms within or across ecosystems is crucial to further our grasp of chemical recycling in the biosphere and also enables optimization of the burgeoning plant-based bioeconomy.

Lignocellulose deconstruction in the biosphere.

Science.gov (United States)

Bomble, Yannick J; Lin, Chien-Yuan; Amore, Antonella; Wei, Hui; Holwerda, Evert K; Ciesielski, Peter N; Donohoe, Bryon S; Decker, Stephen R; Lynd, Lee R; Himmel, Michael E

2017-12-01

Microorganisms have evolved different and yet complementary mechanisms to degrade biomass in the biosphere. The chemical biology of lignocellulose deconstruction is a complex and intricate process that appears to vary in response to specific ecosystems. These microorganisms rely on simple to complex arrangements of glycoside hydrolases to conduct most of these polysaccharide depolymerization reactions and also, as discovered more recently, oxidative mechanisms via lytic polysaccharide monooxygenases or non-enzymatic Fenton reactions which are used to enhance deconstruction. It is now clear that these deconstruction mechanisms are often more efficient in the presence of the microorganisms. In general, a major fraction of the total plant biomass deconstruction in the biosphere results from the action of various microorganisms, primarily aerobic bacteria and fungi, as well as a variety of anaerobic bacteria. Beyond carbon recycling, specialized microorganisms interact with plants to manage nitrogen in the biosphere. Understanding the interplay between these organisms within or across ecosystems is crucial to further our grasp of chemical recycling in the biosphere and also enables optimization of the burgeoning plant-based bioeconomy. Copyright © 2017. Published by Elsevier Ltd.

Simulation of atmospheric CO2 over Europe and western Siberia using the regional scale model REMO

International Nuclear Information System (INIS)

Chevillard, A.; Ciais, P.; Lafont, S.

2002-01-01

The spatial distribution and the temporal variability of atmospheric CO 2 over Europe and western Siberia are investigated using the regional atmospheric model, REMO. The model, of typical horizontal resolution 50 km, is part of a nested modelling framework that has been established as a concerted action during the EUROSIBERIAN CARBONFLUX project. In REMO, the transport of CO 2 is simulated together with climate variables, which offers the possibility of calculating at each time step the land atmosphere CO 2 fluxes as driven by the modelled meteorology. The uptake of CO 2 by photosynthesis is calculated using a light use efficiency formulation, where the absorbed photosynthetically active solar radiation is inferred from satellite measurements. The release of CO 2 from plant and soil respiration is driven by the simulated climate and assumed to be in equilibrium with photosynthesis over the course of one year. Fossil CO 2 emissions and air-sea fluxes within the model domain are prescribed, whereas the influence of sources outside the model domain is computed from as a boundary condition CO 2 fields determined a global transport model. The modelling results are compared against pointwise eddy covariance fluxes, and against atmospheric CO 2 records. We show that a necessary condition to simulate realistically the variability of atmospheric CO 2 over continental Europe is to account for the diurnal cycle of biospheric exchange. Overall, for the study period of July 1998, REMO realistically simulates the short-term variability of fluxes and of atmospheric mixing ratios. However, the mean CO 2 gradients from western Europe to western Siberia are not correctly reproduced. This latter deficiency points out the key role of boundary conditions in a limited-area model, as well as the need for using more realistic geographic mean patterns of biospheric carbon fluxes

The Biosphere: A Decadal Vision

Science.gov (United States)

Peterson, David L.; Curran, Paul J.; Mlynzcak, Marty; Miller, Richard

2003-01-01

This paper focuses on biosphere-climate interactions including the influences of human activities. Recognizing this is only one aspect of biospheric processes, this places an emphasis of those biogeochemical processes that have a profound effect on numerous other aspects of the biosphere and the services it provides, services which are critical to sustaining life on Earth. And, the paper will focus on the various scientific aspects of assessing the availability of fresh water, including its sensitivity to climate variance and land use changes. Finally, this paper hopes to emphasize the potential role that greatly expanded space observations and interactive modeling can play in developing our understanding of Earth and its the living systems.

Estimation of Pre-industrial Nitrous Oxide Emission from the Terrestrial Biosphere

Science.gov (United States)

Xu, R.; Tian, H.; Lu, C.; Zhang, B.; Pan, S.; Yang, J.

2015-12-01

Nitrous oxide (N2O) is currently the third most important greenhouse gases (GHG) after methane (CH4) and carbon dioxide (CO2). Global N2O emission increased substantially primarily due to reactive nitrogen (N) enrichment through fossil fuel combustion, fertilizer production, and legume crop cultivation etc. In order to understand how climate system is perturbed by anthropogenic N2O emissions from the terrestrial biosphere, it is necessary to better estimate the pre-industrial N2O emissions. Previous estimations of natural N2O emissions from the terrestrial biosphere range from 3.3-9.0 Tg N2O-N yr-1. This large uncertainty in the estimation of pre-industrial N2O emissions from the terrestrial biosphere may be caused by uncertainty associated with key parameters such as maximum nitrification and denitrification rates, half-saturation coefficients of soil ammonium and nitrate, N fixation rate, and maximum N uptake rate. In addition to the large estimation range, previous studies did not provide an estimate on preindustrial N2O emissions at regional and biome levels. In this study, we applied a process-based coupled biogeochemical model to estimate the magnitude and spatial patterns of pre-industrial N2O fluxes at biome and continental scales as driven by multiple input data, including pre-industrial climate data, atmospheric CO2 concentration, N deposition, N fixation, and land cover types and distributions. Uncertainty associated with key parameters is also evaluated. Finally, we generate sector-based estimates of pre-industrial N2O emission, which provides a reference for assessing the climate forcing of anthropogenic N2O emission from the land biosphere.

Nominal Performance Biosphere Dose Conversion Factor Analysis

International Nuclear Information System (INIS)

M.A. Wasiolek

2005-01-01

This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the groundwater exposure scenario, and the development of conversion factors for assessing compliance with the groundwater protection standards. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop BDCFs, which are input parameters for the TSPA-LA model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the ''Biosphere Model Report'' in Figure 1-1, contain detailed description of the model input parameters, their development, and the relationship between the parameters and specific features events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the groundwater exposure scenario. This analysis receives direct input from the outputs of the ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) and the five analyses that develop parameter values for the biosphere model (BSC 2005 [DIRS 172827]; BSC 2004 [DIRS 169672]; BSC 2004 [DIRS 169673]; BSC 2004 [DIRS 169458]; BSC 2004 [DIRS 169459]). The results of this report are further analyzed in the ''Biosphere Dose Conversion Factor Importance and Sensitivity Analysis'' (Figure 1-1). The objectives of this analysis are to develop BDCFs for the

Toward Quantifying the Mass-Based Hygroscopicity of Individual Submicron Atmospheric Aerosol Particles with STXM/NEXAFS and SEM/EDX

Science.gov (United States)

Yancey Piens, D.; Kelly, S. T.; OBrien, R. E.; Wang, B.; Petters, M. D.; Laskin, A.; Gilles, M. K.

2014-12-01

The hygroscopic behavior of atmospheric aerosols influences their optical and cloud-nucleation properties, and therefore affects climate. Although changes in particle size as a function of relative humidity have often been used to quantify the hygroscopic behavior of submicron aerosol particles, it has been noted that calculations of hygroscopicity based on size contain error due to particle porosity, non-ideal volume additivity and changes in surface tension. We will present a method to quantify the hygroscopic behavior of submicron aerosol particles based on changes in mass, rather than size, as a function of relative humidity. This method results from a novel experimental approach combining scanning transmission x-ray microscopy with near-edge x-ray absorption fine spectroscopy (STXM/NEXAFS), as well as scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM/EDX) on the same individual particles. First, using STXM/NEXAFS, our methods are applied to aerosol particles of known composition ‒ for instance ammonium sulfate, sodium bromide and levoglucosan ‒ and validated by theory. Then, using STXM/NEXAFS and SEM/EDX, these methods are extended to mixed atmospheric aerosol particles collected in the field at the DOE Atmospheric Radiation Measurement (ARM) Climate Research Facility at the Southern Great Planes sampling site in Oklahoma, USA. We have observed and quantified a range of hygroscopic behaviors which are correlated to the composition and morphology of individual aerosol particles. These methods will have implications for parameterizing aerosol mixing state and cloud-nucleation activity in atmospheric models.

Atmospheric chemistry: Description of the area of performance and a working plan

Science.gov (United States)

Kirchhoff, Volker W. J. H.

1986-11-01

INPE's program in Atmospheric Chemistry Research is described. Research in this area is concerned with atmospheric gases and their chemical reactions, production and loss rates, and their interactions with the biosphere. Atmospheric chemistry includes concepts in Physics, Chemistry, Meteorology, and Biology, which gives it a strong interdisciplinary character. The interaction of some of the atmospheric gases with the biosphere, such as ozone, is very strong and direct. Studying atmospheric chemistry is, therefore, of direct interest to man and the quality of life. Details are described to define the objectives of study, in particular those of our research program at INPE. A working plan is proposed in order to reach the defined goals. Owing to the large anthropogenic interference in the balance of the natural atmosphere it is anticipated that a better understanding of Atmospheric Chemistry will be the great scientific challenge of the next decade.

Centennial evolution of the atmospheric methane budget: what do the carbon isotopes tell us?

Directory of Open Access Journals (Sweden)

K. R. Lassey

2007-01-01

Full Text Available Little is known about how the methane source inventory and sinks have evolved over recent centuries. New and detailed records of methane mixing ratio and isotopic composition (12CH4, 13CH4 and 14CH4 from analyses of air trapped in polar ice and firn can enhance this knowledge. We use existing bottom-up constructions of the source history, including "EDGAR"-based constructions, as inputs to a model of the evolving global budget for methane and for its carbon isotope composition through the 20th century. By matching such budgets to atmospheric data, we examine the constraints imposed by isotope information on those budget evolutions. Reconciling both 12CH4 and 13CH4 budgets with EDGAR-based source histories requires a combination of: a greater proportion of emissions from biomass burning and/or of fossil methane than EDGAR constructions suggest; a greater contribution from natural such emissions than is commonly supposed; and/or a significant role for active chlorine or other highly-fractionating tropospheric sink as has been independently proposed. Examining a companion budget evolution for 14CH4 exposes uncertainties in inferring the fossil-methane source from atmospheric 14CH4 data. Specifically, methane evolution during the nuclear era is sensitive to the cycling dynamics of "bomb 14C" (originating from atmospheric weapons tests through the biosphere. In addition, since ca. 1970, direct production and release of 14CH4 from nuclear-power facilities is influential but poorly quantified. Atmospheric 14CH4 determinations in the nuclear era have the potential to better characterize both biospheric carbon cycling, from photosynthesis to methane synthesis, and the nuclear-power source.

Characteristics of the Receptor for the Biosphere Model

International Nuclear Information System (INIS)

M. Wasiolek; K. Rautenstrauch

2004-01-01

This analysis report is one of a series of technical reports that document the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the geologic repository at Yucca Mountain. This report is one of the five biosphere reports that develop input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the conceptual model, as well as the mathematical model and its input parameters. Figure 1-1 is a graphical representation of the documentation hierarchy for the ERMYN. This figure shows relationships among the products (i.e., scientific analyses and model reports) developed for biosphere modeling and biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (BSC 2004 [DIRS 169573]). The purpose of this analysis report is to define values for biosphere model parameters that are related to the dietary, lifestyle, and dosimetric characteristics of the receptor. The biosphere model, consistent with the licensing rule at 10 CFR Part 63 [DIRS 156605], uses a hypothetical person called the reasonably maximally exposed individual (RMEI) to represent the potentially exposed population. The parameters that define the RMEI are based on the behaviors and characteristics of the residents of the unincorporated town of Amargosa Valley, consistent with the requirements of 10 CFR 63.312 [DIRS 156605]. The output of this report is used as direct input in the two analyses identified in Figure 1-1 that calculate the values of biosphere dose conversion factors (BDCFs) for the groundwater and volcanic ash exposure scenarios. The parameter values developed in this report are reflected in the TSPA through the BDCFs. The analysis was performed in accordance with AP-SIII.9Q, ''Scientific Analyses'', and the technical work plan (BSC 2004 [DIRS 169573])

The system earth. Climate research in the International Geosphere-Biosphere Program (IGBP)

International Nuclear Information System (INIS)

Bolle, H.J.

1993-01-01

Substances that are released through human activity can accumulate in the atmosphere. The greenhouse effect, a precondition for life on Earth, has grown so strongly since the beginning of this century that adverse effects on global living conditions must now be reckoned with. The Earth must be understood as a system whose components interact closely. The international Geosphere-Biosphere Programme pursues the aim of examining this global aspect of our environment. (orig.) [de

BIOSPHERIC ORGANIZATION AS A “CONTINENTS – OCEANIC BASINS” SYSTEM

Directory of Open Access Journals (Sweden)

Sergei P. Gorshkov

2016-01-01

Full Text Available The functional characteristics of the biosphere are reflected in its binominale frame: continents – oceanic basins. The river-basin land, on the one hand, and pericontinental oceanic waters on the other hand, are the main components of the homeostatic mechanism of the biosphere. In the Archean and Early-Middle Proterozoic, seawater biofiltration did not exist. In the Late Proterozoic and part of the Early Paleozoic, biofiltration started to develop and the oceans have become the main heat-engine of the Earth. Today, the maximum concentration of productive phytoplankton and zooplankton – filter bio-systems – is in the pericontinental oceanic zones. This is a response to the maximal flow of nutrients from the land carried mainly with river flow. This is the main signal of a direct link between terrestrial and oceanic ecosystems. The feedback is the atmospheric precipitation induced by heat and moisture flows and carried from the oceans to the land within its primary river-basin part. These links are experiencing anthropogenic destabilization due to some misplaced priorities of sustainable development and its implementation.

Environmental Transport Input Parameters for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

M. A. Wasiolek

2003-06-27

This analysis report is one of the technical reports documenting the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the geologic repository at Yucca Mountain. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows relationships among the reports developed for biosphere modeling and biosphere abstraction products for the TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (TWP) (BSC 2003 [163602]). Some documents in Figure 1-1 may be under development and not available when this report is issued. This figure provides an understanding of how this report contributes to biosphere modeling in support of the license application (LA), but access to the listed documents is not required to understand the contents of this report. This report is one of the reports that develops input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2003 [160699]) describes the conceptual model, the mathematical model, and the input parameters. The purpose of this analysis is to develop biosphere model parameter values related to radionuclide transport and accumulation in the environment. These parameters support calculations of radionuclide concentrations in the environmental media (e.g., soil, crops, animal products, and air) resulting from a given radionuclide concentration at the source of contamination (i.e., either in groundwater or volcanic ash). The analysis was performed in accordance with the TWP (BSC 2003 [163602]). This analysis develops values of parameters associated with many features, events, and processes (FEPs) applicable to the reference biosphere (DTN: M00303SEPFEPS2.000 [162452]), which are addressed in the biosphere model (BSC 2003 [160699]). The treatment of these FEPs is described in BSC (2003 [160699

Environmental Transport Input Parameters for the Biosphere Model

International Nuclear Information System (INIS)

Wasiolek, M. A.

2003-01-01

This analysis report is one of the technical reports documenting the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the geologic repository at Yucca Mountain. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows relationships among the reports developed for biosphere modeling and biosphere abstraction products for the TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (TWP) (BSC 2003 [163602]). Some documents in Figure 1-1 may be under development and not available when this report is issued. This figure provides an understanding of how this report contributes to biosphere modeling in support of the license application (LA), but access to the listed documents is not required to understand the contents of this report. This report is one of the reports that develops input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2003 [160699]) describes the conceptual model, the mathematical model, and the input parameters. The purpose of this analysis is to develop biosphere model parameter values related to radionuclide transport and accumulation in the environment. These parameters support calculations of radionuclide concentrations in the environmental media (e.g., soil, crops, animal products, and air) resulting from a given radionuclide concentration at the source of contamination (i.e., either in groundwater or volcanic ash). The analysis was performed in accordance with the TWP (BSC 2003 [163602]). This analysis develops values of parameters associated with many features, events, and processes (FEPs) applicable to the reference biosphere (DTN: M00303SEPFEPS2.000 [162452]), which are addressed in the biosphere model (BSC 2003 [160699]). The treatment of these FEPs is described in BSC (2003 [160699], Section 6.2). Parameter values

The Effect of Thermal Convection on Earth-Atmosphere CO2 Gas Exchange in Aggregated Soil

Science.gov (United States)

Ganot, Y.; Weisbrod, N.; Dragila, M. I.

2011-12-01

Gas transport in soils and surface-atmosphere gas exchange are important processes that affect different aspects of soil science such as soil aeration, nutrient bio-availability, sorption kinetics, soil and groundwater pollution and soil remediation. Diffusion and convection are the two main mechanisms that affect gas transport, fate and emissions in the soils and in the upper vadose zone. In this work we studied CO2 soil-atmosphere gas exchange under both day-time and night-time conditions, focusing on the impact of thermal convection (TCV) during the night. Experiments were performed in a climate-controlled laboratory. One meter long columns were packed with matrix of different grain size (sand, gravel and soil aggregates). Air with 2000 ppm CO2 was injected into the bottom of the columns and CO2 concentration within the columns was continuously monitored by an Infra Red Gas Analyzer. Two scenarios were compared for each soil: (1) isothermal conditions, representing day time conditions; and (2) thermal gradient conditions, i.e., atmosphere colder than the soil, representing night time conditions. Our results show that under isothermal conditions, diffusion is the major mechanism for surface-atmosphere gas exchange for all grain sizes; while under night time conditions the prevailing mechanism is dependent on the air permeability of the matrix: for sand and gravel it is diffusion, and for soil aggregates it is TCV. Calculated CO2 flux for the soil aggregates column shows that the TCV flux was three orders of magnitude higher than the diffusive flux.

Nominal Performance Biosphere Dose Conversion Factor Analysis

Energy Technology Data Exchange (ETDEWEB)

M.A. Wasiolek

2005-04-28

This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the groundwater exposure scenario, and the development of conversion factors for assessing compliance with the groundwater protection standards. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop BDCFs, which are input parameters for the TSPA-LA model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the ''Biosphere Model Report'' in Figure 1-1, contain detailed description of the model input parameters, their development, and the relationship between the parameters and specific features events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the groundwater exposure scenario. This analysis receives direct input from the outputs of the ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) and the five analyses that develop parameter values for the biosphere model (BSC 2005 [DIRS 172827]; BSC 2004 [DIRS 169672]; BSC 2004 [DIRS 169673]; BSC 2004 [DIRS 169458]; BSC 2004 [DIRS 169459]). The results of this report are further analyzed in the ''Biosphere Dose Conversion Factor Importance and Sensitivity Analysis

Earth applications of closed ecological systems: relevance to the development of sustainability in our global biosphere.

Science.gov (United States)

Nelson, M; Allen, J; Alling, A; Dempster, W F; Silverstone, S

2003-01-01

The parallels between the challenges facing bioregenerative life support in artificial closed ecological systems and those in our global biosphere are striking. At the scale of the current global technosphere and expanding human population, it is increasingly obvious that the biosphere can no longer safely buffer and absorb technogenic and anthropogenic pollutants. The loss of biodiversity, reliance on non-renewable natural resources, and conversion of once wild ecosystems for human use with attendant desertification/soil erosion, has led to a shift of consciousness and the widespread call for sustainability of human activities. For researchers working on bioregenerative life support in closed systems, the small volumes and faster cycling times than in the Earth's biosphere make it starkly clear that systems must be designed to ensure renewal of water and atmosphere, nutrient recycling, production of healthy food, and safe environmental methods of maintaining technical systems. The development of technical systems that can be fully integrated and supportive of living systems is a harbinger of new perspectives as well as technologies in the global environment. In addition, closed system bioregenerative life support offers opportunities for public education and consciousness changing of how to live with our global biosphere. c2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Using atmospheric CO2 data to assess a simplified carbon-climate simulation for the 20th century

International Nuclear Information System (INIS)

Law, Rachel M.; Kowalczyk, Eva A.; Wangs, Ying-Ping

2006-01-01

The CSIRO biosphere model has been coupled to an atmosphere model and a simulation has been performed for the 20th century. Both biosphere and atmosphere are forced with global CO 2 concentration and the atmosphere is also forced with prescribed sea surface temperatures. The simulation follows the C4MIP Phase 1 protocol. We assess the model simulation using atmospheric CO 2 data. Mauna Loa growth rate is well simulated from 1980 but overestimated before that time. The interannual variations in growth rate are reasonably reproduced. Seasonal cycles are underestimated in northern mid-latitudes and are out of phase in the southern hemisphere. The north-south gradient of annual mean CO 2 is substantially overestimated due to a northern hemisphere net biosphere source and a southern tropical sink. Diurnal cycles at three northern hemisphere locations are larger than observed in many months, most likely due to larger respiration than observed

Inhalation Exposure Input Parameters for the Biosphere Model

International Nuclear Information System (INIS)

M. A. Wasiolek

2003-01-01

This analysis is one of the nine reports that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN) biosphere model. The ''Biosphere Model Report'' (BSC 2003a) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents a set of input parameters for the biosphere model, and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for a Yucca Mountain repository. This report, ''Inhalation Exposure Input Parameters for the Biosphere Model'', is one of the five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the plan for development of the biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (BSC 2003b). It should be noted that some documents identified in Figure 1-1 may be under development at the time this report is issued and therefore not available at that time. This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and is not intended to imply that access to the listed documents is required to understand the contents of this analysis report. This analysis report defines and justifies values of mass loading, which is the total mass concentration of resuspended particles (e.g., dust, ash) in a volume of air. Measurements of mass loading are used in the air submodel of ERMYN to calculate concentrations of radionuclides in air surrounding crops and concentrations in air inhaled by a receptor. Concentrations in air to which the

Characteristics of the Receptor for the Biosphere Model

International Nuclear Information System (INIS)

M.A. Wasiolek

2005-01-01

This analysis report is one of a series of technical reports that document the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the geologic repository at Yucca Mountain. This report is one of the five biosphere reports that develop input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the conceptual model, as well as the mathematical model and its input parameters. Figure 1-1 is a graphical representation of the documentation hierarchy for the ERMYN. This figure shows relationships among the products (i.e., scientific analyses and model reports) developed for biosphere modeling and biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan for Biosphere Modeling and Expert Support'' (BSC 2005 [DIRS 172782]). The purpose of this analysis report is to define values for biosphere model parameters that are related to the dietary, lifestyle, and dosimetric characteristics of the receptor. The biosphere model, consistent with the licensing rule at 10 CFR Part 63 [DIRS 173164], uses a hypothetical person called the reasonably maximally exposed individual (RMEI) to represent the potentially exposed population. The parameters that define the RMEI are based on the behaviors and characteristics of the residents of the unincorporated town of Amargosa Valley, consistent with the requirements of 10 CFR 63.312 [DIRS 173164]. The output of this report is used as direct input in the two analyses identified in Figure 1-1 that calculate the values of biosphere dose conversion factors (BDCFs) for the groundwater and volcanic ash exposure scenarios. The parameter values developed in this report are reflected in the TSPA through the BDCFs. The analysis was performed in accordance with LP-SIII.9Q-BSC, ''Scientific Analyses'', and the technical work plan (BSC 2005 [DIRS 172782]). The scope of the revision was

Application of Atmospheric Pressure Photoionization H/D-exchange Mass Spectrometry for Speciation of Sulfur-containing Compounds.

Science.gov (United States)

Acter, Thamina; Kim, Donghwi; Ahmed, Arif; Ha, Ji-Hyoung; Kim, Sunghwan

2017-08-01

Herein we report the observation of atmospheric pressure in-source hydrogen-deuterium exchange (HDX) of thiol group for the first time. The HDX for thiol group was optimized for positive atmospheric pressure photoionization (APPI) mass spectrometry (MS). The optimized HDX-MS was applied for 31 model compounds (thiols, thiophenes, and sulfides) to demonstrate that exchanged peaks were observed only for thiols. The optimized method has been successfully applied to the isolated fractions of sulfur-rich oil samples. The exchange of one and two thiol hydrogens with deuterium was observed in the thiol fraction; no HDX was observed in the other fractions. Thus, the results presented in this study demonstrate that the HDX-MS method using APPI ionization source can be effective for speciation of sulfur compounds. This method has the potential to be used to access corrosion problems caused by thiol-containing compounds. Graphical Abstract ᅟ.

Characteristics of the Receptor for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

M. Wasiolek; K. Rautenstrauch

2004-09-09

This analysis report is one of a series of technical reports that document the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the geologic repository at Yucca Mountain. This report is one of the five biosphere reports that develop input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the conceptual model, as well as the mathematical model and its input parameters. Figure 1-1 is a graphical representation of the documentation hierarchy for the ERMYN. This figure shows relationships among the products (i.e., scientific analyses and model reports) developed for biosphere modeling and biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (BSC 2004 [DIRS 169573]). The purpose of this analysis report is to define values for biosphere model parameters that are related to the dietary, lifestyle, and dosimetric characteristics of the receptor. The biosphere model, consistent with the licensing rule at 10 CFR Part 63 [DIRS 156605], uses a hypothetical person called the reasonably maximally exposed individual (RMEI) to represent the potentially exposed population. The parameters that define the RMEI are based on the behaviors and characteristics of the residents of the unincorporated town of Amargosa Valley, consistent with the requirements of 10 CFR 63.312 [DIRS 156605]. The output of this report is used as direct input in the two analyses identified in Figure 1-1 that calculate the values of biosphere dose conversion factors (BDCFs) for the groundwater and volcanic ash exposure scenarios. The parameter values developed in this report are reflected in the TSPA through the BDCFs. The analysis was performed in accordance with AP-SIII.9Q, ''Scientific Analyses'', and the technical work

Interim report on reference biospheres for radioactive waste disposal

Energy Technology Data Exchange (ETDEWEB)

Dorp, F. van [NAGRA (Switzerland)] [and others

1994-10-01

Primary criteria for repository safety are commonly expressed in terms of risk or dose, and a biosphere model is required to evaluate the corresponding assessment endpoints. Even when other indicators are used to express the safety goals, a biosphere model is still needed in order to justify those indicators. In safety or performance assessments of a repository, the uncertainties in space and time for the different components of the repository system have to be considered. For the biosphere component, prediction of future human habits, in particular, is extremely uncertain. This is especially important in the assessment of deep geological disposal, which involves very long timescales, particularly for wastes containing very long lived radionuclides. Thus, the results of biosphere modelling should not be seen as predictions, but as illustrations of the consequences that may occur, should the postulated release occur today or under other conditions implied by the underlying biosphere model assumptions. Differences in biosphere modelling approaches arise because of differences in regulations, the nature of the wastes to be disposed of, disposal site characteristics, disposal concepts and purposes of the assessment. Differences in treatment of uncertainties can also arise. For example, if doses or risks are anticipated to be far below regulatory limits, assessments may be based upon simplified and, necessarily, conservative biosphere models. At present biosphere models used to assess radioactive waste disposal show significant differences in the features, events and processes (FEPs) included or excluded. In general, the reasons for these differences have not been well documented or explained. Developments in radioecology have implications for biosphere modelling for radioactive waste disposal. In particular, after the Chernobyl accident, radioecological research has been significantly increased. Results of this research are already having and will continue to have a

Interim report on reference biospheres for radioactive waste disposal

Energy Technology Data Exchange (ETDEWEB)

Dorp, F van [NAGRA (Switzerland); and others

1994-10-01

Primary criteria for repository safety are commonly expressed in terms of risk or dose, and a biosphere model is required to evaluate the corresponding assessment endpoints. Even when other indicators are used to express the safety goals, a biosphere model is still needed in order to justify those indicators. In safety or performance assessments of a repository, the uncertainties in space and time for the different components of the repository system have to be considered. For the biosphere component, prediction of future human habits, in particular, is extremely uncertain. This is especially important in the assessment of deep geological disposal, which involves very long timescales, particularly for wastes containing very long lived radionuclides. Thus, the results of biosphere modelling should not be seen as predictions, but as illustrations of the consequences that may occur, should the postulated release occur today or under other conditions implied by the underlying biosphere model assumptions. Differences in biosphere modelling approaches arise because of differences in regulations, the nature of the wastes to be disposed of, disposal site characteristics, disposal concepts and purposes of the assessment. Differences in treatment of uncertainties can also arise. For example, if doses or risks are anticipated to be far below regulatory limits, assessments may be based upon simplified and, necessarily, conservative biosphere models. At present biosphere models used to assess radioactive waste disposal show significant differences in the features, events and processes (FEPs) included or excluded. In general, the reasons for these differences have not been well documented or explained. Developments in radioecology have implications for biosphere modelling for radioactive waste disposal. In particular, after the Chernobyl accident, radioecological research has been significantly increased. Results of this research are already having and will continue to have a

Interim report on reference biospheres for radioactive waste disposal

International Nuclear Information System (INIS)

Dorp, F. van

1994-10-01

Primary criteria for repository safety are commonly expressed in terms of risk or dose, and a biosphere model is required to evaluate the corresponding assessment endpoints. Even when other indicators are used to express the safety goals, a biosphere model is still needed in order to justify those indicators. In safety or performance assessments of a repository, the uncertainties in space and time for the different components of the repository system have to be considered. For the biosphere component, prediction of future human habits, in particular, is extremely uncertain. This is especially important in the assessment of deep geological disposal, which involves very long timescales, particularly for wastes containing very long lived radionuclides. Thus, the results of biosphere modelling should not be seen as predictions, but as illustrations of the consequences that may occur, should the postulated release occur today or under other conditions implied by the underlying biosphere model assumptions. Differences in biosphere modelling approaches arise because of differences in regulations, the nature of the wastes to be disposed of, disposal site characteristics, disposal concepts and purposes of the assessment. Differences in treatment of uncertainties can also arise. For example, if doses or risks are anticipated to be far below regulatory limits, assessments may be based upon simplified and, necessarily, conservative biosphere models. At present biosphere models used to assess radioactive waste disposal show significant differences in the features, events and processes (FEPs) included or excluded. In general, the reasons for these differences have not been well documented or explained. Developments in radioecology have implications for biosphere modelling for radioactive waste disposal. In particular, after the Chernobyl accident, radioecological research has been significantly increased. Results of this research are already having and will continue to have a

The Biosphere as a Living System. On the Harmonization of Human and Biosphere Relationship

Directory of Open Access Journals (Sweden)

Alexey Yablokov

2017-02-01

Full Text Available The evolution of the biosphere has led to creation of astrophysical and telluric stable perfect system biotic regulation, which based on a high degree of closure of natural cycles. The development of human beings as bio-social, beyond the biological patterns, break these closed cycles, and dramatically broke the biotic regulation of the biosphere. As results — sustainable biosphere has become unsustainable anthroposphere. As with the origin of life physico-chemical regularities of the structure of matter turned out to be “mastered” life, as soon as with the emergence of anthroposphere physical-chemicalbiological regularities of evolution are complemented by social ones (including technology development and of the technosphere — as the essential content of anthroposphere. The result of the violation of natural biotic regulation broke a global environmental crisis that boomerang begins it is dangerous to human. It is theoretically possible to overcome this ecological crisis by the transition from the Neolithic paradigm of “nature conquest”, to the organization of “crisis management” of the biosphere (world system governance by the activity of the society restore and “repair” the damaged processes in the biosphere. This requires a new organization in all areas of human activity, i.e., a fundamentally new paradigm of human behavior on the planet. Development within the paradigm of the Neolithic culture (extensive use of natural resources, is inevitably associated with different kinds of wars in their redistribution, leads to an increasing accumulation of non-degradable waste (tertiary anthropogenic products, determines the fatal instability of anthroposphere and, therefore, unsustainable development of civilization. It is a mistake to assume that human’s dependence on nature is reduced — it takes a different form. The forces of human as an intelligence being, “recollecting himself”, about the offense with lifesupporting

Global biomass burning. Atmospheric, climatic, and biospheric implications

International Nuclear Information System (INIS)

Levine, J.S.

1991-01-01

Biomass burning is a significant source of atmospheric gases and, as such, may contribute to global climate changes. Biomass burning includes burning forests and savanna grasslands for land clearing, burning agricultural stubble and waste after harvesting, and burning biomass fuels. The chapters in this volume include the following topics: remote sensing of biomass burning from space;geographical distribution of burning; combustion products of burning in tropical, temperate and boreal ecosystems; burning as a global source of atmospheric gases and particulates; impacts of biomass burning gases and particulates on global climate; and the role of biomass burning on biodiversity and past global extinctions. A total of 1428 references are cited for the 63 chapters. Individual chapters are indexed separately for the data bases

Microbial activity in the marine deep biosphere: progress and prospects.

Science.gov (United States)

Orcutt, Beth N; Larowe, Douglas E; Biddle, Jennifer F; Colwell, Frederick S; Glazer, Brian T; Reese, Brandi Kiel; Kirkpatrick, John B; Lapham, Laura L; Mills, Heath J; Sylvan, Jason B; Wankel, Scott D; Wheat, C Geoff

2013-01-01

The vast marine deep biosphere consists of microbial habitats within sediment, pore waters, upper basaltic crust and the fluids that circulate throughout it. A wide range of temperature, pressure, pH, and electron donor and acceptor conditions exists-all of which can combine to affect carbon and nutrient cycling and result in gradients on spatial scales ranging from millimeters to kilometers. Diverse and mostly uncharacterized microorganisms live in these habitats, and potentially play a role in mediating global scale biogeochemical processes. Quantifying the rates at which microbial activity in the subsurface occurs is a challenging endeavor, yet developing an understanding of these rates is essential to determine the impact of subsurface life on Earth's global biogeochemical cycles, and for understanding how microorganisms in these "extreme" environments survive (or even thrive). Here, we synthesize recent advances and discoveries pertaining to microbial activity in the marine deep subsurface, and we highlight topics about which there is still little understanding and suggest potential paths forward to address them. This publication is the result of a workshop held in August 2012 by the NSF-funded Center for Dark Energy Biosphere Investigations (C-DEBI) "theme team" on microbial activity (www.darkenergybiosphere.org).

Atmospheric Profiles of Carbon Dioxide Obtained with a UAS: Constraints on Square Kilometre Scale Carbon Budgets

Science.gov (United States)

Kunz, M.; Lavric, J. V.; Grant, R. H.; Gerbig, C.; Heimann, M.; Flatt, J. E.; Zeeman, M. J.; Wolf, B.

2016-12-01

The exchange of carbon between biosphere and atmosphere is a topic of high interest, particularly because the magnitude of biospheric climate feedback is uncertain. Soil chambers and eddy covariance systems, the traditional tools for the measurement of exchange fluxes, are subject to inherent limitations: chambers cover only small areas of typically less than on square meter, and eddy covariance is not applicable under very low wind conditions. Complementary methods can help to deal with these limitations and provide more confidence in up-scaling. During the ScaleX 2016 campaign an ecosystem was studied with a combination of multiple measurement approaches, including soil chambers, an eddy covariance station, a weather station, quasi-continuous CO2 measurements on a 10 m tower, multiple UAS with different sensors and remote sensing of temperature, humidity and wind profiles. The campaign took place at Fendt in Southern Germany on a flat valley floor covered by grass. We deployed COCAP, a compact carbon dioxide analyser for airborne platforms developed at the Max Planck Institute for Biogeochemistry in Jena, on a commercial multicopter (DJI S1000). COCAP measures carbon dioxide dry air mole fraction to an accuracy of 2 ppm as well as ambient pressure, temperature and relative humidity. At a total mass of 1 kg it contains a GPS receiver, on-board data logging capabilities and a radio transmitter which allows for real-time data visualisation on a ground station computer. In consecutive vertical profile measurements at night-time, reaching up to a maximum height of 150 m, we see a strong build-up of CO2 close to the ground which we attribute to exchange fluxes from the surface into the atmosphere that are trapped below a nocturnal inversion. We estimate these fluxes from the change in observed column amount of CO2 over time and compare our results to other methods. Challenges in the measurement and data analysis as well as the influence of wind, rotor downwash and

Biosphere 2 test module experimentation program

Science.gov (United States)

Alling, Abigail; Leigh, Linda S.; Maccallum, Taber; Alvarez-Romo, Norberto

1990-01-01

The Biosphere 2 Test Module is a facility which has the capability to do either short or long term closures: five month closures with plants were conducted. Also conducted were investigations of specific problems, such as trace gas purification by bioregenerative systems by in-putting a fixed concentration of a gas and observing its uptake over time. In other Test Module experiments, the concentration of one gas was changed to observe what effects this has on other gases present or on the system. The science of biospherics which encompasses the study of closed biological systems provides an opening into the future in space as well as in the Earth's biosphere.

Agricultural and Environmental Input Parameters for the Biosphere Model

International Nuclear Information System (INIS)

Kaylie Rasmuson; Kurt Rautenstrauch

2003-01-01

This analysis is one of nine technical reports that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN) biosphere model. It documents input parameters for the biosphere model, and supports the use of the model to develop Biosphere Dose Conversion Factors (BDCF). The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for the repository at Yucca Mountain. The ERMYN provides the TSPA with the capability to perform dose assessments. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships between the major activities and their products (the analysis and model reports) that were planned in the biosphere Technical Work Plan (TWP, BSC 2003a). It should be noted that some documents identified in Figure 1-1 may be under development and therefore not available at the time this document is issued. The ''Biosphere Model Report'' (BSC 2003b) describes the ERMYN and its input parameters. This analysis report, ANL-MGR-MD-000006, ''Agricultural and Environmental Input Parameters for the Biosphere Model'', is one of the five reports that develop input parameters for the biosphere model. This report defines and justifies values for twelve parameters required in the biosphere model. These parameters are related to use of contaminated groundwater to grow crops. The parameter values recommended in this report are used in the soil, plant, and carbon-14 submodels of the ERMYN

Nominal Performance Biosphere Dose Conversion Factor Analysis

Energy Technology Data Exchange (ETDEWEB)

M.A. Wasiolek

2003-07-25

This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the groundwater exposure scenario, and the development of conversion factors for assessing compliance with the groundwater protection standard. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop biosphere BDCFs, which are input parameters for the TSPA model. The ''Biosphere Model Report'' (BSC 2003 [DIRS 164186]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports (BSC 2003 [DIRS 160964]; BSC 2003 [DIRS 160965]; BSC 2003 [DIRS 160976]; BSC 2003 [DIRS 161239]; BSC 2003 [DIRS 161241]) contain detailed description of the model input parameters. This report describes biosphere model calculations and their output, the BDCFs, for the groundwater exposure scenario. The objectives of this analysis are to develop BDCFs and conversion factors for the TSPA. The BDCFs will be used in performance assessment for calculating annual doses for a given concentration of radionuclides in groundwater. The conversion factors will be used for calculating gross alpha particle activity in groundwater and the annual dose from beta- and photon-emitting radionuclides.

Validation of a new device to quantify groundwater-surface water exchange

Science.gov (United States)

Cremeans, Mackenzie M.; Devlin, J. F.

2017-11-01

Distributions of flow across the groundwater-surface water interface should be expected to be as complex as the geologic deposits associated with stream or lake beds and their underlying aquifers. In these environments, the conventional Darcy-based method of characterizing flow systems (near streams) has significant limitations, including reliance on parameters with high uncertainties (e.g., hydraulic conductivity), the common use of drilled wells in the case of streambank investigations, and potentially lengthy measurement times for aquifer characterization and water level measurements. Less logistically demanding tools for quantifying exchanges across streambeds have been developed and include drive-point mini-piezometers, seepage meters, and temperature profiling tools. This project adds to that toolbox by introducing the Streambed Point Velocity Probe (SBPVP), a reusable tool designed to quantify groundwater-surface water interactions (GWSWI) at the interface with high density sampling, which can effectively, rapidly, and accurately complement conventional methods. The SBPVP is a direct push device that measures in situ water velocities at the GWSWI with a small-scale tracer test on the probe surface. Tracer tests do not rely on hydraulic conductivity or gradient information, nor do they require long equilibration times. Laboratory testing indicated that the SBPVP has an average accuracy of ± 3% and an average precision of ± 2%. Preliminary field testing, conducted in the Grindsted Å in Jutland, Denmark, yielded promising agreement between groundwater fluxes determined by conventional methods and those estimated from the SBPVP tests executed at similar scales. These results suggest the SBPVP is a viable tool to quantify groundwater-surface water interactions in high definition in sandy streambeds.

Nominal Performance Biosphere Dose Conversion Factor Analysis

Energy Technology Data Exchange (ETDEWEB)

M. Wasiolek

2004-09-08

This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the groundwater exposure scenario, and the development of conversion factors for assessing compliance with the groundwater protection standard. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop biosphere BDCFs, which are input parameters for the TSPA-LA model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the ''Biosphere Model Report'' in Figure 1-1, contain detailed description of the model input parameters, their development, and the relationship between the parameters and specific features events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the groundwater exposure scenario. The objectives of this analysis are to develop BDCFs for the groundwater exposure scenario for the three climate states considered in the TSPA-LA as well as conversion factors for evaluating compliance with the groundwater protection standard. The BDCFs will be used in performance assessment for calculating all-pathway annual doses for a given concentration of radionuclides in groundwater. The conversion factors will be used for calculating gross alpha particle

Nominal Performance Biosphere Dose Conversion Factor Analysis

International Nuclear Information System (INIS)

M. Wasiolek

2004-01-01

This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the groundwater exposure scenario, and the development of conversion factors for assessing compliance with the groundwater protection standard. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop biosphere BDCFs, which are input parameters for the TSPA-LA model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the ''Biosphere Model Report'' in Figure 1-1, contain detailed description of the model input parameters, their development, and the relationship between the parameters and specific features events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the groundwater exposure scenario. The objectives of this analysis are to develop BDCFs for the groundwater exposure scenario for the three climate states considered in the TSPA-LA as well as conversion factors for evaluating compliance with the groundwater protection standard. The BDCFs will be used in performance assessment for calculating all-pathway annual doses for a given concentration of radionuclides in groundwater. The conversion factors will be used for calculating gross alpha particle activity in groundwater and the annual dose

Biosphere modelling for the assessment of radioactive waste repositories: the development of a common basis by the BIOMOVS II working group on reference biospheres

International Nuclear Information System (INIS)

VanDorp, F.

1996-01-01

Performance criteria for radioactive waste repositories are often expressed in terms of dose or risk. The characteristics of biosphere modelling for performance assessment are that: a) potential release occurs in the distant future, b) reliable predictions of human behaviour at the time of release are impracticable, and c) the biosphere is not considered to be a barrier. For these and other reasons, many unexplained differences have arisen in the approaches to biosphere modelling. The BIOMOVS II Working Group on Reference Biospheres has developed a) a recommended methodology for biosphere model development, b) a structured electronic list of features, events and processes (FEPs), and c) an illustrative example of the recommended methodology. The Working Group has successfully tested the Interaction Matrix (or Rock Engineering Systems, RES) approach for developing conceptual models. The BIOMOVS II Working Groups on Reference Biospheres and Complementary Studies have achieved considerable harmonisation in approaches to biosphere modelling. (author)

Impact of a global warming on biospheric sources of methane and its climatic consequences

Science.gov (United States)

Hameed, S.; Cess, R. D.

1980-01-01

Most of atmospheric methane originates by bacterial processes in anaerobic environments within the soil which are found to become more productive with increases in ambient temperature. A warming of climate, due to increasing levels of industrial gases resulting from fossil fuel burning, is thus likely to increase methane abundance within the atmosphere. This may lead to further heating of the atmosphere, since both methane and ozone (which is generated in the troposphere from reactions of methane) have greenhouse effects. This feedback mechanism has been explored with the use of a coupled climate-chemical model of the troposphere, by the calculation of the impact of the predicted global warming due to increased emissions of carbon dioxide and other industrial gases on the biospheric sources of methane.

Zhamanshin astrobleme provides evidence for carbonaceous chondrite and post-impact exchange between ejecta and Earth's atmosphere.

Science.gov (United States)

Magna, Tomáš; Žák, Karel; Pack, Andreas; Moynier, Frédéric; Mougel, Bérengère; Peters, Stefan; Skála, Roman; Jonášová, Šárka; Mizera, Jiří; Řanda, Zdeněk

2017-08-09

Chemical fingerprints of impacts are usually compromised by extreme conditions in the impact plume, and the contribution of projectile matter to impactites does not often exceed a fraction of per cent. Here we use chromium and oxygen isotopes to identify the impactor and impact-plume processes for Zhamanshin astrobleme, Kazakhstan. ε 54 Cr values up to 1.54 in irghizites, part of the fallback ejecta, represent the 54 Cr-rich extremity of the Solar System range and suggest a CI-like chondrite impactor. Δ 17 O values as low as -0.22‰ in irghizites, however, are incompatible with a CI-like impactor. We suggest that the observed 17 O depletion in irghizites relative to the terrestrial range is caused by partial isotope exchange with atmospheric oxygen (Δ 17 O = -0.47‰) following material ejection. In contrast, combined Δ 17 O-ε 54 Cr data for central European tektites (distal ejecta) fall into the terrestrial range and neither impactor fingerprint nor oxygen isotope exchange with the atmosphere are indicated.Identifying the original impactor from craters remains challenging. Here, the authors use chromium and oxygen isotopes to indicate that the Zhamanshin astrobleme impactor was a carbonaceous chrondrite by demonstrating that depleted 17O values are due to exchange with atmospheric oxygen.

Inhalation Exposure Input Parameters for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

M. A. Wasiolek

2003-09-24

This analysis is one of the nine reports that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN) biosphere model. The ''Biosphere Model Report'' (BSC 2003a) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents a set of input parameters for the biosphere model, and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for a Yucca Mountain repository. This report, ''Inhalation Exposure Input Parameters for the Biosphere Model'', is one of the five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the plan for development of the biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan: for Biosphere Modeling and Expert Support'' (BSC 2003b). It should be noted that some documents identified in Figure 1-1 may be under development at the time this report is issued and therefore not available at that time. This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and is not intended to imply that access to the listed documents is required to understand the contents of this analysis report. This analysis report defines and justifies values of mass loading, which is the total mass concentration of resuspended particles (e.g., dust, ash) in a volume of air. Measurements of mass loading are used in the air submodel of ERMYN to calculate concentrations of radionuclides in air surrounding crops and concentrations in air

Characteristics of the Receptor for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

M.A. Wasiolek

2005-04-05

This analysis report is one of a series of technical reports that document the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the geologic repository at Yucca Mountain. This report is one of the five biosphere reports that develop input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the conceptual model, as well as the mathematical model and its input parameters. Figure 1-1 is a graphical representation of the documentation hierarchy for the ERMYN. This figure shows relationships among the products (i.e., scientific analyses and model reports) developed for biosphere modeling and biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan for Biosphere Modeling and Expert Support'' (BSC 2005 [DIRS 172782]). The purpose of this analysis report is to define values for biosphere model parameters that are related to the dietary, lifestyle, and dosimetric characteristics of the receptor. The biosphere model, consistent with the licensing rule at 10 CFR Part 63 [DIRS 173164], uses a hypothetical person called the reasonably maximally exposed individual (RMEI) to represent the potentially exposed population. The parameters that define the RMEI are based on the behaviors and characteristics of the residents of the unincorporated town of Amargosa Valley, consistent with the requirements of 10 CFR 63.312 [DIRS 173164]. The output of this report is used as direct input in the two analyses identified in Figure 1-1 that calculate the values of biosphere dose conversion factors (BDCFs) for the groundwater and volcanic ash exposure scenarios. The parameter values developed in this report are reflected in the TSPA through the BDCFs. The analysis was performed in accordance with LP-SIII.9Q-BSC, ''Scientific Analyses'', and the technical work

Biosphere Reserve for All: Potentials for Involving Underrepresented Age Groups in the Development of a Biosphere Reserve through Intergenerational Practice.

Science.gov (United States)

Mitrofanenko, Tamara; Snajdr, Julia; Muhar, Andreas; Penker, Marianne; Schauppenlehner-Kloyber, Elisabeth

2018-05-22

Stakeholder participation is of high importance in UNESCO biosphere reserves as model regions for sustainable development; however, certain groups remain underrepresented. The paper proposes Intergenerational Practice (IP) as a means of involving youth and elderly women and explores its options and barriers, using the example of the Salzburger Lungau and Kärntner Nockberge Biosphere Reserve in Austria. Case study analysis is used involving mixed methods. The results reveal obstacles and motivations to participating in biosphere reserve implementation and intergenerational activities for the youth and the elderly women and imply that much potential for IP exists in the biosphere reserve region. The authors propose suitable solutions from the intergenerational field to overcome identified participation obstacles and suggest benefits of incorporating IP as a management tool into biosphere reserve activities. Suggestions for future research include evaluating applications of IP in the context of protected areas, testing of methods used in other contexts, and contribution to theory development.

Biosphere modelling for the assessment of radioactive waste repositories; the development of a common basis by the BIOMOVS II reference biospheres working group

International Nuclear Information System (INIS)

Dorp, F. van; Egan, M.; Kessler, J.H.; Nilsson, S.; Pinedo, P.; Smith, G.; Torres, C.

1998-01-01

Performance criteria for radioactive waste repositories are often expressed in terms of dose or risk. The characteristics of biosphere modelling for performance assessment are that: (a) potential release occurs in the distant future, (b) reliable predictions of human behaviour at the time of release are impracticable, and (c) the biosphere is not considered to be a barrier as the geosphere and the engineered barriers. For these and other reasons, differences have arisen in the approaches to biosphere modelling for repository dose and risk assessment. The BIOMOVS II Reference Biospheres Working Group has developed (a) a recommended methodology for biosphere model development, (b) a structured list of features, events and processes (FEPs) which the model should describe, and (c) an illustrative example of the recommended methodology. The Working Group has successfully tested the Interaction Matrix (or Rock Engineering Systems, RES) approach for developing conceptual models. The BIOMOVS II Working Groups on Reference Biospheres and Complementary Studies have laid the basis for considerable harmonisation in approaches to biosphere modelling of long term radionuclide releases. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Soil-Related Input Parameters for the Biosphere Model

International Nuclear Information System (INIS)

Smith, A. J.

2004-01-01

This report presents one of the analyses that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN). The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the details of the conceptual model as well as the mathematical model and the required input parameters. The biosphere model is one of a series of process models supporting the postclosure Total System Performance Assessment (TSPA) for the Yucca Mountain repository. A schematic representation of the documentation flow for the Biosphere input to TSPA is presented in Figure 1-1. This figure shows the evolutionary relationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan for Biosphere Modeling and Expert Support'' (TWP) (BSC 2004 [DIRS 169573]). This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and is not intended to imply that access to the listed documents is required to understand the contents of this report. This report, ''Soil-Related Input Parameters for the Biosphere Model'', is one of the five analysis reports that develop input parameters for use in the ERMYN model. This report is the source documentation for the six biosphere parameters identified in Table 1-1. The purpose of this analysis was to develop the biosphere model parameters associated with the accumulation and depletion of radionuclides in the soil. These parameters support the calculation of radionuclide concentrations in soil from on-going irrigation or ash deposition and, as a direct consequence, radionuclide concentration in other environmental media that are affected by radionuclide concentrations in soil. The analysis was performed in accordance with the TWP (BSC 2004 [DIRS 169573]) where the governing procedure was defined as AP-SIII.9Q, ''Scientific Analyses''. This

HTO deposition through gas exchange between soil and atmosphere

International Nuclear Information System (INIS)

Feinhals, J.

1988-06-01

Theoretical considerations show that the ratio of HTO/H 2 O molecules, i.e. the specific activity, is not the same in atmospheric humidity and moisture absorption but differs by the so-called specific activity coefficient k. On this basis a computer model (ATHOS) was developed which allowed the calculation of both the surface contamination of the soil due to the gas exchange with a contaminated atmosphere and the depth-specific distribution of the soil acitvity. On the one hand the equations base on a modified Philip-de Vries theory, and on the other hand on a large number of soil column experiments which served the examination of the influence of parameters of microclimate and soil physics on the absorption and diffusion of tritiated water vapour under simulated conditions Above all the individual capability of each soil type to absorb moisture must be taken into consideration in connection with the HTO transfer. In this context theoretical and experimental examinations were carried out indicating a practice-related possibility to determine the soil-specific absorption capability. (orig./DG) [de

Posiva biosphere assessment: Revised structure and status 2006

International Nuclear Information System (INIS)

Ikonen, A.

2006-12-01

Posiva's Safety Case is organised into a portfolio consisting of ten main component reports of which the Biosphere Assessment is one. To better facilitate the iterative assessment process by different task groups, the Biosphere Assessment is now organised into a sub-portfolio having folders for reports on specific topics: Site and evolution describes the past, present and future conditions of the surface system of the Olkiluoto site; Biosphere processes contain descriptions of processes prevailing at the site now and in future; Module Descriptions document the radionuclide transport models; Biosphere Assessment Data reports the parameter data used in the assessment with full references to their origin; Cases and variants provide mainly the simulated concentrations in the environmental media as a part of the actual assessment; Exposures of total environment draw conclusions on the dose and effect implications on the basis of the concentrations provided in Cases and variants. Finally, the biosphere assessment is consolidated in the summary report providing the needed high-level information to the main Safety Case and referring to the individual background reports for the details. In addition to the specific folders of the Biosphere Assessment Portfolio, there are also a number of overlapping issues to be considered throughout the assessment. Most important of those are the handling of the geosphere-biosphere interface and the future human activities, and the thorough knowledge quality assessment, the last of which provides tools to evaluate the overall uncertainty and consistency of and confidence to the assessment. In this report, the current strategy of modelling the different aspects of the biosphere from the site investigations to the doses is discussed, and the Biosphere Assessment Portfolio is introduced. Requirements and recommendations are given to the individual folders and/or reports to steer the extensive biosphere modelling and assessment work towards a

The Sword of Damocles and the Biosphere

OpenAIRE

Cairns, John

2011-01-01

The tale of the sword of Damocles can be used to describe the sword hanging by a thread over humankind with the damage it is doing to the present biosphere. The sixth biosphere, or the current biosphere, is experiencing a significant reduction in species caused by human-related activities. The signs of risk have markedly increased by the signs differ considerably from one are to another, and people tend do discount global change because it is unnoticeable in their local area. If humans begin...

A Biosphere model for use in SITE-94

International Nuclear Information System (INIS)

Barrdahl, R.

1996-08-01

A simple biosphere model has been designed for use in the SKI Project SITE-94 related to a hypothetical repository for spent nuclear fuel on the island of Aespoe. The model provides results in terms of radiation dose per 1 Bq/year, unless otherwise indicated, and results will thus have to be scaled with actual flux of radionuclides per year entering the primary biosphere recipients. The model does not include radioactive decay as there is assumed no delay in the model system, except for where explicitly mentioned. Specifically, no radioactive transitions resulting in daughter nuclides are considered. Calculated yearly individual and population committed (50 years) radiation doses to man are expressed as mSv/h, under the assumption of a flux of one Bq/year into the primary biosphere recipient. Calculated radiation doses resulting from the present biosphere model are hypothetical, and should under no circumstances be considered as real. Neither should they be used as quantitative information for decision purposes. The biosphere model is of a rough and primitive character and its precision, relative to the real biosphere in the surroundings of Aespoe is envisaged to be several orders of magnitude. 8 refs

Agricultural and Environmental Input Parameters for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

Kaylie Rasmuson; Kurt Rautenstrauch

2003-06-20

This analysis is one of nine technical reports that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN) biosphere model. It documents input parameters for the biosphere model, and supports the use of the model to develop Biosphere Dose Conversion Factors (BDCF). The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for the repository at Yucca Mountain. The ERMYN provides the TSPA with the capability to perform dose assessments. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships between the major activities and their products (the analysis and model reports) that were planned in the biosphere Technical Work Plan (TWP, BSC 2003a). It should be noted that some documents identified in Figure 1-1 may be under development and therefore not available at the time this document is issued. The ''Biosphere Model Report'' (BSC 2003b) describes the ERMYN and its input parameters. This analysis report, ANL-MGR-MD-000006, ''Agricultural and Environmental Input Parameters for the Biosphere Model'', is one of the five reports that develop input parameters for the biosphere model. This report defines and justifies values for twelve parameters required in the biosphere model. These parameters are related to use of contaminated groundwater to grow crops. The parameter values recommended in this report are used in the soil, plant, and carbon-14 submodels of the ERMYN.

Exchange of nitrogen dioxide (NO2) between plants and the atmosphere under laboratory and field conditions

Science.gov (United States)

Breuninger, C.; Meixner, F. X.; Thielmann, A.; Kuhn, U.; Dindorf, T.; Kesselmeier, J.

2012-04-01

Nitric oxide (NO), nitrogen dioxide (NO2), often denoted as nitrogen oxides (NOx), and ozone (O3) are considered as most important compounds in atmospheric chemistry. In remote areas NOx concentration is related to biological activities of soils and vegetation. The emitted NOx will not entirely be subject of long range transport through the atmosphere. Aside oxidation of NO2 by the OH radical (forming HNO3), a considerable part of it is removed from the atmosphere through the uptake of NO2 by plants. The exchange depends on stomatal activity and on NO2 concentrations in ambient air. It is known that NO2 uptake by plants represents a large NO2 sink, but the magnitude and the NO2 compensation point concentration are still under discussion. Our dynamic chamber system allows exchange measurements of NO2 under field conditions (uncontrolled) as well as studies under controlled laboratory conditions including fumigation experiments. For NO2 detection we used a highly NO2 specific blue light converter (photolytic converter) with subsequent chemiluminescence analysis of the generated NO. Furthermore, as the exchange of NO2 is a complex interaction of transport, chemistry and plant physiology, in our field experiments we determined fluxes of NO, NO2, O3, CO2 and H2O. For a better knowledge of compensation point values for the bi-directional NO2 exchange we investigated a primary representative of conifers, Picea abies, under field and laboratory conditions, and re-analyzed older field data of the deciduous tree Quercus robur.

The IAEA Biomass programme: reference biospheres for long-term safety assessment of high level waste disposal facilities

International Nuclear Information System (INIS)

Metcalf, Phil; Crossland, Ian; Torres, Carlos; Crossland, Ian J.

2002-01-01

Phil Metcalf and Ian Crossland presented the IAEA Biomass project. Phil Metcalf explained that the Biomass project, begun in 1996, by an international forum organised by the IAEA was a very good exercise for exchanging information through technical meetings and documentation such as Biomass newsletters or CD Rom. Ian Crossland continued by giving a presentation of the Biomass theme 1 that concerns the radioactive waste disposal topic. Its objective was mainly to develop the reference biosphere methodology and to demonstrate its usefulness through some exercises related to the development of a practical set of example biospheres such as: 1. drinking water well, 2. agricultural irrigation, with a well source and 3. Set of natural groundwater discharges to natural, semi-natural systems. Input data would always change to accommodate a given repository simulation and location. Thus this project must be seen as a good exercise for the application of a methodology and should be considered as a good source of reference biospheres that might be viewed as a benchmark for comparison with site-specific safety assessments for a selected number of radionuclides. The main conclusion from the Biomass theme 1 project was that there appears to be an international consensus on preparing generic reference biospheres for postclosure safety assessment but waste management organisations should also consider the specific requirements of regulators and other stakeholders

Post-closure biosphere assessment modelling: comparison of complex and more stylised approaches

Energy Technology Data Exchange (ETDEWEB)

Walke, Russell C. [Quintessa Limited, The Hub, 14 Station Road, Henley-on-Thames (United Kingdom); Kirchner, Gerald [University of Hamburg, ZNF, Beim Schlump 83, 20144 Hamburg (Germany); Xu, Shulan; Dverstorp, Bjoern [Swedish Radiation Safety Authority, SE-171 16 Stockholm (Sweden)

2014-07-01

to the biosphere. Some radionuclides do not reach equilibrium within the time frame that the biosphere evolves at the Forsmark site, making associated dose factors sensitive to time scales assumed for biosphere evolution. Comparison of the results generated by both types of model demonstrates that, for areas that evolve from marine, through lakes and mires to terrestrial systems with organic soils, the approach adopted in SKB's model is conservative. However, higher dose factors are possible when potential for long-term irrigation with shallow groundwater is considered. Surveys of groundwater wells in the Forsmark area today show that some shallow groundwater is used to water plants, which demonstrates that small scale irrigation from such sources cannot be ruled out for present-day or warmer climate states. Complex models use more of the available site-specific information and contribute to an understanding of complex process interactions and effects of system heterogeneity. The study shows, however, that simple 'reference' biosphere models enable processes that control potential radionuclide impacts to be identified, taking into account climate variability. They help to build understanding and confidence in more complex modelling approaches, quantify the conservatisms involved and remain a valuable tool for nuclear waste disposal licensing procedures. (authors)

A Pilot Study to Evaluate California's Fossil Fuel CO2 Emissions Using Atmospheric Observations

Science.gov (United States)

Graven, H. D.; Fischer, M. L.; Lueker, T.; Guilderson, T.; Brophy, K. J.; Keeling, R. F.; Arnold, T.; Bambha, R.; Callahan, W.; Campbell, J. E.; Cui, X.; Frankenberg, C.; Hsu, Y.; Iraci, L. T.; Jeong, S.; Kim, J.; LaFranchi, B. W.; Lehman, S.; Manning, A.; Michelsen, H. A.; Miller, J. B.; Newman, S.; Paplawsky, B.; Parazoo, N.; Sloop, C.; Walker, S.; Whelan, M.; Wunch, D.

2016-12-01

Atmospheric CO2 concentration is influenced by human activities and by natural exchanges. Studies of CO2 fluxes using atmospheric CO2 measurements typically focus on natural exchanges and assume that CO2 emissions by fossil fuel combustion and cement production are well-known from inventory estimates. However, atmospheric observation-based or "top-down" studies could potentially provide independent methods for evaluating fossil fuel CO2 emissions, in support of policies to reduce greenhouse gas emissions and mitigate climate change. Observation-based estimates of fossil fuel-derived CO2 may also improve estimates of biospheric CO2 exchange, which could help to characterize carbon storage and climate change mitigation by terrestrial ecosystems. We have been developing a top-down framework for estimating fossil fuel CO2 emissions in California that uses atmospheric observations and modeling. California is implementing the "Global Warming Solutions Act of 2006" to reduce total greenhouse gas emissions to 1990 levels by 2020, and it has a diverse array of ecosystems that may serve as CO2 sources or sinks. We performed three month-long field campaigns in different seasons in 2014-15 to collect flask samples from a state-wide network of 10 towers. Using measurements of radiocarbon in CO2, we estimate the fossil fuel-derived CO2 present in the flask samples, relative to marine background air observed at coastal sites. Radiocarbon (14C) is not present in fossil fuel-derived CO2 because of radioactive decay over millions of years, so fossil fuel emissions cause a measurable decrease in the 14C/C ratio in atmospheric CO2. We compare the observations of fossil fuel-derived CO2 to simulations based on atmospheric modeling and published fossil fuel flux estimates, and adjust the fossil fuel flux estimates in a statistical inversion that takes account of several uncertainties. We will present the results of the top-down technique to estimate fossil fuel emissions for our field

Agricultural and Environmental Input Parameters for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

K. Rasmuson; K. Rautenstrauch

2004-09-14

This analysis is one of 10 technical reports that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN) (i.e., the biosphere model). It documents development of agricultural and environmental input parameters for the biosphere model, and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for the repository at Yucca Mountain. The ERMYN provides the TSPA with the capability to perform dose assessments. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships between the major activities and their products (the analysis and model reports) that were planned in ''Technical Work Plan for Biosphere Modeling and Expert Support'' (BSC 2004 [DIRS 169573]). The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the ERMYN and its input parameters.

Agricultural and Environmental Input Parameters for the Biosphere Model

International Nuclear Information System (INIS)

K. Rasmuson; K. Rautenstrauch

2004-01-01

This analysis is one of 10 technical reports that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN) (i.e., the biosphere model). It documents development of agricultural and environmental input parameters for the biosphere model, and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for the repository at Yucca Mountain. The ERMYN provides the TSPA with the capability to perform dose assessments. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships between the major activities and their products (the analysis and model reports) that were planned in ''Technical Work Plan for Biosphere Modeling and Expert Support'' (BSC 2004 [DIRS 169573]). The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the ERMYN and its input parameters

Modelling the environmental transport of tritium in the vicinity of long term atmospheric and sub-surface sources. Report of the Tritium Working Group of the Biosphere Modelling and Assessment (BIOMASS) Programme, Theme 3

International Nuclear Information System (INIS)

2003-03-01

The IAEA Programme on BIOsphere Modelling and ASSessment (BIOMASS) was launched in Vienna in October 1996. The programme was concerned with developing and improving capabilities to predict the transfer of radionuclides in the environment. The programme had three themes: Theme 1: Radioactive Waste Disposal. The objective was to develop the concept of a standard or reference biosphere for application to the assessment of the long term safety of repositories for radioactive waste. Theme 2: Environmental Releases. BIOMASS provided an international forum for activities aimed at increasing the confidence in methods and models for the assessment of radiation exposure related to environmental releases. Two Working Groups addressed issues concerned with the reconstruction of radiation doses received by people from past releases of radionuclides to the environment and the evaluation of the efficacy of remedial measures. Theme 3: Biosphere Processes. The aim of this Theme was to improve capabilities for modelling the transfer of radionuclides in particular parts of the biosphere identified as being of potential radiological significance and where there were gaps in modelling approaches. This topic was explored using a range of methods including reviews of the literature, model inter-comparison exercises and, where possible, model testing against independent sources of data. Three Working Groups were established to examine the modelling of: (1) long term tritium dispersion in the environment; (2) radionuclide uptake by fruits; and (3) radionuclide migration and accumulation in forest ecosystems. This report describes results of the studies undertaken by the Tritium Working Group under Theme 3. It discusses the six model test exercises (three model-model intercomparisons and three model-data exercises) and the twenty-month field sampling programme undertaken to investigate the environmental transport of tritium in the vicinity of long term atmospheric and sub-surface sources

A Scientific Assessment of the Atmospheric Impact of a Nuclear Exchange

Science.gov (United States)

Reisner, J. M.

2016-12-01

A nuclear exchange at either the regional or global scale will unfortunately lead to large loss of life; however, given the consequences it is important to scientifically quantify this problem and not over exaggerate impacts. Over the past 70 years Los Alamos has been developing the necessary expertize to quantify effects from nuclear weapons. In particular, the rapid advancement of computing power has enabled model calculations over a wide range of spatial and time scales from the source to cdimpacts. In this presentation, results from each scale will be presented along with discussions regarding the importance of the linkage between each scale. For example, source calculations are important for defining the spatial region where the weapon can start potential fires; a consequence of the thermal fluence, rubblization, and other factors such as cloud cover. This information is then used in a first principle urban firestorm model that simulates the production of carbon particles responsible for possible blockage of incoming solar radiation--the so-called nuclear winter mechanism. Hence, the critical piece of this puzzle is the overall carbon footprint that could lead to regional/global cooling; assuming either too much carbon and/or all carbon is transported into the stratosphere will lead to unrealistic estimates of cooling. And finally, another important aspect to be shown in this presentation is how a realistic source of carbon could lead to significant reductions in long-term regional/global impacts of a nuclear exchange.

Quantifying atmospheric transport, chemistry, and mixing using a new trajectory-box model and a global atmospheric-chemistry GCM

Directory of Open Access Journals (Sweden)

H. Riede

2009-12-01

Full Text Available We present a novel method for the quantification of transport, chemistry, and mixing along atmospheric trajectories based on a consistent model hierarchy. The hierarchy consists of the new atmospheric-chemistry trajectory-box model CAABA/MJT and the three-dimensional (3-D global ECHAM/MESSy atmospheric-chemistry (EMAC general circulation model. CAABA/MJT employs the atmospheric box model CAABA in a configuration using the atmospheric-chemistry submodel MECCA (M, the photochemistry submodel JVAL (J, and the new trajectory submodel TRAJECT (T, to simulate chemistry along atmospheric trajectories, which are provided offline. With the same chemistry submodels coupled to the 3-D EMAC model and consistent initial conditions and physical parameters, a unique consistency between the two models is achieved. Since only mixing processes within the 3-D model are excluded from the model consistency, comparisons of results from the two models allow to separate and quantify contributions of transport, chemistry, and mixing along the trajectory pathways. Consistency of transport between the trajectory-box model CAABA/MJT and the 3-D EMAC model is achieved via calculation of kinematic trajectories based on 3-D wind fields from EMAC using the trajectory model LAGRANTO. The combination of the trajectory-box model CAABA/MJT and the trajectory model LAGRANTO can be considered as a Lagrangian chemistry-transport model (CTM moving isolated air parcels. The procedure for obtaining the necessary statistical basis for the quantification method is described as well as the comprehensive diagnostics with respect to chemistry.

The quantification method presented here allows to investigate the characteristics of transport, chemistry, and mixing in a grid-based 3-D model. The analysis of chemical processes within the trajectory-box model CAABA/MJT is easily extendable to include, for example, the impact of different transport pathways or of mixing processes onto

Soil-Related Input Parameters for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

A. J. Smith

2004-09-09

This report presents one of the analyses that support the Environmental Radiation Model for Yucca Mountain Nevada (ERMYN). The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the details of the conceptual model as well as the mathematical model and the required input parameters. The biosphere model is one of a series of process models supporting the postclosure Total System Performance Assessment (TSPA) for the Yucca Mountain repository. A schematic representation of the documentation flow for the Biosphere input to TSPA is presented in Figure 1-1. This figure shows the evolutionary relationships among the products (i.e., analysis and model reports) developed for biosphere modeling, and the biosphere abstraction products for TSPA, as identified in the ''Technical Work Plan for Biosphere Modeling and Expert Support'' (TWP) (BSC 2004 [DIRS 169573]). This figure is included to provide an understanding of how this analysis report contributes to biosphere modeling in support of the license application, and is not intended to imply that access to the listed documents is required to understand the contents of this report. This report, ''Soil-Related Input Parameters for the Biosphere Model'', is one of the five analysis reports that develop input parameters for use in the ERMYN model. This report is the source documentation for the six biosphere parameters identified in Table 1-1. The purpose of this analysis was to develop the biosphere model parameters associated with the accumulation and depletion of radionuclides in the soil. These parameters support the calculation of radionuclide concentrations in soil from on-going irrigation or ash deposition and, as a direct consequence, radionuclide concentration in other environmental media that are affected by radionuclide concentrations in soil. The analysis was performed in accordance with the TWP (BSC 2004 [DIRS 169573]) where the governing procedure

Reconnecting to the biosphere.

Science.gov (United States)

Folke, Carl; Jansson, Asa; Rockström, Johan; Olsson, Per; Carpenter, Stephen R; Chapin, F Stuart; Crépin, Anne-Sophie; Daily, Gretchen; Danell, Kjell; Ebbesson, Jonas; Elmqvist, Thomas; Galaz, Victor; Moberg, Fredrik; Nilsson, Måns; Osterblom, Henrik; Ostrom, Elinor; Persson, Asa; Peterson, Garry; Polasky, Stephen; Steffen, Will; Walker, Brian; Westley, Frances

2011-11-01

Humanity has emerged as a major force in the operation of the biosphere, with a significant imprint on the Earth System, challenging social-ecological resilience. This new situation calls for a fundamental shift in perspectives, world views, and institutions. Human development and progress must be reconnected to the capacity of the biosphere and essential ecosystem services to be sustained. Governance challenges include a highly interconnected and faster world, cascading social-ecological interactions and planetary boundaries that create vulnerabilities but also opportunities for social-ecological change and transformation. Tipping points and thresholds highlight the importance of understanding and managing resilience. New modes of flexible governance are emerging. A central challenge is to reconnect these efforts to the changing preconditions for societal development as active stewards of the Earth System. We suggest that the Millennium Development Goals need to be reframed in such a planetary stewardship context combined with a call for a new social contract on global sustainability. The ongoing mind shift in human relations with Earth and its boundaries provides exciting opportunities for societal development in collaboration with the biosphere--a global sustainability agenda for humanity.

Database description for the biosphere code BIOMOD

International Nuclear Information System (INIS)

Kane, P.; Thorne, M.C.; Coughtrey, P.J.

1983-03-01

The development of a biosphere model for use in comparative radiological assessments of UK low and intermediate level waste repositories is discussed. The nature, content and sources of data contained in the four files that comprise the database for the biosphere code BIOMOD are described. (author)

Taking account of the biosphere in HLW assessment

International Nuclear Information System (INIS)

Smith, G.M.; Grogan, H.A.

1992-01-01

Evaluation of the biosphere in High level Waste assessment is beset with difficulties concerned with the disparity in timescales for geosphere and biosphere processes and prediction of the long term conditions in the biosphere. These issues are discussed against the background of developments on criteria, calculational end points, timescales, environmental change and human activities, relationship to other parts of the assessment, and uncertainty and variability. In this paper an outline for a surface environment assessment program is proposed

Integrated Biosphere Simulator Model (IBIS), Version 2.5

Data.gov (United States)

National Aeronautics and Space Administration — The Integrated Biosphere Simulator (or IBIS) is designed to be a comprehensive model of the terrestrial biosphere. Tthe model represents a wide range of processes,...

Integrated Biosphere Simulator Model (IBIS), Version 2.5

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: The Integrated Biosphere Simulator (or IBIS) is designed to be a comprehensive model of the terrestrial biosphere. Tthe model represents a wide range of...

Microbial activity in the marine deep biosphere: Progress and prospects

Directory of Open Access Journals (Sweden)

Beth N Orcutt

2013-07-01

Full Text Available The vast marine deep biosphere consists of microbial habitats within sediment, pore waters, upper basaltic crust and the fluids that circulate throughout it. A wide range of temperature, pressure, pH, and electron donor and acceptor conditions exists – all of which can combine to affect carbon and nutrient cycling and result in gradients on spatial scales ranging from millimeters to kilometers. Diverse and mostly uncharacterized microorganisms live in these habitats, and potentially play a role in mediating global scale biogeochemical processes. Quantifying the rates at which microbial activity in the subsurface occurs is a challenging endeavor, yet developing an understanding of these rates is essential to determine the impact of subsurface life on Earth's global biogeochemical cycles, and for understanding how microorganisms in these "extreme" environments survive (or even thrive. Here, we synthesize recent advances and discoveries pertaining to microbial activity in the marine deep subsurface, and we highlight topics about which there is still little understanding and suggest potential paths forward to address them. This publication is the result of a workshop held in August 2012 by the NSF-funded Center for Dark Energy Biosphere Investigations (C-DEBI "theme team" on microbial activity (www.darkenergybiosphere.org.

Microbial activity in the marine deep biosphere: progress and prospects

Science.gov (United States)

Orcutt, Beth N.; LaRowe, Douglas E.; Biddle, Jennifer F.; Colwell, Frederick S.; Glazer, Brian T.; Reese, Brandi Kiel; Kirkpatrick, John B.; Lapham, Laura L.; Mills, Heath J.; Sylvan, Jason B.; Wankel, Scott D.; Wheat, C. Geoff

2013-01-01

The vast marine deep biosphere consists of microbial habitats within sediment, pore waters, upper basaltic crust and the fluids that circulate throughout it. A wide range of temperature, pressure, pH, and electron donor and acceptor conditions exists—all of which can combine to affect carbon and nutrient cycling and result in gradients on spatial scales ranging from millimeters to kilometers. Diverse and mostly uncharacterized microorganisms live in these habitats, and potentially play a role in mediating global scale biogeochemical processes. Quantifying the rates at which microbial activity in the subsurface occurs is a challenging endeavor, yet developing an understanding of these rates is essential to determine the impact of subsurface life on Earth's global biogeochemical cycles, and for understanding how microorganisms in these “extreme” environments survive (or even thrive). Here, we synthesize recent advances and discoveries pertaining to microbial activity in the marine deep subsurface, and we highlight topics about which there is still little understanding and suggest potential paths forward to address them. This publication is the result of a workshop held in August 2012 by the NSF-funded Center for Dark Energy Biosphere Investigations (C-DEBI) “theme team” on microbial activity (www.darkenergybiosphere.org). PMID:23874326

Biosphere models for safety assesment of radioactive waste disposal

Energy Technology Data Exchange (ETDEWEB)

Proehl, G; Olyslaegers, G; Zeevaert, T [SCK/CEN, Mol (Belgium); Kanyar, B [University of Veszprem (Hungary). Dept. of Radiochemistry; Pinedo, P; Simon, I [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain); Bergstroem, U; Hallberg, B [Studsvik Ecosafe, Nykoeping (Sweden); Mobbs, S; Chen, Q; Kowe, R [NRPB, Chilton, Didcot (United Kingdom)

2004-07-01

The aim of the BioMoSA project has been to contribute in the confidence building of biosphere models, for application in performance assessments of radioactive waste disposal. The detailed objectives of this project are: development and test of practical biosphere models for application in long-term safety studies of radioactive waste disposal to different European locations, identification of features, events and processes that need to be modelled on a site-specific rather than on a generic base, comparison of the results and quantification of the variability of site-specific models developed according to the reference biosphere methodology, development of a generic biosphere tool for application in long term safety studies, comparison of results from site-specific models to those from generic one, Identification of possibilities and limitations for the application of the generic biosphere model. (orig.)

Biosphere models for safety assessment of radioactive waste disposal

International Nuclear Information System (INIS)

Proehl, G.; Olyslaegers, G.; Zeevaert, T.; Kanyar, B.; Bergstroem, U.; Hallberg, B.; Mobbs, S.; Chen, Q.; Kowe, R.

2004-01-01

The aim of the BioMoSA project has been to contribute in the confidence building of biosphere models, for application in performance assessments of radioactive waste disposal. The detailed objectives of this project are: development and test of practical biosphere models for application in long-term safety studies of radioactive waste disposal to different European locations, identification of features, events and processes that need to be modelled on a site-specific rather than on a generic base, comparison of the results and quantification of the variability of site-specific models developed according to the reference biosphere methodology, development of a generic biosphere tool for application in long term safety studies, comparison of results from site-specific models to those from generic one, Identification of possibilities and limitations for the application of the generic biosphere model. (orig.)

(Chemistry of the global atmosphere)

Energy Technology Data Exchange (ETDEWEB)

Marland, G.

1990-09-27

The traveler attended the conference The Chemistry of the Global Atmosphere,'' and presented a paper on the anthropogenic emission of carbon dioxide (CO{sub 2}) to the atmosphere. The conference included meetings of the International Global Atmospheric Chemistry (IGAC) programme, a core project of the International Geosphere/Biosphere Programme (IGBP) and the traveler participated in meetings on the IGAC project Development of Global Emissions Inventories'' and agreed to coordinate the working group on CO{sub 2}. Papers presented at the conference focused on the latest developments in analytical methods, modeling and understanding of atmospheric CO{sub 2}, CO, CH{sub 4}, N{sub 2}O, SO{sub 2}, NO{sub x}, NMHCs, CFCs, and aerosols.

Gaian bottlenecks and planetary habitability maintained by evolving model biospheres: the ExoGaia model

Science.gov (United States)

Nicholson, Arwen E.; Wilkinson, David M.; Williams, Hywel T. P.; Lenton, Timothy M.

2018-06-01

The search for habitable exoplanets inspires the question - how do habitable planets form? Planet habitability models traditionally focus on abiotic processes and neglect a biotic response to changing conditions on an inhabited planet. The Gaia hypothesis postulates that life influences the Earth's feedback mechanisms to form a self-regulating system, and hence that life can maintain habitable conditions on its host planet. If life has a strong influence, it will have a role in determining a planet's habitability over time. We present the ExoGaia model - a model of simple `planets' host to evolving microbial biospheres. Microbes interact with their host planet via consumption and excretion of atmospheric chemicals. Model planets orbit a `star' that provides incoming radiation, and atmospheric chemicals have either an albedo or a heat-trapping property. Planetary temperatures can therefore be altered by microbes via their metabolisms. We seed multiple model planets with life while their atmospheres are still forming and find that the microbial biospheres are, under suitable conditions, generally able to prevent the host planets from reaching inhospitable temperatures, as would happen on a lifeless planet. We find that the underlying geochemistry plays a strong role in determining long-term habitability prospects of a planet. We find five distinct classes of model planets, including clear examples of `Gaian bottlenecks' - a phenomenon whereby life either rapidly goes extinct leaving an inhospitable planet or survives indefinitely maintaining planetary habitability. These results suggest that life might play a crucial role in determining the long-term habitability of planets.

How does the terrestrial carbon exchange respond to inter-annual climatic variations? A quantification based on atmospheric CO2 data

Science.gov (United States)

Rödenbeck, Christian; Zaehle, Sönke; Keeling, Ralph; Heimann, Martin

2018-04-01

The response of the terrestrial net ecosystem exchange (NEE) of CO2 to climate variations and trends may crucially determine the future climate trajectory. Here we directly quantify this response on inter-annual timescales by building a linear regression of inter-annual NEE anomalies against observed air temperature anomalies into an atmospheric inverse calculation based on long-term atmospheric CO2 observations. This allows us to estimate the sensitivity of NEE to inter-annual variations in temperature (seen as a climate proxy) resolved in space and with season. As this sensitivity comprises both direct temperature effects and the effects of other climate variables co-varying with temperature, we interpret it as inter-annual climate sensitivity. We find distinct seasonal patterns of this sensitivity in the northern extratropics that are consistent with the expected seasonal responses of photosynthesis, respiration, and fire. Within uncertainties, these sensitivity patterns are consistent with independent inferences from eddy covariance data. On large spatial scales, northern extratropical and tropical inter-annual NEE variations inferred from the NEE-T regression are very similar to the estimates of an atmospheric inversion with explicit inter-annual degrees of freedom. The results of this study offer a way to benchmark ecosystem process models in more detail than existing effective global climate sensitivities. The results can also be used to gap-fill or extrapolate observational records or to separate inter-annual variations from longer-term trends.

MAPSS: Mapped Atmosphere-Plant-Soil System Model, Version 1.0

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: MAPSS (Mapped Atmosphere-Plant-Soil System) is a landscape to global vegetation distribution model that was developed to simulate the potential biosphere...

Seven years of recent European net terrestrial carbon dioxide exchange constrained by atmospheric observations

NARCIS (Netherlands)

Peters, W.; Krol, M; van der Werf, G. R.; Houweling, S.; Jones, C. D.; Hughes, J.; Schaefer, K.; Masarie, K. A.; Jacobson, A. R.; Miller, J. B.; Cho, C. H.; Ramonet, M.; Schmidt, M.; Ciattaglia, L.; Apadula, F.; Helta, D.; Meinhardt, F.; di Sarra, A. G.; Piacentino, S.; Sferlazzo, D.; Aalto, T.; Hatakka, J.; Strom, J.; Haszpra, L.; Meijer, H. A. J.; van der Laan, S.; Neubert, R. E. M.; Jordan, A.; Rodo, X.; Morgui, J. -A.; Vermeulen, A. T.; Popa, E.; Rozanski, K.; Zimnoch, M.; Manning, A. C.; Leuenberger, M.; Uglietti, C.; Dolman, A. J.; Ciais, P.; Heimann, M.; Tans, P. P.; Heltai, D.; Ström, J.

We present an estimate of net ecosystem exchange (NEE) of CO(2) in Europe for the years 2001-2007. It is derived with a data assimilation that uses a large set of atmospheric CO(2) mole fraction observations (similar to 70 000) to guide relatively simple descriptions of terrestrial and oceanic net

Soil Methanotrophy Model (MeMo v1.0): a process-based model to quantify global uptake of atmospheric methane by soil

Science.gov (United States)

Murguia-Flores, Fabiola; Arndt, Sandra; Ganesan, Anita L.; Murray-Tortarolo, Guillermo; Hornibrook, Edward R. C.

2018-06-01

Soil bacteria known as methanotrophs are the sole biological sink for atmospheric methane (CH4), a potent greenhouse gas that is responsible for ˜ 20 % of the human-driven increase in radiative forcing since pre-industrial times. Soil methanotrophy is controlled by a plethora of factors, including temperature, soil texture, moisture and nitrogen content, resulting in spatially and temporally heterogeneous rates of soil methanotrophy. As a consequence, the exact magnitude of the global soil sink, as well as its temporal and spatial variability, remains poorly constrained. We developed a process-based model (Methanotrophy Model; MeMo v1.0) to simulate and quantify the uptake of atmospheric CH4 by soils at the global scale. MeMo builds on previous models by Ridgwell et al. (1999) and Curry (2007) by introducing several advances, including (1) a general analytical solution of the one-dimensional diffusion-reaction equation in porous media, (2) a refined representation of nitrogen inhibition on soil methanotrophy, (3) updated factors governing the influence of soil moisture and temperature on CH4 oxidation rates and (4) the ability to evaluate the impact of autochthonous soil CH4 sources on uptake of atmospheric CH4. We show that the improved structural and parametric representation of key drivers of soil methanotrophy in MeMo results in a better fit to observational data. A global simulation of soil methanotrophy for the period 1990-2009 using MeMo yielded an average annual sink of 33.5 ± 0.6 Tg CH4 yr-1. Warm and semi-arid regions (tropical deciduous forest and open shrubland) had the highest CH4 uptake rates of 602 and 518 mg CH4 m-2 yr-1, respectively. In these regions, favourable annual soil moisture content ( ˜ 20 % saturation) and low seasonal temperature variations (variations < ˜ 6 °C) provided optimal conditions for soil methanotrophy and soil-atmosphere gas exchange. In contrast to previous model analyses, but in agreement with recent observational data

Past and Future of the Anthropogenic Biosphere

Science.gov (United States)

Ellis, E. C.

2010-12-01

Human populations and their use of land have now transformed most of the terrestrial biosphere into anthropogenic biomes (anthromes). As anthromes have emerged as the dominant global forms of ecological pattern and process, human interactions with terrestrial ecosystems have become a key earth system process, determining the structure and functioning of the biosphere. This presentation explores Ester Boserup’s land use intensification theories as models for understanding the emergence and dynamics of anthromes and their ecological processes, including their biogeochemistry and community structure, from the mostly wild biosphere of the Holocene to the primarily anthropogenic biosphere of the present and future. Existing global models and data for human population growth and land use over the Holocene differ in their portrayal of the global transition to a mostly anthropogenic biosphere. Yet there is little doubt that human populations have continued to grow over the long term and that anthromes have been increasingly important global ecological systems for millennia. This is conclusive evidence that human interactions with ecosystems can be sustained over the long-term, albeit under conditions that may no longer be realizable by either Earth or human systems. The classic Malthusian paradigm, in which human population growth outstrips natural resources leading to population collapse is unsupported by historical observations at global scale. Boserupian intensification is the better model, providing a robust theoretical foundation in which socio-ecological systems evolve as human populations increase, towards increasingly efficient use of limiting natural resources and enhanced production of anthropogenic ecological services such as food. This is not a story of technical advance, but rather of the forced adoption of ever more energy-intensive technical solutions in support of ever increasing population demands. And it does explain historical changes in the biosphere

Studies of the terrestrial O₂ and carbon cycles in sand dune gases and in biosphere 2

Energy Technology Data Exchange (ETDEWEB)

Severinghaus, Jeffrey Peck [Columbia Univ., New York, NY (United States)

1995-01-01

Molecular oxygen in the atmosphere is coupled tightly to the terrestrial carbon cycle by the processes of photosynthesis, respiration, and burning. This dissertation examines different aspects of this coupling in four chapters. Chapter 1 explores the feasibility of using air from sand dunes to reconstruct atmospheric O₂ composition centuries ago. Such a record would reveal changes in the mass of the terrestrial biosphere, after correction for known fossil fuel combustion, and constrain the fate of anthropogenic CO₂.

MAPSS: Mapped Atmosphere-Plant-Soil System Model, Version 1.0

Data.gov (United States)

National Aeronautics and Space Administration — MAPSS (Mapped Atmosphere-Plant-Soil System) is a landscape to global vegetation distribution model that was developed to simulate the potential biosphere impacts and...

Evaluation of Features, Events, and Processes (FEP) for the Biosphere Model

Energy Technology Data Exchange (ETDEWEB)

M. Wasiolek; P. Rogers

2004-10-27

The purpose of this analysis report is to evaluate and document the inclusion or exclusion of biosphere features, events, and processes (FEPs) with respect to modeling used to support the total system performance assessment (TSPA) for the license application (LA). A screening decision, either ''Included'' or ''Excluded'', is given for each FEP along with the corresponding technical basis for the excluded FEPs and the descriptions of how the included FEPs were incorporated in the biosphere model. This information is required by the U.S. Nuclear Regulatory Commission (NRC) regulations at 10 CFR 63.114 (d, e, and f) [DIRS 156605]. The FEPs addressed in this report concern characteristics of the reference biosphere, the receptor, and the environmental transport and receptor exposure pathways for the groundwater and volcanic ash exposure scenarios considered in biosphere modeling. This revision provides the summary of the implementation of included FEPs in TSPA-LA, (i.e., how the FEP is included); for excluded FEPs, this analysis provides the technical basis for exclusion from TSPA-LA (i.e., why the FEP is excluded). This report is one of the 10 documents constituting the biosphere model documentation suite. A graphical representation of the documentation hierarchy for the biosphere model is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling. The ''Biosphere Model Report'' describes in detail the biosphere conceptual model and mathematical model. The input parameter reports shown to the right of the ''Biosphere Model Report'' contain detailed descriptions of the model input parameters and their development. Outputs from these six reports are used in the ''Nominal Performance Biosphere Dose Conversion Factor Analysis and Disruptive Event Biosphere Dose Conversion Factor Analysis

Global biomass burning: Atmospheric, climatic, and biospheric implications

International Nuclear Information System (INIS)

Levine, J.S.

1991-01-01

As a significant source of atmospheric gases, biomass burning must be addressed as a major environmental problem. Biomass burning includes burning forests and savanna grasslands for land clearing and conversion, burning agricultural stubble and waste after harvesting, and burning biomass fuels. The editor discusses the history of biomass burning and provides an overview of the individual chapters

Quantifying the Importance of the Rare Biosphere for Microbial Community Response to Organic Pollutants in a Freshwater Ecosystem.

Science.gov (United States)

Wang, Yuanqi; Hatt, Janet K; Tsementzi, Despina; Rodriguez-R, Luis M; Ruiz-Pérez, Carlos A; Weigand, Michael R; Kizer, Heidi; Maresca, Gina; Krishnan, Raj; Poretsky, Rachel; Spain, Jim C; Konstantinidis, Konstantinos T

2017-04-15

A single liter of water contains hundreds, if not thousands, of bacterial and archaeal species, each of which typically makes up a very small fraction of the total microbial community (biosphere." How often, and via what mechanisms, e.g., clonal amplification versus horizontal gene transfer, the rare taxa and genes contribute to microbial community response to environmental perturbations represent important unanswered questions toward better understanding the value and modeling of microbial diversity. We tested whether rare species frequently responded to changing environmental conditions by establishing 20-liter planktonic mesocosms with water from Lake Lanier (Georgia, USA) and perturbing them with organic compounds that are rarely detected in the lake, including 2,4-dichlorophenoxyacetic acid (2,4-D), 4-nitrophenol (4-NP), and caffeine. The populations of the degraders of these compounds were initially below the detection limit of quantitative PCR (qPCR) or metagenomic sequencing methods, but they increased substantially in abundance after perturbation. Sequencing of several degraders (isolates) and time-series metagenomic data sets revealed distinct cooccurring alleles of degradation genes, frequently carried on transmissible plasmids, especially for the 2,4-D mesocosms, and distinct species dominating the post-enrichment microbial communities from each replicated mesocosm. This diversity of species and genes also underlies distinct degradation profiles among replicated mesocosms. Collectively, these results supported the hypothesis that the rare biosphere can serve as a genetic reservoir, which can be frequently missed by metagenomics but enables community response to changing environmental conditions caused by organic pollutants, and they provided insights into the size of the pool of rare genes and species. IMPORTANCE A single liter of water or gram of soil contains hundreds of low-abundance bacterial and archaeal species, the so called rare biosphere. The

Simulating dynamics of {delta}{sup 13}C of CO{sub 2} in the planetary boundary layer a boreal forest region: covariation between surface fluxes and atmospheric mixing

Energy Technology Data Exchange (ETDEWEB)

Chen, Baozhang; Chen, Jing M. [Univ. of Toronto, ON (Canada). Dept. of Geography; Tans, Pieter P. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Earth System Research Lab.; Huang, Lin [Environment Canada, Toronto, ON (Canada). Atmospheric Science and Technology Directorate

2006-11-15

Stable isotopes of CO{sub 2} contain unique information on the biological and physical processes that exchange CO{sub 2} between terrestrial ecosystems and the atmosphere. Ecosystem exchange of carbon isotopes with the atmosphere is correlated diurnally and seasonally with the planetary boundary layer (PBL) dynamics. The strength of this kind of covariation affects the vertical gradient of {delta}{sup 13}C and thus the global {delta}{sup 13}C distribution pattern. We need to understand the various processes involved in transport/diffusion of carbon isotope ratio in the PBL and between the PBL and the biosphere and the troposphere. In this study, we employ a one-dimensional vertical diffusion/transport atmospheric model (VDS), coupled to an ecosystem isotope model (BEPS-EASS) to simulate dynamics of {sup 13}CO{sub 2} in the PBL over a boreal forest region in the vicinity of the Fraserdale (FRD) tower (49 deg 52 min 29.9 sec N, 81 deg 34 min 12.3 sec W) in northern Ontario, Canada. The data from intensive campaigns during the growing season in 1999 at this site are used for model validation in the surface layer. The model performance, overall, is satisfactory in simulating the measured data over the whole course of the growing season. We examine the interaction of the biosphere and the atmosphere through the PBL with respect to {delta}{sup 13}C on diurnal and seasonal scales. The simulated annual mean vertical gradient of {delta}{sup 13}C in the PBL in the vicinity of the FRD tower was about 0.025% in 1999. The {delta}{sup 13}C vertical gradient exhibited strong diurnal (29%) and seasonal (71%) variations that do not exactly mimic those of CO{sub 2}. Most of the vertical gradient (96.5% {+-}) resulted from covariation between ecosystem exchange of carbon isotopes and the PBL dynamics, while the rest (3.5%{+-}) was contributed by isotopic disequilibrium between respiration and photosynthesis. This disequilibrium effect on {delta}{sup 13}C of CO{sub 2} dynamics in PBL

Simulating dynamics of (delta){sup 13}C of CO{sub 2} in the planetary boundary layer a boreal forest region: covariation between surface fluxes and atmospheric mixing

Energy Technology Data Exchange (ETDEWEB)

Chen, Baozhang; Chen, Jing M. [Univ. of Toronto, ON (Canada). Dept. of Geography; Tans, Pieter P. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Earth System Research Lab.; Huang, Lin [Environment Canada, Toronto, ON (Canada). Atmospheric Science and Technology Directorate

2006-11-15

Stable isotopes of CO{sub 2} contain unique information on the biological and physical processes that exchange CO{sub 2} between terrestrial ecosystems and the atmosphere. Ecosystem exchange of carbon isotopes with the atmosphere is correlated diurnally and seasonally with the planetary boundary layer (PBL) dynamics. The strength of this kind of covariation affects the vertical gradient of (delta){sup 13}C and thus the global (delta){sup 13}C distribution pattern. We need to understand the various processes involved in transport/diffusion of carbon isotope ratio in the PBL and between the PBL and the biosphere and the troposphere. In this study, we employ a one-dimensional vertical diffusion/transport atmospheric model (VDS), coupled to an ecosystem isotope model (BEPS-EASS) to simulate dynamics of {sup 13}CO{sub 2} in the PBL over a boreal forest region in the vicinity of the Fraserdale (FRD) tower (49 deg 52 min 29.9 sec N, 81 deg 34 min 12.3 sec W) in northern Ontario, Canada. The data from intensive campaigns during the growing season in 1999 at this site are used for model validation in the surface layer. The model performance, overall, is satisfactory in simulating the measured data over the whole course of the growing season. We examine the interaction of the biosphere and the atmosphere through the PBL with respect to (delta){sup 13}C on diurnal and seasonal scales. The simulated annual mean vertical gradient of (delta){sup 13}C in the PBL in the vicinity of the FRD tower was about 0.025% in 1999. The (delta){sup 13}C vertical gradient exhibited strong diurnal (29%) and seasonal (71%) variations that do not exactly mimic those of CO{sub 2}. Most of the vertical gradient (96.5% {+-}) resulted from covariation between ecosystem exchange of carbon isotopes and the PBL dynamics, while the rest (3.5%{+-}) was contributed by isotopic disequilibrium between respiration and photosynthesis. This disequilibrium effect on (delta){sup 13}C of CO{sub 2} dynamics in PBL

10 CFR 63.305 - Required characteristics of the reference biosphere.

Science.gov (United States)

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Required characteristics of the reference biosphere. 63... Standards § 63.305 Required characteristics of the reference biosphere. (a) Features, events, and processes that describe the reference biosphere must be consistent with present knowledge of the conditions in...

Surface-atmosphere exchange of ammonia over peatland using QCL-based eddy-covariance measurements and inferential modeling

DEFF Research Database (Denmark)

Zöll, Undine; Brümmer, Christian; Schrader, Frederik

2016-01-01

Recent advances in laser spectrometry offer new opportunities to investigate ecosystem-atmosphere exchange of environmentally relevant trace gases. In this study, we demonstrate the applicability of a quantum cascade laser (QCL) absorption spectrometer to continuously measure ammonia concentratio...

Biospheric feedback effects in a synchronously coupled model of human and Earth systems

Energy Technology Data Exchange (ETDEWEB)

Thornton, Peter E.; Calvin, Katherine V.; Jones, Andrew D.; Di Vittorio, Alan; Bond-Lamberty, Benjamin; Chini, Louise M.; Shi, Xiaoying; Mao, Jiafu; Collins, William D.; Edmonds, James A.; Thomson, Allison M.; Truesdale, John E.; Craig, Anthony P.; Branstetter, M.; Hurtt, George C.

2017-06-12

Fossil fuel combustion and land-use change are the first and second largest contributors to industrial-era increases in atmospheric carbon dioxide concentration, which is itself the largest driver of present-day climate change1. Projections of fossil fuel consumption and land-use change are thus fundamental inputs for coupled Earth system models (ESM) used to estimate the physical and biological consequences of future climate system forcing2,3. While empirical datasets are available to inform historical analyses4,5, assessments of future climate change have relied on projections of energy and land use based on energy economic models, constrained using historical and present-day data and forced with assumptions about future policy, land-use patterns, and socio-economic development trajectories6. Here we show that the influence of biospheric change – the integrated effect of climatic, ecological, and geochemical processes – on land ecosystems has a significant impact on energy, agriculture, and land-use projections for the 21st century. Such feedbacks have been ignored in previous ESM studies of future climate. We find that synchronous exposure of land ecosystem productivity in the economic system to biospheric change as it develops in an ESM results in a 10% reduction of land area used for crop cultivation; increased managed forest area and land carbon; a 15-20% decrease in global crop price; and a 17% reduction in fossil fuel emissions for a low-mid range forcing scenario7. These simulation results demonstrate that biospheric change can significantly alter primary human system forcings to the climate system. This synchronous two-way coupling approach removes inconsistencies in description of climate change between human and biosphere components of the coupled model, mitigating a major source of uncertainty identified in assessments of future climate projections8-10.

The Biosphere as a Living System. On Peculiarities of the Evolutionary Process on the Biosphere Level

OpenAIRE

Alexej Yablokov; Vladimir Levchenko; Anatolij Kerzhentsev

2016-01-01

The main purpose of this second essay the “biospherology” is to streamline and formalize the existing knowledge about the biosphere, to develop the theoretical basis of the theory of evolution of the biosphere. Despite the vast amount of research on ways of origin and development of life, yet there is no generally accepted theory of evolution of life on Earth, which would not only contain the phenomenology of this process, but also an understanding of the mechanism of functioning of the biosp...

Extended biosphere dataset for safety assessment of radioactive waste geological disposal

International Nuclear Information System (INIS)

Kato, Tomoko; Suzuki, Yuji

2007-01-01

JAEA has an on-going programme of research and development relating to the safety assessment of the deep geological disposal systems of high-level radioactive waste (HLW) and transuranic waste (TRU). In the safety assessment of HLW and TRU disposal systems, biosphere assessment is necessary to estimate future radiological impacts on human beings (e.g. radiation dose). In order to estimate radiation dose, consideration needs to be given to the biosphere into which future releases of radionuclides might occur and to the associated future human behaviour. The data of some biosphere parameters needed to be updated by appropriate data sources for generic and site-specific biosphere assessment to improve reliability for the biosphere assessment, because some data published in the 1980's or the early 90's were found to be inappropriate for the recent biosphere assessment. Therefore, data of the significant parameters (especially for element-dependent) were set up on the basis of recent information, to update the generic biosphere dataset. (author)

Impact of a global warming on biospheric sources of methane and its climatic consequences

Energy Technology Data Exchange (ETDEWEB)

Hameed, S; Cess, R D [State Univ. of New York at Stony Brook, Stony Brook, NY (USA). Lab. for Planetary Atmospheres Research

1983-01-01

Most of atmospheric methane originates by bacterial processes in anaerobic environments within the soil which are found to become more productive with increases in ambient temperature. A warming of climate, due to increasing levels of industrial gases resulting from fossil fuel burning, is thus likely to increase methane abundance within the atmosphere. This may lead to further heating of the atmosphere, since both methane and ozone (which is generated in the troposphere from reactions of methane) have greenhouse effects. We have explored this feedback mechanism using a coupled climate-chemical model of the troposphere, by calculating the impact of the predicted global warming due to increased emissions of carbon dioxide and other industrial gases on the biospheric sources of methane. Although we find this climate feedback to be, by itself, relatively minor, it can produce measurable increases in atmospheric CH/sub 4/ concentration, a quantity which should additionally increase as a consequence of increasing anthropogenic emissions of CO and CH/sub 4/ itself. It would thus seem useful to carefully monitor future atmospheric CH/sub 4/ concentrations.

Impact of a global warming on biospheric sources of methane and its climatic consequences

Energy Technology Data Exchange (ETDEWEB)

Hameed, S; Cess, R D

1983-02-01

Most of atmospheric methane originates by bacterial processes in anaerobic environments within the soil which are found to become more productive with increases in ambient temperature. A warming of climate, due to increasing levels of industrial gases resulting from fossil fuel burning, is thus likely to increase methane abundance within the atmosphere. This may lead to further heating of the atmosphere, since both methane and ozone (which is generated in the troposphere from reactions of methane) have greenhouse effects. We have explored this feedback mechanism using a coupled climate-chemical model of the troposphere, by calculating the impact of the predicted global warming due to increased emissions of carbon dioxide and other industrial gases on the biospheric sources of methane. Although we find this climate feedback to be, by itself, relatively minor, it can produce measurable increases in atmospheric CH/sub 4/ concentration, a quantity which should additionally increase as a consequence of increasing anthropogenic emissions of CO and CH/sub 4/ itself. It would thus seem useful to carefully monitor future atmospheric CH/sub 4/ concentrations.

Reviewing Biosphere Reserves globally: effective conservation action or bureaucratic label?

Science.gov (United States)

Coetzer, Kaera L; Witkowski, Edward T F; Erasmus, Barend F N

2014-02-01

The Biosphere Reserve (BR) model of UNESCO's Man and the Biosphere Programme reflects a shift towards more accountable conservation. Biosphere Reserves attempt to reconcile environmental protection with sustainable development; they explicitly acknowledge humans, and human interests in the conservation landscape while still maintaining the ecological values of existing protected areas. Conceptually, this model is attractive, with 610 sites currently designated globally. Yet the practical reality of implementing dual 'conservation' and 'development' goals is challenging, with few examples successfully conforming to the model's full criteria. Here, we review the history of Biosphere Reserves from first inception in 1974 to the current status quo, and examine the suitability of the designation as an effective conservation model. We track the spatial expansion of Biosphere Reserves globally, assessing the influence of the Statutory Framework of the World Network of Biosphere Reserves and Seville strategy in 1995, when the BR concept refocused its core objectives on sustainable development. We use a comprehensive range of case studies to discuss conformity to the Programme, the social and ecological consequences associated with implementation of the designation, and challenges in aligning conservation and development. Given that the 'Biosphere Reserve' label is a relatively unknown designation in the public arena, this review also provides details on popularising the Biosphere Reserve brand, as well as prospects for further research, currently unexploited, but implicit in the designation. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

Estimation of Net Ecosystem Carbon Exchange for the Conterminous UnitedStates by Combining MODIS and AmeriFlux Data

Energy Technology Data Exchange (ETDEWEB)

Xiao, Jingfeng; Zhuang, Qianlai; Baldocchi, Dennis D.; Law, Beverly E.; Richardson, Andrew D.; Chen, Jiquan; Oren, Ram; Starr, Gregory; Noormets, Asko; Ma, Siyan; Verma, Shashi B.; Wharton, Sonia; Wofsy, Steven C.; Bolstad, Paul V.; Burns, Sean P.; Cook, David R.; Curtis, Peter S.; Drake, Bert G.; Falk, Matthias; Fischer, Marc L.; Foster, David R.; Gu, Lianhong; Hadley, Julian L.; Hollinger, David Y.; Katul, Gabriel G.; Litvak, Marcy; Martin, Timothy A.; Matamala, Roser; McNulty, Steve; Meyers, Tilden P.; Monson, Russell K.; Munger, J. William; Oechel, Walter C.; U, Kyaw Tha Paw; Schmid, Hans Peter; Scott, Russell L.; Sun, Ge; Suyker, Andrew E.; Torn, Margaret S.

2009-03-06

Eddy covariance flux towers provide continuous measurements of net ecosystem carbon exchange (NEE) for a wide range of climate and biome types. However, these measurements only represent the carbon fluxes at the scale of the tower footprint. To quantify the net exchange of carbon dioxide between the terrestrial biosphere and the atmosphere for regions or continents, flux tower measurements need to be extrapolated to these large areas. Here we used remotely-sensed data from the Moderate Resolution Imaging Spectrometer (MODIS) instrument on board NASA's Terra satellite to scale up AmeriFlux NEE measurements to the continental scale. We first combined MODIS and AmeriFlux data for representative U.S. ecosystems to develop a predictive NEE model using a regression tree approach. The predictive model was trained and validated using NEE data over the periods 2000-2004 and 2005-2006, respectively. We found that the model predicted NEE reasonably well at the site level. We then applied the model to the continental scale and estimated NEE for each 1 km x 1 km cell across the conterminous U.S. for each 8-day period in 2005 using spatially-explicit MODIS data. The model generally captured the expected spatial and seasonal patterns of NEE. Our study demonstrated that our empirical approach is effective for scaling up eddy flux NEE measurements to the continental scale and producing wall-to-wall NEE estimates across multiple biomes. Our estimates may provide an independent dataset from simulations with biogeochemical models and inverse modeling approaches for examining the spatiotemporal patterns of NEE and constraining terrestrial carbon budgets for large areas.

Robust optical carbon dioxide isotope analyzer, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Isotopic analysis of carbon dioxide is an important tool for characterization of the exchange and transformation of carbon between the biosphere and the atmosphere....

Natural releases from contaminated groundwater, Example Reference Biosphere 2B

Energy Technology Data Exchange (ETDEWEB)

Simon, I. [CIEMAT/PIRA, Avda Complutense 22, 28040 Madrid (Spain)]. E-mail: isc@csn.es; Naito, M. [Nuclear Waste Management Organization of Japan (NUMO), 4-1-23 Shiba, Minato-ku, Tokyo, 108-0014 (Japan); Thorne, M.C. [Mike Thorne and Associates Limited, Abbotsleigh, Kebroyd Mount, Ripponden, Halifax, West Yorkshire HX6 3JA (United Kingdom); Walke, R. [Enviros QuantiSci, Building D5, Culham Science Centre, Culham, Oxfordshire OX14 3DB (United Kingdom)

2005-07-01

Safety assessment is a tool which, by means of an iterative procedure, allows the evaluation of the performance of a disposal system and its potential impact on human health and the environment. Radionuclides from a deep geological disposal facility may not reach the surface environment until many tens of thousands of years after closure of the facility. The BIOMASS Programme on BIOsphere Modelling and ASSessment developed Examples of 'Reference Biospheres' to illustrate the use of the methodology and to demonstrate how biosphere models can be developed and justified as being fit for purpose. The practical examples are also intended to be useful in their own right. The Example Reference Biosphere 2B presented here involves the consideration of alternative types of geosphere-biosphere interfaces and calculation of doses to members of hypothetical exposure groups arising from a wide range of exposure pathways within agricultural and semi-natural environments, but without allowing for evolution of the corresponding biosphere system. The example presented can be used as a generic analysis in some situations although it was developed around a relatively specific conceptual model. It should be a useful practical example, but the above numerical results are not intended to be understood as prescribed biosphere 'conversion factors'.

Natural releases from contaminated groundwater, Example Reference Biosphere 2B

International Nuclear Information System (INIS)

Simon, I.; Naito, M.; Thorne, M.C.; Walke, R.

2005-01-01

Safety assessment is a tool which, by means of an iterative procedure, allows the evaluation of the performance of a disposal system and its potential impact on human health and the environment. Radionuclides from a deep geological disposal facility may not reach the surface environment until many tens of thousands of years after closure of the facility. The BIOMASS Programme on BIOsphere Modelling and ASSessment developed Examples of 'Reference Biospheres' to illustrate the use of the methodology and to demonstrate how biosphere models can be developed and justified as being fit for purpose. The practical examples are also intended to be useful in their own right. The Example Reference Biosphere 2B presented here involves the consideration of alternative types of geosphere-biosphere interfaces and calculation of doses to members of hypothetical exposure groups arising from a wide range of exposure pathways within agricultural and semi-natural environments, but without allowing for evolution of the corresponding biosphere system. The example presented can be used as a generic analysis in some situations although it was developed around a relatively specific conceptual model. It should be a useful practical example, but the above numerical results are not intended to be understood as prescribed biosphere 'conversion factors'

Spatial patterns of atmospheric deposition of nitrogen and sulfur using ion-exchange resin collectors in Rocky Mountain National Park, USA

Science.gov (United States)

Clow, David W.; Roop, Heidi; Nanus, Leora; Fenn, Mark; Sexstone, Graham A.

2015-01-01

Lakes and streams in Class 1 wilderness areas in the western United States (U.S.) are at risk from atmospheric deposition of nitrogen (N) and sulfur (S), and protection of these resources is mandated under the Federal Clean Air Act and amendments. Assessment of critical loads, which are the maximum exposure to pollution an area can receive without adverse effects on sensitive ecosystems, requires accurate deposition estimates. However, deposition is difficult and expensive to measure in high-elevation wilderness, and spatial patterns in N and S deposition in these areas remain poorly quantified. In this study, ion-exchange resin (IER) collectors were used to measure dissolved inorganic N (DIN) and S deposition during June 2006–September 2007 at approximately 20 alpine/subalpine sites spanning the Continental Divide in Rocky Mountain National Park. Results indicated good agreement between deposition estimated from IER collectors and commonly used wet + dry methods during summer, but poor agreement during winter. Snowpack sampling was found to be a more accurate way of quantifying DIN and S deposition during winter. Summer DIN deposition was significantly greater on the east side of the park than on the west side (25–50%; p ≤ 0.03), consistent with transport of pollutants to the park from urban and agricultural areas to the east. Sources of atmospheric nitrate (NO3−) were examined using N isotopes. The average δ15N of NO3− from IER collectors was 3.5‰ higher during winter than during summer (p model critical loads by filling gaps in geographic coverage of deposition monitoring/modeling programs and thus may enable policy makers to better protect sensitive natural resources in Class 1 Wilderness areas.

Atmospheric deposition of inorganic nitrogen in Spanish forests of Quercus ilex measured with ion-exchange resins and conventional collectors

Science.gov (United States)

Héctor García-Gomez; Sheila Izquieta-Rojano; Laura Aguillaume; Ignacio González-Fernández; Fernando Valiño; David Elustondo; Jesús M. Santamaría; Anna Àvila; Mark E. Fenn; Rocío Alonso

2016-01-01

Atmospheric nitrogen deposition is one of the main threats for biodiversity and ecosystem functioning. Measurement techniques like ion-exchange resin collectors (IECs), which are less expensive and time-consuming than conventional methods, are gaining relevance in the study of atmospheric deposition and are recommended to expand monitoring networks. In the present work...

ISLSCP II C4 Vegetation Percentage

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: The photosynthetic composition (C3 or C4) of vegetation on the land surface is essential for accurate simulations of biosphere-atmosphere exchanges of...

Emissions from vegetation fires and their influence on atmospheric composition over the Amazon Basin (Invited)

Science.gov (United States)

Andreae, M. O.; Artaxo, P.; Bela, M. M.; de Freitas, S. R.; Gerbig, C.; Longo, K. M.; Wiedemann, K. T.; Wofsy, S. C.

2010-12-01

Over the past decades, several campaigns have been conducted in the Amazon Basin, during which the emissions from biomass burning were characterized. Other campaigns, as well as remote sensing studies, have produced clear evidence that the budget of traces gases (including CO2) and aerosols over the Basin are strongly perturbed by vegetation fires. We will briefly review these studies and present some recent measurements made during the the Balanço Atmosférico Regional de Carbono na Amazônia (BARCA) aircraft measurement program, which consisted of two aircraft campaigns during November-December 2008 (BARCA-A) and May-June 2009 (BARCA-B). The measurements covered the altitude range from the surface up to about 4500 m, and spanned across the Amazon Basin. While our results confirm the importance of biomass burning for the atmospheric composition over the Amazon Basin in general, they also highlight some complexities. One is the influence of transatlantic transport: Amazonia is downwind of massive fire regions in Africa, and depending on season and locality, these can make an important contribution to the trace gas and aerosol burden over the Amazon Basin. Another difficulty arises from the fact that representative emission ratios for CO relative to CO2 are difficult to obtain in the field, owing to the influence of biospheric exchange on the distribution of CO2 concentrations. The consequences of these and other uncertainties for a quantitative assessment of the sources of trace gases over Amazonia and for the estimation of carbon exchange with the biosphere will be discussed.

A simplified biosphere model for global climate studies

Science.gov (United States)

Xue, Y.; Sellers, P. J.; Kinter, J. L.; Shukla, J.

1991-01-01

A comprehensive analysis of the simple biosphere model (SIB) of Sellers et al. (1986) is performed in an effort to bridge the gap between the typical hydrological treatment of the land surface biosphere and the conventional general circulation model treatment, which is specified through a single parameter. Approximations are developed that stimulate the effects of reduced soil moisture more simply, maintaining the essence of the biophysical concepts utilized in SIB. Comparing the reduced parameter biosphere with those from the original formulation in a GCM and a zero-dimensional model shows the simplified version to reproduce the original results quite closely.

Demonstration of DECOS: representation of four biosphere states

International Nuclear Information System (INIS)

Ashton, J.

1988-09-01

This report describes the use of the dynamic biosphere code, DECOS, in stand alone mode, to represent a site in four possible biosphere states. The biosphere states have been chosen to illustrate a range of conditions which may prevail at the site. The behaviour of the system in each state has been considered and the capability of DECOS to switch between the states has been demonstrated. The intention of this work is to test the function of DECOS. Results in this report are illustrative and do not form any part of a radiological assessment of the site. (author)

Studies on the radiological assessment and modeling of the biosphere in radioactive waste management in Spain; Estudio sobre la evaluacion radiologica y modelizacion de la biosfera en la gestion de residuos radioactivos en Espna

Energy Technology Data Exchange (ETDEWEB)

Perez-Sanchez, D.; Trueba, C.; Robles, B.

2011-07-01

Assessments of long-term safety in radioactive waste management means that the annual radiation dose due to the possible release of radionuclides to the biosphere does not exceed regulatory limits for members of the public. To quantify these doses should first develop models that describe the behavior of radionuclides in the environment that could also calculate the concentrations in different compartments of the biosphere, then estimated radiation doses to humans and the environment through the different routes of exposure. This paper describes recent results obtained by developing projects related to safety assessment of the biosphere, which include several studies.

A review of measurement and modelling results of particle atmosphere-surface exchange

DEFF Research Database (Denmark)

Pryor, Sara; Gallagher, M.; Sievering, H.

2008-01-01

Atmosphere-surface exchange represents one mechanism by which atmospheric particle mass and number size distributions are modified. Deposition velocities (upsilon(d)) exhibit a pronounced dependence on surface type, due in part to turbulence structure (as manifest in friction velocity), with minima...... agreement between models and observations is found over less-rough surfaces though those data also imply substantially higher surface collection efficiencies than were originally proposed and are manifest in current models. We review theorized dependencies for particle fluxes, describe and critique model...... of approximately 0.01 and 0.2 cm s(-1) over grasslands and 0.1-1 cm s(-1) over forests. However, as noted over 20 yr ago, observations over forests generally do not support the pronounced minimum of deposition velocity (upsilon(d)) for particle diameters of 0.1-2 mu m as manifest in theoretical predictions. Closer...

Arctic sea ice melt leads to atmospheric new particle formation.

Science.gov (United States)

Dall Osto, M; Beddows, D C S; Tunved, P; Krejci, R; Ström, J; Hansson, H-C; Yoon, Y J; Park, Ki-Tae; Becagli, S; Udisti, R; Onasch, T; O Dowd, C D; Simó, R; Harrison, Roy M

2017-06-12

Atmospheric new particle formation (NPF) and growth significantly influences climate by supplying new seeds for cloud condensation and brightness. Currently, there is a lack of understanding of whether and how marine biota emissions affect aerosol-cloud-climate interactions in the Arctic. Here, the aerosol population was categorised via cluster analysis of aerosol size distributions taken at Mt Zeppelin (Svalbard) during a 11 year record. The daily temporal occurrence of NPF events likely caused by nucleation in the polar marine boundary layer was quantified annually as 18%, with a peak of 51% during summer months. Air mass trajectory analysis and atmospheric nitrogen and sulphur tracers link these frequent nucleation events to biogenic precursors released by open water and melting sea ice regions. The occurrence of such events across a full decade was anti-correlated with sea ice extent. New particles originating from open water and open pack ice increased the cloud condensation nuclei concentration background by at least ca. 20%, supporting a marine biosphere-climate link through sea ice melt and low altitude clouds that may have contributed to accelerate Arctic warming. Our results prompt a better representation of biogenic aerosol sources in Arctic climate models.

Global trends of greenhouse gases and stratospheric ozone

International Nuclear Information System (INIS)

Akimoto, H.

1992-01-01

This paper reports that the earth is a closed system in which atmosphere, hydrosphere and biosphere are inter-related by exchanging energy and chemical species. Mankind in itself is a member of biosphere, and is to be harmonized with the earth system. Accompanying the increase of population and energy consumption after the industrial revolution, however, the impact of human activities to the system exceeded the extent of the expected harmonization, which has resulted the global environmental pollution. The structure of the global atmospheric environment system perturbed by the impact of human activities would be summarized

Posiva's Strategy for Biosphere Studies

International Nuclear Information System (INIS)

Hautojaervi, Aimo; Vieno, Timo

2002-01-01

Aimo Hautojaervi (Posiva, Finland) explained that Posiva follows the regulation from authorities that will be published soon on the STUK Web site in an English version. As an example, he said that a dose constraint of 0.1 mSv/a must be considered for several thousand years and release rate constraint for the long term. The values for these constraints were given by STUK and Posiva needs to demonstrate compliance. Posiva welcomes the regulator's clear requirements and guidance in the field of biosphere analyses. Moreover, Aimo Hautojaervi presented the planned future work that will be carried out by Posiva. As well as carrying out biosphere modelling for potential recipients at Olkiluoto, Posiva will conduct biosphere analyses for wells, lakes, seas, etc., and further evaluate human actions and develop biosphere models in close cooperation with SKB. Posiva is also actively seeking international cooperation in these new researches fields, for example within IAEA. Two potentially problematic radionuclides were also mentioned: C-14 and Radon plus decay products. These two radionuclides will be studied in depth in the future Posiva research and development programme

Gene expression in the deep biosphere.

Science.gov (United States)

Orsi, William D; Edgcomb, Virginia P; Christman, Glenn D; Biddle, Jennifer F

2013-07-11

Scientific ocean drilling has revealed a deep biosphere of widespread microbial life in sub-seafloor sediment. Microbial metabolism in the marine subsurface probably has an important role in global biogeochemical cycles, but deep biosphere activities are not well understood. Here we describe and analyse the first sub-seafloor metatranscriptomes from anaerobic Peru Margin sediment up to 159 metres below the sea floor, represented by over 1 billion complementary DNA (cDNA) sequence reads. Anaerobic metabolism of amino acids, carbohydrates and lipids seem to be the dominant metabolic processes, and profiles of dissimilatory sulfite reductase (dsr) transcripts are consistent with pore-water sulphate concentration profiles. Moreover, transcripts involved in cell division increase as a function of microbial cell concentration, indicating that increases in sub-seafloor microbial abundance are a function of cell division across all three domains of life. These data support calculations and models of sub-seafloor microbial metabolism and represent the first holistic picture of deep biosphere activities.

Soil Methanotrophy Model (MeMo v1.0: a process-based model to quantify global uptake of atmospheric methane by soil

Directory of Open Access Journals (Sweden)

F. Murguia-Flores

2018-06-01

Full Text Available Soil bacteria known as methanotrophs are the sole biological sink for atmospheric methane (CH4, a potent greenhouse gas that is responsible for  ∼  20 % of the human-driven increase in radiative forcing since pre-industrial times. Soil methanotrophy is controlled by a plethora of factors, including temperature, soil texture, moisture and nitrogen content, resulting in spatially and temporally heterogeneous rates of soil methanotrophy. As a consequence, the exact magnitude of the global soil sink, as well as its temporal and spatial variability, remains poorly constrained. We developed a process-based model (Methanotrophy Model; MeMo v1.0 to simulate and quantify the uptake of atmospheric CH4 by soils at the global scale. MeMo builds on previous models by Ridgwell et al. (1999 and Curry (2007 by introducing several advances, including (1 a general analytical solution of the one-dimensional diffusion–reaction equation in porous media, (2 a refined representation of nitrogen inhibition on soil methanotrophy, (3 updated factors governing the influence of soil moisture and temperature on CH4 oxidation rates and (4 the ability to evaluate the impact of autochthonous soil CH4 sources on uptake of atmospheric CH4. We show that the improved structural and parametric representation of key drivers of soil methanotrophy in MeMo results in a better fit to observational data. A global simulation of soil methanotrophy for the period 1990–2009 using MeMo yielded an average annual sink of 33.5 ± 0.6 Tg CH4 yr−1. Warm and semi-arid regions (tropical deciduous forest and open shrubland had the highest CH4 uptake rates of 602 and 518 mg CH4 m−2 yr−1, respectively. In these regions, favourable annual soil moisture content ( ∼  20 % saturation and low seasonal temperature variations (variations  <   ∼  6 °C provided optimal conditions for soil methanotrophy and soil–atmosphere gas exchange

Three-dimensional modeling of radiative and convective exchanges in the urban atmosphere

International Nuclear Information System (INIS)

Qu, Yongfeng

2011-01-01

In many micro-meteorological studies, building resolving models usually assume a neutral atmosphere. Nevertheless, urban radiative transfers play an important role because of their influence on the energy budget. In order to take into account atmospheric radiation and the thermal effects of the buildings in simulations of atmospheric flow and pollutant dispersion in urban areas, we have developed a three-dimensional (3D) atmospheric radiative scheme, in the atmospheric module of the Computational Fluid Dynamics model Code-Saturne. The radiative scheme was previously validated with idealized cases, using as a first step, a constant 3D wind field. In this work, the full coupling of the radiative and thermal schemes with the dynamical model is evaluated. The aim of the first part is to validate the full coupling with the measurements of the simple geometry from the 'Mock Urban Setting Test' (MUST) experiment. The second part discusses two different approaches to model the radiative exchanges in urban area with a comparison between Code-Saturne and SOLENE. The third part applies the full coupling scheme to show the contribution of the radiative transfer model on the airflow pattern in low wind speed conditions in a 3D urban canopy. In the last part we use the radiative-dynamics coupling to simulate a real urban environment and validate the modeling approach with field measurements from the 'Canopy and Aerosol Particles Interactions in Toulouse Urban Layer' (CAPITOUL). (author) [fr

Ciliates and the rare biosphere-community ecology and population dynamics.

Science.gov (United States)

Weisse, Thomas

2014-01-01

Application of deep sequencing technologies to environmental samples and some detailed morphological studies suggest that there is a vast, yet unexplored rare ciliate biosphere, tentatively defined in terms of operational taxonomic units. However, very few studies complemented molecular and phylogenetic data with morphological and ecological descriptions of the species inventory. This is mainly because the sampling effort increases strongly with decreasing species abundance. In spite of this limited knowledge, it is clear that species that are rare under certain environmental conditions (temporal rare biosphere) may become abundant when the physical, chemical, and biological variables of their habitat change. Furthermore, some species may always be present in low numbers if their dispersal rates are exceedingly high (accidental rare biosphere). An intriguing question is whether there are some species that are always rare, i.e., in every suitable environment. This permanent rare biosphere is conceptually different from the temporal rare biosphere. This review characterizes typical aquatic habitats of the rare ciliate biosphere, portrays different scenarios under which some or even many species may be permanently rare (background fauna), and identifies some fundamental questions that need to be addressed to achieve a better understanding of the population dynamics of the rare ciliate biosphere. © 2014 The Authors The Journal of Eukaryotic Microbiology published by Wiley Periodicals, Inc. on behalf of International Society of Protistologists.

ISLSCP II C4 Vegetation Percentage

Data.gov (United States)

National Aeronautics and Space Administration — The photosynthetic composition (C3 or C4) of vegetation on the land surface is essential for accurate simulations of biosphere-atmosphere exchanges of carbon, water,...

Biosphere: problems and solutions

Energy Technology Data Exchange (ETDEWEB)

Veziroglu, T.N. (ed.)

1984-01-01

This volume contains a large number of typescript papers from a symposium on the Biosphere, held in Miami Beach in 1984. The topics range from chemical landfills to space debris, with many aspects of chemistry throughout.

Biosphere reserves in action: Case studies of the American experience

Energy Technology Data Exchange (ETDEWEB)

None

1995-06-26

For nearly 20 years, biosphere reserves have offered a unique framework for building the knowledge, skills, and attitudes required for conservation and sustainable use of ecosystems. The 12 case studies in this volume chronicle many of the cooperative efforts to implement the biosphere reserve concept in the United States. Considered together, these efforts involve more than 20 types of protected areas, and the participation of all levels of government, and many private organizations, academic institutions, citizens groups, and individuals. Biosphere reserves are multi-purpose areas that are nominated by the national committee of the Man and the Biosphere Program (MAB) and designated by the United Nations Educational, Scientific and Cultural Organization (UNESCO) to serve as demonstration areas for cooperation in building harmonious relationships between human activities and the conservation of ecosystems and biological diversity. Each biosphere reserve exemplifies the characteristic ecosystems of one of the worlds biogeographical regions. It is a land or coas%arine area involving human communities as integral components and including resources managed for objectives ranging from complete protection to intensive, yet sustainable development. A biosphere reserve is envisioned as a regional ''landscape for learning'' in which monitoring, research, education, and training are encouraged to support sustainable conservation of natural and managed ecosystems. It is a framework for regional cooperation involving government decisionmakers, scientists, resource managers, private organizations and local people (i.e., the biosphere reserve ''stakeholders''). Finally, each biosphere reserve is part of a global network for sharing information and experience to help address complex problems of conservation and development. The 12 case studies presented in this report represent only a few of the possible evolutions of a biosphere reserve in

Components, processes and interactions in the biosphere

Energy Technology Data Exchange (ETDEWEB)

2010-12-15

This report describes the processes and interactions between components in the biosphere that may be important in a safety assessment for radioactive waste disposal. The processes are general, i.e. they can be used in all safety analyses for underground repositories and are not specific to a particular method or location. Processes related to the geosphere and specific repository types (e.g. the KBS-3 method) can be found in /Skagius et al. 1995, SKB 2001, 2006, 2010a/. This report describes a biosphere interaction matrix that has been used in support of SR-Site and that can be used in future safety assessments. The work of defining and characterising processes in the biosphere is ongoing and many persons from different disciplines have been involved in the identification and characterisation of processes

Components, processes and interactions in the biosphere

International Nuclear Information System (INIS)

2010-12-01

This report describes the processes and interactions between components in the biosphere that may be important in a safety assessment for radioactive waste disposal. The processes are general, i.e. they can be used in all safety analyses for underground repositories and are not specific to a particular method or location. Processes related to the geosphere and specific repository types (e.g. the KBS-3 method) can be found in /Skagius et al. 1995, SKB 2001, 2006, 2010a/. This report describes a biosphere interaction matrix that has been used in support of SR-Site and that can be used in future safety assessments. The work of defining and characterising processes in the biosphere is ongoing and many persons from different disciplines have been involved in the identification and characterisation of processes

'Reference Biospheres' for solid radioactive waste disposal. Report of BIOMASS Theme 1 of the BIOsphere Modelling and ASSessment (BIOMASS) Programme. Part of the IAEA Co-ordinated Research Project on Biosphere Modelling and Assessment (BIOMASS)

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

The IAEA Programme on BIOsphere Modelling and ASSessment (BIOMASS) was launched in Vienna in October 1996. The programme was concerned with developing and improving capabilities to predict the transfer of radionuclides in the environment. The programme had three themes: Theme 1: Radioactive Waste Disposal. The objective was to develop the concept of a standard or reference biosphere for application to the assessment of the long-term safety of repositories for radioactive waste. Under the general heading of 'Reference Biospheres', six Task Groups were established: Task Group 1: Principles for the Definition of Critical and Other Exposure Groups. Task Group 2: Principles for the Application of Data to Assessment Models. Task Group 3: Consideration of Alternative Assessment Contexts. Task Group 4: Biosphere System Identification and Justification. Task Group 5: Biosphere System Descriptions. Task Group 6: Model Development. Theme 2: Environmental Releases. BIOMASS provided an international forum for activities aimed at increasing the confidence in methods and models for the assessment of radiation exposure related to environmental releases. Two Working Groups addressed issues concerned with the reconstruction of radiation doses received by people from past releases of radionuclides to the environment and the evaluation of the efficacy of remedial measures. Theme 3: Biosphere Processes. The aim of this Theme was to improve capabilities for modelling the transfer of radionuclides in particular parts of the biosphere identified as being of potential radiological significance and where there were gaps in modelling approaches. This topic was explored using a range of methods including reviews of the literature, model inter-comparison exercises and, where possible, model testing against independent sources of data. Three Working Groups were established to examine the modelling of: (1) long term tritium dispersion in the environment; (2) radionuclide uptake by fruits; and (3

Estimating regional carbon exchange in New England and Quebec by combining atmospheric, ground-based and satellite data

International Nuclear Information System (INIS)

Matross, Daniel M.; Pathmathevan, Mahadevan; Wofsy, Steven C.; Daube, Bruce C.; Gottlieb, Elaine W.; Chow, Victoria Y.; Munger, J.William; Lin, John C.

2006-01-01

We derive regional-scale (∼104 km 2 ) CO 2 flux estimates for summer 2004 in the northeast United States and southern Quebec by assimilating extensive data into a receptor-oriented model-data fusion framework. Surface fluxes are specified using the Vegetation Photosynthesis and Respiration Model (VPRM), a simple, readily optimized biosphere model driven by satellite data, AmeriFlux eddy covariance measurements and meteorological fields. The surface flux model is coupled to a Lagrangian atmospheric adjoint model, the Stochastic Time-Inverted Lagrangian Transport Model (STILT) that links point observations to upwind sources with high spatiotemporal resolution. Analysis of CO 2 concentration data from the NOAA-ESRL tall tower at Argyle, ME and from extensive aircraft surveys, shows that the STILT-VPRM framework successfully links model flux fields to regionally representative atmospheric CO 2 data, providing a bridge between 'bottom-up' and 'top-down' methods for estimating regional CO 2 budgets on timescales from hourly to monthly. The surface flux model, with initial calibration to eddy covariance data, produces an excellent a priori condition for inversion studies constrained by atmospheric concentration data. Exploratory optimization studies show that data from several sites in a region are needed to constrain model parameters for all major vegetation types, because the atmosphere commingles the influence of regional vegetation types, and even high-resolution meteorological analysis cannot disentangle the associated contributions. Airborne data are critical to help define uncertainty within the optimization framework, showing for example, that in summertime CO 2 concentration at Argyle (107 m) is ∼0.6 ppm lower than the mean in the planetary boundary layer

The biosphere rules.

Science.gov (United States)

Unruh, Gregory C

2008-02-01

Sustainability, defined by natural scientists as the capacity of healthy ecosystems to function indefinitely, has become a clarion call for business. Leading companies have taken high-profile steps toward achieving it: Wal-Mart, for example, with its efforts to reduce packaging waste, and Nike, which has removed toxic chemicals from its shoes. But, says Unruh, the director of Thunderbird's Lincoln Center for Ethics in Global Management, sustainability is more than an endless journey of incremental steps. It is a destination, for which the biosphere of planet Earth--refined through billions of years of trial and error--is a perfect model. Unruh distills some lessons from the biosphere into three rules: Use a parsimonious palette. Managers can rethink their sourcing strategies and dramatically simplify the number and types of materials their companies use in production, making recycling cost-effective. After the furniture manufacturer Herman Miller discovered that its leading desk chair had 200 components made from more than 800 chemical compounds, it designed an award-winning successor whose far more limited materials palette is 96% recyclable. Cycle up, virtuously. Manufacturers should design recovery value into their products at the outset. Shaw Industries, for example, recycles the nylon fiber from its worn-out carpet into brand-new carpet tile. Exploit the power of platforms. Platform design in industry tends to occur at the component level--but the materials in those components constitute a more fundamental platform. Patagonia, by recycling Capilene brand performance underwear, has achieved energy costs 76% below those for virgin sourcing. Biosphere rules can teach companies how to build ecologically friendly products that both reduce manufacturing costs and prove highly attractive to consumers. And managers need not wait for a green technological revolution to implement them.

Atmospheric deposition and air-sea gas exchange fluxes of DDT and HCH in the Yangtze River Estuary, East China Sea

Science.gov (United States)

Li, Zhongxia; Lin, Tian; Li, Yuanyuan; Jiang, Yuqing; Guo, Zhigang

2017-07-01

The Yangtze River Estuary (YRE) is strongly influenced by the Yangtze River and lies on the pathway of the East Asian Monsoon. This study examined atmospheric deposition and air-sea gas exchange fluxes of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) to determine whether the YRE is a sink or source of selected pesticides at the air-water interface under the influences of river input and atmospheric transport. The air-sea gas exchange of DDT was characterized by net volatilization with a marked difference in its fluxes between summer (140 ng/m2/d) and the other three seasons (12 ng/m2/d), possibly due to the high surface seawater temperatures and larger riverine input in summer. However, there was no obvious seasonal variation in the atmospheric HCH deposition, and the air-sea gas exchange reached equilibrium because of low HCH levels in the air and seawater after the long-term banning of HCH and the degradation. The gas exchange flux of HCH was comparable to the dry and wet deposition fluxes at the air-water interface. This suggests that the influences from the Yangtze River input and East Asian continental outflow on the fate of HCH in the YRE were limited. The gas exchange flux of DDT was about fivefold higher than the total dry and wet deposition fluxes. DDT residues in agricultural soil transported by enhanced riverine runoff were responsible for sustaining such a high net volatilization in summer. Moreover, our results indicated that there were fresh sources of DDT from the local environment to sustain net volatilization throughout the year.

Integrate Data into Scientific Workflows for Terrestrial Biosphere Model Evaluation through Brokers

Science.gov (United States)

Wei, Y.; Cook, R. B.; Du, F.; Dasgupta, A.; Poco, J.; Huntzinger, D. N.; Schwalm, C. R.; Boldrini, E.; Santoro, M.; Pearlman, J.; Pearlman, F.; Nativi, S.; Khalsa, S.

2013-12-01

Terrestrial biosphere models (TBMs) have become integral tools for extrapolating local observations and process-level understanding of land-atmosphere carbon exchange to larger regions. Model-model and model-observation intercomparisons are critical to understand the uncertainties within model outputs, to improve model skill, and to improve our understanding of land-atmosphere carbon exchange. The DataONE Exploration, Visualization, and Analysis (EVA) working group is evaluating TBMs using scientific workflows in UV-CDAT/VisTrails. This workflow-based approach promotes collaboration and improved tracking of evaluation provenance. But challenges still remain. The multi-scale and multi-discipline nature of TBMs makes it necessary to include diverse and distributed data resources in model evaluation. These include, among others, remote sensing data from NASA, flux tower observations from various organizations including DOE, and inventory data from US Forest Service. A key challenge is to make heterogeneous data from different organizations and disciplines discoverable and readily integrated for use in scientific workflows. This presentation introduces the brokering approach taken by the DataONE EVA to fill the gap between TBMs' evaluation scientific workflows and cross-organization and cross-discipline data resources. The DataONE EVA started the development of an Integrated Model Intercomparison Framework (IMIF) that leverages standards-based discovery and access brokers to dynamically discover, access, and transform (e.g. subset and resampling) diverse data products from DataONE, Earth System Grid (ESG), and other data repositories into a format that can be readily used by scientific workflows in UV-CDAT/VisTrails. The discovery and access brokers serve as an independent middleware that bridge existing data repositories and TBMs evaluation scientific workflows but introduce little overhead to either component. In the initial work, an OpenSearch-based discovery broker

Quantifying the Pathway and Predicting Spontaneous Emulsification during Material Exchange in a Two Phase Liquid System.

Science.gov (United States)

Spooner, Stephen; Rahnama, Alireza; Warnett, Jason M; Williams, Mark A; Li, Zushu; Sridhar, Seetharaman

2017-10-30

Kinetic restriction of a thermodynamically favourable equilibrium is a common theme in materials processing. The interfacial instability in systems where rate of material exchange is far greater than the mass transfer through respective bulk phases is of specific interest when tracking the transient interfacial area, a parameter integral to short processing times for productivity streamlining in all manufacturing where interfacial reaction occurs. This is even more pertinent in high-temperature systems for energy and cost savings. Here the quantified physical pathway of interfacial area change due to material exchange in liquid metal-molten oxide systems is presented. In addition the predicted growth regime and emulsification behaviour in relation to interfacial tension as modelled using phase-field methodology is shown. The observed in-situ emulsification behaviour links quantitatively the geometry of perturbations as a validation method for the development of simulating the phenomena. Thus a method is presented to both predict and engineer the formation of micro emulsions to a desired specification.

Theoretical foundation, goals, and methodology of a new science--biospherics

Science.gov (United States)

Shaffer, J A

1994-01-01

Scientific endeavor is motivated by mankind's needs, desires, and inherent nature to explore. The history of scientific revolutions involves paradigmatic breakthroughs that uncover previously unknown perspectives by which a phenomenon can be viewed. In this issue a noted scientist, Nickolai Pechurkin, gives a seminal brief on the theoretical foundation, goals, and methodology leading to a new science--biospherics. While biospherics has so far eluded a simple definition, it is not something taken from "whole cloth." Biospherics has many antecedents, but most noticeably arises from the global scale research and theory associated with the technological advances of the Space-Age. The Space-Age also created the need for totally closed life-support systems which involve experimentation with artificial biospheres.

Enhanced transfer of terrestrially derived carbon to the atmosphere in a flooding event

Science.gov (United States)

Bianchi, Thomas S.; Garcia-Tigreros, Fenix; Yvon-Lewis, Shari A.; Shields, Michael; Mills, Heath J.; Butman, David; Osburn, Christopher; Raymond, Peter A.; Shank, G. Christopher; DiMarco, Steven F.; Walker, Nan; Kiel Reese, Brandi; Mullins-Perry, Ruth; Quigg, Antonietta; Aiken, George R.; Grossman, Ethan L.

2013-01-01

Rising CO2 concentration in the atmosphere, global climate change, and the sustainability of the Earth's biosphere are great societal concerns for the 21st century. Global climate change has, in part, resulted in a higher frequency of flooding events, which allow for greater exchange between soil/plant litter and aquatic carbon pools. Here we demonstrate that the summer 2011 flood in the Mississippi River basin, caused by extreme precipitation events, resulted in a “flushing” of terrestrially derived dissolved organic carbon (TDOC) to the northern Gulf of Mexico. Data from the lower Atchafalaya and Mississippi rivers showed that the DOC flux to the northern Gulf of Mexico during this flood was significantly higher than in previous years. We also show that consumption of radiocarbon-modern TDOC by bacteria in floodwaters in the lower Atchafalaya River and along the adjacent shelf contributed to northern Gulf shelf waters changing from a net sink to a net source of CO2 to the atmosphere in June and August 2011. This work shows that enhanced flooding, which may or may not be caused by climate change, can result in rapid losses of stored carbon in soils to the atmosphere via processes in aquatic ecosystems.

The General Laws of Chemical Elements Composition Dynamics in the Biosphere

Science.gov (United States)

Korzh, Vyacheslav D.

2013-04-01

The key point of investigation of the specificity of the biosphere elemental composition formation is determination of patterns of redistribution of elemental average concentrations among various phases, like solid - liquid ( the lithosphere - the hydrosphere), which occurs as a result of a global continuous processing of inert matter by living substances. Our task here is to investigate this process in the system "lithosphere - hydrosphere" in view of the integrated involvement of living material in it. This process is most active in biogeochemical barriers, i.e. in places of "the life condensation" and runs under a nonlinear regularity that has been unknown before. It is established that this process results in a general relative increase in concentrations of chemical elements in the solid phase in proportion as their prevalence in the environment is reduced. This process running in various natural systems has practically the same parameter of nonlinearity (v) approximately equal to 0.7. For proto-lithosphere -"living material" - soil v = 0.75. For river - "living material" - ocean v = 0.67. For the contemporary factual awareness level these estimations of nonlinearity indices are practically negligible. Hence, it is for the first time that the existence of a universal constant of nonlinearity of elemental composition evolution in the biosphere has been proved and its quantitative evaluation has been made. REFERENCES 1. Korzh V.D. 1974. Some general laws governing the turnover of substance within the ocean-atmosphere-continent-ocean cycle. // Journal de Recherches Atmospheriques. Vol. 8. P. 653-660. 2. Korzh V.D. 2008. The general laws in the formation of the elemental composition of the Hydrosphere and Biosphere.// J. Ecologica, Vol. XV, P. 13-21. 3. Korzh V.D. 2012. Determination of general laws of elemental composition in Hydrosphere // Water: chemistry & ecology, Journal of water science and its practical application. # 1, P.56-62.

Impact of a global warming on biospheric sources of methane and its climatic consequences

Energy Technology Data Exchange (ETDEWEB)

Hameed, S; Cess, R D

1983-01-01

Most atmospheric methane originates by bacterial processes in anaerobic environments within the soil, which become more productive with increases in ambient temperature. A warming of the climate, due to increasing levels of industrial gases resulting from fossil fuel burning, is likely to increase methane concentrations within the atmosphere, possibly leading to further heating, since both methane and ozone (which is generated in the troposphere from reactions of methane) have greenhouse effects. Investigators explored this feedback mechanism using a coupled climate-chemical model of the troposphere, by calculating the impact of the predicted global warming due to increased emissions of carbon dioxide and other industrial gases on the biospheric sources of methane. Although they found this climate feedback to be, by itself, relatively minor, it can produce measurable increases in atmospheric CH/sub 4/ concentration, a quantity that should additionally increase as a consequence of increasing anthropogenic emissions of CO and CH/sub 4/.

Biosphere dose conversion Factor Importance and Sensitivity Analysis

International Nuclear Information System (INIS)

M. Wasiolek

2004-01-01

This report presents importance and sensitivity analysis for the environmental radiation model for Yucca Mountain, Nevada (ERMYN). ERMYN is a biosphere model supporting the total system performance assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis concerns the output of the model, biosphere dose conversion factors (BDCFs) for the groundwater, and the volcanic ash exposure scenarios. It identifies important processes and parameters that influence the BDCF values and distributions, enhances understanding of the relative importance of the physical and environmental processes on the outcome of the biosphere model, includes a detailed pathway analysis for key radionuclides, and evaluates the appropriateness of selected parameter values that are not site-specific or have large uncertainty

'Reference Biospheres' for solid radioactive waste disposal: the BIOMASS Methodology

International Nuclear Information System (INIS)

Crossland, I.G.; Pinedo, P.; Kessler, J.H.; Torres-Vidal, C.; Walters, B.

2005-01-01

The BIOMASS Theme 1 project has developed a methodology for the logical and defensible construction of 'assessment biospheres': mathematical representations of biospheres used in the total system performance assessment of radioactive waste disposal. The BIOMASS Methodology provides a systematic approach to decision making, including decisions on how to address biosphere change. The BIOMASS Methodology was developed through consultation and collaboration with many relevant organisations, including regulators, operators and a variety of independent experts. It has been developed to be practical and to be consistent with recommendations from ICRP and IAEA on radiation protection in the context of the disposal of long-lived solid radioactive wastes. The five main steps in the methodology are described in this paper. The importance of a clear assessment context, to clarify intentions and to support a coherent biosphere assessment process within an overall repository performance assessment, is strongly emphasised. A well described assessment context is an important tool for ensuring consistency across the performance assessment as a whole. The use of interaction matrices has been found to be helpful in clarifying the interactions between different habitats within the biosphere system and the significant radionuclide transfer pathways within the biosphere system. Matrices also provide a useful means of checking for consistency

Implementation of a Marauding Insect Module (MIM, version 1.0) in the Integrated BIosphere Simulator (IBIS, version 2.6b4) dynamic vegetation-land surface model

Science.gov (United States)

Landry, Jean-Sébastien; Price, David T.; Ramankutty, Navin; Parrott, Lael; Damon Matthews, H.

2016-04-01

Insects defoliate and kill plants in many ecosystems worldwide. The consequences of these natural processes on terrestrial ecology and nutrient cycling are well established, and their potential climatic effects resulting from modified land-atmosphere exchanges of carbon, energy, and water are increasingly being recognized. We developed a Marauding Insect Module (MIM) to quantify, in the Integrated BIosphere Simulator (IBIS), the consequences of insect activity on biogeochemical and biogeophysical fluxes, also accounting for the effects of altered vegetation dynamics. MIM can simulate damage from three different insect functional types: (1) defoliators on broadleaf deciduous trees, (2) defoliators on needleleaf evergreen trees, and (3) bark beetles on needleleaf evergreen trees, with the resulting impacts being estimated by IBIS based on the new, insect-modified state of the vegetation. MIM further accounts for the physical presence and gradual fall of insect-killed dead standing trees. The design of MIM should facilitate the addition of other insect types besides the ones already included and could guide the development of similar modules for other process-based vegetation models. After describing IBIS-MIM, we illustrate the usefulness of the model by presenting results spanning daily to centennial timescales for vegetation dynamics and cycling of carbon, energy, and water in a simplified setting and for bark beetles only. More precisely, we simulated 100 % mortality events from the mountain pine beetle for three locations in western Canada. We then show that these simulated impacts agree with many previous studies based on field measurements, satellite data, or modelling. MIM and similar tools should therefore be of great value in assessing the wide array of impacts resulting from insect-induced plant damage in the Earth system.

Biosphere modeling for safety assessment to high-level radioactive waste geological disposal. Application of reference biosphere methodology to safety assesment of geological disposal

International Nuclear Information System (INIS)

Baba, Tomoko; Ishihara, Yoshinao; Ishiguro, Katsuhiko; Suzuki, Yuji; Naito, Morimasa

2000-01-01

In the safety assessment of a high-level radioactive waste disposal system, it is required to estimate future radiological impacts on human beings. Consideration of living habits and the human environment in the future involves a large degree of uncertainty. To avoid endless speculation aimed at reducing such uncertainty, an approach is applied for identifying and justifying a 'reference biosphere' for use in safety assessment in Japan. considering a wide range of Japanese geological environments, saline specific reference biospheres' were developed using an approach consistent with the BIOMOVS II reference biosphere methodology. (author)

Carbon cycling and gas exchange in soils

International Nuclear Information System (INIS)

Trumbore, S.E.

1989-01-01

This thesis summaries three independent projects, each of which describes a method which can be used to study the role of soils in regulating the atmospheric concentrations of CO 2 and other trace gases. The first chapter uses the distribution of natural and bomb produced radiocarbon in fractionated soil organic matter to quantify the turnover of carbon in soils. A comparison of 137 Cs and 14 C in the modern soil profiles indicates that carbon is transported vertically in the soil as dissolved organic material. The remainder of the work reported is concerned with the use of inert trace gases to explore the physical factors which control the seasonal to diel variability in the fluxes of CO 2 and other trace gases from soils. Chapter 2 introduces a method for measuring soil gas exchange rates in situ using sulfur hexafluoride as a purposeful tracer. The measurement method uses standard flux box technology, and includes simultaneous determination of the fluxes and soil atmosphere concentrations of CO 2 and CH 4 . In Chapter 3, the natural tracer 222 Rn is used as an inert analog for exchange both in the soils and forest canopy of the Amazon rain forest

Tropical rainforest biome of Biosphere 2. Structure, composition and results of the first 2 years of operation

Energy Technology Data Exchange (ETDEWEB)

Leigh, Linda S. [Systems Ecology and Energy Analysis Program, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL (United States); Burgess, Tony; Marino, Bruno D.V.; Wei, Yong Dan [Biosphere 2 Center, Inc. P.O. Box 689, Oracle, AZ (United States)

1999-06-01

The tropical rainforest biome in the Biosphere 2 mesocosm was managed with rainfall and temperature conditions to simulate a natural rainforest typical of the new world tropics. The establishment of the biome was based on the introduction of excessive numbers of species allowing self-organization of an ecologically unique rainforest. Over 282 species of plants from rainforest areas were planted within the topographically diverse rainforest biome (area of 1900 m{sup 2}, volume of 35,000 m{sup 3}), just before the Biosphere 2 closure in 1991. Approximately 61% of these species survived when counted in 1993, representing a plant species richness reduction to 172 species in 0.19 hectare. Rank order graphs show that a high diversity community resulted not unlike insular rainforests. The plants of the rainforest mesocosm, however, grew under anomalous conditions of soil (amended desert grassland soil), atmospheric composition (CO{sub 2} up to 4500 ppm by volume (ppmv)) and rainwater composition (high salinity and nutrients). Stem growth rates of a dominant canopy tree, Cecropia, were up to four times higher but had reduced diameter at breast height compared to natural counterparts. Human intervention in plant succession was also an important factor in shaping the ecology of the rainforest biome of Biosphere 2

Improvement of biosphere assessment methodology for performance assessment of geological disposal facility. 2

International Nuclear Information System (INIS)

Miki, Takahito; Yoshida, Hideji; Ikeda, Takao

2002-02-01

This report contains results on study of Geosphere-Biosphere Interface (GBI), development of biosphere assessment model for gaseous and volatile radionuclides, review of biosphere assessment and research on safety indicators. Regarding study of Geosphere-Biosphere Interface (GBI), FEP database for the Geosphere-Biosphere Transitions Zone (GBTZ) were compiled. Furthermore, release scenarios were identified from the FEP database, and review of conservativeness and robustness of the conceptual and mathematical models developed previously by JNC were undertaken. Regarding development of biosphere assessment model for gaseous and volatile radionuclides, the conceptual and mathematical models were developed, and it was confirmed that the impact of the exposure pathway regarding gas release to flux-to-dose conversion factor is small. Regarding review of biosphere assessment data, the parameters which were used on JNC second progress report were reviewed and classified using the biosphere data protocol categories. Furthermore, the data for key parameter (important but poorly characterized parameters) were revised. Regarding research on safety indicator, some kinds of safety indicators, especially for the non-radioactive contaminant and for the non-human biota, are reviewed. (author)

Earth Applications of Closed Ecological Systems: Relevance to the Development of Sustainability in our Global Biosphere

Science.gov (United States)

Dempster, W.; van Thillo, M.; Alling, A.; Allen, J.; Silverstone, S.; Nelson, M.

The parallels between the challenges facing bioregenerative life support and closed ecological systems and those in our global biosphere are striking. At the scale of the current global technosphere and human population, it is increasingly obvious that the biosphere can no longer be counted on to be vast enough to safely buffer and absorb technogenic and anthropogenic pollutants. With an increasing percentage of the world's natural resources and primary productivity being dictated by, and directed to, humans, our species is starting to appreciate its survival and quality of life depends on regulating its activities, and insuring that crucial biogeochemical cycles continue to function. This shift of consciousness has led to the widespread call for moving towards the sustainability of human activities. For researchers working on bioreenerative life support, the small volumes and faster cycling times have made it obvious that systems must be created in to ensure renewal of water and atmosphere, nutrient recycling, and where all technical systems can be safely integrated with the maintenance of safe environmental conditions. The development of technical systems that can be fully integrated with the living systems that they support should be a harbinger of new perspectives in the global environment. The paper will review some of these environmental technologies which are emerging from bioregenerative life support system research such as high-yield intensive agricultural methods, waste treatment and nutrient recycling, air purification, modeling, sensor and control systems and their potential applications in the global biosphere. In addition, a review of the human experience in closed ecological systems shows that these can offer opportunities for public education and consciousness-changing of how humans regard our global biosphere.

Investigations on iodine-129 in the biosphere

International Nuclear Information System (INIS)

Handl, J.; Oliver, E.; Jakob, D.

1992-01-01

In order to detect characteristic regional differences or temporal changes of iodine-129 concentrations in the biosphere, thyroids from humans, grazing livestock and roedeer (Capreolus capreolus L.) are collected in various parts of the world, which are differing in the exposure to I-129 immissions from nuclear sources. For reasons of comparison all samples are analysed for their I-129/I-127 atom ratios. Human thyroids taken from Lower Saxony (Federal Republic of Germany), which is a region not directly affected by reprocessing plants showed I-129/I-127 values between 8x10 -9 and 6x10 -8 for a period from February 1988 to September 1990. Those atom ratios correspond to the level of biospheric I-129 in background areas of Europe exposed to fallout atmospheric nuclear weapons tests during the 1950s and 1960s. Thyroid glands of roedeer taken from the Heby commune in Middle Sweden during spring 1990 showed I-129/I-127 ratios between 2x10 -7 and 4x10 -7 . Two soil samples taken from Krasnaya Gora and Mirny locations in Russia (about 200 km northwest of Chernobyl) exhibited ratios of about 1x10 -6 . According to the Cs-137 levels, the Swedish Heby area as well as both Russian locations were found to be seriously Chernobyl contaminated. Ratios found in human and bovine thyroids collected in the 10th Region in southern Chile (40deg-42degS) indicated values between 1x10 -10 and 9x10 -9 . On the basis of the prenuclear range of I-129/I-127 ratios between 4x10 -11 and 3x10 -9 , which were found in human thyroids analysed in the USA before 1945 the Chilean values can be considered only slightly elevated as compared to those determined in samples of Northern Hemisphere today. (orig.) [de

Biospheres and solar system exploration

Science.gov (United States)

Paine, Thomas O.

1990-01-01

The implications of biosphere technology is briefly examined. The exploration status and prospects of each world in the solar system is briefly reviewed, including the asteroid belt, the moon, and comets. Five program elements are listed as particularly critical for future interplanetary operations during the coming extraterrestrial century. They include the following: (1) a highway to Space (earth orbits); (2) Orbital Spaceports to support spacecraft assembly, storage, repair, maintenance, refueling, launch, and recovery; (3) a Bridge Between Worlds to transport cargo and crews to the moon and beyond to Mars; (4) Prospecting and Resource Utilization Systems to map and characterize the resources of planets, moons, and asteroids; and (5) Closed Ecology Biospheres. The progress in these five field is reviewed.

Comparison of GCM subgrid fluxes calculated using BATS and SiB schemes with a coupled land-atmosphere high-resolution model

Energy Technology Data Exchange (ETDEWEB)

Shen, Jinmei; Arritt, R.W. [Iowa State Univ., Ames, IA (United States)

1996-12-31

The importance of land-atmosphere interactions and biosphere in climate change studies has long been recognized, and several land-atmosphere interaction schemes have been developed. Among these, the Simple Biosphere scheme (SiB) of Sellers et al. and the Biosphere Atmosphere Transfer Scheme (BATS) of Dickinson et al. are two of the most widely known. The effects of GCM subgrid-scale inhomogeneities of surface properties in general circulation models also has received increasing attention in recent years. However, due to the complexity of land surface processes and the difficulty to prescribe the large number of parameters that determine atmospheric and soil interactions with vegetation, many previous studies and results seem to be contradictory. A GCM grid element typically represents an area of 10{sup 4}-10{sup 6} km{sup 2}. Within such an area, there exist variations of soil type, soil wetness, vegetation type, vegetation density and topography, as well as urban areas and water bodies. In this paper, we incorporate both BATS and SiB2 land surface process schemes into a nonhydrostatic, compressible version of AMBLE model (Atmospheric Model -- Boundary-Layer Emphasis), and compare the surface heat fluxes and mesoscale circulations calculated using the two schemes. 8 refs., 5 figs.

BASIN TCP Stable Isotope Composition of CO2 in Terrestrial Ecosystems

Data.gov (United States)

National Aeronautics and Space Administration — This data set reports stable isotope ratio data of CO2 (13C/12C and 18O/16O) associated with photosynthetic and respiratory exchanges across the biosphere-atmosphere...

Estimation of net ecosystem carbon exchange for the conterminous United States by combining MODIS and AmeriFlux data

Energy Technology Data Exchange (ETDEWEB)

Xiao, Jingfeng; Zhuang, Qianlai; Baldocchi, Dennis D.; Bolstad, Paul V.; Burns, Sean P.; Chen, Jiquan; Cook, David R.; Curtis, Peter S.; Drake, Bert G.; Foster, David R.; Gu, Lianhong; Hadley, Julian L.; Hollinger, David Y.; Katul, Gabriel G.; Law, Beverly E.; Litvak, Marcy; Ma, Siyan; Martin, Timothy A.; Matamala, Roser; McNulty, Steve; Meyers, Tilden P.; Monson, Russell K.; Munger, J. William; Noormets, Asko; Oechel, Walter C.; Oren, Ram; Richardson, Andrew D.; Schmid, Hans Peter; Scott, Russell L.; Starr, Gregory; Sun, Ge; Suyker, Andrew E.; Torn, Margaret S.; Paw, Kyaw; Verma, Shashi B.; Wharton, Sonia; Wofsy, Steven C.

2008-10-01

Eddy covariance flux towers provide continuous measurements of net ecosystem carbon exchange (NEE) for a wide range of climate and biome types. However, these measurements only represent the carbon fluxes at the scale of the tower footprint. To quantify the net exchange of carbon dioxide between the terrestrial biosphere and the atmosphere for regions or continents, flux tower measurements need to be extrapolated to these large areas. Here we used remotely sensed data from the Moderate Resolution Imaging Spectrometer (MODIS) instrument on board the National Aeronautics and Space Administration's (NASA) Terra satellite to scale up AmeriFlux NEE measurements to the continental scale. We first combined MODIS and AmeriFlux data for representative U.S. ecosystems to develop a predictive NEE model using a modified regression tree approach. The predictive model was trained and validated using eddy flux NEE data over the periods 2000-2004 and 2005-2006, respectively. We found that the model predicted NEE well (r = 0.73, p < 0.001). We then applied the model to the continental scale and estimated NEE for each 1 km x 1 km cell across the conterminous U.S. for each 8-day interval in 2005 using spatially explicit MODIS data. The model generally captured the expected spatial and seasonal patterns of NEE as determined from measurements and the literature. Our study demonstrated that our empirical approach is effective for scaling up eddy flux NEE measurements to the continental scale and producing wall-to-wall NEE estimates across multiple biomes. Our estimates may provide an independent dataset from simulations with biogeochemical models and inverse modeling approaches for examining the spatiotemporal patterns of NEE and constraining terrestrial carbon budgets over large areas.

Spanish methodological approach for biosphere assessment of radioactive waste disposal

International Nuclear Information System (INIS)

Agueero, A.; Pinedo, P.; Cancio, D.; Simon, I.; Moraleda, M.; Perez-Sanchez, D.; Trueba, C.

2007-01-01

The development of radioactive waste disposal facilities requires implementation of measures that will afford protection of human health and the environment over a specific temporal frame that depends on the characteristics of the wastes. The repository design is based on a multi-barrier system: (i) the near-field or engineered barrier, (ii) far-field or geological barrier and (iii) the biosphere system. Here, the focus is on the analysis of this last system, the biosphere. A description is provided of conceptual developments, methodological aspects and software tools used to develop the Biosphere Assessment Methodology in the context of high-level waste (HLW) disposal facilities in Spain. This methodology is based on the BIOMASS 'Reference Biospheres Methodology' and provides a logical and systematic approach with supplementary documentation that helps to support the decisions necessary for model development. It follows a five-stage approach, such that a coherent biosphere system description and the corresponding conceptual, mathematical and numerical models can be built. A discussion on the improvements implemented through application of the methodology to case studies in international and national projects is included. Some facets of this methodological approach still require further consideration, principally an enhanced integration of climatology, geography and ecology into models considering evolution of the environment, some aspects of the interface between the geosphere and biosphere, and an accurate quantification of environmental change processes and rates

Spanish methodological approach for biosphere assessment of radioactive waste disposal.

Science.gov (United States)

Agüero, A; Pinedo, P; Cancio, D; Simón, I; Moraleda, M; Pérez-Sánchez, D; Trueba, C

2007-10-01

The development of radioactive waste disposal facilities requires implementation of measures that will afford protection of human health and the environment over a specific temporal frame that depends on the characteristics of the wastes. The repository design is based on a multi-barrier system: (i) the near-field or engineered barrier, (ii) far-field or geological barrier and (iii) the biosphere system. Here, the focus is on the analysis of this last system, the biosphere. A description is provided of conceptual developments, methodological aspects and software tools used to develop the Biosphere Assessment Methodology in the context of high-level waste (HLW) disposal facilities in Spain. This methodology is based on the BIOMASS "Reference Biospheres Methodology" and provides a logical and systematic approach with supplementary documentation that helps to support the decisions necessary for model development. It follows a five-stage approach, such that a coherent biosphere system description and the corresponding conceptual, mathematical and numerical models can be built. A discussion on the improvements implemented through application of the methodology to case studies in international and national projects is included. Some facets of this methodological approach still require further consideration, principally an enhanced integration of climatology, geography and ecology into models considering evolution of the environment, some aspects of the interface between the geosphere and biosphere, and an accurate quantification of environmental change processes and rates.

Using remote-sensing and the Simple Biosphere model (SiB4) to analyze the seasonality and productivity of the terrestrial biosphere.

Science.gov (United States)

Cheeseman, M.; Denning, S.; Baker, I. T.

2017-12-01

Understanding the variability and seasonality of carbon fluxes from the terrestrial biosphere is integral to understanding the mechanisms and drivers of the global carbon cycle. However, there are many regions across the globe where in situ observations are sparse, such as the Amazon rainforest and the African Sahel. The latest version of the Simple-Biosphere model (SiB4) predicts a suite of biophysical variables such as terrestrial carbon flux (GPP), solar induced fluorescence (SIF), fraction of photosynthetically active radiation (FPAR), and leaf area index (LAI). By comparing modeled values to a suite of satellite and in situ observations we produce a robust analysis of the seasonality and productivity of the terrestrial biosphere in a variety of biome types across the globe.

A model of accumulation of radionuclides in biosphere originating from groundwater contamination

International Nuclear Information System (INIS)

Gaerdenaes, Annemieke; Jansson, Per-Erik; Karlberg, Louise

2006-03-01

The objective of this study is to introduce a module in CoupModel describing the transport and accumulation in the biosphere of a radionuclide originating from a ground water contamination. Two model approaches describing the plant uptake of a radionuclide were included, namely passive and active uptake. Passive uptake means in this study that the root uptake rate of a radionuclide is governed by water uptake. Normal mechanism for the passive water uptake is the convective flux of water from the soil to the plant. An example of element taken up passively is Ca. Active plant uptake is in this model defined as the root uptake rate of a radionuclide that is governed by carbon assimilation i.e. photosynthesis and plant growth. The actively taken up element can for example be an element essential to plant, but not available in high enough concentration by passive uptake alone, like the major nutrients N and P or an element that very well resembles a plant nutrient, like Cs resembles K. Active uptake of trace element may occur alone or in addition to passive uptake. Normal mechanism for the active uptake is molecular diffusion from the soil solution to the roots or via any other organism living in symbiosis with the roots like the mycorrhiza. Also a model approach describing adsorption was introduced. CoupModel dynamically couples and simulates the flows of water, heat, carbon and nitrogen in the soil/plant/atmosphere system. Any number of plants may be defined and are divided into roots, leaves, stem and grain. The soil is considered in one vertical profile that may be represented into a maximum of 100 layers. The model is the windows-successor and integrated version of the DOS-models SOIL and SOILN, which have been widely used on different ecosystems and climate regions during 25 years time period. To this soil/plant/atmosphere model were introduced a module describing accumulation of a radionuclide in the biosphere originating from groundwater contamination. The

A model of accumulation of radionuclides in biosphere originating from groundwater contamination

Energy Technology Data Exchange (ETDEWEB)

Gaerdenaes, Annemieke [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Soil Sciences; Jansson, Per-Erik; Karlberg, Louise [Royal Inst. of Technology, Stockholm (Sweden). Dept. Land and Water Resources

2006-03-15

The objective of this study is to introduce a module in CoupModel describing the transport and accumulation in the biosphere of a radionuclide originating from a ground water contamination. Two model approaches describing the plant uptake of a radionuclide were included, namely passive and active uptake. Passive uptake means in this study that the root uptake rate of a radionuclide is governed by water uptake. Normal mechanism for the passive water uptake is the convective flux of water from the soil to the plant. An example of element taken up passively is Ca. Active plant uptake is in this model defined as the root uptake rate of a radionuclide that is governed by carbon assimilation i.e. photosynthesis and plant growth. The actively taken up element can for example be an element essential to plant, but not available in high enough concentration by passive uptake alone, like the major nutrients N and P or an element that very well resembles a plant nutrient, like Cs resembles K. Active uptake of trace element may occur alone or in addition to passive uptake. Normal mechanism for the active uptake is molecular diffusion from the soil solution to the roots or via any other organism living in symbiosis with the roots like the mycorrhiza. Also a model approach describing adsorption was introduced. CoupModel dynamically couples and simulates the flows of water, heat, carbon and nitrogen in the soil/plant/atmosphere system. Any number of plants may be defined and are divided into roots, leaves, stem and grain. The soil is considered in one vertical profile that may be represented into a maximum of 100 layers. The model is the windows-successor and integrated version of the DOS-models SOIL and SOILN, which have been widely used on different ecosystems and climate regions during 25 years time period. To this soil/plant/atmosphere model were introduced a module describing accumulation of a radionuclide in the biosphere originating from groundwater contamination. The

Carbon dioxide exchange between atmosphere and ocean and the question of an increase of atmospheric CO/sub 2/ during the past decades

Energy Technology Data Exchange (ETDEWEB)

Revelle, R; Suess, H E

1957-01-01

From a comparison of C/sup 14//C/sup 12/ and C/sup 13//C/sup 12/ ratios in wood and in marine material and from a slight decrease of the C/sup 14/ concentration in terrestrial plants over the past 50 years it can be concluded that the average lifetime of a CO/sub 2/ molecule in the atmosphere before it is dissolved into the sea is of the order of 10 years. This means that most of the CO/sub 2/ released by artificial fuel combustion since the beginning of the industrial revolution must have been absorbed by the oceans. The increase of atmospheric CO/sub 2/ from this cause is at present small but may become significant during future decades of industrial fuel combustion continues to rise exponentially. Present data on the total amount of CO/sub 2/ in the atmosphere, on the rates and mechanisms of exchange, and on possible fluctuations in terrestrial and marine organic carbon, are inadequate for accurate measurement of future changes in atmospheric CO/sub 2/. An opportunity exists during the international geophysical year to obtain much of the necessary information.

Analysis specifications for the CC3 biosphere model biotrac

Energy Technology Data Exchange (ETDEWEB)

Szekely, J G; Wojciechowski, L C; Stephens, M E; Halliday, H A

1994-12-01

The CC3 (Canadian Concept, generation 3) model BIOTRAC (Biosphere Transport and Consequences) describes the movement in the biosphere of releases from an underground disposal vault, and the consequent radiological dose to a reference individual. Concentrations of toxic substances in different parts of the biosphere are also calculated. BIOTRAC was created specifically for the postclosure analyses of the Environmental Impact Statement that AECL is preparing on the concept for disposal of Canada`s nuclear fuel waste. The model relies on certain assumptions and constraints on the system, which are described by Davis et al. Accordingly, great care must be exercised if BIOTRAC is used for any other purpose.

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.

Advective transport of CO2 in permeable media induced by atmospheric pressure fluctuations: 1. An analytical model

Science.gov (United States)

W. J. Massman

2006-01-01

Advective flows within soils and snowpacks caused by pressure fluctuations at the upper surface of either medium can significantly influence the exchange rate of many trace gases from the underlying substrate to the atmosphere. Given the importance of many of these trace gases in understanding biogeochemical cycling and global change, it is crucial to quantify (as much...

Improvement of thermal exchange between feedstock and effluent in a hydrocarbon processing unit under hydrogen atmosphere by partial recycling of the product

Energy Technology Data Exchange (ETDEWEB)

Orieux, A.

1990-01-19

Heat exchange is improved in light naphta hydroisomerization and catalytic reforming by recirculation of a part of the product in the thermal exchange zone at a temperature higher than the dew point of the effluent under hydrogen atmosphere and preferentially as a temperature lower than the temperature of the recycled product.

An overview of biosphere modelling for the assessment of solid waste disposal

International Nuclear Information System (INIS)

Smith, G.M.

1990-01-01

The purpose of this paper is to discuss the role of biosphere modelling in relation to the overall assessment of disposal of solid radioactive waste. Model structure and data requirements are strongly influenced by a number of basic factors. Firstly, the alternative forms of safety criteria and regulatory requirements imply different end-points for biosphere models. Secondly, alternative disposal concepts can influence the significance of the biosphere as a barrier or diluting/concentrating feature affecting exposure of man. Thirdly, the range of different possibilities for release to the biosphere, including releases following intrusion, is very extensive. The requirements and state of development of biosphere models are discussed in relation to these factors along with methods being adopted to provide some expression of confidence in model results. 37 refs

Atmospheric CO2 inversions on the mesoscale using data-driven prior uncertainties: quantification of the European terrestrial CO2 fluxes

Science.gov (United States)

Kountouris, Panagiotis; Gerbig, Christoph; Rödenbeck, Christian; Karstens, Ute; Koch, Thomas F.; Heimann, Martin

2018-03-01

Optimized biogenic carbon fluxes for Europe were estimated from high-resolution regional-scale inversions, utilizing atmospheric CO2 measurements at 16 stations for the year 2007. Additional sensitivity tests with different data-driven error structures were performed. As the atmospheric network is rather sparse and consequently contains large spatial gaps, we use a priori biospheric fluxes to further constrain the inversions. The biospheric fluxes were simulated by the Vegetation Photosynthesis and Respiration Model (VPRM) at a resolution of 0.1° and optimized against eddy covariance data. Overall we estimate an a priori uncertainty of 0.54 GtC yr-1 related to the poor spatial representation between the biospheric model and the ecosystem sites. The sink estimated from the atmospheric inversions for the area of Europe (as represented in the model domain) ranges between 0.23 and 0.38 GtC yr-1 (0.39 and 0.71 GtC yr-1 up-scaled to geographical Europe). This is within the range of posterior flux uncertainty estimates of previous studies using ground-based observations.

Improvement of biosphere assessment methodology for performance assessment of geological disposal facility. 2. Outline

International Nuclear Information System (INIS)

Miki, Takahito; Yoshida, Hideji; Ikeda, Takao

2002-02-01

This report contains results on study of Geosphere-Biosphere Interface (GBI), development of biosphere assessment model for gaseous and volatile radionuclides, review of biosphere assessment and research on safety indicators. Regarding study of Geosphere-Biosphere Interface (GBI), FEP database for the Geosphere-Biosphere Transitions Zone (GBTZ) were compiled. Furthermore, release scenarios were identified from the FEP database, and review of conservativeness and robustness of the conceptual and mathematical models developed previously by JNC were undertaken. Regarding development of biosphere assessment model for gaseous and volatile radionuclides, the conceptual and mathematical models were developed, and it was confirmed that the impact of the exposure pathway regarding gas release to flux-to-dose conversion factor is small. Regarding review of biosphere assessment data, the parameters which were used on JNC second progress report were reviewed and classified using the biosphere data protocol categories. Furthermore, the data for key parameter (important but poorly characterized parameters) were revised. Regarding research on safety indicator, some kinds of safety indicators, especially for the non-radioactive contaminant and for the non-human biota, are reviewed. (author)

Ciliates and the rare biosphere: a review.

Science.gov (United States)

Dunthorn, Micah; Stoeck, Thorsten; Clamp, John; Warren, Alan; Mahé, Frédéric

2014-01-01

Here we provide a brief review of the rare biosphere from the perspective of ciliates and other microbial eukaryotes. We trace research on rarity from its lack of much in-depth focus in morphological and Sanger sequencing projects, to its central importance in analyses using high throughput sequencing strategies. The problem that the rare biosphere is potentially comprised of mostly errors is then discussed in the light of asking community-comparative, novel-diversity, and ecosystem-functioning questions. © 2014 The Author(s) Journal of Eukaryotic Microbiology © 2014 International Society of Protistologists.

The biosphere: current status

International Nuclear Information System (INIS)

Thorne, M.C.

1988-06-01

This paper outlines the biosphere models and data required to assess the post-closure radiological impact of deep geological repositories for low and intermediate level radioactive wastes. It then goes on to show how these requirements are being met either within the Nirex Safety Assessment Research Programme or from other research programmes. (Author)

Energy flows of the biosphere

Energy Technology Data Exchange (ETDEWEB)

Gorshkov, V.G.

1980-01-01

Mankind consumes more than 90% of the animal production of the world. The locking of a significant part of the biosphere energy flow onto the anthropogenic chain leads to the dislodging of natural forms of organisms of the biosphere, change of its functioning and self-regulation. For the maintenance of stable existence of a small set of cultivated plants and domestic animals not forming the complete set indispensable for reaction to the change of natural conditions, man is compelled to follow the path of auxiliary investments of energy and to compensate for the destruction of closed circulations of food substances by the flow of fertilizers extracted from natural deposits. Energy assessments show the lack of realism of many projects for increasing the global energy flow in the anthropogenic channel by increasing the full flow of energy of the biosphere. To obtain the net production of the contemporary plowed field in hotbed on the basis of hydroponics there is required 2 x 10/sup 14/ watts of additional energy. To provide for the inflow of such an amount of energy (and also vast volumes of fresh water) presents extremely complicated problems. According to the author's calculations, in a provisional conversion of all production of green plants, all gas and petroleum and edible food with an efficiency equal to 1%, it is possible to provide food reserves equal to one annual harvest of the plowed fields of the world of 2 x 10/sup 9/ tons.

Rapid and long-term effects of water deficit on gas exchange and hydraulic conductance of silver birch trees grown under varying atmospheric humidity.

Science.gov (United States)

Sellin, Arne; Niglas, Aigar; Õunapuu-Pikas, Eele; Kupper, Priit

2014-03-24

Effects of water deficit on plant water status, gas exchange and hydraulic conductance were investigated in Betula pendula under artificially manipulated air humidity in Eastern Estonia. The study was aimed to broaden an understanding of the ability of trees to acclimate with the increasing atmospheric humidity predicted for northern Europe. Rapidly-induced water deficit was imposed by dehydrating cut branches in open-air conditions; long-term water deficit was generated by seasonal drought. The rapid water deficit quantified by leaf (ΨL) and branch water potentials (ΨB) had a significant (P gas exchange parameters, while inclusion of ΨB in models resulted in a considerably better fit than those including ΨL, which supports the idea that stomatal openness is regulated to prevent stem rather than leaf xylem dysfunction. Under moderate water deficit (ΨL≥-1.55 MPa), leaf conductance to water vapour (gL), transpiration rate and leaf hydraulic conductance (KL) were higher (P water deficit (ΨLwater availability, i.e. due to higher soil water potential in H treatment. Two functional characteristics (gL, KL) exhibited higher (P water deficit in trees grown under increased air humidity. The experiment supported the hypothesis that physiological traits in trees acclimated to higher air humidity exhibit higher sensitivity to rapid water deficit with respect to two characteristics - leaf conductance to water vapour and leaf hydraulic conductance. Disproportionate changes in sensitivity of stomatal versus leaf hydraulic conductance to water deficit will impose greater risk of desiccation-induced hydraulic dysfunction on the plants, grown under high atmospheric humidity, in case of sudden weather fluctuations, and might represent a potential threat in hemiboreal forest ecosystems. There is no trade-off between plant hydraulic capacity and photosynthetic water-use efficiency on short time scale.

Summary of the IAEA's BIOMASS reference biosphere methodology for Environment Agency staff

International Nuclear Information System (INIS)

Coughtrey, P.

2001-01-01

The International Atomic Energy Agency (IAEA) programme on BIOsphere Modelling and ASSessment (BIOMASS) was launched in October 1996, and will complete during 2001. The BIOMASS programme aimed to develop and apply a methodology for defining biospheres for practical radiological assessment of releases from radioactive waste disposal. This report provides a summary description of the BIOMASS methodology. The BIOMASS methodology has been developed through international collaboration and represents a major milestone in biosphere modelling. It provides an approach supported by a wide range of developers, regulators, biosphere experts and safety assessment specialists. The Environment Agency participated actively in the BIOMASS programme

World campaign for the biosphere

Energy Technology Data Exchange (ETDEWEB)

Worthington, E.B.

1982-07-01

Four aims are included in the Draft Declaration about the Champaign for The Biosphere; 1) education and allied activities, 2) scientific understanding, 3) practical activities, and 4) accommodation of humanity to The Biosphere. There is a strong case for application to practical affairs of what is already known. The campaign might focus initially on problems that illustrate changing attitudes which are the result of research and experience. Examples include the Green revolution in agriculture and, in engineering, the swing of changing attitudes to the primary and ancillary effects of large projects for hydro-power and irrigation. The need for conservation of natural resources by rational, ecologically wise use is stressed. Educational and medical programs for planned parenthood are already available. The problem will be to boost them to top priority in the countries that need them most. (JMT)

The biosphere: Problems and solutions; Proceedings of the Miami International Symposium on the Biosphere, Miami Beach, FL, April 23, 24, 1984

Science.gov (United States)

Veziroglu, T. N.

The objective of the Miami International Symposium on the Biosphere was to provide a forum for the presentation of the latest research findings on the environmental effects of human activities. The topics discussed are related to biosphere reserves, environmental aspects of hydrocarbon fuels, radioactivity and nuclear waste, land management, acid rains, water quality, water resources, coastal resources management, the pollution of rivers, industrial waste, economic development and the environment, health hazards and solutions, endangered species, environmentally compatible systems, space pollution, and global considerations. Attention is given to questions regarding global security and sustainable development, environethics as a global strategy for environmental quality, a gestalt approach to the environment, potential indicators for monitoring biosphere reserves, a review of regional impacts associated with the development of U.S. synthetic fuel resources, water resources in the Soviet Union, and pollution-free pesticides.

Atmospheric turbulence and diffusion research

International Nuclear Information System (INIS)

Hosker, R.P. Jr.

1993-01-01

The Atmospheric Turbulence and Diffusion Division (well known in the atmospheric dispersion community as the Atmospheric Turbulence and Diffusion Laboratory, ATDL) is one of several field facilities of NOAAs Air Resources Laboratory, headquartered in Silver Spring, Maryland. The laboratory conducts research on matters of atmospheric diffusion and turbulent exchange, concerning air quality. ATDD focuses attention on the physics of the lower atmosphere, with special emphasis on the processes contributing to atmospheric transport, dispersion, deposition, and air-surface exchange, and on the development of predictive capabilities using the results of this research. Research is directed toward issues of national and global importance related to the missions of DOE, to DOE's Oak Ridge Field Office, and to NOAA. The program is divided into four major projects: plume transport and diffusion in the planetary boundary layer, complex topography, canopy micrometeorology, and air-surface exchange

Simulation of carbon isotope discrimination of the terrestrial biosphere

Science.gov (United States)

Suits, N. S.; Denning, A. S.; Berry, J. A.; Still, C. J.; Kaduk, J.; Miller, J. B.; Baker, I. T.

2005-03-01

We introduce a multistage model of carbon isotope discrimination during C3 photosynthesis and global maps of C3/C4 plant ratios to an ecophysiological model of the terrestrial biosphere (SiB2) in order to predict the carbon isotope ratios of terrestrial plant carbon globally at a 1° resolution. The model is driven by observed meteorology from the European Centre for Medium-Range Weather Forecasts (ECMWF), constrained by satellite-derived Normalized Difference Vegetation Index (NDVI) and run for the years 1983-1993. Modeled mean annual C3 discrimination during this period is 19.2‰; total mean annual discrimination by the terrestrial biosphere (C3 and C4 plants) is 15.9‰. We test simulation results in three ways. First, we compare the modeled response of C3 discrimination to changes in physiological stress, including daily variations in vapor pressure deficit (vpd) and monthly variations in precipitation, to observed changes in discrimination inferred from Keeling plot intercepts. Second, we compare mean δ13C ratios from selected biomes (Broadleaf, Temperate Broadleaf, Temperate Conifer, and Boreal) to the observed values from Keeling plots at these biomes. Third, we compare simulated zonal δ13C ratios in the Northern Hemisphere (20°N to 60°N) to values predicted from high-frequency variations in measured atmospheric CO2 and δ13C from terrestrially dominated sites within the NOAA-Globalview flask network. The modeled response to changes in vapor pressure deficit compares favorably to observations. Simulated discrimination in tropical forests of the Amazon basin is less sensitive to changes in monthly precipitation than is suggested by some observations. Mean model δ13C ratios for Broadleaf, Temperate Broadleaf, Temperate Conifer, and Boreal biomes compare well with the few measurements available; however, there is more variability in observations than in the simulation, and modeled δ13C values for tropical forests are heavy relative to observations

Higher stability in forest-atmosphere exchange observed in a structurally diverse forest.

Science.gov (United States)

Tamrakar, R.; Rayment, M.; Moyano, F.; Herbst, M.; Mund, M.; Knohl, A.

2016-12-01

We tested the hypothesis that structurally diverse forests have greater stability on exchange processes with the atmosphere compared to forests with less diverse structure. In a case study, we assessed how net ecosystem exchange (NEE) and normalized maximum assimilation (Amax) varied over time in two forests in Germany based on 11 years of continuous eddy flux measurements. The two sites differ in structure as well as in species composition: one (Hainich) is an unmanaged, uneven-aged and heterogeneous mixed beech forest (65% beech), the other (Leinefelde) is a managed, even-aged and homogeneous pure beech stand. The two selected forests are of similar mean ages (about 130 years old) and exposed to similar air temperatures and vapour pressure deficits. Even though Hainich (the unmanaged forest) received higher rainfall (720 ± 134 mm vs 599±166 mm), the soil water availability showed no significant difference between both sites. Based on detailed biomass inventory, trees in Hainich are well distributed in all diameter at breast height (dbh) classes (10 to 90cm dbh) whereas in Leinefelde (the managed forest) trees are mostly confined to dbh classes of 40 to 55 cm. Our results showed a strong difference in inter-annual variability of NEE, which was lower in the unmanaged than in the managed site (coefficient of variation (CV) of 0.13 and 0.27, respectively). The lowest NEE was observed in both sites in 2004, a mast year and a year after the strong summer drought of 2003. The variation in the inter-annual normalized maximum assimilation (Amax) was lower in Hainich (standard deviation of 2.5 compared to 3.9 µmol m-2 s-1). Also, the seasonal course of Amax differed between the two forests which could explain why the mixed forest was more affected by the late summer drought of 2003, despite showing a more conservative carbon budget than the pure stand in the long term. The interannual anomaly in Amax was correlated with fruit production, the latter being larger in

PRO-QUEST: a rapid assessment method based on progressive saturation for quantifying exchange rates using saturation times in CEST.

Science.gov (United States)

Demetriou, Eleni; Tachrount, Mohamed; Zaiss, Moritz; Shmueli, Karin; Golay, Xavier

2018-03-05

To develop a new MRI technique to rapidly measure exchange rates in CEST MRI. A novel pulse sequence for measuring chemical exchange rates through a progressive saturation recovery process, called PRO-QUEST (progressive saturation for quantifying exchange rates using saturation times), has been developed. Using this method, the water magnetization is sampled under non-steady-state conditions, and off-resonance saturation is interleaved with the acquisition of images obtained through a Look-Locker type of acquisition. A complete theoretical framework has been set up, and simple equations to obtain the exchange rates have been derived. A reduction of scan time from 58 to 16 minutes has been obtained using PRO-QUEST versus the standard QUEST. Maps of both T 1 of water and B 1 can simply be obtained by repetition of the sequence without off-resonance saturation pulses. Simulations and calculated exchange rates from experimental data using amino acids such as glutamate, glutamine, taurine, and alanine were compared and found to be in good agreement. The PRO-QUEST sequence was also applied on healthy and infarcted rats after 24 hours, and revealed that imaging specificity to ischemic acidification during stroke was substantially increased relative to standard amide proton transfer-weighted imaging. Because of the reduced scan time and insensitivity to nonchemical exchange factors such as direct water saturation, PRO-QUEST can serve as an excellent alternative for researchers and clinicians interested to map pH changes in vivo. © 2018 International Society for Magnetic Resonance in Medicine.

Human Migration and Agricultural Expansion: An Impending Threat to the Maya Biosphere Reserve

Science.gov (United States)

Sader, Steven; Reining, Conard; Sever, Thomas L.; Soza, Carlos

1997-01-01

Evidence is presented of the current threats to the Maya Biosphere Reserve in northern Guatemala as derived through time-series Landsat Thematic Mapper observations and analysis. Estimates of deforestation rates and trends are examined for different management units within the reserve and buffer zones. The satellite imagery was used to quantify and monitor rates, patterns, and trends of forest clearing during a time period corresponding to new road construction and significant human migration into the newly accessible forest region. Satellite imagery is appropriate technology in a vast and remote tropical region where aerial photography and extensive field-based methods are not cost-effective and current, timely data is essential for establishing conservation priorities.

Quantifying Fast and Slow Responses of Terrestrial Carbon Exchange across a Water Availability Gradient in North American Flux Sites

Science.gov (United States)

Biederman, J. A.; Scott, R. L.; Goulden, M.

2014-12-01

Climate change is predicted to increase the frequency and severity of water limitation, altering terrestrial ecosystems and their carbon exchange with the atmosphere. Here we compare site-level temporal sensitivity of annual carbon fluxes to interannual variations in water availability against cross-site spatial patterns over a network of 19 eddy covariance flux sites. This network represents one order of magnitude in mean annual productivity and includes western North American desert shrublands and grasslands, savannahs, woodlands, and forests with continuous records of 4 to 12 years. Our analysis reveals site-specific patterns not identifiable in prior syntheses that pooled sites. We interpret temporal variability as an indicator of ecosystem response to annual water availability due to fast-changing factors such as leaf stomatal response and microbial activity, while cross-site spatial patterns are used to infer ecosystem adjustment to climatic water availability through slow-changing factors such as plant community and organic carbon pools. Using variance decomposition, we directly quantify how terrestrial carbon balance depends on slow- and fast-changing components of gross ecosystem production (GEP) and total ecosystem respiration (TER). Slow factors explain the majority of variance in annual net ecosystem production (NEP) across the dataset, and their relative importance is greater at wetter, forest sites than desert ecosystems. Site-specific offsets from spatial patterns of GEP and TER explain one third of NEP variance, likely due to slow-changing factors not directly linked to water, such as disturbance. TER and GEP are correlated across sites as previously shown, but our site-level analysis reveals surprisingly consistent linear relationships between these fluxes in deserts and savannahs, indicating fast coupling of TER and GEP in more arid ecosystems. Based on the uncertainty associated with slow and fast factors, we suggest a framework for improved

Factual biosphere database for Dounreay and the surrounding area

International Nuclear Information System (INIS)

Broderick, M.A.

1991-12-01

This report documents from open published sources a factual database appropriate to the Dounreay region including the coastal marine environment for present day biosphere conditions. A detailed description of the present day environment in the Dounreay area is provided. This includes a description of the natural environment and climate. Site specific data required for biosphere modelling are also outlined. (author)

Factual biosphere database for Dounreay and the surrounding area

Energy Technology Data Exchange (ETDEWEB)

Broderick, M A [ANS Consultants Ltd., Epsom (United Kingdom)

1991-12-01

This report documents from open published sources a factual database appropriate to the Dounreay region including the coastal marine environment for present day biosphere conditions. A detailed description of the present day environment in the Dounreay area is provided. This includes a description of the natural environment and climate. Site specific data required for biosphere modelling are also outlined. (author).

Factual biosphere database for Sellafield and the surrounding area