A terrestrial biosphere model optimized to atmospheric CO2 concentration and above ground woody biomass

Science.gov (United States)

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

2013-12-01

This study documents an optimization of a prognostic biosphere model (VISIT; Vegetation Integrative Similator for Trace gases) to observations of atmospheric CO2 concentration and above ground woody biomass by using a Bayesian inversion method combined with an atmospheric tracer transport model (NIES-TM; National Institute for Environmental Studies / Frontier Research Center for Global Change (NIES/FRCGC) off-line global atmospheric tracer transport model). The assimilated observations include 74 station records of surface atmospheric CO2 concentration and aggregated grid data sets of above ground woody biomass (AGB) and net primary productivity (NPP) over the globe. Both the biosphere model and the atmospheric transport model are used at a horizontal resolution of 2.5 deg x 2.5 deg grid with temporal resolutions of a day and an hour, respectively. The atmospheric transport model simulates atmospheric CO2 concentration with nine vertical levels using daily net ecosystem CO2 exchange rate (NEE) from the biosphere model, oceanic CO2 flux, and fossil fuel emission inventory. The models are driven by meteorological data from JRA-25 (Japanese 25-year ReAnalysis) and JCDAS (JMA Climate Data Assimilation System). Statistically optimum physiological parameters in the biosphere model are found by iterative minimization of the corresponding Bayesian cost function. We select thirteen physiological parameter with high sensitivity to NEE, NPP, and AGB for the minimization. Given the optimized physiological parameters, the model shows error reductions in seasonal variation of the CO2 concentrations especially in the northern hemisphere due to abundant observation stations, while errors remain at a few stations that are located in coastal coastal area and stations in the southern hemisphere. The model also produces moderate estimates of the mean magnitudes and probability distributions in AGB and NPP for each biome. However, the model fails in the simulation of the terrestrial

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.

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

Terrestrial acidification during the end-Permian biosphere crisis?

NARCIS (Netherlands)

Sephton, Mark A.; Jiao, Dan; Engel, Michael H.; Looy, Cindy V.; Visscher, Henk

Excessive acid rainfall associated with emplacement of the Siberian Traps magmatic province is increasingly accepted as a major contributing factor to the end-Permian biosphere crisis. However, direct proxy evidence of terrestrial acidification is so far not available. In this paper, we seek to

The terrestrial biosphere in the SFR region

Energy Technology Data Exchange (ETDEWEB)

Jerling, L; Isaeus, M [Stockholm Univ. (Sweden). Dept. of Botany; Lanneck, J [Stockholm Univ. (Sweden). Dept. of Physical Geography; Lindborg, T; Schueldt, R [Danish Nature Council, Copenhagen (Denmark)

2001-03-01

This report is a part of the SKB project 'SAFE' (Safety Assessment of the Final Repository of Radioactive Operational Waste). The aim of project SAFE is to update the previous safety analysis of SFR-1.SFR-1 is a facility for disposal of low and intermediate level radioactive waste, which is situated in bedrock beneath the Baltic Sea, one km off the coast near the Forsmark nuclear power plant in Northern Uppland. A part of the SAFE-analysis aims at analysing the transport of radionuclides in the ecosystems.To do so one has to build a model that includes a large amount of information concerning the biosphere.The first step is to collect and compile descriptions of the biosphere.This report is a first attempt to characterise the terrestrial environment of the SFR area of Forsmark. In the first part of the report the terrestrial environment, land class distribution and production of the area is described. The primary production in different terrestrial ecosystems is estimated for a model area in the Forsmark region. The estimations are based on the actual land class distribution and the values for the total primary production (d.w. above ground biomass)and the amount carbon produced, presented as g/m{sup 2} for each land class respectively. An important aspect of the biosphere is the vegetation and its development. The future development of vegetation is of interest since production,decomposition and thus storage of organic material, vary strongly among vegetation types and this has strong implications for the transport of radionuclides.Therefore an attempt to describe the development of terrestrial vegetation has been made in the second part. Any prediction of future vegetation is based on knowledge of the past together with premises for the future development.The predictions made, thus, becomes marred with errors enforced by the assumptions and incomplete information of the past. The assumptions made for the predictions in this report are crude and results in a

The terrestrial biosphere in the SFR region

International Nuclear Information System (INIS)

Jerling, L.; Isaeus, M.

2001-03-01

This report is a part of the SKB project 'SAFE' (Safety Assessment of the Final Repository of Radioactive Operational Waste). The aim of project SAFE is to update the previous safety analysis of SFR-1.SFR-1 is a facility for disposal of low and intermediate level radioactive waste, which is situated in bedrock beneath the Baltic Sea, one km off the coast near the Forsmark nuclear power plant in Northern Uppland. A part of the SAFE-analysis aims at analysing the transport of radionuclides in the ecosystems.To do so one has to build a model that includes a large amount of information concerning the biosphere.The first step is to collect and compile descriptions of the biosphere.This report is a first attempt to characterise the terrestrial environment of the SFR area of Forsmark. In the first part of the report the terrestrial environment, land class distribution and production of the area is described. The primary production in different terrestrial ecosystems is estimated for a model area in the Forsmark region. The estimations are based on the actual land class distribution and the values for the total primary production (d.w. above ground biomass)and the amount carbon produced, presented as g/m 2 for each land class respectively. An important aspect of the biosphere is the vegetation and its development. The future development of vegetation is of interest since production,decomposition and thus storage of organic material, vary strongly among vegetation types and this has strong implications for the transport of radionuclides.Therefore an attempt to describe the development of terrestrial vegetation has been made in the second part. Any prediction of future vegetation is based on knowledge of the past together with premises for the future development.The predictions made, thus, becomes marred with errors enforced by the assumptions and incomplete information of the past. The assumptions made for the predictions in this report are crude and results in a coarse

The terrestrial biosphere in the SFR region

Energy Technology Data Exchange (ETDEWEB)

Jerling, L.; Isaeus, M. [Stockholm Univ. (Sweden). Dept. of Botany; Lanneck, J. [Stockholm Univ. (Sweden). Dept. of Physical Geography; Lindborg, T.; Schueldt, R. [Danish Nature Council, Copenhagen (Denmark)

2001-03-01

This report is a part of the SKB project 'SAFE' (Safety Assessment of the Final Repository of Radioactive Operational Waste). The aim of project SAFE is to update the previous safety analysis of SFR-1.SFR-1 is a facility for disposal of low and intermediate level radioactive waste, which is situated in bedrock beneath the Baltic Sea, one km off the coast near the Forsmark nuclear power plant in Northern Uppland. A part of the SAFE-analysis aims at analysing the transport of radionuclides in the ecosystems.To do so one has to build a model that includes a large amount of information concerning the biosphere.The first step is to collect and compile descriptions of the biosphere.This report is a first attempt to characterise the terrestrial environment of the SFR area of Forsmark. In the first part of the report the terrestrial environment, land class distribution and production of the area is described. The primary production in different terrestrial ecosystems is estimated for a model area in the Forsmark region. The estimations are based on the actual land class distribution and the values for the total primary production (d.w. above ground biomass)and the amount carbon produced, presented as g/m{sup 2} for each land class respectively. An important aspect of the biosphere is the vegetation and its development. The future development of vegetation is of interest since production,decomposition and thus storage of organic material, vary strongly among vegetation types and this has strong implications for the transport of radionuclides.Therefore an attempt to describe the development of terrestrial vegetation has been made in the second part. Any prediction of future vegetation is based on knowledge of the past together with premises for the future development.The predictions made, thus, becomes marred with errors enforced by the assumptions and incomplete information of the past. The assumptions made for the predictions in this report are crude and results

European-wide simulations of croplands using an improved terrestrial biosphere model: Phenology and productivity

Science.gov (United States)

Smith, P. C.; de Noblet-Ducoudré, N.; Ciais, P.; Peylin, P.; Viovy, N.; Meurdesoif, Y.; Bondeau, A.

2010-03-01

Aiming at producing improved estimates of carbon source/sink spatial and interannual patterns across Europe (35% croplands), this work combines the terrestrial biosphere model Organizing Carbon and Hydrology in Dynamic Ecosystems (ORCHIDEE), for vegetation productivity, water balance, and soil carbon dynamics, and the generic crop model Simulateur Multidisciplinaire pour les Cultures Standard (STICS), for phenology, irrigation, nitrogen balance, and harvest. The ORCHIDEE-STICS model, relying on three plant functional types for the representation of temperate agriculture, is evaluated over the last few decades at various spatial and temporal resolutions. The simulated leaf area index seasonal cycle is largely improved relative to the original ORCHIDEE simulating grasslands, and compares favorably with remote-sensing observations (correlation doubles over Europe). Crop yield is derived from annual net primary productivity and compared with wheat and grain maize harvest data for five European countries. Discrepancies between 30 year mean simulated and reported yields are large in Mediterranean countries. Interannual variability amplitude expressed relative to the mean is reduced toward the observed variability (≈10%) when using ORCHIDEE-STICS. Overall, this study highlights the importance of accounting for the specific phenologies of crops sown both in winter and in spring and for irrigation applied to spring crops in regional/global models of the terrestrial carbon cycle. Limitations suggest to account for temporal and spatial variability in agricultural practices for further simulation improvement.

Terrestrial Biosphere Dynamics in the Climate System: Past and Future

Science.gov (United States)

Overpeck, J.; Whitlock, C.; Huntley, B.

2002-12-01

The paleoenvironmental record makes it clear that climate change as large as is likely to occur in the next two centuries will drive change in the terrestrial biosphere that is both large and difficult to predict, or plan for. Many species, communities and ecosystems could experience rates of climate change, and "destination climates" that are unprecedented in their time on earth. The paleorecord also makes it clear that a wide range of possible climate system behavior, such as decades-long droughts, increases in large storm and flood frequency, and rapid sea level rise, all occurred repeatedly in the past, and for poorly understood reasons. These types of events, if they were to reoccur in the future, could have especially devastating impacts on biodiversity, both because their timing and spatial extent cannot be anticipated, and because the biota's natural defenses have been compromised by land-use, reductions in genetic flexibility, pollution, excess water utilization, invasive species, and other human influences. Vegetation disturbance (e.g., by disease, pests and fire) will undoubtedly be exacerbated by climate change (stress), but could also speed the rate at which terrestrial biosphere change takes place in the future. The paleoenvironmental record makes it clear that major scientific challenges include an improved ability to model regional biospheric change, both past and future. This in turn will be a prerequisite to obtaining realistic estimates of future biogeochemical and biophysical feedbacks, and thus to obtaining better assessments of future climate change. These steps will help generate the improved understanding of climate variability that is needed to manage global biodiversity. However, the most troubling message from the paleoenvironmental record is that unchecked anthropogenic climate change could make the Earth's 6th major mass extinction unavoidable.

NACP Regional: Original Observation Data and Biosphere and Inverse Model Outputs

Data.gov (United States)

National Aeronautics and Space Administration — This data set contains the originally-submitted observation measurement data, terrestrial biosphere model output data, and inverse model simulations that various...

NACP Regional: Original Observation Data and Biosphere and Inverse Model Outputs

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: This data set contains the originally-submitted observation measurement data, terrestrial biosphere model output data, and inverse model simulations that...

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...

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...

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)

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)

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

Directory of Open Access Journals (Sweden)

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

Terrestrial biosphere carbon storage under alternative climate projections

Energy Technology Data Exchange (ETDEWEB)

Schaphoff, S.; Lucht, W.; Gerten, D.; Sitch, S.; Cramer, W. [Potsdam Institute for Climate Impact Research, P.O. Box 601203, D-14412 Potsdam (Germany); Prentice, I.C. [QUEST, Department of Earth Sciences, University of Bristol, Wills Memorial Building, Bristol, BS8 1RJ (United Kingdom)

2006-01-15

This study investigates commonalities and differences in projected land biosphere carbon storage among climate change projections derived from one emission scenario by five different general circulation models (GCMs). Carbon storage is studied using a global biogeochemical process model of vegetation and soil that includes dynamic treatment of changes in vegetation composition, a recently enhanced version of the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM). Uncertainty in future terrestrial carbon storage due to differences in the climate projections is large. Changes by the end of the century range from -106 to +201 PgC, thus, even the sign of the response whether source or sink, is uncertain. Three out of five climate projections produce a land carbon source by the year 2100, one is approximately neutral and one a sink. A regional breakdown shows some robust qualitative features. Large areas of the boreal forest are shown as a future CO2 source, while a sink appears in the arctic. The sign of the response in tropical and sub-tropical ecosystems differs among models, due to the large variations in simulated precipitation patterns. The largest uncertainty is in the response of tropical rainforests of South America and Central Africa.

Terrestrial biosphere carbon storage under alternative climate projections

International Nuclear Information System (INIS)

Schaphoff, S.; Lucht, W.; Gerten, D.; Sitch, S.; Cramer, W.; Prentice, I.C.

2006-01-01

This study investigates commonalities and differences in projected land biosphere carbon storage among climate change projections derived from one emission scenario by five different general circulation models (GCMs). Carbon storage is studied using a global biogeochemical process model of vegetation and soil that includes dynamic treatment of changes in vegetation composition, a recently enhanced version of the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM). Uncertainty in future terrestrial carbon storage due to differences in the climate projections is large. Changes by the end of the century range from -106 to +201 PgC, thus, even the sign of the response whether source or sink, is uncertain. Three out of five climate projections produce a land carbon source by the year 2100, one is approximately neutral and one a sink. A regional breakdown shows some robust qualitative features. Large areas of the boreal forest are shown as a future CO2 source, while a sink appears in the arctic. The sign of the response in tropical and sub-tropical ecosystems differs among models, due to the large variations in simulated precipitation patterns. The largest uncertainty is in the response of tropical rainforests of South America and Central Africa

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

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)

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

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

TAME - the terrestrial-aquatic model of the environment: model definition

International Nuclear Information System (INIS)

Klos, R.A.; Mueller-Lemans, H.; Dorp, F. van; Gribi, P.

1996-10-01

TAME - the Terrestrial-Aquatic Model of the Environment is a new computer model for use in assessments of the radiological impact of the release of radionuclides to the biosphere, following their disposal in underground waste repositories. Based on regulatory requirements, the end-point of the calculations is the maximum annual individual dose to members of a hypothetical population group inhabiting the biosphere region. Additional mid- and end-points in the TAME calculations are dose as function of time from eleven exposure pathways, foodstuff concentrations and the distribution of radionuclides in the modelled biosphere. A complete description of the mathematical representations of the biosphere in TAME is given in this document, based on a detailed review of the underlying conceptual framework for the model. Example results are used to illustrate features of the conceptual and mathematical models. The end-point of dose is shown to be robust for the simplifying model assumptions used to define the biosphere for the example calculations. TAME comprises two distinct sub-models - one representing the transport of radionuclides in the near-surface environment and one for the calculation of dose to individual inhabitants of that biosphere. The former is the result of a detailed review of the modelling requirements for such applications and is based on a comprehensive consideration of all features, events and processes (FEPs) relevant to Swiss biospheres, both in the present-day biosphere and in potential future biosphere states. Representations of the transport processes are derived from first principles. Mass balance for water and solid material fluxes is used to determine the rates of contaminant transfer between components of the biosphere system. The calculation of doses is based on existing representations of exposure pathways and draws on experience both from Switzerland and elsewhere. (author) figs., tabs., refs

TAME - the terrestrial-aquatic model of the environment: model definition

Energy Technology Data Exchange (ETDEWEB)

Klos, R.A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Mueller-Lemans, H. [Tergoso AG fuer Umweltfragen, Sargans (Switzerland); Dorp, F. van [Nationale Genossenschaft fuer die Lagerung Radioaktiver Abfaelle (NAGRA), Baden (Switzerland); Gribi, P. [Colenco AG, Baden (Switzerland)

1996-10-01

TAME - the Terrestrial-Aquatic Model of the Environment is a new computer model for use in assessments of the radiological impact of the release of radionuclides to the biosphere, following their disposal in underground waste repositories. Based on regulatory requirements, the end-point of the calculations is the maximum annual individual dose to members of a hypothetical population group inhabiting the biosphere region. Additional mid- and end-points in the TAME calculations are dose as function of time from eleven exposure pathways, foodstuff concentrations and the distribution of radionuclides in the modelled biosphere. A complete description of the mathematical representations of the biosphere in TAME is given in this document, based on a detailed review of the underlying conceptual framework for the model. Example results are used to illustrate features of the conceptual and mathematical models. The end-point of dose is shown to be robust for the simplifying model assumptions used to define the biosphere for the example calculations. TAME comprises two distinct sub-models - one representing the transport of radionuclides in the near-surface environment and one for the calculation of dose to individual inhabitants of that biosphere. The former is the result of a detailed review of the modelling requirements for such applications and is based on a comprehensive consideration of all features, events and processes (FEPs) relevant to Swiss biospheres, both in the present-day biosphere and in potential future biosphere states. Representations of the transport processes are derived from first principles. Mass balance for water and solid material fluxes is used to determine the rates of contaminant transfer between components of the biosphere system. The calculation of doses is based on existing representations of exposure pathways and draws on experience both from Switzerland and elsewhere. (author) figs., tabs., refs.

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)

Terrestrial biosphere models underestimate photosynthetic capacity and CO2 assimilation in the Arctic.

Science.gov (United States)

Rogers, Alistair; Serbin, Shawn P; Ely, Kim S; Sloan, Victoria L; Wullschleger, Stan D

2017-12-01

Terrestrial biosphere models (TBMs) are highly sensitive to model representation of photosynthesis, in particular the parameters maximum carboxylation rate and maximum electron transport rate at 25°C (V c,max.25 and J max.25 , respectively). Many TBMs do not include representation of Arctic plants, and those that do rely on understanding and parameterization from temperate species. We measured photosynthetic CO 2 response curves and leaf nitrogen (N) content in species representing the dominant vascular plant functional types found on the coastal tundra near Barrow, Alaska. The activation energies associated with the temperature response functions of V c,max and J max were 17% lower than commonly used values. When scaled to 25°C, V c,max.25 and J max.25 were two- to five-fold higher than the values used to parameterize current TBMs. This high photosynthetic capacity was attributable to a high leaf N content and the high fraction of N invested in Rubisco. Leaf-level modeling demonstrated that current parameterization of TBMs resulted in a two-fold underestimation of the capacity for leaf-level CO 2 assimilation in Arctic vegetation. This study highlights the poor representation of Arctic photosynthesis in TBMs, and provides the critical data necessary to improve our ability to project the response of the Arctic to global environmental change. No claim to original US Government works. New Phytologist © 2017 New Phytologist Trust.

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

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

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.

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

Trends and Future Challenges in Sampling the Deep Terrestrial Biosphere

Directory of Open Access Journals (Sweden)

Michael J Wilkins

2014-09-01

Full Text Available Research in the deep terrestrial biosphere is driven by interest in novel biodiversity and metabolisms, biogeochemical cycling, and the impact of human activities on this ecosystem. As this interest continues to grow, it is important to ensure that when subsurface investigations are proposed, materials recovered from the subsurface are sampled and preserved in an appropriate manner to limit contamination and ensure preservation of accurate microbial, geochemical, and mineralogical signatures. On February 20th, 2014, a workshop on Trends and Future Challenges in Sampling The Deep Subsurface was coordinated in Columbus, Ohio by The Ohio State University and West Virginia University faculty, and sponsored by The Ohio State University and the Sloan Foundation’s Deep Carbon Observatory. The workshop aims were to identify and develop best practices for the collection, preservation, and analysis of terrestrial deep rock samples. This document summarizes the information shared during this workshop.

Trends and future challenges in sampling the deep terrestrial biosphere.

Science.gov (United States)

Wilkins, Michael J; Daly, Rebecca A; Mouser, Paula J; Trexler, Ryan; Sharma, Shihka; Cole, David R; Wrighton, Kelly C; Biddle, Jennifer F; Denis, Elizabeth H; Fredrickson, Jim K; Kieft, Thomas L; Onstott, Tullis C; Peterson, Lee; Pfiffner, Susan M; Phelps, Tommy J; Schrenk, Matthew O

2014-01-01

Research in the deep terrestrial biosphere is driven by interest in novel biodiversity and metabolisms, biogeochemical cycling, and the impact of human activities on this ecosystem. As this interest continues to grow, it is important to ensure that when subsurface investigations are proposed, materials recovered from the subsurface are sampled and preserved in an appropriate manner to limit contamination and ensure preservation of accurate microbial, geochemical, and mineralogical signatures. On February 20th, 2014, a workshop on "Trends and Future Challenges in Sampling The Deep Subsurface" was coordinated in Columbus, Ohio by The Ohio State University and West Virginia University faculty, and sponsored by The Ohio State University and the Sloan Foundation's Deep Carbon Observatory. The workshop aims were to identify and develop best practices for the collection, preservation, and analysis of terrestrial deep rock samples. This document summarizes the information shared during this workshop.

Using satellite data to improve the leaf phenology of a global terrestrial biosphere model

Science.gov (United States)

MacBean, N.; Maignan, F.; Peylin, P.; Bacour, C.; Bréon, F.-M.; Ciais, P.

2015-12-01

Correct representation of seasonal leaf dynamics is crucial for terrestrial biosphere models (TBMs), but many such models cannot accurately reproduce observations of leaf onset and senescence. Here we optimised the phenology-related parameters of the ORCHIDEE TBM using satellite-derived Normalized Difference Vegetation Index data (MODIS NDVI v5) that are linearly related to the model fAPAR. We found the misfit between the observations and the model decreased after optimisation for all boreal and temperate deciduous plant functional types, primarily due to an earlier onset of leaf senescence. The model bias was only partially reduced for tropical deciduous trees and no improvement was seen for natural C4 grasses. Spatial validation demonstrated the generality of the posterior parameters for use in global simulations, with an increase in global median correlation of 0.56 to 0.67. The simulated global mean annual gross primary productivity (GPP) decreased by ~ 10 PgC yr-1 over the 1990-2010 period due to the substantially shortened growing season length (GSL - by up to 30 days in the Northern Hemisphere), thus reducing the positive bias and improving the seasonal dynamics of ORCHIDEE compared to independent data-based estimates. Finally, the optimisations led to changes in the strength and location of the trends in the simulated vegetation productivity as represented by the GSL and mean annual fraction of absorbed photosynthetically active radiation (fAPAR), suggesting care should be taken when using un-calibrated models in attribution studies. We suggest that the framework presented here can be applied for improving the phenology of all global TBMs.

European-wide simulations of present cropland phenology, productivity and carbon fluxes using an improved terrestrial biosphere model

Science.gov (United States)

Smith, P. C.; Ciais, P.; de Noblet, N.; Peylin, P.; Viovy, N.; Bondeau, A.

2009-04-01

Aiming at producing improved estimates of carbon source/sink spatial and interannual patterns across Europe (35% croplands), this work combines the terrestrial biosphere model ORCHIDEE (for vegetation productivity, water balance, soil carbon dynamics) and the generic crop model STICS (for phenology, irrigation, nitrogen balance, harvest). The ORCHIDEE-STICS model, relying on three plant functional types for the representation of temperate agriculture, is evaluated over the last few decades at various spatial and temporal resolutions. The simulated Leaf Area Index seasonal cycle is largely improved relative to the original ORCHIDEE simulating grasslands, and compares favourably with remote-sensing observations (the Figure of Merit in Time doubles over Europe). Crop yield is derived from annual Net Primary Productivity and compared with wheat and grain maize harvest data for five European countries. Discrepancies between 30-year mean simulated and reported yields remain large in Mediterranean countries. Interannual variability amplitude expressed relative to the mean is reduced towards the observed variability (~10%) when using ORCHIDEE-STICS. The simulated 2003 anomalous carbon source from European ecosystems to the atmosphere due to the 2003 summer heat wave is in good agreement with atmospheric inversions (~0.2 GtC, from May to October). The anomaly is twice as large in the ORCHIDEE alone simulation, owing to the unrealistically high exposure of herbaceous plants to the extreme summer conditions. Overall, this study highlights the importance of accounting for the specific phonologies of crops sown both in winter and in spring and for irrigation applied to summer crops in regional/global models of the terrestrial carbon cycle. Limitations suggest accounting for temporal and spatial variability in agricultural practices for further simulation improvement.

An extensive phase space for the potential martian biosphere.

Science.gov (United States)

Jones, Eriita G; Lineweaver, Charles H; Clarke, Jonathan D

2011-12-01

We present a comprehensive model of martian pressure-temperature (P-T) phase space and compare it with that of Earth. Martian P-T conditions compatible with liquid water extend to a depth of ∼310 km. We use our phase space model of Mars and of terrestrial life to estimate the depths and extent of the water on Mars that is habitable for terrestrial life. We find an extensive overlap between inhabited terrestrial phase space and martian phase space. The lower martian surface temperatures and shallower martian geotherm suggest that, if there is a hot deep biosphere on Mars, it could extend 7 times deeper than the ∼5 km depth of the hot deep terrestrial biosphere in the crust inhabited by hyperthermophilic chemolithotrophs. This corresponds to ∼3.2% of the volume of present-day Mars being potentially habitable for terrestrial-like life.

Multi-model analysis of terrestrial carbon cycles in Japan: limitations and implications of model calibration using eddy flux observations

Directory of Open Access Journals (Sweden)

K. Ichii

2010-07-01

Full Text Available Terrestrial biosphere models show large differences when simulating carbon and water cycles, and reducing these differences is a priority for developing more accurate estimates of the condition of terrestrial ecosystems and future climate change. To reduce uncertainties and improve the understanding of their carbon budgets, we investigated the utility of the eddy flux datasets to improve model simulations and reduce variabilities among multi-model outputs of terrestrial biosphere models in Japan. Using 9 terrestrial biosphere models (Support Vector Machine – based regressions, TOPS, CASA, VISIT, Biome-BGC, DAYCENT, SEIB, LPJ, and TRIFFID, we conducted two simulations: (1 point simulations at four eddy flux sites in Japan and (2 spatial simulations for Japan with a default model (based on original settings and a modified model (based on model parameter tuning using eddy flux data. Generally, models using default model settings showed large deviations in model outputs from observation with large model-by-model variability. However, after we calibrated the model parameters using eddy flux data (GPP, RE and NEP, most models successfully simulated seasonal variations in the carbon cycle, with less variability among models. We also found that interannual variations in the carbon cycle are mostly consistent among models and observations. Spatial analysis also showed a large reduction in the variability among model outputs. This study demonstrated that careful validation and calibration of models with available eddy flux data reduced model-by-model differences. Yet, site history, analysis of model structure changes, and more objective procedure of model calibration should be included in the further analysis.

Multi-model analysis of terrestrial carbon cycles in Japan: limitations and implications of model calibration using eddy flux observations

Science.gov (United States)

Ichii, K.; Suzuki, T.; Kato, T.; Ito, A.; Hajima, T.; Ueyama, M.; Sasai, T.; Hirata, R.; Saigusa, N.; Ohtani, Y.; Takagi, K.

2010-07-01

Terrestrial biosphere models show large differences when simulating carbon and water cycles, and reducing these differences is a priority for developing more accurate estimates of the condition of terrestrial ecosystems and future climate change. To reduce uncertainties and improve the understanding of their carbon budgets, we investigated the utility of the eddy flux datasets to improve model simulations and reduce variabilities among multi-model outputs of terrestrial biosphere models in Japan. Using 9 terrestrial biosphere models (Support Vector Machine - based regressions, TOPS, CASA, VISIT, Biome-BGC, DAYCENT, SEIB, LPJ, and TRIFFID), we conducted two simulations: (1) point simulations at four eddy flux sites in Japan and (2) spatial simulations for Japan with a default model (based on original settings) and a modified model (based on model parameter tuning using eddy flux data). Generally, models using default model settings showed large deviations in model outputs from observation with large model-by-model variability. However, after we calibrated the model parameters using eddy flux data (GPP, RE and NEP), most models successfully simulated seasonal variations in the carbon cycle, with less variability among models. We also found that interannual variations in the carbon cycle are mostly consistent among models and observations. Spatial analysis also showed a large reduction in the variability among model outputs. This study demonstrated that careful validation and calibration of models with available eddy flux data reduced model-by-model differences. Yet, site history, analysis of model structure changes, and more objective procedure of model calibration should be included in the further analysis.

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

Geological facilities are the preferred option for disposal of high-level radioactive waste, due to their potential to provide isolation from the surface environment (biosphere) on very long time scales. Safety cases developed in support of geological disposal include assessment of potential impacts on humans and wildlife in order to demonstrate compliance with regulatory criteria. As disposal programmes move from site-independent/generic assessments through site selection to applications for construction/operation and closure, the degree of understanding of the present-day site increases, together with increased site-specific information. Assessments need to strike a balance between simple models and more complex approaches that draw more extensively on this 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 complex biosphere model 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 model is built on a landscape evolution model, whereby radionuclide releases to distinct hydrological basins/sub-catchments (termed 'objects') are represented as they evolve through land rise and climate change. The site is located on the Baltic coast with a terrestrial landscape including lakes, mires, forest and agriculture. The land at the site is projected to continue to rise due to post-glacial uplift leading to ecosystem transitions in excess of ten thousand years. The simple biosphere models developed for this study include the most plausible transport processes and represent various types of ecosystem. The complex biosphere models adopt a relatively coarse representation of the near-surface strata, which is shown to be conservative, but also to under-estimate the time scale required for potential doses to reach equilibrium with radionuclide fluxes

Dating the Anthropocene: Towards an empirical global history of human transformation of the terrestrial biosphere

Directory of Open Access Journals (Sweden)

Erle C. Ellis

2013-12-01

Full Text Available Abstract Human use of land is a major cause of the global environmental changes that define the Anthropocene. Archaeological and paleoecological evidence confirm that human populations and their use of land transformed ecosystems at sites around the world by the late Pleistocene and historical models indicate this transformation may have reached globally significant levels more than 3000 years ago. Yet these data in themselves remain insufficient to conclusively date the emergence of land use as a global force transforming the biosphere, with plausible dates ranging from the late Pleistocene to AD 1800. Conclusive empirical dating of human transformation of the terrestrial biosphere will require unprecedented levels of investment in sustained interdisciplinary collaboration and the development of a geospatial cyberinfrastructure to collate and integrate the field observations of archaeologists, paleoecologists, paleoenvironmental scientists, environmental historians, geoscientists, geographers and other human and environmental scientists globally from the Pleistocene to the present. Existing field observations may yet prove insufficient in terms of their spatial and temporal coverage, but by assessing these observations within a spatially explicit statistically robust global framework, major observational gaps can be identified, stimulating data gathering in underrepresented regions and time periods. Like the Anthropocene itself, building scientific understanding of the human role in shaping the biosphere requires both sustained effort and leveraging the most powerful social systems and technologies ever developed on this planet.

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 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.)

Response of Water Use Efficiency to Global Environmental Change Based on Output From Terrestrial Biosphere Models

Science.gov (United States)

Zhou, Sha; Yu, Bofu; Schwalm, Christopher R.; Ciais, Philippe; Zhang, Yao; Fisher, Joshua B.; Michalak, Anna M.; Wang, Weile; Poulter, Benjamin; Huntzinger, Deborah N.; Niu, Shuli; Mao, Jiafu; Jain, Atul; Ricciuto, Daniel M.; Shi, Xiaoying; Ito, Akihiko; Wei, Yaxing; Huang, Yuefei; Wang, Guangqian

2017-11-01

Water use efficiency (WUE), defined as the ratio of gross primary productivity and evapotranspiration at the ecosystem scale, is a critical variable linking the carbon and water cycles. Incorporating a dependency on vapor pressure deficit, apparent underlying WUE (uWUE) provides a better indicator of how terrestrial ecosystems respond to environmental changes than other WUE formulations. Here we used 20th century simulations from four terrestrial biosphere models to develop a novel variance decomposition method. With this method, we attributed variations in apparent uWUE to both the trend and interannual variation of environmental drivers. The secular increase in atmospheric CO2 explained a clear majority of total variation (66 ± 32%: mean ± one standard deviation), followed by positive trends in nitrogen deposition and climate, as well as a negative trend in land use change. In contrast, interannual variation was mostly driven by interannual climate variability. To analyze the mechanism of the CO2 effect, we partitioned the apparent uWUE into the transpiration ratio (transpiration over evapotranspiration) and potential uWUE. The relative increase in potential uWUE parallels that of CO2, but this direct CO2 effect was offset by 20 ± 4% by changes in ecosystem structure, that is, leaf area index for different vegetation types. However, the decrease in transpiration due to stomatal closure with rising CO2 was reduced by 84% by an increase in leaf area index, resulting in small changes in the transpiration ratio. CO2 concentration thus plays a dominant role in driving apparent uWUE variations over time, but its role differs for the two constituent components: potential uWUE and transpiration.

Characterisation of DOC and its relation to the deep terrestrial biosphere

Science.gov (United States)

Vieth, Andrea; Vetter, Alexandra; Sachse, Anke; Horsfield, Brian

2010-05-01

-rich layers like coals and source rocks which may provide carbon sources for the deep biosphere by leaching water soluble organic compounds. We investigated the potential of a series of Eocene-Pleistocene coals, mudstones and sandstones from New Zealand with different maturities (Ro between 0.29 and 0.39) and total organic carbon content (TOC) regarding their potential to release such compounds. The water extraction of these New Zealand coals using Soxhlet apparatus resulted in yields of LMWOA that may feed the local deep terrestrial biosphere over geological periods of time (VIETH et al., 2008). However, the DOC of the water extracts mainly consisted of humic substances. To investigate the effect of thermal maturity of the organic matter as well as the effect of the organic matter type on the extraction yields, we examined additional coal samples (Ro between 0.29 and 0.80) and source rock samples from low to medium maturity (Ro between 0.3 to 1.1). Within our presentation we would like to show the compositional diversity and variability of dissolved organic compounds in natural formation fluids as well as in water extracts from a series of very different lithologies and discuss their effects on the carbon cycling in the deep terrestrial subsurface. References: Andrews, J. N., Youngman, M. J., Goldbrunner, J. E., and Darling, W. G., 1987. The geochemistry of formation waters in the Molasse Basin of Upper Austria. Environmental Geology 10, 43-57. Vieth, A., Mangelsdorf, K., Sykes, R., and Horsfield, B., 2008. Water extraction of coals - potential to estimate low molecular weight organic acids as carbon feedstock for the deep terrestrial biosphere? Organic Geochemistry 39, 985-991.

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

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

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

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

Response of Water Use Efficiency to Global Environmental Change Based on Output From Terrestrial Biosphere Models

Energy Technology Data Exchange (ETDEWEB)

Zhou, Sha [Tsinghua Univ., Beijing (China); Yu, Bofu [Griffith Univ., Nathan Queensland (Australia); Schwalm, Christopher R. [Woods Hole Research Center, Falmouth, MA (United States); Northern Arizona Univ., Flagstaff, AZ (United States); Ciais, Philippe [Lab. des Sciences du Climat et de l' Environnement, Gif-sur-Yvette (France); Zhang, Yao [Univ. of Oklahoma, Norman, OK (United States); Fisher, Joshua B. [California Institute of Technology, Pasadena, CA (United States); Michalak, Anna M. [Carnegie Institution for Science, Stanford, CA (United States); Wang, Weile [California State Uni., Monterey Bay, Seasid, CA (United States); Poulter, Benjamin [Montana State Univ., Bozeman, MT (United States); Huntzinger, Deborah N. [Northern Arizona Univ., Flagstaff, AZ (United States); Niu, Shuli [Institute of Geographic Sciences and Natural Resources Research, Beijing (China); Chinese Academy of Sciences (CAS), Beijing (China); Mao, Jiafu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jain, Atul [Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States); Ricciuto, Daniel M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shi, Xiaoying [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ito, Akihiko [Tohoku Univ., Sendai (Japan); Wei, Yaxing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Huang, Yuefei [Tsinghua Univ., Beijing (China); Qinghai Univ., Xining (China); Wang, Guangqian [Tsinghua Univ., Beijing (China)

2017-10-18

Here, water use efficiency (WUE), defined as the ratio of gross primary productivity and evapotranspiration at the ecosystem scale, is a critical variable linking the carbon and water cycles. Incorporating a dependency on vapor pressure deficit, apparent underlying WUE (uWUE) provides a better indicator of how terrestrial ecosystems respond to environmental changes than other WUE formulations. Here we used 20th century simulations from four terrestrial biosphere models to develop a novel variance decomposition method. With this method, we attributed variations in apparent uWUE to both the trend and interannual variation of environmental drivers. The secular increase in atmospheric CO₂ explained a clear majority of total variation (66 ± 32%: mean ± one standard deviation), followed by positive trends in nitrogen deposition and climate, as well as a negative trend in land use change. In contrast, interannual variation was mostly driven by interannual climate variability. To analyze the mechanism of the CO₂ effect, we partitioned the apparent uWUE into the transpiration ratio (transpiration over evapotranspiration) and potential uWUE. The relative increase in potential uWUE parallels that of CO₂, but this direct CO₂ effect was offset by 20 ± 4% by changes in ecosystem structure, that is, leaf area index for different vegetation types. However, the decrease in transpiration due to stomatal closure with rising CO₂ was reduced by 84% by an increase in leaf area index, resulting in small changes in the transpiration ratio. CO₂ concentration thus plays a dominant role in driving apparent uWUE variations over time, but its role differs for the two constituent components: potential uWUE and transpiration.

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.

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

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)

Aerosol-induced thermal effects increase modelled terrestrial photosynthesis and transpiration

International Nuclear Information System (INIS)

Steiner, Allison L.; Chameides, W.L.

2005-01-01

Previous studies suggest that the radiative effects of atmospheric aerosols (reducing total radiation while increasing the diffuse fraction) can enhance terrestrial productivity. Here, simulations using a regional climate/terrestrial biosphere model suggest that atmospheric aerosols could also enhance terrestrial photosynthesis and transpiration through an interaction between solar radiation, leaf temperature and stomatal conductance. During midday, clear-sky conditions, sunlit-leaf temperatures can exceed the optimum for photosynthesis, depressing both photosynthesis and transpiration. Aerosols decrease surface solar radiation, thereby reducing leaf temperatures and enhancing sunlit-leaf photosynthesis and transpiration. This modelling study finds that, under certain conditions, this thermal response of aerosols can have a greater impact on photosynthesis and transpiration than the radiative response. This implies that a full understanding of the impact of aerosols on climate and the global carbon cycle requires consideration of the biophysical responses of terrestrial vegetation as well as atmospheric radiative and thermodynamic effects

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 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.

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

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

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

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

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

B33C-0612: Evaluation of Simulated Biospheric Carbon Dioxide Fluxes and Atmospheric Concentrations Using Global in Situ Observations

Science.gov (United States)

Philip, Sajeev; Johnson, Matthew S.; Potter, Christopher S.; Genovese, Vanessa

2016-01-01

Atmospheric mixing ratios of carbon dioxide (CO2) are largely controlled by anthropogenic emission sources and biospheric sources/sinks. Global biospheric fluxes of CO2 are controlled by complex processes facilitating the exchange of carbon between terrestrial ecosystems and the atmosphere. These processes which play a key role in these terrestrial ecosystem-atmosphere carbon exchanges are currently not fully understood, resulting in large uncertainties in the quantification of biospheric CO2 fluxes. Current models with these inherent deficiencies have difficulties simulating the global carbon cycle with high accuracy. We are developing a new modeling platform, GEOS-Chem-CASA by integrating the year-specific NASA-CASA (National Aeronautics and Space Administration - Carnegie Ames Stanford Approach) biosphere model with the GEOS-Chem (Goddard Earth Observation System-Chemistry) chemical transport model to improve the simulation of atmosphere-terrestrial ecosystem carbon exchange. We use NASA-CASA to explicitly represent the exchange of CO2 between terrestrial ecosystem and atmosphere by replacing the baseline GEOS-Chem land net CO2 flux and forest biomass burning CO2 emissions. We will present the estimation and evaluation of these "bottom-up" land CO2 fluxes, simulated atmospheric mixing ratios, and forest disturbance changes over the last decade. In addition, we will present our initial comparison of atmospheric column-mean dry air mole fraction of CO2 predicted by the model and those retrieved from NASA's OCO-2 (Orbiting Carbon Observatory-2) satellite instrument and model-predicted surface CO2 mixing ratios with global in situ observations. This evaluation is the first step necessary for our future work planned to constrain the estimates of biospheric carbon fluxes through "top-down" inverse modeling, which will improve our understanding of the processes controlling atmosphere-terrestrial ecosystem greenhouse gas exchanges, especially over regions which lack in

Soil-related Input Parameters for the Biosphere Model

International Nuclear Information System (INIS)

A. J. Smith

2003-01-01

This analysis 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. 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 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, 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 2003 [163602]). 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. 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 Biosphere Model Report'' (BSC 2003 [160699]) describes in detail the conceptual model as well as the mathematical model and its input parameters. The purpose of this analysis was to develop the biosphere model parameters needed to evaluate doses from pathways 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 and ash

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

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

Risk of severe climate change impact on the terrestrial biosphere

International Nuclear Information System (INIS)

Heyder, Ursula; Schaphoff, Sibyll; Gerten, Dieter; Lucht, Wolfgang

2011-01-01

The functioning of many ecosystems and their associated resilience could become severely compromised by climate change over the 21st century. We present a global risk analysis of terrestrial ecosystem changes based on an aggregate metric of joint changes in macroscopic ecosystem features including vegetation structure as well as carbon and water fluxes and stores. We apply this metric to global ecosystem simulations with a dynamic global vegetation model (LPJmL) under 58 WCRP CMIP3 climate change projections. Given the current knowledge of ecosystem processes and projected climate change patterns, we find that severe ecosystem changes cannot be excluded on any continent. They are likely to occur (in > 90% of the climate projections) in the boreal-temperate ecotone where heat and drought stress might lead to large-scale forest die-back, along boreal and mountainous tree lines where the temperature limitation will be alleviated, and in water-limited ecosystems where elevated atmospheric CO 2 concentration will lead to increased water use efficiency of photosynthesis. Considerable ecosystem changes can be expected above 3 K local temperature change in cold and tropical climates and above 4 K in the temperate zone. Sensitivity to temperature change increases with decreasing precipitation in tropical and temperate ecosystems. In summary, there is a risk of substantial restructuring of the global land biosphere on current trajectories of climate change.

Risk of severe climate change impact on the terrestrial biosphere

Energy Technology Data Exchange (ETDEWEB)

Heyder, Ursula; Schaphoff, Sibyll; Gerten, Dieter; Lucht, Wolfgang, E-mail: Ursula.Heyder@pik-potsdam.de, E-mail: Sibyll.Schaphoff@pik-potsdam.de [Potsdam Institute for Climate Impact Research, Telegraphenberg A62, 14473 Potsdam (Germany)

2011-07-15

The functioning of many ecosystems and their associated resilience could become severely compromised by climate change over the 21st century. We present a global risk analysis of terrestrial ecosystem changes based on an aggregate metric of joint changes in macroscopic ecosystem features including vegetation structure as well as carbon and water fluxes and stores. We apply this metric to global ecosystem simulations with a dynamic global vegetation model (LPJmL) under 58 WCRP CMIP3 climate change projections. Given the current knowledge of ecosystem processes and projected climate change patterns, we find that severe ecosystem changes cannot be excluded on any continent. They are likely to occur (in > 90% of the climate projections) in the boreal-temperate ecotone where heat and drought stress might lead to large-scale forest die-back, along boreal and mountainous tree lines where the temperature limitation will be alleviated, and in water-limited ecosystems where elevated atmospheric CO{sub 2} concentration will lead to increased water use efficiency of photosynthesis. Considerable ecosystem changes can be expected above 3 K local temperature change in cold and tropical climates and above 4 K in the temperate zone. Sensitivity to temperature change increases with decreasing precipitation in tropical and temperate ecosystems. In summary, there is a risk of substantial restructuring of the global land biosphere on current trajectories of climate change.

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

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

European-wide simulations of croplands using an improved terrestrial biosphere model: 2. Interannual yields and anomalous CO2 fluxes in 2003

Science.gov (United States)

Smith, P. C.; Ciais, P.; Peylin, P.; de Noblet-Ducoudré, N.; Viovy, N.; Meurdesoif, Y.; Bondeau, A.

2010-12-01

Aiming at producing improved estimates of carbon source/sink spatial and interannual patterns across Europe (35% croplands), this work uses the ORCHIDEE-STICS terrestrial biosphere model including a more realistic representation of croplands, described in part 1 (Smith et al., 2010). Crop yield is derived from annual Net Primary Productivity and compared with wheat and grain maize harvest data for five European countries. Over a 34 year period, the best correlation coefficient obtained between observed and simulated yield time series is for irrigated maize in Italy (R = 0.73). In the data as well as in the model, 1976 and 2003 appear as climate anomalies causing a ≈40% yield drop in the most affected regions. Simulated interannual yield anomalies and the spatial pattern of the yield drop in 2003 are found to be more realistic than the results from ORCHIDEE with no representation of croplands. The simulated 2003 anomalous carbon source from European ecosystems to the atmosphere due to the 2003 summer heat wave is in good agreement with atmospheric inversions (0.20GtC, from May to October). The anomaly is twice too large in the ORCHIDEE alone simulation, owing to the unrealistically high exposure of herbaceous plants to the extreme summer conditions. The mechanisms linking abnormally high summer temperatures, the crop productivity drop, and significant carbon source from European ecosystems in 2003 are discussed. Overall, this study highlights the importance of accounting for the specific phenologies of crops sown both in winter and in spring and for irrigation applied to summer crops in regional/global models of the terrestrial carbon cycle.

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

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.

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

Challenging terrestrial biosphere models with data from the long-term multifactor Prairie Heating and CO2 Enrichment experiment.

Science.gov (United States)

De Kauwe, Martin G; Medlyn, Belinda E; Walker, Anthony P; Zaehle, Sönke; Asao, Shinichi; Guenet, Bertrand; Harper, Anna B; Hickler, Thomas; Jain, Atul K; Luo, Yiqi; Lu, Xingjie; Luus, Kristina; Parton, William J; Shu, Shijie; Wang, Ying-Ping; Werner, Christian; Xia, Jianyang; Pendall, Elise; Morgan, Jack A; Ryan, Edmund M; Carrillo, Yolima; Dijkstra, Feike A; Zelikova, Tamara J; Norby, Richard J

2017-09-01

Multifactor experiments are often advocated as important for advancing terrestrial biosphere models (TBMs), yet to date, such models have only been tested against single-factor experiments. We applied 10 TBMs to the multifactor Prairie Heating and CO 2 Enrichment (PHACE) experiment in Wyoming, USA. Our goals were to investigate how multifactor experiments can be used to constrain models and to identify a road map for model improvement. We found models performed poorly in ambient conditions; there was a wide spread in simulated above-ground net primary productivity (range: 31-390 g C m -2  yr -1 ). Comparison with data highlighted model failures particularly with respect to carbon allocation, phenology, and the impact of water stress on phenology. Performance against the observations from single-factors treatments was also relatively poor. In addition, similar responses were predicted for different reasons across models: there were large differences among models in sensitivity to water stress and, among the N cycle models, N availability during the experiment. Models were also unable to capture observed treatment effects on phenology: they overestimated the effect of warming on leaf onset and did not allow CO 2 -induced water savings to extend the growing season length. Observed interactive (CO 2  × warming) treatment effects were subtle and contingent on water stress, phenology, and species composition. As the models did not correctly represent these processes under ambient and single-factor conditions, little extra information was gained by comparing model predictions against interactive responses. We outline a series of key areas in which this and future experiments could be used to improve model predictions of grassland responses to global change. © 2017 John Wiley & Sons Ltd.

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

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.

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.)

Water extraction of coals - potential for estimating low molecular weight organic acids as carbon feedstock for the deep terrestrial biosphere

Energy Technology Data Exchange (ETDEWEB)

Vieth, A.; Mangelsdorf, K.; Sykes, R.; Horsfield, B. [Geoforschungszentrum Potsdam, Potsdam (Germany)

2008-08-15

With the recent increasing interest in the deep biosphere, the question arises as to where the carbon sources that support deep microbial communities are derived from. Our research was focussed on the water-soluble, low molecular weight (LMW) organic acids that are potentially available from different sedimentary lithologies to serve as a carbon source to feed the deep biosphere. A series of Eocene-Pleistocene coals, mudstones and sandstones of varying rank (maturity) and total organic carbon (TOC) content from the Waikato Basin, New Zealand, has been Soxhlet-extracted using water. The combined concentration of recovered formate, acetate and oxalate range from 366 to 2499 {mu} g/g sediment and appear to be dependent on rank, organofacies and TOC. The yields indicate the potential of carbonaceous sediments to feed the local deep terrestrial biosphere over geological periods of time. The existence of living microbial organisms in the mudstones and sandstones was proved by the identification of intact phospholipids (PLs).

Estimation of vegetation photosynthetic capacity from space-based measurements of chlorophyll fluorescence for terrestrial biosphere models.

Science.gov (United States)

Zhang, Yongguang; Guanter, Luis; Berry, Joseph A; Joiner, Joanna; van der Tol, Christiaan; Huete, Alfredo; Gitelson, Anatoly; Voigt, Maximilian; Köhler, Philipp

2014-12-01

Photosynthesis simulations by terrestrial biosphere models are usually based on the Farquhar's model, in which the maximum rate of carboxylation (Vcmax ) is a key control parameter of photosynthetic capacity. Even though Vcmax is known to vary substantially in space and time in response to environmental controls, it is typically parameterized in models with tabulated values associated to plant functional types. Remote sensing can be used to produce a spatially continuous and temporally resolved view on photosynthetic efficiency, but traditional vegetation observations based on spectral reflectance lack a direct link to plant photochemical processes. Alternatively, recent space-borne measurements of sun-induced chlorophyll fluorescence (SIF) can offer an observational constraint on photosynthesis simulations. Here, we show that top-of-canopy SIF measurements from space are sensitive to Vcmax at the ecosystem level, and present an approach to invert Vcmax from SIF data. We use the Soil-Canopy Observation of Photosynthesis and Energy (SCOPE) balance model to derive empirical relationships between seasonal Vcmax and SIF which are used to solve the inverse problem. We evaluate our Vcmax estimation method at six agricultural flux tower sites in the midwestern US using spaced-based SIF retrievals. Our Vcmax estimates agree well with literature values for corn and soybean plants (average values of 37 and 101 μmol m(-2)  s(-1) , respectively) and show plausible seasonal patterns. The effect of the updated seasonally varying Vcmax parameterization on simulated gross primary productivity (GPP) is tested by comparing to simulations with fixed Vcmax values. Validation against flux tower observations demonstrate that simulations of GPP and light use efficiency improve significantly when our time-resolved Vcmax estimates from SIF are used, with R(2) for GPP comparisons increasing from 0.85 to 0.93, and for light use efficiency from 0.44 to 0.83. Our results support the use of

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

Recent patterns of methane and nitrous oxide fluxes in the terrestrial biosphere: The bottom-up approach (Invited)

Science.gov (United States)

Tian, H.

2013-12-01

Accurately estimating methane and nitrous oxide emissions from terrestrial ecosystems is critical for resolving global budgets of these greenhouse gases (GHGs) and continuing to mitigate climate warming. In this study, we use a bottom-up approach to estimate annual budgets of both methane and nitrous oxide in global terrestrial ecosystem during 1981-2010 and analyze the underlying mechanisms responsible for spatial and temporal variations in these GHGs. Both methane and nitrous oxide emissions significantly increased from 1981 to 2010, primarily owing to increased air temperature, nitrogen fertilizer use, and land use change. Methane and nitrous oxide emissions increased the fastest in Asia due to the more prominent environmental changes compared to other continents. The cooling effects by carbon dioxide sink in the terrestrial biosphere might be completely offset by increasing methane and nitrous oxide emissions, resulting in a positive global warming potential. Asia and South America were the largest contributors to increasing global warming potential. This study suggested that current management practices might not be effective enough to reduce future global warming.

Future of Plant Functional Types in Terrestrial Biosphere Models

Science.gov (United States)

Wullschleger, S. D.; Euskirchen, E. S.; Iversen, C. M.; Rogers, A.; Serbin, S.

2015-12-01

Earth system models describe the physical, chemical, and biological processes that govern our global climate. While it is difficult to single out one component as being more important than another in these sophisticated models, terrestrial vegetation is a critical player in the biogeochemical and biophysical dynamics of the Earth system. There is much debate, however, as to how plant diversity and function should be represented in these models. Plant functional types (PFTs) have been adopted by modelers to represent broad groupings of plant species that share similar characteristics (e.g. growth form) and roles (e.g. photosynthetic pathway) in ecosystem function. In this review the PFT concept is traced from its origin in the early 1800s to its current use in regional and global dynamic vegetation models (DVMs). Special attention is given to the representation and parameterization of PFTs and to validation and benchmarking of predicted patterns of vegetation distribution in high-latitude ecosystems. These ecosystems are sensitive to changing climate and thus provide a useful test case for model-based simulations of past, current, and future distribution of vegetation. Models that incorporate the PFT concept predict many of the emerging patterns of vegetation change in tundra and boreal forests, given known processes of tree mortality, treeline migration, and shrub expansion. However, representation of above- and especially belowground traits for specific PFTs continues to be problematic. Potential solutions include developing trait databases and replacing fixed parameters for PFTs with formulations based on trait co-variance and empirical trait-environment relationships. Surprisingly, despite being important to land-atmosphere interactions of carbon, water, and energy, PFTs such as moss and lichen are largely absent from DVMs. Close collaboration among those involved in modelling with the disciplines of taxonomy, biogeography, ecology, and remote sensing will be

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.

The biosphere today and tomorrow in the SFR area

Energy Technology Data Exchange (ETDEWEB)

Kautsky, Ulrik (ed.)

2001-06-01

This report is a compilation of the work done mainly in the SAFE project for the biosphere from about 14 reports. The SAFE project is the updated safety analysis of SFR-1, the LLW and ILW repository at Forsmark. The aim of the report is to summarize the available information about the present-day biosphere in the area surrounding SFR and to use this information, together with information about the previous development of the biosphere, to predict the future development of the area in a more comparable way than the underlying reports. The data actually used for the models have been taken from the original reports which also justify or validate the data. The report compiles information about climate, oceanography, landscape, sedimentation, shoreline displacement, marine, lake and terrestrial ecosystems.

The biosphere today and tomorrow in the SFR area

International Nuclear Information System (INIS)

Kautsky, Ulrik

2001-06-01

This report is a compilation of the work done mainly in the SAFE project for the biosphere from about 14 reports. The SAFE project is the updated safety analysis of SFR-1, the LLW and ILW repository at Forsmark. The aim of the report is to summarize the available information about the present-day biosphere in the area surrounding SFR and to use this information, together with information about the previous development of the biosphere, to predict the future development of the area in a more comparable way than the underlying reports. The data actually used for the models have been taken from the original reports which also justify or validate the data. The report compiles information about climate, oceanography, landscape, sedimentation, shoreline displacement, marine, lake and terrestrial ecosystems

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.

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.

Asia-MIP: Multi Model-data Synthesis of Terrestrial Carbon Cycles in Asia

Science.gov (United States)

Ichii, K.; Kondo, M.; Ito, A.; Kang, M.; Sasai, T.; SATO, H.; Ueyama, M.; Kobayashi, H.; Saigusa, N.; Kim, J.

2013-12-01

Asia, which is characterized by monsoon climate and intense human activities, is one of the prominent understudied regions in terms of terrestrial carbon budgets and mechanisms of carbon exchange. To better understand terrestrial carbon cycle in Asia, we initiated multi-model and data intercomparison project in Asia (Asia-MIP). We analyzed outputs from multiple approaches: satellite-based observations (AVHRR and MODIS) and related products, empirically upscaled estimations (Support Vector Regression) using eddy-covariance observation network in Asia (AsiaFlux, CarboEastAsia, FLUXNET), ~10 terrestrial biosphere models (e.g. BEAMS, Biome-BGC, LPJ, SEIB-DGVM, TRIFFID, VISIT models), and atmospheric inversion analysis (e.g. TransCom models). We focused on the two difference temporal coverage: long-term (30 years; 1982-2011) and decadal (10 years; 2001-2010; data intensive period) scales. The regions of covering Siberia, Far East Asia, East Asia, Southeast Asia and South Asia (60-80E, 10S-80N), was analyzed in this study for assessing the magnitudes, interannual variability, and key driving factors of carbon cycles. We will report the progress of synthesis effort to quantify terrestrial carbon budget in Asia. First, we analyzed the recent trends in Gross Primary Productivities (GPP) using satellite-based observation (AVHRR) and multiple terrestrial biosphere models. We found both model outputs and satellite-based observation consistently show an increasing trend in GPP in most of the regions in Asia. Mechanisms of the GPP increase were analyzed using models, and changes in temperature and precipitation play dominant roles in GPP increase in boreal and temperate regions, whereas changes in atmospheric CO2 and precipitation are important in tropical regions. However, their relative contributions were different. Second, in the decadal analysis (2001-2010), we found that the negative GPP and carbon uptake anomalies in 2003 summer in Far East Asia is one of the largest

Assessment and simulation of global terrestrial latent heat flux by synthesis of CMIP5 climate models and surface eddy covariance observations

Science.gov (United States)

Yunjun Yao; Shunlin Liang; Xianglan Li; Shaomin Liu; Jiquan Chen; Xiaotong Zhang; Kun Jia; Bo Jiang; Xianhong Xie; Simon Munier; Meng Liu; Jian Yu; Anders Lindroth; Andrej Varlagin; Antonio Raschi; Asko Noormets; Casimiro Pio; Georg Wohlfahrt; Ge Sun; Jean-Christophe Domec; Leonardo Montagnani; Magnus Lund; Moors Eddy; Peter D. Blanken; Thomas Grunwald; Sebastian Wolf; Vincenzo Magliulo

2016-01-01

The latent heat flux (LE) between the terrestrial biosphere and atmosphere is a major driver of the globalhydrological cycle. In this study, we evaluated LE simulations by 45 general circulation models (GCMs)in the Coupled Model Intercomparison Project Phase 5 (CMIP5) by a comparison...

Radioecological modelling of the biosphere as illustrated by the example of the model area Oberbauenstock

International Nuclear Information System (INIS)

Boehringer, J.; Fritschi, M.; Schwanner, I.; Resele, G.

1986-06-01

The biosphere model is the final link in the chain of radionuclide transport models used for radiation dose calculations for nuclear waste repositories. The dispersion of radionuclides from a low and intermediate level waste repository in the biosphere and their uptake by man through food pathways is investigated with a compartment model. The relevant biosphere parameters were based on the model site at Oberbauenstock and compiled as a model data set for further use in the biosphere modelling. Nuclide concentrations in the biosphere compartments and foodstuffs as well as annual individual radiation doses are calculated with the computer program BIOSPH. The present report contains a description of the model area and its subdivision into 4 compartments, a compilation of the relevant parameters and the simplifying assumptions that have been made, discussion of mathematical modelling of nuclide transport in the biosphere and of the calculation of the individual radiation doses, a technical description of the computer program BIOSPH and a detailed presentation of the results from the model calculations. (author)

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.)

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

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)

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

'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

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.

Biodiversity of Terrestrial Vegetation during Past Warm Periods

Science.gov (United States)

Davies-Barnard, T.; Valdes, P. J.; Ridgwell, A.

2016-12-01

Previous modelling studies of vegetation have generally used a small number of plant functional types to understand how the terrestrial biosphere responds to climate changes. Whilst being useful for understanding first order climate feedbacks, this climate-envelope approach makes a lot of assumptions about past vegetation being very similar to modern. A trait-based method has the advantage for paleo modelling in that there are substantially less assumptions made. In a novel use of the trait-based dynamic vegetation model JeDi, forced with output from climate model HadCM3, we explore past biodiversity and vegetation carbon changes. We use JeDi to model an optimal 2000 combinations of fifteen different traits to enable assessment of the overall level of biodiversity as well as individual growth strategies. We assess the vegetation shifts and biodiversity changes in past greenhouse periods to better understand the impact on the terrestrial biosphere. This work provides original insights into the response of vegetation and terrestrial carbon to climate and hydrological changes in high carbon dioxide climates over time, including during the Late Permian and Cretaceous. We evaluate how the location of biodiversity hotspots and species richness in past greenhouse climates is different to the present day.

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

Implications of Uncertainty in Fossil Fuel Emissions for Terrestrial Ecosystem Modeling

Science.gov (United States)

King, A. W.; Ricciuto, D. M.; Mao, J.; Andres, R. J.

2017-12-01

Given observations of the increase in atmospheric CO2, estimates of anthropogenic emissions and models of oceanic CO2 uptake, one can estimate net global CO2 exchange between the atmosphere and terrestrial ecosystems as the residual of the balanced global carbon budget. Estimates from the Global Carbon Project 2016 show that terrestrial ecosystems are a growing sink for atmospheric CO2 (averaging 2.12 Gt C y-1 for the period 1959-2015 with a growth rate of 0.03 Gt C y-1 per year) but with considerable year-to-year variability (standard deviation of 1.07 Gt C y-1). Within the uncertainty of the observations, emissions estimates and ocean modeling, this residual calculation is a robust estimate of a global terrestrial sink for CO2. A task of terrestrial ecosystem science is to explain the trend and variability in this estimate. However, "within the uncertainty" is an important caveat. The uncertainty (2σ; 95% confidence interval) in fossil fuel emissions is 8.4% (±0.8 Gt C in 2015). Combined with uncertainty in other carbon budget components, the 2σ uncertainty surrounding the global net terrestrial ecosystem CO2 exchange is ±1.6 Gt C y-1. Ignoring the uncertainty, the estimate of a general terrestrial sink includes 2 years (1987 and 1998) in which terrestrial ecosystems are a small source of CO2 to the atmosphere. However, with 2σ uncertainty, terrestrial ecosystems may have been a source in as many as 18 years. We examine how well global terrestrial biosphere models simulate the trend and interannual variability of the global-budget estimate of the terrestrial sink within the context of this uncertainty (e.g., which models fall outside the 2σ uncertainty and in what years). Models are generally capable of reproducing the trend in net terrestrial exchange, but are less able to capture interannual variability and often fall outside the 2σ uncertainty. The trend in the residual carbon budget estimate is primarily associated with the increase in atmospheric CO2

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.

Modeling and Monitoring Terrestrial Primary Production in a Changing Global Environment: Toward a Multiscale Synthesis of Observation and Simulation

Directory of Open Access Journals (Sweden)

Shufen Pan

2014-01-01

Full Text Available There is a critical need to monitor and predict terrestrial primary production, the key indicator of ecosystem functioning, in a changing global environment. Here we provide a brief review of three major approaches to monitoring and predicting terrestrial primary production: (1 ground-based field measurements, (2 satellite-based observations, and (3 process-based ecosystem modelling. Much uncertainty exists in the multi-approach estimations of terrestrial gross primary production (GPP and net primary production (NPP. To improve the capacity of model simulation and prediction, it is essential to evaluate ecosystem models against ground and satellite-based measurements and observations. As a case, we have shown the performance of the dynamic land ecosystem model (DLEM at various scales from site to region to global. We also discuss how terrestrial primary production might respond to climate change and increasing atmospheric CO2 and uncertainties associated with model and data. Further progress in monitoring and predicting terrestrial primary production requires a multiscale synthesis of observations and model simulations. In the Anthropocene era in which human activity has indeed changed the Earth’s biosphere, therefore, it is essential to incorporate the socioeconomic component into terrestrial ecosystem models for accurately estimating and predicting terrestrial primary production in a changing global environment.

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

A biosphere model for use in the SKI Project SITE-94

International Nuclear Information System (INIS)

Barrdahl, R.A.G.

1995-04-01

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 near Oskarshamn in southern Sweden. The model provides results in terms of radiation dose per Bq/y, 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 in terms of Sv/y and radiation dose rates to fish are expressed as mSv/h. 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

Models for dose assessments. Modules for various biosphere types

Energy Technology Data Exchange (ETDEWEB)

Bergstroem, U.; Nordlinder, S.; Aggeryd, I. [Studsvik Eco and Safety AB, Nykoeping (Sweden)

1999-12-01

The main objective of this study was to provide a basis for illustrations of yearly dose rates to the most exposed individual from hypothetical leakages of radionuclides from a deep bedrock repository for spent nuclear fuel and other radioactive waste. The results of this study will be used in the safety assessment SR 97 and in a study on the design and long-term safety for a repository planned to contain long-lived low and intermediate level waste. The repositories will be designed to isolate the radionuclides for several hundred thousands of years. In the SR 97 study, however, hypothetical scenarios for leakage are postulated. Radionuclides are hence assumed to be transported in the geosphere by groundwater, and probably discharge into the biosphere. This may occur in several types of ecosystems. A number of categories of such ecosystems were identified, and turnover of radionuclides was modelled separately for each ecosystem. Previous studies had focused on generic models for wells, lakes and coastal areas. These models were, in this study, developed further to use site-specific data. In addition, flows of groundwater, containing radionuclides, to agricultural land and peat bogs were considered. All these categories are referred to as modules in this report. The forest ecosystems were not included, due to a general lack of knowledge of biospheric processes in connection with discharge of groundwater in forested areas. Examples of each type of module were run with the assumption of a continuous annual release into the biosphere of 1 Bq for each radionuclide during 10 000 years. The results are presented as ecosystem specific dose conversion factors (EDFs) for each nuclide at the year 10 000, assuming stationary ecosystems and prevailing living conditions and habits. All calculations were performed with uncertainty analyses included. Simplifications and assumptions in the modelling of biospheric processes are discussed. The use of modules may be seen as a step

Models for dose assessments. Modules for various biosphere types

International Nuclear Information System (INIS)

Bergstroem, U.; Nordlinder, S.; Aggeryd, I.

1999-12-01

The main objective of this study was to provide a basis for illustrations of yearly dose rates to the most exposed individual from hypothetical leakages of radionuclides from a deep bedrock repository for spent nuclear fuel and other radioactive waste. The results of this study will be used in the safety assessment SR 97 and in a study on the design and long-term safety for a repository planned to contain long-lived low and intermediate level waste. The repositories will be designed to isolate the radionuclides for several hundred thousands of years. In the SR 97 study, however, hypothetical scenarios for leakage are postulated. Radionuclides are hence assumed to be transported in the geosphere by groundwater, and probably discharge into the biosphere. This may occur in several types of ecosystems. A number of categories of such ecosystems were identified, and turnover of radionuclides was modelled separately for each ecosystem. Previous studies had focused on generic models for wells, lakes and coastal areas. These models were, in this study, developed further to use site-specific data. In addition, flows of groundwater, containing radionuclides, to agricultural land and peat bogs were considered. All these categories are referred to as modules in this report. The forest ecosystems were not included, due to a general lack of knowledge of biospheric processes in connection with discharge of groundwater in forested areas. Examples of each type of module were run with the assumption of a continuous annual release into the biosphere of 1 Bq for each radionuclide during 10 000 years. The results are presented as ecosystem specific dose conversion factors (EDFs) for each nuclide at the year 10 000, assuming stationary ecosystems and prevailing living conditions and habits. All calculations were performed with uncertainty analyses included. Simplifications and assumptions in the modelling of biospheric processes are discussed. The use of modules may be seen as a step

Application of a generic biosphere model for dose assessments to five European sites

International Nuclear Information System (INIS)

Chen, Q; Kowe, R; Mobbs, S F; Proehl, G; Olyslaegers, G; Zeevaert, T; Kanyar, B; Pinedo, P; Simon, I; Bergstroem, U; Hallberg, B; Jones, J A; Oatway, W B; Watson, S J

2006-01-01

The BIOMOSA (BIOsphere MOdels for Safety Assessment of radioactive waste disposal) project was part of the EC fifth framework research programme. The main goal of this project was to improve the scientific basis for the application of biosphere models in the framework of long-term safety studies of radioactive waste disposal facilities and to enhance the confidence in using biosphere models for performance assessments. The study focused on the development and application of a generic biosphere tool BIOGEM (BIOsphere GEneric Model) using the IAEA BIOMASS reference biosphere methodology, and the comparison between BIOGEM and five site-specific biosphere models. The site-specific models and the generic model were applied to five typical locations in Europe, resulting in estimates of the annual effective individual doses to the critical groups and the ranking of the importance of the exposure pathways for each of the sites. Uncertainty in the results was also estimated by means of stochastic calculations based on variation of the site-specific parameter values. This paper describes the generic model and the deterministic and stochastic results obtained when it was applied to the five sites. Details of the site-specific models and the corresponding results are described in two companion papers. This paper also presents a comparison of the results between the generic model and site-specific models. In general, there was an acceptable agreement of the BIOGEM for both the deterministic and stochastic results with the results from the site-specific models

Biosphere transport of radionuclides. First modelling by using a selected example

International Nuclear Information System (INIS)

Bundi, A.

1984-12-01

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 doses to man, however, should not be used as reference data for safety analyses. (author)

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

Biosphere analyses for the safety assessment SR-Site - synthesis and summary of results

Energy Technology Data Exchange (ETDEWEB)

Saetre, Peter [comp.

2010-12-15

This report summarises nearly 20 biosphere reports and gives a synthesis of the work performed within the SR-Site Biosphere project, i.e. the biosphere part of SR-Site. SR-Site Biosphere provides the main project with dose conversion factors (LDFs), given a unit release rate, for calculation of human doses under different release scenarios, and assesses if a potential release from the repository would have detrimental effects on the environment. The intention of this report is to give sufficient details for an overview of methods, results and major conclusions, with references to the biosphere reports where methods, data and results are presented and discussed in detail. The philosophy of the biosphere assessment was to make estimations of the radiological risk for humans and the environment as realistic as possible, based on the knowledge of present-day conditions at Forsmark and the past and expected future development of the site. This was achieved by using the best available knowledge, understanding and data from extensive site investigations from two sites. When sufficient information was not available, uncertainties were handled cautiously. A systematic identification and evaluation of features and processes that affect transport and accumulation of radionuclides at the site was conducted, and the results were summarised in an interaction matrix. Data and understanding from the site investigation was an integral part of this work, the interaction matrix underpinned the development of the radionuclide model used in the biosphere assessment. Understanding of the marine, lake and river and terrestrial ecosystems at the site was summarized in a conceptual model, and relevant features and process have been characterized to capture site specific parameter values. Detailed investigations of the structure and history of the regolith at the site and simulations of regolith dynamics were used to describe the present day state at Forsmark and the expected development of

A Biosphere Assessment: Influence due to Geosphere-Biosphere Interfaces

International Nuclear Information System (INIS)

Lee, Youn Myoung; Hwang, Yong Soo

2009-01-01

Recently the geosphere-biosphere interfaces (GBIs), which is recognized as a zone (GBIZ) beyond the simple conceptual boundaries between the geosphere and biosphere modeling domains for safety assessment, has been raised to an important issue for the biosphere assessment. For the licensing process of the repository, the final step of a series of safety and performance assessment should be concerned how nuclides released from the geological media could make their farther transfer in the biosphere giving rise to doses to humans. Unlike in the case of geosphere, the distinct characteristics of biosphere modeling includes the potential release and subsequent exposure taking place not in the near future with rather unreliable predictions of human behavior at the time of its release. And also unlike the near- and far-field of geospheres such as near field engineering structures and natural geological media, the biosphere is not conceived as a barrier itself that could be well designed or optimized, which always causes the necessity of site-specific modeling approach as much as possible. Through every step of whole geosphere and biosphere modeling, nuclides transport from various geological media to the biosphere over the GBI, biosphere modeling can be done independently, not even knowing what happens in the geosphere, making access possible to it in a separate manner, even though, to some extent, it might somehow need to be accounted for geosphere transport, as is similarly being currently done in many other countries. In general, to show the performance of the repository, dose exposure to the critical group due to nuclide release from the repository should be evaluated and the results compared to the risk or dose presented by regulatory bodies, as safety and performance criteria for HLW repository are usually expressed in terms of quantitative risk or dose. For a real site-specific treatment and incorporation of geological features such as aquifers into the biosphere

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...

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

International Nuclear Information System (INIS)

Wasiolek, M. A.

2003-01-01

The purpose of this report is to document the evaluation of biosphere features, events, and processes (FEPs) that relate to the license application (LA) process as required by the U.S. Nuclear Regulatory Commission (NRC) regulations at 10 CFR 63.114 (d, e, and f) [DIRS 156605]. The evaluation determines whether specific biosphere-related FEPs should be included or excluded from consideration in the Total System Performance Assessment (TSPA). This analysis documents the technical basis for screening decisions as required at 10 CFR 63.114 (d, e, and f) [DIRS 156605]. For FEPs that are included in the TSPA, this analysis provides a TSPA disposition, which summarizes how the FEP has been included and addressed in the TSPA model, and cites the analysis reports and model reports that provide the technical basis and description of its disposition. For FEPs that are excluded from the TSPA, this analysis report provides a screening argument, which identifies the basis for the screening decision (i.e., low probability, low consequence, or by regulation) and discusses the technical basis that supports that decision. In cases, where a FEP covers multiple technical areas and is shared with other FEP analysis reports, this analysis may provide only a partial technical basis for the screening of the FEP. The full technical basis for these shared FEPs is addressed collectively by all FEP analysis reports that cover technical disciplines sharing a FEP. FEPs must be included in the TSPA unless they can be excluded by low probability, low consequence, or regulation. A FEP can be excluded from the TSPA by low probability per 10 CFR 63.114(d) [DIRS 156605], by showing that it has less than one chance in 10,000 of occurring over 10,000 years (or an approximately equivalent annualized probability of 10 -8 ). A FEP can be excluded from the TSPA by low consequence per 10 CFR 63.114 (e or f) [DIRS 156605], by showing that omitting the FEP would not significantly change the magnitude and

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

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

Energy Technology Data Exchange (ETDEWEB)

M. A. Wasiolek

2003-10-09

The purpose of this report is to document the evaluation of biosphere features, events, and processes (FEPs) that relate to the license application (LA) process as required by the U.S. Nuclear Regulatory Commission (NRC) regulations at 10 CFR 63.114 (d, e, and f) [DIRS 156605]. The evaluation determines whether specific biosphere-related FEPs should be included or excluded from consideration in the Total System Performance Assessment (TSPA). This analysis documents the technical basis for screening decisions as required at 10 CFR 63.114 (d, e, and f) [DIRS 156605]. For FEPs that are included in the TSPA, this analysis provides a TSPA disposition, which summarizes how the FEP has been included and addressed in the TSPA model, and cites the analysis reports and model reports that provide the technical basis and description of its disposition. For FEPs that are excluded from the TSPA, this analysis report provides a screening argument, which identifies the basis for the screening decision (i.e., low probability, low consequence, or by regulation) and discusses the technical basis that supports that decision. In cases, where a FEP covers multiple technical areas and is shared with other FEP analysis reports, this analysis may provide only a partial technical basis for the screening of the FEP. The full technical basis for these shared FEPs is addressed collectively by all FEP analysis reports that cover technical disciplines sharing a FEP. FEPs must be included in the TSPA unless they can be excluded by low probability, low consequence, or regulation. A FEP can be excluded from the TSPA by low probability per 10 CFR 63.114(d) [DIRS 156605], by showing that it has less than one chance in 10,000 of occurring over 10,000 years (or an approximately equivalent annualized probability of 10{sup -8}). A FEP can be excluded from the TSPA by low consequence per 10 CFR 63.114 (e or f) [DIRS 156605], by showing that omitting the FEP would not significantly change the magnitude and

Biosphere analyses for the safety assessment SR-Site - synthesis and summary of results

International Nuclear Information System (INIS)

Saetre, Peter

2010-12-01

This report summarises nearly 20 biosphere reports and gives a synthesis of the work performed within the SR-Site Biosphere project, i.e. the biosphere part of SR-Site. SR-Site Biosphere provides the main project with dose conversion factors (LDFs), given a unit release rate, for calculation of human doses under different release scenarios, and assesses if a potential release from the repository would have detrimental effects on the environment. The intention of this report is to give sufficient details for an overview of methods, results and major conclusions, with references to the biosphere reports where methods, data and results are presented and discussed in detail. The philosophy of the biosphere assessment was to make estimations of the radiological risk for humans and the environment as realistic as possible, based on the knowledge of present-day conditions at Forsmark and the past and expected future development of the site. This was achieved by using the best available knowledge, understanding and data from extensive site investigations from two sites. When sufficient information was not available, uncertainties were handled cautiously. A systematic identification and evaluation of features and processes that affect transport and accumulation of radionuclides at the site was conducted, and the results were summarised in an interaction matrix. Data and understanding from the site investigation was an integral part of this work, the interaction matrix underpinned the development of the radionuclide model used in the biosphere assessment. Understanding of the marine, lake and river and terrestrial ecosystems at the site was summarized in a conceptual model, and relevant features and process have been characterized to capture site specific parameter values. Detailed investigations of the structure and history of the regolith at the site and simulations of regolith dynamics were used to describe the present day state at Forsmark and the expected development of

The status of world biosphere modelling for waste disposal assessments following BIOMOVS II

International Nuclear Information System (INIS)

Klos, R.; Reid, J.A.K.; Santucci, P.; Bergstrom, U.

1996-01-01

Biosphere modelling for radioactive waste disposal assessments faces unique problems. Models for such applications tend to be quite distinct from other similar environmental assessment tools. Over the past few years, two of the Working Groups in the second international biosphere model validation study (BIOMOVS II) have been considering the special requirements for such models. The BIOMOVS II Reference Biospheres Working Group has concentrated on the elaboration of the methodology for the definition of models for such assessments. lie Complementary Studies Working Group has dealt with how the Features, Events and Processes (FEPS) included in the participating models are represented, in the context of the representation of a temperate inland biosphere. The aim of Complementary Studies was to move forward from the first phase of BIOMOVS, with the analysis going further and deeper into principles on which the participating models are based. Ten of the leading models from around the world have participated in the Complementary Studies model intercomparison exercise. This paper presents some key findings using the international biosphere FEP-list produced by the Reference Biospheres Working Group as a framework for discussing the current state-of-the-art. Common features of the models as well as reasons for the model differences are discussed. Areas where the international community could benefit from a harmonisation of approaches are also identified, setting out possible future requirements and developments. In the Complementary Studies intercomparison, the hypothetical release of radionuclides to an inland valley biosphere was considered. The radionuclides considered in the study were selected because of their relevance for underground repositories for long-lived radioactive wastes and because their individual properties made them suitable probes for many of the important Features, Events and Processes (FEPS) in long timescale biosphere modelling. The data

Terrestrial nitrogen-carbon cycle interactions at the global scale.

Science.gov (United States)

Zaehle, S

2013-07-05

Interactions between the terrestrial nitrogen (N) and carbon (C) cycles shape the response of ecosystems to global change. However, the global distribution of nitrogen availability and its importance in global biogeochemistry and biogeochemical interactions with the climate system remain uncertain. Based on projections of a terrestrial biosphere model scaling ecological understanding of nitrogen-carbon cycle interactions to global scales, anthropogenic nitrogen additions since 1860 are estimated to have enriched the terrestrial biosphere by 1.3 Pg N, supporting the sequestration of 11.2 Pg C. Over the same time period, CO2 fertilization has increased terrestrial carbon storage by 134.0 Pg C, increasing the terrestrial nitrogen stock by 1.2 Pg N. In 2001-2010, terrestrial ecosystems sequestered an estimated total of 27 Tg N yr(-1) (1.9 Pg C yr(-1)), of which 10 Tg N yr(-1) (0.2 Pg C yr(-1)) are due to anthropogenic nitrogen deposition. Nitrogen availability already limits terrestrial carbon sequestration in the boreal and temperate zone, and will constrain future carbon sequestration in response to CO2 fertilization (regionally by up to 70% compared with an estimate without considering nitrogen-carbon interactions). This reduced terrestrial carbon uptake will probably dominate the role of the terrestrial nitrogen cycle in the climate system, as it accelerates the accumulation of anthropogenic CO2 in the atmosphere. However, increases of N2O emissions owing to anthropogenic nitrogen and climate change (at a rate of approx. 0.5 Tg N yr(-1) per 1°C degree climate warming) will add an important long-term climate forcing.

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

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

Biosphere modelling for dose assessments of radioactive waste repositories. Final report

International Nuclear Information System (INIS)

Klos, R.

1996-09-01

opportunity for an in-depth comparison of the FEPs included in the conceptual models for a terrestrial biosphere in a temperate climate state. There is generally good agreement between the models when the maximum total dose over all exposure pathways. Other intermediate quantities show, individually, greater variation, and this can be understood in terms of the structures of the participating models. The conformity of model results is better than in the corresponding test cases in BIOMOVS I because of: tighter specification of the test case than in the first phase of BIOMOVS; the influence of the first phase of BIOMOVS, in which experience was gained in representing biosphere transport FEPs. This experience was used to update mathematical models in the time up to the inception of BIOMOVS II; convergent evolution of the models. There is consensus about which FEPs should be included in this kind of biosphere and these are then represented in similar ways. However, when the details of the mathematical representations of the FEPs are examined, considerable variation is soon encountered. It arises from differences in the conceptual bases for the models and is seen in: the influence on the model structure; where the most detail is found in the model; the degree of conservatism applied to the model. Representational uncertainty has been shown to be present in both the transport and exposure pathway sub-models, and the relative importance of the sub-models in contributing to the uncertainty varies between radionuclides. The implication is that, in general terms, improvement to modelling techniques should be applied equally to each of the sub-models. The maximum annual individual dose over all exposure pathways is a useful performance indicator. On the basis of the results presented here, this quantity is robust to differences in representation for both deterministic and stochastic calculations, i.e., the many different representations do not change the value greatly despite

Biosphere modelling for dose assessments of radioactive waste repositories. Final report

Energy Technology Data Exchange (ETDEWEB)

Klos, R. [Paul Scherrer Inst., Wuerenlingen (Switzerland)] [and others

1996-09-01

opportunity for an in-depth comparison of the FEPs included in the conceptual models for a terrestrial biosphere in a temperate climate state. There is generally good agreement between the models when the maximum total dose over all exposure pathways. Other intermediate quantities show, individually, greater variation, and this can be understood in terms of the structures of the participating models. The conformity of model results is better than in the corresponding test cases in BIOMOVS I because of: tighter specification of the test case than in the first phase of BIOMOVS; the influence of the first phase of BIOMOVS, in which experience was gained in representing biosphere transport FEPs. This experience was used to update mathematical models in the time up to the inception of BIOMOVS II; convergent evolution of the models. There is consensus about which FEPs should be included in this kind of biosphere and these are then represented in similar ways. However, when the details of the mathematical representations of the FEPs are examined, considerable variation is soon encountered. It arises from differences in the conceptual bases for the models and is seen in: the influence on the model structure; where the most detail is found in the model; the degree of conservatism applied to the model. Representational uncertainty has been shown to be present in both the transport and exposure pathway sub-models, and the relative importance of the sub-models in contributing to the uncertainty varies between radionuclides. The implication is that, in general terms, improvement to modelling techniques should be applied equally to each of the sub-models. The maximum annual individual dose over all exposure pathways is a useful performance indicator. On the basis of the results presented here, this quantity is robust to differences in representation for both deterministic and stochastic calculations, i.e., the many different representations do not change the value greatly despite

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.

SITE-94, Biosphere Model for SKI Project on the island of Aspro

International Nuclear Information System (INIS)

Barrdahl, Runo Alfons Gunnar

2003-01-01

1 - Description of program or function: A simple biosphere model has been designed for use in the SKI project related to a hypothetical repository for spent nuclear fuel on the island of Aspro near Oskarshamn in Southern Sweden. Project SITE-94 studies the safety aspects of this hypothetical repository. Any weakness in repository performance will reveal itself as a leakage of radionuclides out of the repository, and finally into the biosphere where man and nature are at risk of being exposed. Thus, as the final link in estimating such leakage, a biosphere model will provide an estimate of resulting radiation impact on man and nature. 2 - Methods: The present biosphere model involves a stationary scenario (Reference Scenario) and a climate evolution and geological scenario (Central Scenario). The stationary and time evolution scenarios contain as primary recipients a well and the bay of Borholm, i.e., the waters surrounding the island of Aspo. The time evolution scenario additionally incorporates as primary recipients a waste sample from intrusion and, in a remote future time, the Baltic Sea. Transport of radionuclides within the model system is assumed to be essentially immediate, except for in sediment subject to land rise. Except for this pathway, radioactive decay is therefore not included at all in the model. Land rise sediment is modeled to be subject to radioactive decay from the time the sediment no longer constitutes sea bottom until the desired time point of the model. Correction for radioactive decay is thus generally supposed to be made outside the biosphere model. Unless otherwise indicated, yearly individual and population committed (50 years) radiation doses to man are considered, and all scenarios involve a constant flux of 1 Bq/y of each radionuclide considered into the respective primary recipient. Nominal values of radionuclide flux will finally be multiplied with the radiation dose per one Bq per year resulting from the model in order to obtain

Evaluation of Terrestrial Carbon Cycle with the Land Use Harmonization Dataset

Science.gov (United States)

Sasai, T.; Nemani, R. R.

2017-12-01

CO2 emission by land use and land use change (LULUC) has still had a large uncertainty (±50%). We need to more accurately reveal a role of each LULUC process on terrestrial carbon cycle, and to develop more complicated land cover change model, leading to improve our understanding of the mechanism of global warming. The existing biosphere model studies do not necessarily have enough major LULUC process in the model description (e.g., clear cutting and residual soil carbon). The issue has the potential for causing an underestimation of the effect of LULUC on the global carbon exchange. In this study, the terrestrial biosphere model was modified with several LULUC processes according to the land use harmonization data set. The global mean LULUC emission from the year 1850 to 2000 was 137.2 (PgC 151year-1), and we found the noticeable trend in tropical region. As with the case of primary production in the existing studies, our results emphasized the role of tropical forest on wood productization and residual soil organic carbon by cutting. Global mean NEP was decreased by LULUC. NEP is largely affected by decreasing leaf biomass (photosynthesis) by deforestation process and increasing plant growth rate by regrowth process. We suggested that the model description related to deforestation, residual soil decomposition, wood productization and plant regrowth is important to develop a biosphere model for estimating long-term global carbon cycle.

Review of Project SAFE: Comments on biosphere conceptual model description and risk assessment methodology

International Nuclear Information System (INIS)

Klos, Richard; Wilmot, Roger

2002-09-01

The Swedish Nuclear Fuel and Waste Management Company's (SKB's) most recent assessment of the safety of the Forsmark repository for low-level and intermediate-level waste (Project SAFE) is currently undergoing review by the Swedish regulators. As part of its review, the Swedish Radiation Protection Institute (SSI) identified that two components of SAFE require more detailed review: (i) the conceptual model description of the biosphere system, and (ii) SKB's risk assessment methodology. We have reviewed the biosphere system interaction matrix and how this has been used in the identification, justification and description of biosphere models for radiological assessment purposes. The risk assessment methodology has been reviewed considering in particular issues associated with scenario selection, assessment timescale, and the probability and risk associated with the well scenario. There is an extensive range of supporting information on which biosphere modelling in Project SAFE is based. However, the link between this material and the biosphere models themselves is not clearly set out. This leads to some contradictions and mis-matches between description and implementation. One example concerns the representation of the geosphere-biosphere interface. The supporting description of lakes indicates that interaction between groundwaters entering the biosphere through lake bed sediments could lead to accumulations of radionuclides in sediments. These sediments may become agricultural areas at some time in the future. In the numerical modelling of the biosphere carried out in Project SAFE, the direct accumulation of contaminants in bed sediments is not represented. Application of a more rigorous procedure to ensure numerical models are fit for purpose is recommended, paying more attention to issues associated with the geosphere-biosphere interface. A more structured approach to risk assessment would be beneficial, with a better explanation of the difference between

Biosphere model for assessing doses from nuclear waste disposal

International Nuclear Information System (INIS)

Zach, R.; Amiro, B.D.; Davis, P.A.; Sheppard, S.C.; Szekeley, J.G.

1994-01-01

The biosphere model, BIOTRAC, for predicting long term nuclide concentrations and radiological doses from Canada's nuclear fuel waste disposal concept of a vault deep in plutonic rock of the Canadian Shield is presented. This generic, boreal zone biosphere model is based on scenario analysis and systems variability analysis using Monte Carlo simulation techniques. Conservatism is used to bridge uncertainties, even though this creates a small amount of extra nuclide mass. Environmental change over the very long assessment period is mainly handled through distributed parameter values. The dose receptors are a critical group of humans and four generic non-human target organisms. BIOTRAC includes six integrated submodels and it interfaces smoothly with a geosphere model. This interface includes a bedrock well. The geosphere model defines the discharge zones of deep groundwater where nuclides released from the vault enter the biosphere occupied by the dose receptors. The size of one of these zones is reduced when water is withdrawn from the bedrock well. Sensitivity analysis indicates 129 I is by far the most important radionuclide. Results also show bedrock-well water leads to higher doses to man than lake water, but the former doses decrease with the size of the critical group. Under comparable circumstances, doses to the non-human biota are greater than those for man

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

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 GoldSim Based Biosphere Assessment Model for a HLW Repository

International Nuclear Information System (INIS)

Lee, Youn-Myoung; Hwang, Yong-Soo; Kang, Chul-Hyung

2007-01-01

To demonstrate the performance of a repository, the dose exposure to a human being due to nuclide releases from a repository should be evaluated and the results compared to the dose limit presented by the regulatory bodies. To evaluate a dose rate to an individual due to a long-term release of nuclides from a HLW repository, biosphere assessment models and their implemented codes such as ACBIO1 and ACBIO2 have been developed with the aid of AMBER during the last few years. BIOMASS methodology has been adopted for a HLW repository currently being considered in Korea, which has a similar concept to the Swedish KBS-3 HLW repository. Recently, not just only for verifying the purpose for biosphere assessment models but also for varying the possible alternatives to assess the consequences in a biosphere due to a HLW repository, another version of the assessment modesl has been newly developed in the frame of development programs for a total system performance assessment modeling tool by utilizing GoldSim. Through a current study, GoldSim approach for a biosphere modeling is introduced. Unlike AMBER by which a compartment scheme can be rather simply constructed with an appropriate transition rate between compartments, GoldSim was designed to facilitate the object-oriented modules by which specific models can be addressed in an additional manner, like solving jig saw puzzles

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

Disruptive Event 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 volcanic ash exposure scenario, and the development of dose factors for calculating inhalation dose during volcanic eruption. 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 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 descriptions 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 volcanic ash exposure scenario. This analysis receives direct input from the outputs of the ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) and from the five analyses that develop parameter values for the biosphere model (BSC 2004 [DIRS 169671]; BSC 2004 [DIRS 169672]; BSC 2004 [DIRS 169673]; BSC 2004 [DIRS 169458]; and BSC 2004 [DIRS 169459]). The results of this report are further analyzed in the ''Biosphere Dose Conversion Factor Importance and Sensitivity Analysis''. The objective of this

Disruptive Event 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 volcanic ash exposure scenario, and the development of dose factors for calculating inhalation dose during volcanic eruption. 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 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 descriptions 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 volcanic ash exposure scenario. This analysis receives direct input from the outputs of the ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) and from the five analyses that develop parameter values for the biosphere model (BSC 2004 [DIRS 169671]; BSC 2004 [DIRS 169672]; BSC 2004 [DIRS 169673]; BSC 2004 [DIRS 169458]; and BSC 2004 [DIRS 169459]). The results of this report are further analyzed in the ''Biosphere Dose Conversion Factor Importance and Sensitivity Analysis''. The objective of this analysis was to develop the BDCFs for the volcanic ash

DISRUPTIVE EVENT 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 volcanic ash exposure scenario, and the development of dose factors for calculating inhalation dose during volcanic eruption. 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 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 descriptions 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 volcanic ash exposure scenario. This analysis receives direct input from the outputs of the ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) and from 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]; and 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 objective of this analysis was to develop the BDCFs for the volcanic

BIOSPHERE MODELING AT YUCCA MOUNTAIN, NEVADA

International Nuclear Information System (INIS)

NING LIU; JEFFERY, J.; TAPPEN, DE WU; CHAO-HSIUNG TUNG

1998-01-01

The objectives of the biosphere modeling efforts are to assess how radionuclides potentially released from the proposed repository could be transported through a variety of environmental media. The study of these transport mechanisms, referred to as pathways, is critical in calculating the potential radiation dose to man. Since most of the existing and pending regulations applicable to the Project are radiation dose based standards, the biosphere modeling effort will provide crucial technical input to support the Viability Assessment (VA), the Working Draft of License Application (WDLA), and the Environmental Impact Statement (EIS). In 1982, the Nuclear Waste Policy Act (NWPA) was enacted into law. This federal law, which was amended in 1987, addresses the national issue of geologic disposal of high-level nuclear waste generated by commercial nuclear power plants, as well as defense programs during the past few decades. As required by the law, the Department of Energy (DOE) is conducting a site characterization project at Yucca Mountain, Nevada, approximately 100 miles northwest of Las Vegas, Nevada, to determine if the site is suitable for the nation's first high-level nuclear waste repository

Analysis of Critical Issues in Biosphere Assessment Modelling and Site Investigation

Energy Technology Data Exchange (ETDEWEB)

Egan, M.J.; Thorne, M.C.; Little, R.H.; Pasco, R.F. [Quintessa Limited, Henley-on-Thames (United Kingdom)

2003-07-01

The aim of this document is to present a critical review of issues concerned with the treatment of the biosphere and geosphere-biosphere interface in long-term performance assessment studies for nuclear waste disposal in Sweden. The review covers three main areas of investigation: a review of SKB's plans for undertaking site investigations at candidate locations for the development of a deep geological repository for spent fuel; identification of critical uncertainties associated with SKB's treatment of the geosphere-biosphere interface in recent performance assessments; and a preliminary modelling investigation of the significance of features, events and processes in the near-surface environment in terms of their effect on the accumulation and redistribution of radionuclides at the geosphere-biosphere interface. Overall, SKB's proposals for site investigations are considered to be comprehensive and, if they can be carried out to the specification presented, will constitute a benchmark that other waste management organisations will have to work hard to emulate. The main concern is that expertise for undertaking the investigations and reporting the results could be stretched very thin. The authors have also identified weaknesses in the documentation concerning the collection of evidence for environmental change and on developing scenarios for future environmental change. A fundamental assumption adopted in the renewed assessment of the SFR 1 repository, which is not discussed or justified in any of the documentation that has been reviewed, is that radionuclides enter the water column of the coastal and lake models directly, without passing first through the bed sediments. The modelling study reported herein suggests that SKB's models are robust to range of alternative conceptual descriptions relating to the geosphere-biosphere interface. There are however situations, in which contaminated groundwater is released via sediment rather than directly

Analysis of Critical Issues in Biosphere Assessment Modelling and Site Investigation

International Nuclear Information System (INIS)

Egan, M.J.; Thorne, M.C.; Little, R.H.; Pasco, R.F.

2003-07-01

The aim of this document is to present a critical review of issues concerned with the treatment of the biosphere and geosphere-biosphere interface in long-term performance assessment studies for nuclear waste disposal in Sweden. The review covers three main areas of investigation: a review of SKB's plans for undertaking site investigations at candidate locations for the development of a deep geological repository for spent fuel; identification of critical uncertainties associated with SKB's treatment of the geosphere-biosphere interface in recent performance assessments; and a preliminary modelling investigation of the significance of features, events and processes in the near-surface environment in terms of their effect on the accumulation and redistribution of radionuclides at the geosphere-biosphere interface. Overall, SKB's proposals for site investigations are considered to be comprehensive and, if they can be carried out to the specification presented, will constitute a benchmark that other waste management organisations will have to work hard to emulate. The main concern is that expertise for undertaking the investigations and reporting the results could be stretched very thin. The authors have also identified weaknesses in the documentation concerning the collection of evidence for environmental change and on developing scenarios for future environmental change. A fundamental assumption adopted in the renewed assessment of the SFR 1 repository, which is not discussed or justified in any of the documentation that has been reviewed, is that radionuclides enter the water column of the coastal and lake models directly, without passing first through the bed sediments. The modelling study reported herein suggests that SKB's models are robust to range of alternative conceptual descriptions relating to the geosphere-biosphere interface. There are however situations, in which contaminated groundwater is released via sediment rather than directly to the water column

Assimilating solar-induced chlorophyll fluorescence into the terrestrial biosphere model BETHY-SCOPE v1.0: model description and information content

Science.gov (United States)

Norton, Alexander J.; Rayner, Peter J.; Koffi, Ernest N.; Scholze, Marko

2018-04-01

The synthesis of model and observational information using data assimilation can improve our understanding of the terrestrial carbon cycle, a key component of the Earth's climate-carbon system. Here we provide a data assimilation framework for combining observations of solar-induced chlorophyll fluorescence (SIF) and a process-based model to improve estimates of terrestrial carbon uptake or gross primary production (GPP). We then quantify and assess the constraint SIF provides on the uncertainty in global GPP through model process parameters in an error propagation study. By incorporating 1 year of SIF observations from the GOSAT satellite, we find that the parametric uncertainty in global annual GPP is reduced by 73 % from ±19.0 to ±5.2 Pg C yr-1. This improvement is achieved through strong constraint of leaf growth processes and weak to moderate constraint of physiological parameters. We also find that the inclusion of uncertainty in shortwave down-radiation forcing has a net-zero effect on uncertainty in GPP when incorporated into the SIF assimilation framework. This study demonstrates the powerful capacity of SIF to reduce uncertainties in process-based model estimates of GPP and the potential for improving our predictive capability of this uncertain carbon flux.

Potential Applications of Gosat Based Carbon Budget Products to Refine Terrestrial Ecosystem Model

Science.gov (United States)

Kondo, M.; Ichii, K.

2011-12-01

Estimation of carbon exchange in terrestrial ecosystem associates with difficulties due to complex entanglement of physical and biological processes: thus, the net ecosystem productivity (NEP) estimated from simulation often differs among process-based terrestrial ecosystem models. In addition to complexity of the system, validation can only be conducted in a point scale since reliable observation is only available from ground observations. With a lack of large spatial data, extension of model simulation to a global scale results in significant uncertainty in the future carbon balance and climate change. Greenhouse gases Observing SATellite (GOSAT), launched by the Japanese space agency (JAXA) in January, 2009, is the 1st operational satellite promised to deliver the net land-atmosphere carbon budget to the terrestrial biosphere research community. Using that information, the model reproducibility of carbon budget is expected to improve: hence, gives a better estimation of the future climate change. This initial analysis is to seek and evaluate the potential applications of GOSAT observation toward the sophistication of terrestrial ecosystem model. The present study was conducted in two processes: site-based analysis using eddy covariance observation data to assess the potential use of terrestrial carbon fluxes (GPP, RE, and NEP) to refine the model, and extension of the point scale analysis to spatial using Carbon Tracker product as a prototype of GOSAT product. In the first phase of the experiment, it was verified that an optimization routine adapted to a terrestrial model, Biome-BGC, yielded the improved result with respect to eddy covariance observation data from AsiaFlux Network. Spatial data sets used in the second phase were consists of GPP from empirical algorithm (e.g. support vector machine), NEP from Carbon Tracker, and RE from the combination of these. These spatial carbon flux estimations was used to refine the model applying the exactly same

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 modelling for safety assessment of geological disposal taking account of denudation of contaminated soils. Research document

International Nuclear Information System (INIS)

Kato, Tomoko

2003-03-01

Biosphere models for safety assessment of geological disposal have been developed on the assumption that the repository-derived radionuclides reach surface environment by groundwater. In the modelling, river, deep well and marine have been considered as geosphere-biosphere (GBIs) and some Japanese-specific ''reference biospheres'' have been developed using an approach consistent with the BIOMOVS II/BIOMASS Reference Biosphere Methodology. In this study, it is assumed that the repository-derived radionuclide would reach surface environment in the form of solid phase by uplift and erosion of contaminated soil and sediment. The radionuclides entered into the surface environment by these processes could be distributed between solid and liquid phases and could spread within the biosphere via solid phase and also liquid phase. Based on these concepts, biosphere model that considers variably saturated zone under surface soil (VSZ) as a GBI was developed for calculating the flux-to-dose conversion factors of three exposure groups (farming, freshwater fishing, marine fishing) based on the Reference Biosphere Methodology. The flux-to-dose conversion factors for faming exposure group were the highest, and ''inhalation of dust'', external irradiation from soil'' and ''ingestion of soil'' were the dominant exposure pathways for most of radionuclides considered in this model. It is impossible to compare the flux-to-dose conversion factors calculated by the biosphere model in this study with those calculated by the biosphere models developed in the previous studies because the migration processes considered when the radionuclides entered the surface environment through the aquifer are different among the models; i.e. it has been assumed that the repository-derived radionuclides entered the GBIs such as river, deep well and marine via groundwater without dilution and retardation at the aquifer in the previous biosphere models. Consequently, it must be modelled the migration of

Review of Project SAFE: Comments on biosphere conceptual model description and risk assessment methodology

Energy Technology Data Exchange (ETDEWEB)

Klos, Richard; Wilmot, Roger [Galson Sciences Ltd (United Kingdom)

2002-09-01

The Swedish Nuclear Fuel and Waste Management Company's (SKB's) most recent assessment of the safety of the Forsmark repository for low-level and intermediate-level waste (Project SAFE) is currently undergoing review by the Swedish regulators. As part of its review, the Swedish Radiation Protection Institute (SSI) identified that two components of SAFE require more detailed review: (i) the conceptual model description of the biosphere system, and (ii) SKB's risk assessment methodology. We have reviewed the biosphere system interaction matrix and how this has been used in the identification, justification and description of biosphere models for radiological assessment purposes. The risk assessment methodology has been reviewed considering in particular issues associated with scenario selection, assessment timescale, and the probability and risk associated with the well scenario. There is an extensive range of supporting information on which biosphere modelling in Project SAFE is based. However, the link between this material and the biosphere models themselves is not clearly set out. This leads to some contradictions and mis-matches between description and implementation. One example concerns the representation of the geosphere-biosphere interface. The supporting description of lakes indicates that interaction between groundwaters entering the biosphere through lake bed sediments could lead to accumulations of radionuclides in sediments. These sediments may become agricultural areas at some time in the future. In the numerical modelling of the biosphere carried out in Project SAFE, the direct accumulation of contaminants in bed sediments is not represented. Application of a more rigorous procedure to ensure numerical models are fit for purpose is recommended, paying more attention to issues associated with the geosphere-biosphere interface. A more structured approach to risk assessment would be beneficial, with a better explanation of the difference

The landscape-scale radionuclide transport model used in Posiva biosphere assessment 2012

Energy Technology Data Exchange (ETDEWEB)

Broed, R. [Facilia A (Finland); Hjerpe, T. [Facilia AB (Finland); Ikonen, A.T.K. [Environmental Research and Assessment EnviroCase, Ltd. (Finland)

2014-07-01

Construction of a deep geological repository for spent nuclear fuel in the Olkiluoto Island on the south-western coast of Finland is under preparation. This work presents the reference landscape-scale model for radionuclide fate and transport in the biosphere that was implemented as a part of the safety case underpinning the nuclear construction license of the repository in 2012. The model was implemented with a large number of biosphere objects, covering any radiologically significant areas of the site and downstream locations, in order to account for the uncertainty in the geosphere release location. One important factor considered is the effect of land uplift, which has the consequence that the modelled landscape evolves with time, i.e. new land areas is continuously emerging from the sea and by overgrowth of lakes, and the modelled biosphere objects can change their biotope and composition over time. For example, a biosphere object that initially represents a part of the coast, can due to the land uplift eventually represent a lake. This lake might then at a later stage have dried up and formed a wetland that eventually is turned into a cropland. This means that the ecosystem-specific model parts used in one biosphere object, the related model parameters, and the available exposure pathways vary with time. A time-period of 10,000 years is simulated, with the assumption that a single spent fuel disposal canister initially fails its containment functions. The resulting activity concentrations in the environmental media that are produced by the simulation with the landscape model are used to estimate the doses to members of the public and dose-rates to non-human biota inhabiting the modelled region. In this work the focus is on the reference case model which represents a defective canister in a deposition hole that is cautiously selected, leading to geosphere releases just north of the current northern shoreline, but also a brief overview of two alternative models

Comparison of biospheric models of radionuclides transfer

International Nuclear Information System (INIS)

Garcia-Olivares, A.; Carrasco, E.

1992-01-01

The international BIOMOVS A4 exercise has made possible that a set of biospheric transfer models could predict the daily radionuclide concentration in soils, forage and some animal products (cow milk and beef) after the Chernobyl accident. The aim was to compare these predictions with experimental results in 13 locations around the world. The data provided were essentially the daily air contamination and precipitation and some site-dependent parameters. It was a blind test, the locations and experimental measures were not revealed in advance. Twenty-three models (quasi-steady state and time-dependent models) were involved in the study. In this paper an explicit criterion has been used in order to select the models that better fitted the experimental results. In nine selected locations a comparative analysis between these models has been carried out for obtaining the structural and parametric coincidences that could explain their relatively good performance. The first evidence obtained has been that a wide set of models were able to predict the order of magnitude of the nuclides time-integrated concentrations in several important biospheric comportments. But only a few models, all of them with a 'dynamical' structure, fitted the daily behavior with the reasonable agreement. The dynamical structure of the five most successful models at predicting for Caesium 137 (CIRCLE, ECOSYS, PATHWAY, PRYMA and RAGTIME) shows some common patterns that may be relevant for a better modelling of nuclear accident scenarios. (author)

Description, calibration and sensitivity analysis of the local ecosystem submodel of a global model of carbon and nitrogen cycling and the water balance in the terrestrial biosphere

Energy Technology Data Exchange (ETDEWEB)

Kercher, J.R. [Lawrence Livermore National Lab., CA (United States); Chambers, J.Q. [Lawrence Livermore National Lab., CA (United States)]|[California Univ., Santa Barbara, CA (United States). Dept. of Biological Sciences

1995-10-01

We have developed a geographically-distributed ecosystem model for the carbon, nitrogen, and water dynamics of the terrestrial biosphere TERRA. The local ecosystem model of TERRA consists of coupled, modified versions of TEM and DAYTRANS. The ecosystem model in each grid cell calculates water fluxes of evaporation, transpiration, and runoff; carbon fluxes of gross primary productivity, litterfall, and plant and soil respiration; and nitrogen fluxes of vegetation uptake, litterfall, mineralization, immobilization, and system loss. The state variables are soil water content; carbon in live vegetation; carbon in soil; nitrogen in live vegetation; organic nitrogen in soil and fitter; available inorganic nitrogen aggregating nitrites, nitrates, and ammonia; and a variable for allocation. Carbon and nitrogen dynamics are calibrated to specific sites in 17 vegetation types. Eight parameters are determined during calibration for each of the 17 vegetation types. At calibration, the annual average values of carbon in vegetation C, show site differences that derive from the vegetation-type specific parameters and intersite variation in climate and soils. From calibration, we recover the average C{sub v} of forests, woodlands, savannas, grasslands, shrublands, and tundra that were used to develop the model initially. The timing of the phases of the annual variation is driven by temperature and light in the high latitude and moist temperate zones. The dry temperate zones are driven by temperature, precipitation, and light. In the tropics, precipitation is the key variable in annual variation. The seasonal responses are even more clearly demonstrated in net primary production and show the same controlling factors.

Variability of Phenology and Fluxes of Water and Carbon with Observed and Simulated Soil Moisture in the Ent Terrestrial Biosphere Model (Ent TBM Version 1.0.1.0.0)

Science.gov (United States)

Kim, Y.; Moorcroft, P. R.; Aleinov, Igor; Puma, M. J.; Kiang, N. Y.

2015-01-01

The Ent Terrestrial Biosphere Model (Ent TBM) is a mixed-canopy dynamic global vegetation model developed specifically for coupling with land surface hydrology and general circulation models (GCMs). This study describes the leaf phenology submodel implemented in the Ent TBM version 1.0.1.0.0 coupled to the carbon allocation scheme of the Ecosystem Demography (ED) model. The phenology submodel adopts a combination of responses to temperature (growing degree days and frost hardening), soil moisture (linearity of stress with relative saturation) and radiation (light length). Growth of leaves, sapwood, fine roots, stem wood and coarse roots is updated on a daily basis. We evaluate the performance in reproducing observed leaf seasonal growth as well as water and carbon fluxes for four plant functional types at five Fluxnet sites, with both observed and prognostic hydrology, and observed and prognostic seasonal leaf area index. The phenology submodel is able to capture the timing and magnitude of leaf-out and senescence for temperate broadleaf deciduous forest (Harvard Forest and Morgan- Monroe State Forest, US), C3 annual grassland (Vaira Ranch, US) and California oak savanna (Tonzi Ranch, US). For evergreen needleleaf forest (Hyytiäla, Finland), the phenology submodel captures the effect of frost hardening of photosynthetic capacity on seasonal fluxes and leaf area. We address the importance of customizing parameter sets of vegetation soil moisture stress response to the particular land surface hydrology scheme. We identify model deficiencies that reveal important dynamics and parameter needs.

Variability of phenology and fluxes of water and carbon with observed and simulated soil moisture in the Ent Terrestrial Biosphere Model (Ent TBM version 1.0.1.0.0)

Science.gov (United States)

Kim, Y.; Moorcroft, P. R.; Aleinov, I.; Puma, M. J.; Kiang, N. Y.

2015-12-01

The Ent Terrestrial Biosphere Model (Ent TBM) is a mixed-canopy dynamic global vegetation model developed specifically for coupling with land surface hydrology and general circulation models (GCMs). This study describes the leaf phenology submodel implemented in the Ent TBM version 1.0.1.0.0 coupled to the carbon allocation scheme of the Ecosystem Demography (ED) model. The phenology submodel adopts a combination of responses to temperature (growing degree days and frost hardening), soil moisture (linearity of stress with relative saturation) and radiation (light length). Growth of leaves, sapwood, fine roots, stem wood and coarse roots is updated on a daily basis. We evaluate the performance in reproducing observed leaf seasonal growth as well as water and carbon fluxes for four plant functional types at five Fluxnet sites, with both observed and prognostic hydrology, and observed and prognostic seasonal leaf area index. The phenology submodel is able to capture the timing and magnitude of leaf-out and senescence for temperate broadleaf deciduous forest (Harvard Forest and Morgan-Monroe State Forest, US), C3 annual grassland (Vaira Ranch, US) and California oak savanna (Tonzi Ranch, US). For evergreen needleleaf forest (Hyytiäla, Finland), the phenology submodel captures the effect of frost hardening of photosynthetic capacity on seasonal fluxes and leaf area. We address the importance of customizing parameter sets of vegetation soil moisture stress response to the particular land surface hydrology scheme. We identify model deficiencies that reveal important dynamics and parameter needs.

Inverse modeling of the terrestrial carbon flux in China with flux covariance among inverted regions

Science.gov (United States)

Wang, H.; Jiang, F.; Chen, J. M.; Ju, W.; Wang, H.

2011-12-01

Quantitative understanding of the role of ocean and terrestrial biosphere in the global carbon cycle, their response and feedback to climate change is required for the future projection of the global climate. China has the largest amount of anthropogenic CO2 emission, diverse terrestrial ecosystems and an unprecedented rate of urbanization. Thus information on spatial and temporal distributions of the terrestrial carbon flux in China is of great importance in understanding the global carbon cycle. We developed a nested inversion with focus in China. Based on Transcom 22 regions for the globe, we divide China and its neighboring countries into 17 regions, making 39 regions in total for the globe. A Bayesian synthesis inversion is made to estimate the terrestrial carbon flux based on GlobalView CO2 data. In the inversion, GEOS-Chem is used as the transport model to develop the transport matrix. A terrestrial ecosystem model named BEPS is used to produce the prior surface flux to constrain the inversion. However, the sparseness of available observation stations in Asia poses a challenge to the inversion for the 17 small regions. To obtain additional constraint on the inversion, a prior flux covariance matrix is constructed using the BEPS model through analyzing the correlation in the net carbon flux among regions under variable climate conditions. The use of the covariance among different regions in the inversion effectively extends the information content of CO2 observations to more regions. The carbon flux over the 39 land and ocean regions are inverted for the period from 2004 to 2009. In order to investigate the impact of introducing the covariance matrix with non-zero off-diagonal values to the inversion, the inverted terrestrial carbon flux over China is evaluated against ChinaFlux eddy-covariance observations after applying an upscaling methodology.

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.

The Jena Diversity-Dynamic Global Vegetation Model (JeDi-DGVM: a diverse approach to representing terrestrial biogeography and biogeochemistry based on plant functional trade-offs

Directory of Open Access Journals (Sweden)

R. Pavlick

2013-06-01

Full Text Available Terrestrial biosphere models typically abstract the immense diversity of vegetation forms and functioning into a relatively small set of predefined semi-empirical plant functional types (PFTs. There is growing evidence, however, from the field ecology community as well as from modelling studies that current PFT schemes may not adequately represent the observed variations in plant functional traits and their effect on ecosystem functioning. In this paper, we introduce the Jena Diversity-Dynamic Global Vegetation Model (JeDi-DGVM as a new approach to terrestrial biosphere modelling with a richer representation of functional diversity than traditional modelling approaches based on a small number of fixed PFTs. JeDi-DGVM simulates the performance of a large number of randomly generated plant growth strategies, each defined by a set of 15 trait parameters which characterize various aspects of plant functioning including carbon allocation, ecophysiology and phenology. Each trait parameter is involved in one or more functional trade-offs. These trade-offs ultimately determine whether a strategy is able to survive under the climatic conditions in a given model grid cell and its performance relative to the other strategies. The biogeochemical fluxes and land surface properties of the individual strategies are aggregated to the grid-cell scale using a mass-based weighting scheme. We evaluate the simulated global biogeochemical patterns against a variety of field and satellite-based observations following a protocol established by the Carbon-Land Model Intercomparison Project. The land surface fluxes and vegetation structural properties are reasonably well simulated by JeDi-DGVM, and compare favourably with other state-of-the-art global vegetation models. We also evaluate the simulated patterns of functional diversity and the sensitivity of the JeDi-DGVM modelling approach to the number of sampled strategies. Altogether, the results demonstrate the

Radioactive waste disposal assessment - overview of biosphere processes and models

International Nuclear Information System (INIS)

Coughtrey, P.J.

1992-09-01

This report provides an overview of biosphere processes and models in the general context of the radiological assessment of radioactive waste disposal as a basis for HMIP's response to biosphere aspects of Nirex's submissions for disposal of radioactive wastes in a purpose-built repository at Sellafield, Cumbria. The overview takes into account published information from the UK as available from Nirex's safety and assessment research programme and HMIP's disposal assessment programme, as well as that available from studies in the UK and elsewhere. (Author)

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

1.3 Radioactivity in the biosphere

International Nuclear Information System (INIS)

1985-01-01

The term biosphere is defined comprising specific properties of the live envelope of the Earth. The classification of its sources is discussed. The concepts of ecology and ecosystem are defined and the differences are characterized between the aquatic and terrestrial ecosystems. Radiation ecology studies the interaction of radioactive materials and of radiation with the environment. Ecologically important radionuclides are listed with their ecological importance and the highest permissible concentrations in the air and water. Radionuclides are classified by their relative toxicity. (J.C.)

Impacts of large-scale climatic disturbances on the terrestrial carbon cycle

Directory of Open Access Journals (Sweden)

Lucht Wolfgang

2006-07-01

Full Text Available Abstract Background The amount of carbon dioxide in the atmosphere steadily increases as a consequence of anthropogenic emissions but with large interannual variability caused by the terrestrial biosphere. These variations in the CO2 growth rate are caused by large-scale climate anomalies but the relative contributions of vegetation growth and soil decomposition is uncertain. We use a biogeochemical model of the terrestrial biosphere to differentiate the effects of temperature and precipitation on net primary production (NPP and heterotrophic respiration (Rh during the two largest anomalies in atmospheric CO2 increase during the last 25 years. One of these, the smallest atmospheric year-to-year increase (largest land carbon uptake in that period, was caused by global cooling in 1992/93 after the Pinatubo volcanic eruption. The other, the largest atmospheric increase on record (largest land carbon release, was caused by the strong El Niño event of 1997/98. Results We find that the LPJ model correctly simulates the magnitude of terrestrial modulation of atmospheric carbon anomalies for these two extreme disturbances. The response of soil respiration to changes in temperature and precipitation explains most of the modelled anomalous CO2 flux. Conclusion Observed and modelled NEE anomalies are in good agreement, therefore we suggest that the temporal variability of heterotrophic respiration produced by our model is reasonably realistic. We therefore conclude that during the last 25 years the two largest disturbances of the global carbon cycle were strongly controlled by soil processes rather then the response of vegetation to these large-scale climatic events.

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

Carbon isotope discrimination of arctic and boreal biomes inferred from remote atmospheric measurements and a biosphere-atmosphere model - art. no. 1028

Energy Technology Data Exchange (ETDEWEB)

Randerson, J.T.; Still, C.J.; Balle, J.J.; Fung, I.Y.; Doney, S.C.; Tans, P.P.; Conway, T.J.; White, J.W.C.; Vaughn, B.; Suits, N.; Denning, A.S. [CALTECH, Pasadena, CA (United States). Div. of Geology & Planetary Science

2002-07-01

Estimating discrimination against C-13 during photosynthesis at landscape, regional, and biome scales is difficult because of large-scale variability in plant stress, vegetation composition, and photosynthetic pathway. The authors present estimates of C-13 discrimination for northern biomes based on a biosphere-atmosphere model and on National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostics Laboratory and Institute of Arctic and Alpine Research remote flask measurements. With the inversion approach, solutions were found for three ecophysiological parameters of the northern biosphere {delta}{sup 13}C discrimination, a net primary production light use efficiency, and a temperature sensitivity of heterotrophic respiration (a Q10 factor) that provided a best fit between modeled and observed {delta}{sup 13}C and CO{sub 2}. The analysis attempted to explicitly correct for fossil fuel emissions, remote C4 ecosystem fluxes, ocean exchange, and isotopic disequilibria of terrestrial heterotrophic respiration caused by the Suess effect. A photosynthetic discrimination was obtained for arctic and boreal biomes between 19.0 and 19.6%. The inversion analysis suggests that Q10 and light use efficiency values that minimize the cost function covary. The optimal light use efficiency was 0.47 gC MJ{sup -1} photosynthetically active radiation, and the optimal Q10 value was 1.52. Fossil fuel and ocean exchange contributed proportionally more to month-to-month changes in the atmospheric growth rate of {delta}{sup 13}C and CO{sub 2} during winter months, suggesting that remote atmospheric observations during the summer may yield more precise estimates of the isotopic composition of the biosphere.

Terrestrial cycling of (CO2)-C-13 by photosynthesis, respiration, and biomass burning in SiBCASA

NARCIS (Netherlands)

Velde, van der I.R.; Miller, J.B.; Schaefer, K.; Werf, van der G.R.; Krol, M.C.; Peters, W.

2014-01-01

We present an enhanced version of the SiBCASA terrestrial biosphere model that is extended with (a) biomass burning emissions from the SiBCASA carbon pools using remotely sensed burned area from the Global Fire Emissions Database (GFED), (b) an isotopic discrimination scheme that calculates 13C

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.

Modeling the impact of climate change in Germany with biosphere models for long-term safety assessment of nuclear waste repositories

International Nuclear Information System (INIS)

Staudt, C.; Semiochkina, N.; Kaiser, J.C.; Pröhl, G.

2013-01-01

Biosphere models are used to evaluate the exposure of populations to radionuclides from a deep geological repository. Since the time frame for assessments of long-time disposal safety is 1 million years, potential future climate changes need to be accounted for. Potential future climate conditions were defined for northern Germany according to model results from the BIOCLIM project. Nine present day reference climate regions were defined to cover those future climate conditions. A biosphere model was developed according to the BIOMASS methodology of the IAEA and model parameters were adjusted to the conditions at the reference climate regions. The model includes exposure pathways common to those reference climate regions in a stylized biosphere and relevant to the exposure of a hypothetical self-sustaining population at the site of potential radionuclide contamination from a deep geological repository. The end points of the model are Biosphere Dose Conversion factors (BDCF) for a range of radionuclides and scenarios normalized for a constant radionuclide concentration in near-surface groundwater. Model results suggest an increased exposure of in dry climate regions with a high impact of drinking water consumption rates and the amount of irrigation water used for agriculture. - Highlights: ► We model Biosphere Dose Conversion Factors for a representative group exposed to radionuclides from a waste repository. ► The BDCF are modeled for different soil types. ► One model is used for the assessment of the influence of climate change during the disposal time frame.

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

The role of tectonic uplift, climate, and vegetation in the long-term terrestrial phosphorous cycle

Directory of Open Access Journals (Sweden)

C. Buendía

2010-06-01

Full Text Available Phosphorus (P is a crucial element for life and therefore for maintaining ecosystem productivity. Its local availability to the terrestrial biosphere results from the interaction between climate, tectonic uplift, atmospheric transport, and biotic cycling. Here we present a mathematical model that describes the terrestrial P-cycle in a simple but comprehensive way. The resulting dynamical system can be solved analytically for steady-state conditions, allowing us to test the sensitivity of the P-availability to the key parameters and processes. Given constant inputs, we find that humid ecosystems exhibit lower P availability due to higher runoff and losses, and that tectonic uplift is a fundamental constraint. In particular, we find that in humid ecosystems the biotic cycling seem essential to maintain long-term P-availability. The time-dependent P dynamics for the Franz Josef and Hawaii chronosequences show how tectonic uplift is an important constraint on ecosystem productivity, while hydroclimatic conditions control the P-losses and speed towards steady-state. The model also helps describe how, with limited uplift and atmospheric input, as in the case of the Amazon Basin, ecosystems must rely on mechanisms that enhance P-availability and retention. Our novel model has a limited number of parameters and can be easily integrated into global climate models to provide a representation of the response of the terrestrial biosphere to global change.

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 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

Impact of Biomass Burning Aerosols on the Biosphere over Amazonia

Science.gov (United States)

Malavelle, F.; Haywood, J.; Mercado, L.; Folberth, G.; Bellouin, N.

2014-12-01

biosphere has been implemented within a fully coupled Earth System Model, namely the UK Met Office Hadley Centre HadGEM2-ES model. We present results from ten-year experiments (2000-2010) designed to investigate the sensitivity of the terrestrial biosphere to the burden and absorbing nature of Amazonian BB aerosols.

Developpement of a GoldSim Biosphere Model, Evaluation, and Its Verification

International Nuclear Information System (INIS)

Lee, Youn Myoung; Hwang, Yong Soo

2009-12-01

For the purpose of evaluating dose rate to individual due to long-term release of nuclides from the repository for an HLW or a pyroprocessing repository, a biosphere assessment model and the implemented program based on BIOMASS methodology have been developed by utilizing GoldSim, a general model developing tool. To show its practicability and usability as well as to see the sensitivity of parametric and scenario variations to the annual exposure, some probabilistic calculations are made and investigated. For the cases when changing the exposure groups and associated GBIs as well as varying selected input values, all of which seem important for the biosphere evaluation, dose rate per nuclide release rate is probabilistically calculated and analyzed. A series of comparison studies with JAEA, Japan have been also carried out to verify the model

Data-driven diagnostics of terrestrial carbon dynamics over North America

Science.gov (United States)

Jingfeng Xiao; Scott V. Ollinger; Steve Frolking; George C. Hurtt; David Y. Hollinger; Kenneth J. Davis; Yude Pan; Xiaoyang Zhang; Feng Deng; Jiquan Chen; Dennis D. Baldocchi; Bevery E. Law; M. Altaf Arain; Ankur R. Desai; Andrew D. Richardson; Ge Sun; Brian Amiro; Hank Margolis; Lianhong Gu; Russell L. Scott; Peter D. Blanken; Andrew E. Suyker

2014-01-01

The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection between the terrestrial biosphere and the Earth's climate. Despite the general agreement that the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution of the sink remain uncertain. We use a data-driven approach to upscale...

A comparative Study between GoldSim and AMBER Based Biosphere Assessment Models for an HLW Repository

International Nuclear Information System (INIS)

Lee, Youn-Myoung; Hwang, Yong-Soo

2007-01-01

To demonstrate the performance of a repository, the dose exposure rate to human being due to long-term nuclide releases from a high-level waste repository (HLW) should be evaluated and the results compared to the dose limit presented by the regulatory bodies. To evaluate such a dose rate to an individual, biosphere assessment models have been developed and implemented for a practical calculation with the aid of such commercial tools as AMBER and GoldSim, both of which are capable of probabilistic and deterministic calculation. AMBER is a general purpose compartment modeling tool and GoldSim is another multipurpose simulation tool for dynamically modeling complex systems, supporting a higher graphical user interface than AMBER and a postprocessing feature. And also unlike AMBER, any kind of compartment scheme can be rather simply constructed with an appropriate transition rate between compartments, GoldSim is designed to facilitate the object-oriented modules to address any specialized programs, similar to solving jig saw puzzles. During the last couple of years a compartment modeling approach for a biosphere has been mainly carried out with AMBER in KAERI in order to conservatively or rather roughly provide dose conversion factors to get the final exposure rate due to a nuclide flux into biosphere over various geosphere-biosphere interfaces (GBIs) calculated through nuclide transport modules. This caused a necessity for a newly devised biosphere model that could be coupled to a nuclide transport model with less conservatism in the frame of the development of a total system performance assessment modeling tool, which could be successfully done with the aid of GoldSim. Therefore, through the current study, some comparison results of the AMBER and the GoldSim approaches for the same case of a biosphere modeling without any consideration of geosphere transport are introduced by extending a previous study

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

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

1km Global Terrestrial Carbon Flux: Estimations and Evaluations

Science.gov (United States)

Murakami, K.; Sasai, T.; Kato, S.; Saito, M.; Matsunaga, T.; Hiraki, K.; Maksyutov, S. S.

2017-12-01

Estimating global scale of the terrestrial carbon flux change with high accuracy and high resolution is important to understand global environmental changes. Furthermore the estimations of the global spatiotemporal distribution may contribute to the political and social activities such as REDD+. In order to reveal the current state of terrestrial carbon fluxes covering all over the world and a decadal scale. The satellite-based diagnostic biosphere model is suitable for achieving this purpose owing to observing on the present global land surface condition uniformly at some time interval. In this study, we estimated the global terrestrial carbon fluxes with 1km grids by using the terrestrial biosphere model (BEAMS). And we evaluated our new carbon flux estimations on various spatial scales and showed the transition of forest carbon stocks in some regions. Because BEAMS required high resolution meteorological data and satellite data as input data, we made 1km interpolated data using a kriging method. The data used in this study were JRA-55, GPCP, GOSAT L4B atmospheric CO2 data as meteorological data, and MODIS land product as land surface satellite data. Interpolating process was performed on the meteorological data because of insufficient resolution, but not on MODIS data. We evaluated our new carbon flux estimations using the flux tower measurement (FLUXNET2015 Datasets) in a point scale. We used 166 sites data for evaluating our model results. These flux sites are classified following vegetation type (DBF, EBF, ENF, mixed forests, grass lands, croplands, shrub lands, Savannas, wetlands). In global scale, the BEAMS estimations was underestimated compared to the flux measurements in the case of carbon uptake and release. The monthly variations of NEP showed relatively high correlations in DBF and mixed forests, but the correlation coefficients of EBF, ENF, and grass lands were less than 0.5. In the meteorological factors, air temperature and solar radiation showed

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.

Radioactive waste management. International projects on biosphere modelling

International Nuclear Information System (INIS)

Carboneras, P.; Cancio, D.

1993-01-01

The paper presents a general overview and discussion on the state of art concerning the biospheric transfer and accumulation of contaminants. A special emphasis is given to the progress achieved in the field of radioactive contaminants and particularly to those implied in radioactive waste disposal. The objectives and advances of the international projects BIOMOVS and VAMP on validation of model predictions are also described. (Author)

Application of biosphere models in the Biomosa project: a comparative assessment of five European radioactive waste disposal sites

International Nuclear Information System (INIS)

Kowe, R.; Mobbs, S.; Proehl, G.; Bergstrom, U.; Kanyar, B.; Olyslaegers, G.; Zeevaert, T.; Simon, I.

2004-01-01

The BIOMOSA (Biosphere Models for Safety Assessment of Radioactive Waste Disposal) project is a part of the EC fifth framework research programme. The main goal of this project is the improvement of the scientific basis for the application of biosphere models in the framework of long-term safety studies of radioactive waste disposal facilities. Furthermore, the outcome of the project will provide operators and regulatory bodies with guidelines for performance assessments of repository systems. The study focuses on the development and application of site-specific models and a generic biosphere tool BIOGEM (Biosphere Generic Model), using the experience from the national programmes and the IAEA BIOMASS reference biosphere methodology. The models were applied to 5 typical locations in the EU, resulting in estimates of the annual individual doses to the critical groups and the ranking of the importance of the pathways for each of the sites. The results of the site-specific and generic models were then compared. In all cases the doses calculated by the generic model were less than the doses obtained from the site-specific models. Uncertainty in the results was estimated by means of stochastic calculations which allow a comparison of the overall model uncertainty with the variability across the different sites considered. (author)

Microbial rhodopsins on leaf surfaces of terrestrial plants

OpenAIRE

Atamna-Ismaeel, Nof; Finkel, Omri M.; Glaser, Fabian; Sharon, Itai; Schneider, Ron; Post, Anton F.; Spudich, John L.; von Mering, Christian; Vorholt, Julia A.; Iluz, David; Béjà, Oded; Belkin, Shimshon

2011-01-01

The above-ground surfaces of terrestrial plants, the phyllosphere, comprise the main interface between the terrestrial biosphere and solar radiation. It is estimated to host up to 1026 microbial cells that may intercept part of the photon flux impinging on the leaves. Based on 454-pyrosequencing-generated metagenome data, we report on the existence of diverse microbial rhodopsins in five distinct phyllospheres from tamarisk (Tamarix nilotica), soybean (Glycine max), Arabidopsis (Arabidopsis t...

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)

Modeling the impact of climate change in Germany with biosphere models for long-term safety assessment of nuclear waste repositories.

Science.gov (United States)

Staudt, C; Semiochkina, N; Kaiser, J C; Pröhl, G

2013-01-01

Biosphere models are used to evaluate the exposure of populations to radionuclides from a deep geological repository. Since the time frame for assessments of long-time disposal safety is 1 million years, potential future climate changes need to be accounted for. Potential future climate conditions were defined for northern Germany according to model results from the BIOCLIM project. Nine present day reference climate regions were defined to cover those future climate conditions. A biosphere model was developed according to the BIOMASS methodology of the IAEA and model parameters were adjusted to the conditions at the reference climate regions. The model includes exposure pathways common to those reference climate regions in a stylized biosphere and relevant to the exposure of a hypothetical self-sustaining population at the site of potential radionuclide contamination from a deep geological repository. The end points of the model are Biosphere Dose Conversion factors (BDCF) for a range of radionuclides and scenarios normalized for a constant radionuclide concentration in near-surface groundwater. Model results suggest an increased exposure of in dry climate regions with a high impact of drinking water consumption rates and the amount of irrigation water used for agriculture. Copyright © 2012 Elsevier Ltd. All rights reserved.

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 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

Terrestrial biogeochemical feedbacks in the climate system: from past to future

Energy Technology Data Exchange (ETDEWEB)

Arneth, A.; Harrison, S. P.; Zaehle, S.; Tsigaridis, K; Menon, S; Bartlein, P.J.; Feichter, J; Korhola, A; Kulmala, M; O' Donnell, D; Schurgers, G; Sorvari, S; Vesala, T

2010-01-05

The terrestrial biosphere plays a major role in the regulation of atmospheric composition, and hence climate, through multiple interlinked biogeochemical cycles (BGC). Ice-core and other palaeoenvironmental records show a fast response of vegetation cover and exchanges with the atmosphere to past climate change, although the phasing of these responses reflects spatial patterning and complex interactions between individual biospheric feedbacks. Modern observations show a similar responsiveness of terrestrial biogeochemical cycles to anthropogenically-forced climate changes and air pollution, with equally complex feedbacks. For future conditions, although carbon cycle-climate interactions have been a major focus, other BGC feedbacks could be as important in modulating climate changes. The additional radiative forcing from terrestrial BGC feedbacks other than those conventionally attributed to the carbon cycle is in the range of 0.6 to 1.6 Wm{sup -2}; all taken together we estimate a possible maximum of around 3 Wm{sup -2} towards the end of the 21st century. There are large uncertainties associated with these estimates but, given that the majority of BGC feedbacks result in a positive forcing because of the fundamental link between metabolic stimulation and increasing temperature, improved quantification of these feedbacks and their incorporation in earth system models is necessary in order to develop coherent plans to manage ecosystems for climate mitigation.

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

Biosphere conceptual model development in the frame of Baita Bihor repository safety project

International Nuclear Information System (INIS)

Paunescu, N.; Margineanu, R.; Ene, D.

2002-01-01

The topic of this paper is the development of the biosphere model in the frame of the preliminary performance assessment of the Romanian National L and ILW repository, Baita-Bihor. The work presents the actual understanding of the radionuclide pathways through the repository adjacent area and their conceptualization, collection of required data, implementation of model and preliminary calculation results. The model takes into consideration a leaching scenario from the near field and the transport of radionuclides by river water. The critical group is a small community of inhabitants relying on the local resources, which constitutes an agriculture community 'small farm system'. On the basis of the defined specifications (biosphere equations and data), application of model and dose rate estimates were performed by the ABRICOT code. (author)

Estimation Terrestrial Net Primary Productivity Based on CASA Model: a Case Study in Minnan Urban Agglomeration, China

International Nuclear Information System (INIS)

Hua, L Z; Liu, H; Zhang, X L; Zheng, Y; Man, W; Yin, K

2014-01-01

Net Primary Productivity (NPP) is a key component of the terrestrial carbon cycle. The research of net primary productivity will help in understanding the amount of carbon fixed by terrestrial vegetation and its influencing factors. Model simulation is considered as a cost-effective and time-efficient method for the estimation of regional and global NPP. In the paper, a terrestrial biosphere model, CASA (Carnegie Ames Stanford Approach), was applied to estimate monthly NPP in Minnan urban agglomeration (i.e. Xiamen, Zhangzhou and Quanzhou cities) of Fujian province, China, in 2009 and 2010, by incorporating satellite observation of SPOT Vegetation NDVI data together with other climatic parameters and landuse map. The model estimates average annual terrestrial NPP of Minnan area as 16.3 million Mg C. NPP decreased from southwest to the northeast. The higher NPP values exceeding 720 gC·m − 2 ·a −1 showed in North Zhangzhou city and lower values under 500 gC·m − 2 ·a −1 showed in the some areas of northeast Quanzhou city. Seasonal variations of NPP were large. It was about 45% of the total annual NPP in the three months in summer, and the NPP values were very low in winter. From 2009 to 2010, the value of annual NPP showed a slightly decrease trend, approximately 7.8% because the annual temperature for 2010 decline 13.6% compared with 2009 in despite of an increase in rainfall of about 34.3%. The results indicate that temperature was a main limiting factor on vegetation growth, but water is not a limiting factor in the rainy area

Group dynamics challenges: Insights from Biosphere 2 experiments

Science.gov (United States)

Nelson, Mark; Gray, Kathelin; Allen, John P.

2015-07-01

Successfully managing group dynamics of small, physically isolated groups is vital for long duration space exploration/habitation and for terrestrial CELSS (Controlled Environmental Life Support System) facilities with human participants. Biosphere 2 had important differences and shares some key commonalities with both Antarctic and space environments. There were a multitude of stress factors during the first two year closure experiment as well as mitigating factors. A helpful tool used at Biosphere 2 was the work of W.R. Bion who identified two competing modalities of behavior in small groups. Task-oriented groups are governed by conscious acceptance of goals, reality-thinking in relation to time and resources, and intelligent management of challenges. The opposing unconscious mode, the "basic-assumption" ("group animal") group, manifests through Dependency/Kill the Leader, Fight/Flight and Pairing. These unconscious dynamics undermine and can defeat the task group's goal. The biospherians experienced some dynamics seen in other isolated teams: factions developing reflecting personal chemistry and disagreements on overall mission procedures. These conflicts were exacerbated by external power struggles which enlisted support of those inside. Nevertheless, the crew evolved a coherent, creative life style to deal with some of the deprivations of isolation. The experience of the first two year closure of Biosphere 2 vividly illustrates both vicissitudes and management of group dynamics. The crew overrode inevitable frictions to creatively manage both operational and research demands and opportunities of the facility, thus staying 'on task' in Bion's group dynamics terminology. The understanding that Biosphere 2 was their life support system may also have helped the mission to succeed. Insights from the Biosphere 2 experience can help space and remote missions cope successfully with the inherent challenges of small, isolated crews.

Group dynamics challenges: Insights from Biosphere 2 experiments.

Science.gov (United States)

Nelson, Mark; Gray, Kathelin; Allen, John P

2015-07-01

Successfully managing group dynamics of small, physically isolated groups is vital for long duration space exploration/habitation and for terrestrial CELSS (Controlled Environmental Life Support System) facilities with human participants. Biosphere 2 had important differences and shares some key commonalities with both Antarctic and space environments. There were a multitude of stress factors during the first two year closure experiment as well as mitigating factors. A helpful tool used at Biosphere 2 was the work of W.R. Bion who identified two competing modalities of behavior in small groups. Task-oriented groups are governed by conscious acceptance of goals, reality-thinking in relation to time and resources, and intelligent management of challenges. The opposing unconscious mode, the "basic-assumption" ("group animal") group, manifests through Dependency/Kill the Leader, Fight/Flight and Pairing. These unconscious dynamics undermine and can defeat the task group's goal. The biospherians experienced some dynamics seen in other isolated teams: factions developing reflecting personal chemistry and disagreements on overall mission procedures. These conflicts were exacerbated by external power struggles which enlisted support of those inside. Nevertheless, the crew evolved a coherent, creative life style to deal with some of the deprivations of isolation. The experience of the first two year closure of Biosphere 2 vividly illustrates both vicissitudes and management of group dynamics. The crew overrode inevitable frictions to creatively manage both operational and research demands and opportunities of the facility, thus staying 'on task' in Bion's group dynamics terminology. The understanding that Biosphere 2 was their life support system may also have helped the mission to succeed. Insights from the Biosphere 2 experience can help space and remote missions cope successfully with the inherent challenges of small, isolated crews. Copyright © 2015 The Committee on

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

New era of satellite chlorophyll fluorescence and soil moisture observations leads to advances in the predictive understanding of global terrestrial coupled carbon-water cycles

Science.gov (United States)

Qiu, B.; Xue, Y.; Fisher, J.; Guo, W.

2017-12-01

The terrestrial carbon cycle and water cycle are coupled through a multitude of connected processes among soil, roots, leaves, and the atmosphere. The strength and sensitivity of these couplings are not yet well known at the global scale, which contributes to uncertainty in predicting the terrestrial water and carbon budgets. For the first time, we now have synchronous, high fidelity, global-scale satellite observations of critical terrestrial carbon and water cycle components: sun-induced chlorophyll fluorescence (SIF) and soil moisture. We used these observations within the framework of a well-established global terrestrial biosphere model (Simplified Simple Biosphere Model version 2.0, SSiB2) to investigate carbon-water coupling processes. We updated SSiB2 to include a mechanistic representation of SIF and tested the sensitivity of model parameters to improve the simulation of both SIF and soil moisture with the ultimate objective of improving the first-order terrestrial carbon component, gross primary production (GPP). Although several vegetation parameters, such as leaf area index (LAI) and green leaf fraction, improved the simulated SIF, and several soil parameters, such as hydraulic conductivity, improved simulated soil moisture, their effects were mainly limited to their respective cycles. One parameter emerged as the key coupler between the carbon and water cycles: the wilting point. Updates to the wilting point significantly improved the simulations for both soil moisture and SIF, as well as GPP. This study demonstrates the value of synchronous global measurements of the terrestrial carbon and water cycles in improving the understanding of coupled carbon-water cycles.

The PSACOIN level 1B exercise: A probabilistic code intercomparison involving a four compartment biosphere model

International Nuclear Information System (INIS)

Klos, R.A.; Sinclair, J.E.; Torres, C.; Mobbs, S.F.; Galson, D.A.

1991-01-01

The probabilistic Systems Assessment Code (PSAC) User Group of the OECD Nuclear Energy Agency has organised a series of code intercomparison studies of relevance to the performance assessment of underground repositories for radioactive wastes - known collectively by the name PSACOIN. The latest of these to be undertaken is designated PSACOIN Level 1b, and the case specification provides a complete assessment model of the behaviour of radionuclides following release into the biosphere. PSACOIN Level 1b differs from other biosphere oriented intercomparison exercises in that individual dose is the end point of the calculations as opposed to any other intermediate quantity. The PSACOIN Level 1b case specification describes a simple source term which is used to simulate the release of activity to the biosphere from certain types of near surface waste repository, the transport of radionuclides through the biosphere and their eventual uptake by humankind. The biosphere sub model comprises 4 compartments representing top and deep soil layers, river water and river sediment. The transport of radionuclides between the physical compartments is described by ten transfer coefficients and doses to humankind arise from the simultaneous consumption of water, fish, meat, milk, and grain as well as from dust inhalation and external γ-irradiation. The parameters of the exposure pathway sub model are chosen to be representative of an individual living in a small agrarian community. (13 refs., 3 figs., 2 tabs.)

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

Parallel Computing for Terrestrial Ecosystem Carbon Modeling

International Nuclear Information System (INIS)

Wang, Dali; Post, Wilfred M.; Ricciuto, Daniel M.; Berry, Michael

2011-01-01

Terrestrial ecosystems are a primary component of research on global environmental change. Observational and modeling research on terrestrial ecosystems at the global scale, however, has lagged behind their counterparts for oceanic and atmospheric systems, largely because the unique challenges associated with the tremendous diversity and complexity of terrestrial ecosystems. There are 8 major types of terrestrial ecosystem: tropical rain forest, savannas, deserts, temperate grassland, deciduous forest, coniferous forest, tundra, and chaparral. The carbon cycle is an important mechanism in the coupling of terrestrial ecosystems with climate through biological fluxes of CO 2 . The influence of terrestrial ecosystems on atmospheric CO 2 can be modeled via several means at different timescales. Important processes include plant dynamics, change in land use, as well as ecosystem biogeography. Over the past several decades, many terrestrial ecosystem models (see the 'Model developments' section) have been developed to understand the interactions between terrestrial carbon storage and CO 2 concentration in the atmosphere, as well as the consequences of these interactions. Early TECMs generally adapted simple box-flow exchange models, in which photosynthetic CO 2 uptake and respiratory CO 2 release are simulated in an empirical manner with a small number of vegetation and soil carbon pools. Demands on kinds and amount of information required from global TECMs have grown. Recently, along with the rapid development of parallel computing, spatially explicit TECMs with detailed process based representations of carbon dynamics become attractive, because those models can readily incorporate a variety of additional ecosystem processes (such as dispersal, establishment, growth, mortality etc.) and environmental factors (such as landscape position, pest populations, disturbances, resource manipulations, etc.), and provide information to frame policy options for climate change

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.

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.

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

Biosphere Modeling and Analyses in Support of Total System Performance Assessment

International Nuclear Information System (INIS)

Tappen, J. J.; Wasiolek, M. A.; Wu, D. W.; Schmitt, J. F.; Smith, A. J.

2002-01-01

The Nuclear Waste Policy Act of 1982 established the obligations of and the relationship between the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) for the management and disposal of high-level radioactive wastes. In 1985, the EPA promulgated regulations that included a definition of performance assessment that did not consider potential dose to a member of the general public. This definition would influence the scope of activities conducted by DOE in support of the total system performance assessment program until 1995. The release of a National Academy of Sciences (NAS) report on the technical basis for a Yucca Mountain-specific standard provided the impetus for the DOE to initiate activities that would consider the attributes of the biosphere, i.e. that portion of the earth where living things, including man, exist and interact with the environment around them. The evolution of NRC and EPA Yucca Mountain-specific regulations, originally proposed in 1999, was critical to the development and integration of biosphere modeling and analyses into the total system performance assessment program. These proposed regulations initially differed in the conceptual representation of the receptor of interest to be considered in assessing performance. The publication in 2001 of final regulations in which the NRC adopted standard will permit the continued improvement and refinement of biosphere modeling and analyses activities in support of assessment activities

Biosphere Modeling and Analyses in Support of Total System Performance Assessment

International Nuclear Information System (INIS)

Jeff Tappen; M.A. Wasiolek; D.W. Wu; J.F. Schmitt

2001-01-01

The Nuclear Waste Policy Act of 1982 established the obligations of and the relationship between the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) for the management and disposal of high-level radioactive wastes. In 1985, the EPA promulgated regulations that included a definition of performance assessment that did not consider potential dose to a member of the general public. This definition would influence the scope of activities conducted by DOE in support of the total system performance assessment program until 1995. The release of a National Academy of Sciences (NAS) report on the technical basis for a Yucca Mountain-specific standard provided the impetus for the DOE to initiate activities that would consider the attributes of the biosphere, i.e. that portion of the earth where living things, including man, exist and interact with the environment around them. The evolution of NRC and EPA Yucca Mountain-specific regulations, originally proposed in 1999, was critical to the development and integration of biosphere modeling and analyses into the total system performance assessment program. These proposed regulations initially differed in the conceptual representation of the receptor of interest to be considered in assessing performance. The publication in 2001 of final regulations in which the NRC adopted standard will permit the continued improvement and refinement of biosphere modeling and analyses activities in support of assessment activities

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

The terrestrial ecosystems at Forsmark and Laxemar-Simpevarp. SR-Site Biosphere

Energy Technology Data Exchange (ETDEWEB)

Loefgren, Anders [ed.; EcoAnalytica, Haegersten (Sweden)

2010-12-15

The ecosystem is in most cases the link between radionuclides released from a repository and the exposure of humans and other biota to them. This report describes the terrestrial ecosystems in the Forsmark and Laxemar-Simpevarp areas by summarizing and performing cross-disciplinary analyses of data from a large number of reports produced during the site investigations, Figure 1-2. The report describes the terrestrial landscape, divided here into the three main categories: forests, wetlands and agriculture land, by identifying properties that are important for element accumulation and transport

The terrestrial ecosystems at Forsmark and Laxemar-Simpevarp. SR-Site Biosphere

International Nuclear Information System (INIS)

Loefgren, Anders

2010-12-01

The ecosystem is in most cases the link between radionuclides released from a repository and the exposure of humans and other biota to them. This report describes the terrestrial ecosystems in the Forsmark and Laxemar-Simpevarp areas by summarizing and performing cross-disciplinary analyses of data from a large number of reports produced during the site investigations, Figure 1-2. The report describes the terrestrial landscape, divided here into the three main categories: forests, wetlands and agriculture land, by identifying properties that are important for element accumulation and transport

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.

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 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

; spontaneity and non-directional changes of the development programs; securing successful changes by natural selection; geometrical progression of reproduction as a “spring” of life. There are four basic levels of organization of life: molecular-genetics, ontogenetics, species-populational, ecosystemic. Among the main features of the evolution of the biosphere: spreading of life on the planet; the uprising of the biosphere’ turnover of matters on the basis of the use of solar energy; increasing of the closeness of this turnover; strengthening the energy flow through the biosphere; the increase in mass of organic matter involved in this cycle; the emergence of the genetic code; the emergence of eukaryotes; increasing of the structural and functional diversity of the biosphere. Among the major achievements of evolution in the plant world: improving the chemical mechanisms of photosynthesis, plants access to land (the appearance of vascular and root systems; the growth of the photosynthetic capacity of terrestrial plant communities. Among the main achievements of evolution in the animal world: the appearance of the skeleton, hemoglobin; increasing the independence from the external factors (growth of a homeostasis; the emergence of the nervous system and sociality. Among the patterns of evolution of organs and functions in different groups of living organisms: the intensification of functions; intensification of the multifunctionality and duplications of biological systems components; supplementation (rather than substitution of new functions to the old. Chorologically (spatially biosphere is composed of ecosystems of all sizes, including biogeocoenoses (which are the ecosystems within the boundaries of the phytocenosis. Biogeocoenoses are minimal spatial unit of biosphere with its own evolutionary destiny (but not "one more" name of an ecosystem, is as usual treated in the western literature. The Biosphere as whole is not only the largest Earth’ ecosystem, but also

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.

Histories of terrestrial planets

International Nuclear Information System (INIS)

Benes, K.

1981-01-01

The uneven historical development of terrestrial planets - Mercury, Venus, Earth, Moon and Mars - is probably due to the differences in their size, weight and rotational dynamics in association with the internal planet structure, their distance from the Sun, etc. A systematic study of extraterrestrial planets showed that the time span of internal activity was not the same for all bodies. It is assumed that the initial history of all terrestrial planets was marked with catastrophic events connected with the overall dynamic development of the solar system. In view of the fact that the cores of small terrestrial bodies cooled quicker, their geological development almost stagnated after two or three thousand million years. This is what probably happened to the Mercury and the Moon as well as the Mars. Therefore, traces of previous catastrophic events were preserved on the surface of the planets. On the other hand, the Earth is the most metamorphosed terrestrial planet and compared to the other planets appears to be atypical. Its biosphere is significantly developed as well as the other shell components, its hydrosphere and atmosphere, and its crust is considerably differentiated. (J.P.)

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

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)

A comparison between the example reference biosphere model ERB 2B and a process-based model: simulation of a natural release scenario.

Science.gov (United States)

Almahayni, T

2014-12-01

The BIOMASS methodology was developed with the objective of constructing defensible assessment biospheres for assessing potential radiological impacts of radioactive waste repositories. To this end, a set of Example Reference Biospheres were developed to demonstrate the use of the methodology and to provide an international point of reference. In this paper, the performance of the Example Reference Biosphere model ERB 2B associated with the natural release scenario, discharge of contaminated groundwater to the surface environment, was evaluated by comparing its long-term projections of radionuclide dynamics and distribution in a soil-plant system to those of a process-based, transient advection-dispersion model (AD). The models were parametrised with data characteristic of a typical rainfed winter wheat crop grown on a sandy loam soil under temperate climate conditions. Three safety-relevant radionuclides, (99)Tc, (129)I and (237)Np with different degree of sorption were selected for the study. Although the models were driven by the same hydraulic (soil moisture content and water fluxes) and radiological (Kds) input data, their projections were remarkably different. On one hand, both models were able to capture short and long-term variation in activity concentration in the subsoil compartment. On the other hand, the Reference Biosphere model did not project any radionuclide accumulation in the topsoil and crop compartments. This behaviour would underestimate the radiological exposure under natural release scenarios. The results highlight the potential role deep roots play in soil-to-plant transfer under a natural release scenario where radionuclides are released into the subsoil. When considering the relative activity and root depth profiles within the soil column, much of the radioactivity was taken up into the crop from the subsoil compartment. Further improvements were suggested to address the limitations of the Reference Biosphere model presented in this paper

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.

Transport in biosphere of radionuclides released from finally disposed nuclear waste - background information for transport and dose model

International Nuclear Information System (INIS)

Hulmi, R.; Savolainen, I.

1981-07-01

An outline is made about the biosphere transport and dose models employed in the estimation of doses due to releases from finally disposed nuclear waste. The models often divide into two parts; the first one describes the transport of radionuclides in those parts of biosphere where the time scale is large (e.g. soil, sea and sea sediment), the second part of the model describes the transport of nuclides in the systems where the time scale is small (e.g. food chains, plants and animals). The description of biosphere conditions includes remarkable uncertainty due to the complexity of the biosphere and its ecosystems. Therefore studies of scenario type are recommended: some values of parametres describing the conditions are assumed, and the consequences are estimated by using these values. The effect of uncertainty in various factors on the uncertainty of final results should be investigated with the employment of alternative scenarios and parametric sensitivity studies. In addition to the ordinary results, intermediate results should be presented. A proposal for the structure of a transport and dose program based on dynamic linear compartment model is presented and mathematical solution alternatives are studied also

Overview of the development of a biosphere modelling capability for UK DoE (HMIP)

International Nuclear Information System (INIS)

Nancarrow, D.J.; Ashton, J.; Little, R.H.

1990-01-01

A programme of research has been funded, since 1982, by the United Kingdom Department of the Environment (Her Majesty's Inspectorate of Pollution, HMIP), to develop a procedure for post-closure radiological assessment of underground disposal facilities for low and intermediate level radioactive wastes. It is conventional to regard the disposal system as comprising the engineered barriers of the repository, the geological setting which provides natural barriers to migration, and the surface environment or biosphere. The requirement of a biosphere submodel, therefore, is to provide estimates, for given radionuclide inputs, of the dose or probability distribution function of dose to a maximally exposed individual as a function of time. This paper describes the development of the capability for biosphere modelling for HMIP in the context of the development of other assessment procedures. 11 refs., 3 figs., 2 tabs

Biosphere assessment for high-level radioactive waste disposal: modelling experiences and discussion on key parameters by sensitivity analysis in JNC

International Nuclear Information System (INIS)

Kato, Tomoko; Makino, Hitoshi; Uchida, Masahiro; Suzuki, Yuji

2004-01-01

In the safety assessment of the deep geological disposal system of the high-level radioactive waste (HLW), biosphere assessment is often necessary to estimate future radiological impacts on human beings (e.g. radiation dose). In order to estimate the dose, the surface environment (biosphere) into which future releases of radionuclides might occur and the associated future human behaviour needs to be considered. However, for a deep repository, such releases might not occur for many thousands of years after disposal. Over such timescales, it is impossible to predict with any certainty how the biosphere and human behaviour will evolve. To avoid endless speculation aimed at reducing such uncertainty, the 'Reference Biospheres' concept has been developed for use in the safety assessment of HLW disposal. As the aim of the safety assessment with a hypothetical HLW disposal system by JNC was to demonstrate the technical feasibility and reliability of the Japanese disposal concept for a range of geological and surface environments, some biosphere models were developed using the 'Reference Biospheres' concept and the BIOMASS Methodology. These models have been used to derive factors to convert the radionuclide flux from a geosphere to a biosphere into a dose (flux to dose conversion factors). Moreover, sensitivity analysis for parameters in the biosphere models was performed to evaluate and understand the relative importance of parameters. It was concluded that transport parameters in the surface environments, annual amount of food consumption, distribution coefficients on soils and sediments, transfer coefficients of radionuclides to animal products and concentration ratios for marine organisms would have larger influence on the flux to dose conversion factors than any other parameters. (author)

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'

Development of a distributed biosphere hydrological model and its evaluation with the Southern Great Plains Experiments (SGP97 and SGP99)

Science.gov (United States)

A distributed biosphere hydrological model, the so called water and energy budget-based distributed hydrological model (WEB-DHM), has been developed by fully coupling a biosphere scheme (SiB2) with a geomorphology-based hydrological model (GBHM). SiB2 describes the transfer of turbulent fluxes (ener...

Detecting robust signals of interannual variability of gross primary productivity in Asia from multiple terrestrial carbon cycle models and long-term satellite-based vegetation data

Science.gov (United States)

Ichii, K.; Kondo, M.; Ueyama, M.; Kato, T.; Ito, A.; Sasai, T.; Sato, H.; Kobayashi, H.; Saigusa, N.

2014-12-01

Long term record of satellite-based terrestrial vegetation are important to evaluate terrestrial carbon cycle models. In this study, we demonstrate how multiple satellite observation can be used for evaluating past changes in gross primary productivity (GPP) and detecting robust anomalies in terrestrial carbon cycle in Asia through our model-data synthesis analysis, Asia-MIP. We focused on the two different temporal coverages: long-term (30 years; 1982-2011) and decadal (10 years; 2001-2011; data intensive period) scales. We used a NOAA/AVHRR NDVI record for long-term analysis and multiple satellite data and products (e.g. Terra-MODIS, SPOT-VEGETATION) as historical satellite data, and multiple terrestrial carbon cycle models (e.g. BEAMS, Biome-BGC, ORCHIDEE, SEIB-DGVM, and VISIT). As a results of long-term (30 years) trend analysis, satellite-based time-series data showed that approximately 40% of the area has experienced a significant increase in the NDVI, while only a few areas have experienced a significant decreasing trend over the last 30 years. The increases in the NDVI were dominant in the sub-continental regions of Siberia, East Asia, and India. Simulations using the terrestrial biosphere models also showed significant increases in GPP, similar to the results for the NDVI, in boreal and temperate regions. A modeled sensitivity analysis showed that the increases in GPP are explained by increased temperature and precipitation in Siberia. Precipitation, solar radiation, CO2fertilization and land cover changes are important factors in the tropical regions. However, the relative contributions of each factor to GPP changes are different among the models. Year-to-year variations of terrestrial GPP were overall consistently captured by the satellite data and terrestrial carbon cycle models if the anomalies are large (e.g. 2003 summer GPP anomalies in East Asia and 2002 spring GPP anomalies in mid to high latitudes). The behind mechanisms can be consistently

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)

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

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)

Modeling Carbon Turnover in Five Terrestrial Ecosystems in the Boreal Zone Using Multiple Criteria of Acceptance

International Nuclear Information System (INIS)

Karlberg, Louise; Gustafsson, David; Jansson, Per-Erik

2006-01-01

Estimates of carbon fluxes and turnover in ecosystems are key elements in the understanding of climate change and in predicting the accumulation of trace elements in the biosphere. In this paper we present estimates of carbon fluxes and turnover times for five terrestrial ecosystems using a modeling approach. Multiple criteria of acceptance were used to parameterize the model, thus incorporating large amounts of multi-faceted empirical data in the simulations in a standardized manner. Mean turnover times of carbon were found to be rather similar between systems with a few exceptions, even though the size of both the pools and the fluxes varied substantially. Depending on the route of the carbon through the ecosystem, turnover times varied from less than one year to more than one hundred, which may be of importance when considering trace element transport and retention. The parameterization method was useful both in the estimation of unknown parameters, and to identify variability in carbon turnover in the selected ecosystems

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.

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

Large historical growth in global terrestrial gross primary production

Energy Technology Data Exchange (ETDEWEB)

Campbell, J. E.; Berry, J. A.; Seibt, U.; Smith, S. J.; Montzka, S. A.; Launois, T.; Belviso, S.; Bopp, L.; Laine, M.

2017-04-05

Growth in terrestrial gross primary production (GPP) may provide a feedback for climate change, but there is still strong disagreement on the extent to which biogeochemical processes may suppress this GPP growth at the ecosystem to continental scales. The consequent uncertainty in modeling of future carbon storage by the terrestrial biosphere constitutes one of the largest unknowns in global climate projections for the next century. Here we provide a global, measurement-based estimate of historical GPP growth using long-term atmospheric carbonyl sulfide (COS) records derived from ice core, firn, and ambient air samples. We interpret these records using a model that relates changes in the COS concentration to changes in its sources and sinks, the largest of which is proportional to GPP. The COS history was most consistent with simulations that assume a large historical GPP growth. Carbon-climate models that assume little to no GPP growth predicted trajectories of COS concentration over the anthropogenic era that differ from those observed. Continued COS monitoring may be useful for detecting ongoing changes in GPP while extending the ice core record to glacial cycles could provide further opportunities to evaluate earth system models.

Short description of the BIOS-model, and selection of biosphere parameters to be used in radionuclide transport and dose

International Nuclear Information System (INIS)

Jong, E.J. de; Koester, H.W.; Vries, W.J. de.

1990-02-01

In the framework of the PACOMA-project (Performance assessment of confinements for medium and alpha waste), initiated by the European Commission, possible future radiation doses, due to contamination of the biosphere by radionuclides originating from radioactive waste disposed in salt-formations, were calculated. In all cases considered radionuclides coming out of the geosphere enter a river. For the biosphere calculations the BIOS-model, developed by the NRPB in England, is used. A short description of the model, as well as of the adjustments made at the RIVM to calculate the total individual and collective doses and the subdoses of different exposure pathways is given. The values of biosphere parameters selected for the model are presented, together with the literature consulted. (author). 17 refs., 3 figs.; 2 tabs

Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting.

Science.gov (United States)

Butman, David; Stackpoole, Sarah; Stets, Edward; McDonald, Cory P; Clow, David W; Striegl, Robert G

2016-01-05

Inland water ecosystems dynamically process, transport, and sequester carbon. However, the transport of carbon through aquatic environments has not been quantitatively integrated in the context of terrestrial ecosystems. Here, we present the first integrated assessment, to our knowledge, of freshwater carbon fluxes for the conterminous United States, where 106 (range: 71-149) teragrams of carbon per year (TgC⋅y(-1)) is exported downstream or emitted to the atmosphere and sedimentation stores 21 (range: 9-65) TgC⋅y(-1) in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant flux at 69 (range: 36-110) TgC⋅y(-1) or 65% of the total aquatic carbon flux for the conterminous United States. Comparing our results with the output of a suite of terrestrial biosphere models (TBMs), we suggest that within the current modeling framework, calculations of net ecosystem production (NEP) defined as terrestrial only may be overestimated by as much as 27%. However, the internal production and mineralization of carbon in freshwaters remain to be quantified and would reduce the effect of including aquatic carbon fluxes within calculations of terrestrial NEP. Reconciliation of carbon mass-flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional research and modeling capacity.

Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting

Science.gov (United States)

Butman, David; Stackpoole, Sarah; Stets, Edward; McDonald, Cory P.; Clow, David W.; Striegl, Robert G.

2016-01-01

Inland water ecosystems dynamically process, transport, and sequester carbon. However, the transport of carbon through aquatic environments has not been quantitatively integrated in the context of terrestrial ecosystems. Here, we present the first integrated assessment, to our knowledge, of freshwater carbon fluxes for the conterminous United States, where 106 (range: 71–149) teragrams of carbon per year (TgC⋅y−1) is exported downstream or emitted to the atmosphere and sedimentation stores 21 (range: 9–65) TgC⋅y−1 in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant flux at 69 (range: 36–110) TgC⋅y−1 or 65% of the total aquatic carbon flux for the conterminous United States. Comparing our results with the output of a suite of terrestrial biosphere models (TBMs), we suggest that within the current modeling framework, calculations of net ecosystem production (NEP) defined as terrestrial only may be overestimated by as much as 27%. However, the internal production and mineralization of carbon in freshwaters remain to be quantified and would reduce the effect of including aquatic carbon fluxes within calculations of terrestrial NEP. Reconciliation of carbon mass–flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional research and modeling capacity. PMID:26699473

Scale-dependent performances of CMIP5 earth system models in simulating terrestrial vegetation carbon

Science.gov (United States)

Jiang, L.; Luo, Y.; Yan, Y.; Hararuk, O.

2013-12-01

Mitigation of global changes will depend on reliable projection for the future situation. As the major tools to predict future climate, Earth System Models (ESMs) used in Coupled Model Intercomparison Project Phase 5 (CMIP5) for the IPCC Fifth Assessment Report have incorporated carbon cycle components, which account for the important fluxes of carbon between the ocean, atmosphere, and terrestrial biosphere carbon reservoirs; and therefore are expected to provide more detailed and more certain projections. However, ESMs are never perfect; and evaluating the ESMs can help us to identify uncertainties in prediction and give the priorities for model development. In this study, we benchmarked carbon in live vegetation in the terrestrial ecosystems simulated by 19 ESMs models from CMIP5 with an observationally estimated data set of global carbon vegetation pool 'Olson's Major World Ecosystem Complexes Ranked by Carbon in Live Vegetation: An Updated Database Using the GLC2000 Land Cover Product' by Gibbs (2006). Our aim is to evaluate the ability of ESMs to reproduce the global vegetation carbon pool at different scales and what are the possible causes for the bias. We found that the performance CMIP5 ESMs is very scale-dependent. While CESM1-BGC, CESM1-CAM5, CESM1-FASTCHEM and CESM1-WACCM, and NorESM1-M and NorESM1-ME (they share the same model structure) have very similar global sums with the observation data but they usually perform poorly at grid cell and biome scale. In contrast, MIROC-ESM and MIROC-ESM-CHEM simulate the best on at grid cell and biome scale but have larger differences in global sums than others. Our results will help improve CMIP5 ESMs for more reliable prediction.

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Surface and near-surface hydrological modelling in the biosphere assessment BSA-2012

International Nuclear Information System (INIS)

Karvonen, T.

2013-05-01

The Finnish nuclear waste disposal company, Posiva Oy, is planning an underground repository for spent nuclear fuel to be constructed on the island of Olkiluoto on the south-west coast of Finland. This study is part of the biosphere assessment (BSA-2012) within the safety case for the repository. The surface hydrological modelling described in this report is aimed at providing link between radionuclide transport in the geosphere and in the biosphere systems. The SVAT-model and Olkiluoto site scale surface hydrological model were calibrated and validated in the present day conditions using the input data provided by the Olkiluoto Monitoring Programme (OMO). During the next 10 000 years the terrain and ecosystem development is to a large extent driven by the postglacial crustal uplift. UNTAMO is a GIS toolbox developed for simulating land-uplift driven or other changes in the biosphere. All the spatial and temporal input data (excluding meteorological data) needed in the surface hydrological modelling were provided by the UNTAMO toolbox. The specific outputs given by UNTAMO toolbox are time-dependent evolution of the biosphere objects. They are continuous and sufficiently homogeneous sub-areas of the modelled area that could potentially receive radionuclides released from the repository. Possible ecosystem types for biosphere objects are coast, lake, river, forest, cropland, pasture and wetland. The primary goal of this study was to compute vertical and horizontal water fluxes in the biosphere objects. These data will be used in the biosphere radionuclide transport calculations. The method adopted here is based on calculating average vertical and horizontal fluxes for biosphere objects from the results of the full 3D-model. It was not necessary to develop any simplified hydrological model for the biosphere objects. This report includes modelling results from for the Reference Case (present day climate) and Terr M axAgri Case (maximum extent of agricultural areas and

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.

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)

A qualitative reasoning model of algal bloom in the Danube Delta Biosphere Reserve (DDBR)

NARCIS (Netherlands)

Cioaca, E.; Linnebank, F.E.; Bredeweg, B.; Salles, P.

2009-01-01

This paper presents a Qualitative Reasoning model of the algal bloom phenomenon and its effects in the Danube Delta Biosphere Reserve (DDBR) in Romania. Qualitative Reasoning models represent processes and their cause-effect relationships in a flexible and conceptually rich manner and as such can be

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

Green Ocean Amazon 2014/15 Terrestrial Ecosystem Project (Geco) Field Campaign Report

Energy Technology Data Exchange (ETDEWEB)

Jardine, Kolby [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2016-06-01

In conjunction with the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility GoAmazon campaign, the Terrestrial Ecosystem Science (TES)-funded Green Ocean Amazon (GoAmazon 2014/15) terrestrial ecosystem project (Geco) was designed to: • evaluate the strengths and weaknesses of leaf-level algorithms for biogenic volatile organic compounds (BVOCs) emissions in Amazon forests near Manaus, Brazil, and • conduct mechanistic field studies to characterize biochemical and physiological processes governing leaf- and landscape-scale tropical forest BVOC emissions, and the influence of environmental drivers that are expected to change with a warming climate. Through a close interaction between modeling and observational activities, including the training of MS and PhD graduate students, post-doctoral students, and technicians at the National Institute for Amazon Research (INPA), the study aimed at improving the representation of BVOC-mediated biosphere-atmosphere interactions and feedbacks under a warming climate. BVOCs can form cloud condensation nuclei (CCN) that influence precipitation dynamics and modify the quality of down welling radiation for photosynthesis. However, our ability to represent these coupled biosphere-atmosphere processes in Earth system models suffers from poor understanding of the functions, identities, quantities, and seasonal patterns of BVOC emissions from tropical forests as well as their biological and environmental controls. The Model of Emissions of Gases and Aerosols from Nature (MEGAN), the current BVOC sub-model of the Community Earth System Model (CESM), was evaluated to explore mechanistic controls over BVOC emissions. Based on that analysis, a combination of observations and experiments were studied in forests near Manaus, Brazil, to test existing parameterizations and algorithm structures in MEGAN. The model was actively modified as needed to improve tropical BVOC emission simulations on

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.

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)

Biosphere modelling for the safety assessment of high-level radioactive waste disposal in the Japanese H12 assessment

International Nuclear Information System (INIS)

Kato, Tomoko; Suzuki, Yuji; Ishiguro, Katsuhiko; Naito, Morimasa; Ishiguro, Katsuhiko; Ikeda, Takao; Little, Richard H.; Smith, Graham M.

2002-01-01

JNC has an on-going programme of research and development relating to the safety assessment of the deep geological disposal system of high-level radioactive waste (HLW). In the safety assessment of a HLW disposal system, it is often necessary to estimate future radiological impacts on human beings (e.g. radiation dose). In order to estimate dose, consideration needs to be given to the surface environment (biosphere) into which future releases of radionuclides might occur and to the associated future human behaviour. However, for a deep repository, such releases might not occur for many thousands of years after disposal. Over such timescales, it is not possible to predict with any certainty how the biosphere and human behaviour will evolve. To avoid endless speculation aimed at reducing such uncertainty, the reference biosphere le concept has been developed for use in the safety assessment of HLW disposal. The Reference Biospheres Methodology was originally developed by the BIOMOVS II Reference Biospheres Working Group and subsequently enhanced within Theme 1 of the BIOMASS programme. As the aim of the H12 assessment with a hypothetical HLW disposal system was to demonstrate the technical feasibility and reliability of the Japanese disposal concept for a range of geological and surface environments, some assessment specific reference biospheres were developed for the biosphere modelling in the H12 assessment using an approach consistent with the BIOMOVS II/BIOMASS approach. They have been used to derive factors to convert the radionuclide flux from a geosphere to a biosphere into a dose. The influx to dose conversion factor also have been derived for a range of different geosphere-biosphere interfaces (well, river and marine) and potential exposure groups (farming, freshwater-fishing and marine-fishing). This paper summarises the approach used for the derivation of the influx to dose conversion factor also for the range of geosphere-biosphere interfaces and

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.

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

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

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)

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

Terrestrial carbon storage dynamics: Chasing a moving target

Science.gov (United States)

Luo, Y.; Shi, Z.; Jiang, L.; Xia, J.; Wang, Y.; Kc, M.; Liang, J.; Lu, X.; Niu, S.; Ahlström, A.; Hararuk, O.; Hastings, A.; Hoffman, F. M.; Medlyn, B. E.; Rasmussen, M.; Smith, M. J.; Todd-Brown, K. E.; Wang, Y.

2015-12-01

Terrestrial ecosystems have been estimated to absorb roughly 30% of anthropogenic CO2 emissions. Past studies have identified myriad drivers of terrestrial carbon storage changes, such as fire, climate change, and land use changes. Those drivers influence the carbon storage change via diverse mechanisms, which have not been unified into a general theory so as to identify what control the direction and rate of terrestrial carbon storage dynamics. Here we propose a theoretical framework to quantitatively determine the response of terrestrial carbon storage to different exogenous drivers. With a combination of conceptual reasoning, mathematical analysis, and numeric experiments, we demonstrated that the maximal capacity of an ecosystem to store carbon is time-dependent and equals carbon input (i.e., net primary production, NPP) multiplying by residence time. The capacity is a moving target toward which carbon storage approaches (i.e., the direction of carbon storage change) but usually does not attain. The difference between the capacity and the carbon storage at a given time t is the unrealized carbon storage potential. The rate of the storage change is proportional to the magnitude of the unrealized potential. We also demonstrated that a parameter space of NPP, residence time, and carbon storage potential can well characterize carbon storage dynamics quantified at six sites ranging from tropical forests to tundra and simulated by two versions (carbon-only and coupled carbon-nitrogen) of the Australian Community Atmosphere-Biosphere Land Ecosystem (CABLE) Model under three climate change scenarios (CO2 rising only, climate warming only, and RCP8.5). Overall this study reveals the unified mechanism unerlying terrestrial carbon storage dynamics to guide transient traceability analysis of global land models and synthesis of empirical studies.

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)

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

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.

Does Your Terrestrial Model Capture Key Arctic-Boreal Relationships?: Functional Benchmarks in the ABoVE Model Benchmarking System

Science.gov (United States)

Stofferahn, E.; Fisher, J. B.; Hayes, D. J.; Schwalm, C. R.; Huntzinger, D. N.; Hantson, W.

2017-12-01

The Arctic-Boreal Region (ABR) is a major source of uncertainties for terrestrial biosphere model (TBM) simulations. These uncertainties are precipitated by a lack of observational data from the region, affecting the parameterizations of cold environment processes in the models. Addressing these uncertainties requires a coordinated effort of data collection and integration of the following key indicators of the ABR ecosystem: disturbance, vegetation / ecosystem structure and function, carbon pools and biogeochemistry, permafrost, and hydrology. We are continuing to develop the model-data integration framework for NASA's Arctic Boreal Vulnerability Experiment (ABoVE), wherein data collection is driven by matching observations and model outputs to the ABoVE indicators via the ABoVE Grid and Projection. The data are used as reference datasets for a benchmarking system which evaluates TBM performance with respect to ABR processes. The benchmarking system utilizes two types of performance metrics to identify model strengths and weaknesses: standard metrics, based on the International Land Model Benchmarking (ILaMB) system, which relate a single observed variable to a single model output variable, and functional benchmarks, wherein the relationship of one variable to one or more variables (e.g. the dependence of vegetation structure on snow cover, the dependence of active layer thickness (ALT) on air temperature and snow cover) is ascertained in both observations and model outputs. This in turn provides guidance to model development teams for reducing uncertainties in TBM simulations of the ABR.

DETRA: Model description and evaluation of model performance

International Nuclear Information System (INIS)

Suolanen, V.

1996-01-01

The computer code DETRA is a generic tool for environmental transfer analyses of radioactive or stable substances. The code has been applied for various purposes, mainly problems related to the biospheric transfer of radionuclides both in safety analyses of disposal of nuclear wastes and in consideration of foodchain exposure pathways in the analyses of off-site consequences of reactor accidents. For each specific application an individually tailored conceptual model can be developed. The biospheric transfer analyses performed by the code are typically carried out for terrestrial, aquatic and food chain applications. 21 refs, 35 figs, 15 tabs

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.)

User's guide to the biosphere code ECOS

International Nuclear Information System (INIS)

Kane, P.; Thorne, M.C.

1984-10-01

This report constitutes the user's guide to the biosphere model ECOS and provides a detailed description of the processes modelled and mathematical formulations used. The FORTRAN code ECOS is an equilibrium-type compartmental biosphere code. ECOS was designed with the objective of producing a general but comprehensive code for use in the assessment of the radiological impact of unspecified geological repositories for radioactive waste. ECOS transforms the rate of release of activity from the geosphere to the rate of accumulation of weighted committed effective dose equivalent (dose). Both maximum individual dose (critical group dose) and collective dose rates may be computed. (author)

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.

The deep, hot biosphere: Twenty-five years of retrospection.

Science.gov (United States)

Colman, Daniel R; Poudel, Saroj; Stamps, Blake W; Boyd, Eric S; Spear, John R

2017-07-03

Twenty-five years ago this month, Thomas Gold published a seminal manuscript suggesting the presence of a "deep, hot biosphere" in the Earth's crust. Since this publication, a considerable amount of attention has been given to the study of deep biospheres, their role in geochemical cycles, and their potential to inform on the origin of life and its potential outside of Earth. Overwhelming evidence now supports the presence of a deep biosphere ubiquitously distributed on Earth in both terrestrial and marine settings. Furthermore, it has become apparent that much of this life is dependent on lithogenically sourced high-energy compounds to sustain productivity. A vast diversity of uncultivated microorganisms has been detected in subsurface environments, and we show that H 2 , CH 4 , and CO feature prominently in many of their predicted metabolisms. Despite 25 years of intense study, key questions remain on life in the deep subsurface, including whether it is endemic and the extent of its involvement in the anaerobic formation and degradation of hydrocarbons. Emergent data from cultivation and next-generation sequencing approaches continue to provide promising new hints to answer these questions. As Gold suggested, and as has become increasingly evident, to better understand the subsurface is critical to further understanding the Earth, life, the evolution of life, and the potential for life elsewhere. To this end, we suggest the need to develop a robust network of interdisciplinary scientists and accessible field sites for long-term monitoring of the Earth's subsurface in the form of a deep subsurface microbiome initiative.

Ground-based grasslands data to support remote sensing and ecosystem modeling of terrestrial primary production

Science.gov (United States)

Olson, R. J.; Scurlock, J. M. O.; Turner, R. S.; Jennings, S. V.

1995-01-01

Estimating terrestrial net primary production (NPP) using remote-sensing tools and ecosystem models requires adequate ground-based measurements for calibration, parameterization, and validation. These data needs were strongly endorsed at a recent meeting of ecosystem modelers organized by the International Geosphere-Biosphere Program's (IGBP's) Data and Information System (DIS) and its Global Analysis, Interpretation, and Modelling (GAIM) Task Force. To meet these needs, a multinational, multiagency project is being coordinated by the IGBP DIS to compile existing NPP data from field sites and to regionalize NPP point estimates to various-sized grid cells. Progress at Oak Ridge National Laboratory (ORNL) on compiling NPP data for grasslands as part of the IGBP DIS data initiative is described. Site data and associated documentation from diverse field studies are being acquired for selected grasslands and are being reviewed for completeness, consistency, and adequacy of documentation, including a description of sampling methods. Data are being compiled in a database with spatial, temporal, and thematic characteristics relevant to remote sensing and global modeling. NPP data are available from the ORNL Distributed Active Archive Center (DAAC) for biogeochemical dynamics. The ORNL DAAC is part of the Earth Observing System Data and Information System, of the US National Aeronautics and Space Administration.

Ground-based grasslands data to support remote sensing and ecosystem modeling of terrestrial primary production

Energy Technology Data Exchange (ETDEWEB)

Olson, R.J.; Turner, R.S. [Oak Ridge National Lab., TN (United States); Scurlock, J.M.O. [King`s College London, (England); Jennings, S.V. [Tennessee Univ., Knoxville, TN (United States)

1995-12-31

Estimating terrestrial net primary production (NPP) using remote- sensing tools and ecosystem models requires adequate ground-based measurements for calibration, parameterization, and validation. These data needs were strongly endorsed at a recent meeting of ecosystem modelers organized by the International Geosphere-Biosphere Programme`s (IGBP`s) Data and Information System (DIS) and its Global Analysis, Interpretation, and Modelling (GAIM) Task Force. To meet these needs, a multinational, multiagency project is being coordinated by the IGBP DIS to compile existing NPP data from field sites and to regionalize NPP point estimates to various-sized grid cells. Progress at Oak Ridge National Laboratory (ORNL) on compiling NPP data for grasslands as part of the IGBP DIS data initiative is described. Site data and associated documentation from diverse field studies are being acquired for selected grasslands and are being reviewed for completeness, consistency, and adequacy of documentation, including a description of sampling methods. Data are being compiled in a database with spatial, temporal, and thematic characteristics relevant to remote sensing and global modeling. NPP data are available from the ORNL Distributed Active Archive Center (DAAC) for biogeochemical dynamics. The ORNL DAAC is part of the Earth Observing System Data and Information System, of the US National Aeronautics and Space Administration.

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 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)

Illstrative probabilistic biosphere model for Yucca Mountain individual risk calculations

International Nuclear Information System (INIS)

Wilems, R.E.

1994-01-01

The proposed EPA Standards for the disposal of spent fuel, high-level and transuranic radioactive waste prescribe future biosphere--one in which no sustained human activity occurs inside the controlled zone, yet sustained use of groundwater occurs just outside the controlled zone boundary. Performance assessments have generally assumed a person at this location extracts all his water needs directly from the projected contaminated plume for all of his life. Dose to this maximally-exposed individual is too conservative a measure of performance for a nuclear waste repository and does not reflect the isolation characteristics of a site. A better measure is individual risk in which uncertainties in biosphere characteristics for the longer periods of performance, for a site like Yucca Mountain only those characteristics associated with well water scenarios need be prescribed. Such a prescription of the biosphere is appropriate because the goal of the regulations is to provide indicators of future performance so the regulators can make a responsible decision regarding reasonable assurance of public health and safety

Reference biospheres for the long term safety assessment of radioactive waste disposal facilities

International Nuclear Information System (INIS)

Crossland, I.G.; Torres, C.

2002-01-01

Regulatory guidance on the safety assessment of radioactive waste disposals usually requires the consequences of any radionuclide releases to be considered in terms of their potential impact on human health. This requires consideration of the prevailing biosphere and the habits of the potentially exposed humans within it. However, it could take many thousands of years for migrating radionuclides to reach the surface environment. In these circumstances, an assessment model that was based on the present-day biosphere could be inappropriate while future biospheres would be unpredictable. These and other considerations suggest that a standardised, or reference biosphere, approach may be useful. Theme 1 of the IAEA BIOMASS project was established to develop the concept of reference biospheres into a practical system that can be applied to the assessment of the long term safety of geological disposal facilities for radioactive waste. The technical phase of the project lasted for four years until November 2000 and brought together disparate interests from many countries including waste disposal agencies, regulators and technical experts. Building on the experience from earlier BIOMOVS projects, a methodology was constructed for the logical and defensible construction of mathematical biosphere models that can be used in the total system performance assessment of radioactive waste disposal. The methodology was then further developed through the creation of a series of BIOMASS Example Reference Biospheres ('Examples'). These are stylised biosphere models that, in addition to illustrating the methodology, are intended to be useful assessment tools in their own right. (author)

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)

The biosphere at Laxemar. Data, assumptions and models used in the SR-Can assessment

Energy Technology Data Exchange (ETDEWEB)

Karlsson, Sara; Kautsky, Ulrik; Loefgren, Anders; Soederbaeck, Bjoern [eds.

2006-10-15

This is essentially a compilation of a variety of reports concerning the site investigations, the research activities and information derived from other sources important for the safety assessment. The main objective is to present prerequisites, methods and data used, in the biosphere modelling for the safety assessment SR-Can at the Laxemar site. A major part of the report focuses on how site-specific data are used, recalculated or modified in order to be applicable in the safety assessment context; and the methods and sub-models that are the basis for the biosphere modelling. Furthermore, the assumptions made as to the future states of surface ecosystems are mainly presented in this report. A similar report is provided for the Forsmark area. This report summarises the method adopted for safety assessment following a radionuclide release into the biosphere. The approach utilises the information about the site as far as possible and presents a way of calculating risk to humans. A central tool in the work is the description of the topography, where there is good understanding of the present conditions and the development over time is fairly predictable. The topography affects surface hydrology, sedimentation, size of drainage areas and the characteristics of ecosystems. Other parameters are human nutritional intake, which is assumed to be constant over time, and primary production (photosynthesis), which also is a fairly constant parameter over time. The Landscape Dose Factor approach (LDF) gives an integrated measure for the site and also resolves the issues relating to the size of the group with highest exposure. If this approach is widely accepted as method, still some improvements and refinement are necessary in collecting missing site data, reanalysing site data, reviewing radionuclide specific data, reformulating ecosystem models and evaluating the results with further sensitivity analysis.

The biosphere at Laxemar. Data, assumptions and models used in the SR-Can assessment

International Nuclear Information System (INIS)

Karlsson, Sara; Kautsky, Ulrik; Loefgren, Anders; Soederbaeck, Bjoern

2006-10-01

This is essentially a compilation of a variety of reports concerning the site investigations, the research activities and information derived from other sources important for the safety assessment. The main objective is to present prerequisites, methods and data used, in the biosphere modelling for the safety assessment SR-Can at the Laxemar site. A major part of the report focuses on how site-specific data are used, recalculated or modified in order to be applicable in the safety assessment context; and the methods and sub-models that are the basis for the biosphere modelling. Furthermore, the assumptions made as to the future states of surface ecosystems are mainly presented in this report. A similar report is provided for the Forsmark area. This report summarises the method adopted for safety assessment following a radionuclide release into the biosphere. The approach utilises the information about the site as far as possible and presents a way of calculating risk to humans. A central tool in the work is the description of the topography, where there is good understanding of the present conditions and the development over time is fairly predictable. The topography affects surface hydrology, sedimentation, size of drainage areas and the characteristics of ecosystems. Other parameters are human nutritional intake, which is assumed to be constant over time, and primary production (photosynthesis), which also is a fairly constant parameter over time. The Landscape Dose Factor approach (LDF) gives an integrated measure for the site and also resolves the issues relating to the size of the group with highest exposure. If this approach is widely accepted as method, still some improvements and refinement are necessary in collecting missing site data, reanalysing site data, reviewing radionuclide specific data, reformulating ecosystem models and evaluating the results with further sensitivity analysis

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.

A roadmap for improving the representation of photosynthesis in Earth system models.

Science.gov (United States)

Rogers, Alistair; Medlyn, Belinda E; Dukes, Jeffrey S; Bonan, Gordon; von Caemmerer, Susanne; Dietze, Michael C; Kattge, Jens; Leakey, Andrew D B; Mercado, Lina M; Niinemets, Ülo; Prentice, I Colin; Serbin, Shawn P; Sitch, Stephen; Way, Danielle A; Zaehle, Sönke

2017-01-01

Accurate representation of photosynthesis in terrestrial biosphere models (TBMs) is essential for robust projections of global change. However, current representations vary markedly between TBMs, contributing uncertainty to projections of global carbon fluxes. Here we compared the representation of photosynthesis in seven TBMs by examining leaf and canopy level responses of photosynthetic CO 2 assimilation (A) to key environmental variables: light, temperature, CO 2 concentration, vapor pressure deficit and soil water content. We identified research areas where limited process knowledge prevents inclusion of physiological phenomena in current TBMs and research areas where data are urgently needed for model parameterization or evaluation. We provide a roadmap for new science needed to improve the representation of photosynthesis in the next generation of terrestrial biosphere and Earth system models. No claim to original US Government works New Phytologist © 2016 New Phytologist Trust.

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.

Technical note: A hydrological routing scheme for the Ecosystem Demography model (ED2+R tested in the Tapajós River basin in the Brazilian Amazon

Directory of Open Access Journals (Sweden)

F. F. Pereira

2017-09-01

Full Text Available Land surface models are excellent tools for studying how climate change and land use affect surface hydrology. However, in order to assess the impacts of Earth processes on river flows, simulated changes in runoff need to be routed through the landscape. In this technical note, we describe the integration of the Ecosystem Demography (ED2 model with a hydrological routing scheme. The purpose of the study was to create a tool capable of incorporating to hydrological predictions the terrestrial ecosystem responses to climate, carbon dioxide, and land-use change, as simulated with terrestrial biosphere models. The resulting ED2+R model calculates the lateral routing of surface and subsurface runoff resulting from the terrestrial biosphere models' vertical water balance in order to determine spatiotemporal patterns of river flows within the simulated region. We evaluated the ED2+R model in the Tapajós, a 476 674 km2 river basin in the southeastern Amazon, Brazil. The results showed that the integration of ED2 with the lateral routing scheme results in an adequate representation (Nash–Sutcliffe efficiency up to 0.76, Kling–Gupta efficiency up to 0.86, Pearson's R up to 0.88, and volume ratio up to 1.06 of daily to decadal river flow dynamics in the Tapajós. These results are a consistent step forward with respect to the no river representation common among terrestrial biosphere models, such as the initial version of ED2.

Isotopic identification of nitrogen hotspots across natural terrestrial ecosystems

Directory of Open Access Journals (Sweden)

E. Bai

2012-08-01

Full Text Available Nitrogen (N influences local biological processes, ecosystem productivity, the composition of the atmospheric-climate system, and the human endeavour as a whole. Here we use natural variations in N isotopes, coupled with two models, to trace global pathways of N loss from the land to the water and atmosphere. We show that denitrification accounts for approximately 35 % of total N losses from the natural soil, with NO, N₂O, and N₂ fluxes equal to 15.7 ± 4.7 Tg N yr⁻¹, 10.2 ± 3.0 Tg N yr⁻¹, and 21.0 ± 6.1 Tg N yr⁻¹, respectively. Our analysis points to tropical regions as the major "hotspot" of nitrogen export from the terrestrial biosphere, accounting for 71 % of global N losses from the natural land surface. The poorly studied Congo Basin is further identified as one of the major natural sources of atmospheric N₂O. Extra-tropical areas, by contrast, lose a greater fraction of N via leaching pathways (~77 % of total N losses than do tropical biomes, likely contributing to N limitations of CO₂ uptake at higher latitudes. Our results provide an independent constraint on global models of the N cycle among different regions of the unfertilized biosphere.

Biogeochemical signals from deep microbial life in terrestrial crust.

Directory of Open Access Journals (Sweden)

Yohey Suzuki

Full Text Available In contrast to the deep subseafloor biosphere, a volumetrically vast and stable habitat for microbial life in the terrestrial crust remains poorly explored. For the long-term sustainability of a crustal biome, high-energy fluxes derived from hydrothermal circulation and water radiolysis in uranium-enriched rocks are seemingly essential. However, the crustal habitability depending on a low supply of energy is unknown. We present multi-isotopic evidence of microbially mediated sulfate reduction in a granitic aquifer, a representative of the terrestrial crust habitat. Deep meteoric groundwater was collected from underground boreholes drilled into Cretaceous Toki granite (central Japan. A large sulfur isotopic fractionation of 20-60‰ diagnostic to microbial sulfate reduction is associated with the investigated groundwater containing sulfate below 0.2 mM. In contrast, a small carbon isotopic fractionation (<30‰ is not indicative of methanogenesis. Except for 2011, the concentrations of H2 ranged mostly from 1 to 5 nM, which is also consistent with an aquifer where a terminal electron accepting process is dominantly controlled by ongoing sulfate reduction. High isotopic ratios of mantle-derived 3He relative to radiogenic 4He in groundwater and the flux of H2 along adjacent faults suggest that, in addition to low concentrations of organic matter (<70 µM, H2 from deeper sources might partly fuel metabolic activities. Our results demonstrate that the deep biosphere in the terrestrial crust is metabolically active and playing a crucial role in the formation of reducing groundwater even under low-energy fluxes.

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

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 Sellafield region including the coastal marine environment for present day biosphere conditions. A detailed description of the present day environment in the Sellafield 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

International Nuclear Information System (INIS)

Broderick, M.A.

1991-12-01

This report documents from open published sources a factual database appropriate to the Sellafield region including the coastal marine environment for present day biosphere conditions. A detailed description of the present day environment in the Sellafield area is provided. This includes a description of the natural environment and climate. Site specific data required for biosphere modelling are also outlined. (author)

Biosphere Modeling for the Dose Assessment of a HLW Repository: Development of ACBIO

Energy Technology Data Exchange (ETDEWEB)

Lee, Youn Myoung; Hwang, Yong Soo; Kang, Chul Hyung

2006-01-15

For the purpose of evaluating a dose rate to an individual due to a long-term release of nuclides from a HLW repository, a biosphere assessment model and an implemented code, ACBIO, based on the BIOMASS methodology have been developed by utilizing AMBER, a general compartment modeling tool. To demonstrate its practicability and usability as well as to observe the sensitivity of the compartment scheme, the concentration, the activity in the compartments as well as the annual flux between the compartments at their peak values, were calculated and investigated. For each case when changing the structure of the compartments and GBIs as well as varying selected input Kd values, all of which seem very important among the others, the dose rate per nuclide release rate is calculated separately and analyzed. From the maximum dose rates, the flux to dose conversion factors for each nuclide were derived, which are used for converting the nuclide release rate appearing from the geosphere through various GBIs to dose rates (Sv/y) for an individual in a critical group. It has also been observed that the compartment scheme, the identification of a possible exposure group and the GBIs could all be highly sensitive to the final consequences in a biosphere modeling.

Biosphere Modeling for the Dose Assessment of a HLW Repository: Development of ACBIO

International Nuclear Information System (INIS)

Lee, Youn Myoung; Hwang, Yong Soo; Kang, Chul Hyung

2006-01-01

For the purpose of evaluating a dose rate to an individual due to a long-term release of nuclides from a HLW repository, a biosphere assessment model and an implemented code, ACBIO, based on the BIOMASS methodology have been developed by utilizing AMBER, a general compartment modeling tool. To demonstrate its practicability and usability as well as to observe the sensitivity of the compartment scheme, the concentration, the activity in the compartments as well as the annual flux between the compartments at their peak values, were calculated and investigated. For each case when changing the structure of the compartments and GBIs as well as varying selected input Kd values, all of which seem very important among the others, the dose rate per nuclide release rate is calculated separately and analyzed. From the maximum dose rates, the flux to dose conversion factors for each nuclide were derived, which are used for converting the nuclide release rate appearing from the geosphere through various GBIs to dose rates (Sv/y) for an individual in a critical group. It has also been observed that the compartment scheme, the identification of a possible exposure group and the GBIs could all be highly sensitive to the final consequences in a biosphere modeling

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 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.

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.

A summary of biospheric research 1975-1997

Energy Technology Data Exchange (ETDEWEB)

Edlund, O.; Bergstroem, U.; Hallberg, B.; Karlsson, Sara [Studsvik Eco and Safety AB, Nykoeping (Sweden)

1999-12-01

The aim of this study is to present a summary of the work performed within the frame of SKB's biosphere programme during 1975 - 1997. The studies focused on field studies and theoretical model development. Important problems identified during this time period are pointed out. Summaries of the biospheric parts of the safety analyses performed since 1977 are given. Models are described as well as basic assumptions. Already the first analysis had an overall approach including dispersion from local to global zones with multiple exposure pathways. Compartment models have been used whereby the rate constants in the first assessments were mostly based on observed redistribution of radionuclides in nature. During the years emphasis has been laid on the description of processes mathematically and additional processes have been included in the models. In general, standard biospheres with constant environmental conditions were applied with focus on releases of radionuclides to wells, lakes and coastal areas. Drinking water has shown to be an important exposure pathway but not always the dominant one. Some screening calculations performed showed that peat bogs may be important recipients when doses to humans are concerned. The field studies initially focused on the naturally existing isotopes of U and Ra. A lot of studies were performed to gain data concerning the levels of these radionuclides in soils and waters. The studies also obtained information about back-ground values and the distribution between various biospheric components which was used to support model assumptions. A special sampling programme with the purpose to outline influence of drying up of lakes on the dose to individuals of critical group was also performed. The dose calculations showed that the doses could increase two orders of magnitude for immobile elements when the lake had dried up. Investigations of the natural abundance of radionuclides in soil and flora were performed later. After the

A summary of biospheric research 1975-1997

International Nuclear Information System (INIS)

Edlund, O.; Bergstroem, U.; Hallberg, B.; Karlsson, Sara

1999-12-01

The aim of this study is to present a summary of the work performed within the frame of SKB's biosphere programme during 1975 - 1997. The studies focused on field studies and theoretical model development. Important problems identified during this time period are pointed out. Summaries of the biospheric parts of the safety analyses performed since 1977 are given. Models are described as well as basic assumptions. Already the first analysis had an overall approach including dispersion from local to global zones with multiple exposure pathways. Compartment models have been used whereby the rate constants in the first assessments were mostly based on observed redistribution of radionuclides in nature. During the years emphasis has been laid on the description of processes mathematically and additional processes have been included in the models. In general, standard biospheres with constant environmental conditions were applied with focus on releases of radionuclides to wells, lakes and coastal areas. Drinking water has shown to be an important exposure pathway but not always the dominant one. Some screening calculations performed showed that peat bogs may be important recipients when doses to humans are concerned. The field studies initially focused on the naturally existing isotopes of U and Ra. A lot of studies were performed to gain data concerning the levels of these radionuclides in soils and waters. The studies also obtained information about back-ground values and the distribution between various biospheric components which was used to support model assumptions. A special sampling programme with the purpose to outline influence of drying up of lakes on the dose to individuals of critical group was also performed. The dose calculations showed that the doses could increase two orders of magnitude for immobile elements when the lake had dried up. Investigations of the natural abundance of radionuclides in soil and flora were performed later. After the Chernobyl

The carbon cycle in a land surface model: modelling, validation and implementation at a global scale; Cycle du carbone dans un modele de surface continentale: modelisation, validation et mise en oeuvre a l'echelle globale

Energy Technology Data Exchange (ETDEWEB)

Gibelin, A L

2007-05-15

ISBA-A-gs is an option of the CNRM land surface model ISBA which allows for the simulation of carbon exchanges between the terrestrial biosphere and the atmosphere. The model was implemented for the first time at the global scale as a stand-alone model. Several global simulations were performed to assess the sensitivity of the turbulent fluxes and Leaf Area Index to a doubling of the CO{sub 2} atmospheric concentration, and to the climate change simulated by the end of the 21. century. In addition, a new option of ISBA, referred to as ISBA-CC, was developed in order to simulate a more detailed ecosystem respiration by separating the autotrophic respiration and the heterotrophic respiration. The vegetation dynamics and the carbon fluxes were validated at a global scale using satellite datasets, and at a local scale using data from 26 sites of the FLUXNET network. All these results show that the model is sufficiently realistic to be coupled with a general circulation model, in order to account for interactions between the terrestrial biosphere, the atmosphere and the carbon cycle. (author)

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

Soil-to-Plant Concentration Ratios for Assessing Food Chain Pathways in Biosphere Models

Energy Technology Data Exchange (ETDEWEB)

Napier, Bruce A.; Fellows, Robert J.; Krupka, Kenneth M.

2007-10-01

This report describes work performed for the U.S. Nuclear Regulatory Commission’s project Assessment of Food Chain Pathway Parameters in Biosphere Models, which was established to assess and evaluate a number of key parameters used in the food-chain models used in performance assessments of radioactive waste disposal facilities. Section 2 of this report summarizes characteristics of samples of soils and groundwater from three geographical regions of the United States, the Southeast, Northwest, and Southwest, and analyses performed to characterize their physical and chemical properties. Because the uptake and behavior of radionuclides in plant roots, plant leaves, and animal products depends on the chemistry of the water and soil coming in contact with plants and animals, water and soil samples collected from these regions of the United States were used in experiments at Pacific Northwest National Laboratory to determine radionuclide soil-to-plant concentration ratios. Crops and forage used in the experiments were grown in the soils, and long-lived radionuclides introduced into the groundwater provide the contaminated water used to water the grown plants. The radionuclides evaluated include 99Tc, 238Pu, and 241Am. Plant varieties include alfalfa, corn, onion, and potato. The radionuclide uptake results from this research study show how regional variations in water quality and soil chemistry affect radionuclide uptake. Section 3 summarizes the procedures and results of the uptake experiments, and relates the soil-to-plant uptake factors derived. In Section 4, the results found in this study are compared with similar values found in the biosphere modeling literature; the study’s results are generally in line with current literature, but soil- and plant-specific differences are noticeable. This food-chain pathway data may be used by the NRC staff to assess dose to persons in the reference biosphere (e.g., persons who live and work in an area potentially affected by

Building capital through bioregional planning and biosphere reserves

Directory of Open Access Journals (Sweden)

David Brunckhorst

2001-02-01

Full Text Available ABSTRACT: The need to implement innovative approaches to sustainability is now more critical than ever. This discussion draws on parts of the puzzle that must be assembled to achieve integrated, cross-tenure and jurisdictional management of whole regions and their peoples for a sustainable future. A regional, landscape ecology approach helps us to move on from theory and historical lessons to boldly design and adaptively develop novel on-ground models. To take an entirely different approach from conventional thinking, I draw from Common Property Resource (CPR theory and experience, together with practical experience from the Bookmark Biosphere project. The characteristics of successful enduring Common Property regimes are identified and discussed in light of critical needs to maintain and restore social and ecological capital. I then highlight the concepts and logistical objectives behind the 30-year-old UNESCO Biosphere Reserve Program, which appears to have great potential as an operational framework within which these changes can be made. The Biosphere Reserve Program is maturing through integration of cultural needs and aspirations for quality of life, while conserving natural values and ecosystem processes. In particular, progress is being made through bioregional planning and management incorporating a variety of IUCN protected area types with novel, sustainable, resource-use diversification. The novel arrangements, experience and lessons from one developing model, Bookmark Biosphere Reserve in South Australia, are described as an example. I wish to encourage more models like the Bookmark experiment to evolve through even greater creativity and engagement with public and private partners. On-ground models that demonstrate innovative alternative land use management in the rangelands or integration across the coastal-marine interface are especially needed.

Beyond the principle of plentitude: a review of terrestrial planet habitability.

Science.gov (United States)

Gaidos, E; Deschenes, B; Dundon, L; Fagan, K; Menviel-Hessler, L; Moskovitz, N; Workman, M

2005-04-01

We review recent work that directly or indirectly addresses the habitability of terrestrial (rocky) planets like the Earth. Habitability has been traditionally defined in terms of an orbital semimajor axis within a range known as the habitable zone, but it is also well known that the habitability of Earth is due to many other astrophysical, geological, and geochemical factors. We focus this review on (1) recent refinements to habitable zone calculations; (2) the formation and orbital stability of terrestrial planets; (3) the tempo and mode of geologic activity (e.g., plate tectonics) on terrestrial planets; (4) the delivery of water to terrestrial planets in the habitable zone; and (5) the acquisition and loss of terrestrial planet carbon and nitrogen, elements that constitute important atmospheric gases responsible for habitable conditions on Earth's surface as well as being the building blocks of the biosphere itself. Finally, we consider recent work on evidence for the earliest habitable environments and the appearance of life itself on our planet. Such evidence provides us with an important, if nominal, calibration point for our search for other habitable worlds.

The carbon cycle in a land surface model: modelling, validation and implementation at a global scale; Cycle du carbone dans un modele de surface continentale: modelisation, validation et mise en oeuvre a l'echelle globale

Energy Technology Data Exchange (ETDEWEB)

Gibelin, A.L

2007-05-15

ISBA-A-gs is an option of the CNRM land surface model ISBA which allows for the simulation of carbon exchanges between the terrestrial biosphere and the atmosphere. The model was implemented for the first time at the global scale as a stand-alone model. Several global simulations were performed to assess the sensitivity of the turbulent fluxes and Leaf Area Index to a doubling of the CO{sub 2} atmospheric concentration, and to the climate change simulated by the end of the 21. century. In addition, a new option of ISBA, referred to as ISBA-CC, was developed in order to simulate a more detailed ecosystem respiration by separating the autotrophic respiration and the heterotrophic respiration. The vegetation dynamics and the carbon fluxes were validated at a global scale using satellite datasets, and at a local scale using data from 26 sites of the FLUXNET network. All these results show that the model is sufficiently realistic to be coupled with a general circulation model, in order to account for interactions between the terrestrial biosphere, the atmosphere and the carbon cycle. (author)

Database for radionuclide transport in the biosphere

International Nuclear Information System (INIS)

Jiskra, J.

1985-01-01

The biosphere model is the final link in the chain of radionuclide transport models, used for radiation dose calculations from high level waste repositories. This report presents the data needed for biosphere calculations and discusses them where necessary. The first part is dedicated to the nuclide specific parameters like distribution coefficients (water - soil), concentration ratios (soil - plant) and distribution factors (for milk, meat etc.) which are reported in the literature. The second part contains the choice of regions, their division into compartments and the discussion of nutritional habits for man and animals. At the end a theoretical population for each region is estimated based on the consumption rates and on the yield of agricultural products, assuming an autonomous nutrition. (Auth.)

"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

What Drives Carbon Isotope Fractionation by the Terrestrial Biosphere?

Science.gov (United States)

Still, Christopher; Rastogi, Bharat

2017-11-01

During photosynthesis, terrestrial plants preferentially assimilate the lighter and much more abundant form of carbon, 12C, which accounts for roughly 99% of naturally occurring forms of this element. This photosynthetic preference for lighter carbon is driven principally by differences in molecular diffusion of carbon dioxide with differing 13C/12C across stomatal pores on leaves, followed by differences in carboxylation rates by the Rubisco enzyme that is central to the process of photosynthesis. As a result of these slight preferences, which work out to about a 2% difference in the fixation rates of 12CO2 versus 13CO2 by C3 vegetation, plant tissues are depleted in the heavier form of carbon (13C) relative to atmospheric CO2. This difference has been exploited in a wide range of scientific applications, as the photosynthetic isotope signature is passed to ecosystem carbon pools and through ecological food webs. What is less appreciated is the signature that terrestrial carbon exchanges leave on atmospheric CO2, as the net uptake of carbon by land plants during their growing season not only draws down the local CO2 concentration, it also leaves behind relatively more CO2 molecules containing 13C. The converse happens outside the growing season, when autotrophic and heterotrophic respiration predominate. During these periods, atmospheric CO2 concentration increases and its corresponding carbon isotope composition becomes relatively depleted in 13C as the products of photosynthesis are respired, along with some small isotope fractionation that happen downstream of the initial photosynthetic assimilation. Similar phenomena were first observed at shorter time scales by the eminent carbon cycle scientist, Charles (Dave) Keeling. Keeling collected samples of air in glass flasks from sites along the Big Sur coast that he later measured for CO2 concentration and carbon isotope composition (δ13C) in his lab (Keeling, 1998). From these samples, Keeling observed increasing

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

Models of radionuclide distribution in the biosphere for radioactive waste storage safety assessment, collection of data and calculation of the biosphere dose conversion factors. Research report

International Nuclear Information System (INIS)

Landa, Jiri

2008-12-01

The core of the report is structured as follows: The biosphere dose conversion factor (BDCF); Foreign approaches (Sweden - SKB, USA - YMP, BIOPROTA); Definition and conversion factors for activity; Effective dose rate calculation (ingestion, inhalation, external irradiation); Analysis of the activity of the surface compartment, i.e. soil; Basic conceptual models of ecosystems; BDCF calculation/determination; and Systemization of the literature. (P.A.)

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

Science.gov (United States)

Thornton, P. E.; Calvin, K. V.; Jones, A. D.; Di Vittorio, A. V.; Bond-Lamberty, B. P.; Chini, L. P.; Shi, X.; Mao, J.; Collins, W. D.; Edmonds, J.; Hurtt, G. C.

2017-12-01

Fossil fuel combustion and land-use change are the two largest contributors to industrial-era increases in atmospheric CO2 concentration. Projections of these are thus fundamental inputs for coupled Earth system models (ESMs) used to estimate the physical and biological consequences of future climate system forcing. While historical datasets are available to inform past and current climate analyses, assessments of future climate change have relied on projections of energy and land use from energy economic models, constrained by assumptions about future policy, land-use patterns, and socio-economic development trajectories. In this work we show that the climatic impacts on land ecosystems drives significant feedbacks in energy, agriculture, land-use, and carbon cycle projections for the 21st century. We find that exposure of human appropriated land ecosystem productivity to biospheric change results in reductions of land area used for crops; increases in managed forest area and carbon stocks; decreases in global crop prices; and reduction in fossil fuel emissions for a low-mid range forcing scenario. Land ecosystem response to increased carbon dioxide concentration, increased anthropogenic nitrogen deposition, and changes in temperature and precipitation all play a role. The feedbacks between climate-induced biospheric change and human system forcings to the climate system demonstrated in this work are handled inconsistently, or excluded altogether, in the one-way asynchronous coupling of energy economic models to ESMs used to date.

Transfer into the biosphere of radionuclides released from deep storage of radioactive wastes. Bibliographical study; Transfert dans la biosphere des radionucleides issus des stockages profonds de dechets radioactifs. Etude bibliographique

Energy Technology Data Exchange (ETDEWEB)

Guedon, V.; Siclet, F.

1995-03-01

Most countries with civilian nuclear programs today are encountering difficulty in implementing a nuclear waste management policy that is both technically safe in the long term and accepted by the public. To meet both criteria, the solution most generally envisaged is deep storage either of untreated spent nuclear fuel or of highly radioactive wastes resulting from reprocessing. In order to predict the potential impact of such storage on man, one needs to understand the path followed by radionuclides in the geosphere, and later in the biosphere. Given the time scales involved and the critical nature of the elements concerned, it is indispensable to turn to mathematical modeling of the phenomena. This report presents what is hoped to be a complete inventory of the radionuclides contained in ``high level`` wastes (categories B AND C). The elements concerned in studies on deep storage are essentially long-life radionuclides (both actinides and certain fission and activation products). Their physico-chemical characteristics and their behavior in various ecological compartments are examined. Bibliographical data bearing on: solubility (in an oxidizing, reducing medium), distribution factors (water/rock-sediment-soil), concentration and transfer factors (in aquatic and terrestrial mediums), dose conversion factors (in the case of internal and external irradiation), principal paths of exposure for each radionuclide studied, are presented in this report. Initial results from international projects to model what happens to radionuclides in the biosphere are also presented. In general, they are optimistic as to the future, but nonetheless point to a need to improve the conceptual base of the models, to ensure that all major phenomena and processes are taken into consideration and to examine any possible amplification (author). 67 refs., 39 figs., 20 tabs.

Traceable components of terrestrial carbon storage capacity in biogeochemical models.

Science.gov (United States)

Xia, Jianyang; Luo, Yiqi; Wang, Ying-Ping; Hararuk, Oleksandra

2013-07-01

Biogeochemical models have been developed to account for more and more processes, making their complex structures difficult to be understood and evaluated. Here, we introduce a framework to decompose a complex land model into traceable components based on mutually independent properties of modeled biogeochemical processes. The framework traces modeled ecosystem carbon storage capacity (Xss ) to (i) a product of net primary productivity (NPP) and ecosystem residence time (τE ). The latter τE can be further traced to (ii) baseline carbon residence times (τ'E ), which are usually preset in a model according to vegetation characteristics and soil types, (iii) environmental scalars (ξ), including temperature and water scalars, and (iv) environmental forcings. We applied the framework to the Australian Community Atmosphere Biosphere Land Exchange (CABLE) model to help understand differences in modeled carbon processes among biomes and as influenced by nitrogen processes. With the climate forcings of 1990, modeled evergreen broadleaf forest had the highest NPP among the nine biomes and moderate residence times, leading to a relatively high carbon storage capacity (31.5 kg cm(-2) ). Deciduous needle leaf forest had the longest residence time (163.3 years) and low NPP, leading to moderate carbon storage (18.3 kg cm(-2) ). The longest τE in deciduous needle leaf forest was ascribed to its longest τ'E (43.6 years) and small ξ (0.14 on litter/soil carbon decay rates). Incorporation of nitrogen processes into the CABLE model decreased Xss in all biomes via reduced NPP (e.g., -12.1% in shrub land) or decreased τE or both. The decreases in τE resulted from nitrogen-induced changes in τ'E (e.g., -26.7% in C3 grassland) through carbon allocation among plant pools and transfers from plant to litter and soil pools. Our framework can be used to facilitate data model comparisons and model intercomparisons via tracking a few traceable components for all terrestrial carbon

Some viewpoints on reference biospheres in Finnish performance assessments

International Nuclear Information System (INIS)

Rasilainen, K.; Kattilakoski, E.; Suolanen, V.; Vieno, T.; Vuori, S.

2002-01-01

Viewpoints are presented concerning biosphere studies in performance assessments of nuclear waste disposal. The points are based on experiences from several Finnish performance assessments. The latest performance assessment for spent fuel disposal, TILA-99, was considered in the Decision in Principle process for the site selection of the repository. The points given are also based on experiences from participation in international projects dealing with biosphere modelling, for instance BIOMOVS and BIOMASS. (author)

Increased light-use efficiency in northern terrestrial ecosystems indicated by CO ₂ and greening observations: INCREASE IN NH LIGHT USE EFFICIENCY

Energy Technology Data Exchange (ETDEWEB)

Thomas, Rebecca T. [Science and Solutions for a Changing Planet DTP, Imperial College London, London UK; AXA Chair Programme in Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, London UK; Department of Physics, Imperial College London, London UK; Prentice, Iain Colin [AXA Chair Programme in Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, London UK; Grantham Institute: Climate Change and the Environment, Imperial College London, London UK; Graven, Heather [Department of Physics, Imperial College London, London UK; Grantham Institute: Climate Change and the Environment, Imperial College London, London UK; Ciais, Philippe [Laboratoire des Sciences du Climat et de l' Environnement, Saint-Aubin France; Fisher, Joshua B. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena California USA; Hayes, Daniel J. [School of Forest Resources, University of Maine, Orono Maine USA; Huang, Maoyi [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Huntzinger, Deborah N. [School of Earth Sciences and Environmental Sustainability, Northern Arizona University, Flagstaff Arizona USA; Ito, Akihiko [Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba Japan; Jain, Atul [Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, Urbana Illinois USA; Mao, Jiafu [Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge Tennessee USA; Michalak, Anna M. [Department of Global Ecology, Carnegie Institution for Science, Stanford California USA; Peng, Shushi [Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing China; Poulter, Benjamin [Department of Ecology, Montana State University, Bozeman Montana USA; Ricciuto, Daniel M. [Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge Tennessee USA; Shi, Xiaoying [Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge Tennessee USA; Schwalm, Christopher [Woods Hole Research Center, Falmouth Massachusetts USA; Tian, Hanqin [International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn Alabama USA; Zeng, Ning [Department of Atmospheric and Oceanic Science and Earth System Science Interdisciplinary Center, University of Maryland, College Park Maryland USA

2016-11-04

Observations show an increasing amplitude in the seasonal cycle of CO2 (ASC) north of 45°N of 56 ± 9.8% over the last 50 years and an increase in vegetation greenness of 7.5–15% in high northern latitudes since the 1980s. However, the causes of these changes remain uncertain. Historical simulations from terrestrial biosphere models in the Multiscale Synthesis and Terrestrial Model Intercomparison Project are compared to the ASC and greenness observations, using the TM3 atmospheric transport model to translate surface fluxes into CO2 concentrations. We find that the modeled change in ASC is too small but the mean greening trend is generally captured. Modeled increases in greenness are primarily driven by warming, whereas ASC changes are primarily driven by increasing CO2. We suggest that increases in ecosystem-scale light use efficiency (LUE) have contributed to the observed ASC increase but are underestimated by current models. We highlight potential mechanisms that could increase modeled LUE.

Simultaneous reproduction of global carbon exchange and storage of terrestrial forest ecosystems

Science.gov (United States)

Kondo, M.; Ichii, K.

2012-12-01

Understanding the mechanism of the terrestrial carbon cycle is essential for assessing the impact of climate change. Quantification of both carbon exchange and storage is the key to the understanding, but it often associates with difficulties due to complex entanglement of environmental and physiological factors. Terrestrial ecosystem models have been the major tools to assess the terrestrial carbon budget for decades. Because of its strong association with climate change, carbon exchange has been more rigorously investigated by the terrestrial biosphere modeling community. Seeming success of model based assessment of carbon budge often accompanies with the ill effect, substantial misrepresentation of storage. In practice, a number of model based analyses have paid attention solely on terrestrial carbon fluxes and often neglected carbon storage such as forest biomass. Thus, resulting model parameters are inevitably oriented to carbon fluxes. This approach is insufficient to fully reduce uncertainties about future terrestrial carbon cycles and climate change because it does not take into account the role of biomass, which is equivalently important as carbon fluxes in the system of carbon cycle. To overcome this issue, a robust methodology for improving the global assessment of both carbon budget and storage is needed. One potentially effective approach to identify a suitable balance of carbon allocation proportions for each individual ecosystem. Carbon allocations can influence the plant growth by controlling the amount of investment acquired from photosynthesis, as well as carbon fluxes by controlling the carbon content of leaves and litter, both are active media for photosynthesis and decomposition. Considering those aspects, there may exist the suitable balance of allocation proportions enabling the simultaneous reproduction of carbon budget and storage. The present study explored the existence of such suitable balances of allocation proportions, and examines the

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

Observing the continental-scale carbon balance: assessment of sampling complementarity and redundancy in a terrestrial assimilation system by means of quantitative network design

OpenAIRE

Kaminski, T.; Rayner, P. J.; Vossbeck, M.; Scholze, M.; Koffi, E.

2012-01-01

This paper investigates the relationship between the heterogeneity of the terrestrial carbon cycle and the optimal design of observing networks to constrain it. We combine the methods of quantitative network design and carbon-cycle data assimilation to a hierarchy of increasingly heterogeneous descriptions of the European terrestrial biosphere as indicated by increasing diversity of plant functional types. We employ three types of observat...

Potential for hydrogen-oxidizing chemolithoautotrophic and diazotrophic populations to initiate biofilm formation in oligotrophic, deep terrestrial subsurface waters.

Science.gov (United States)

Wu, Xiaofen; Pedersen, Karsten; Edlund, Johanna; Eriksson, Lena; Åström, Mats; Andersson, Anders F; Bertilsson, Stefan; Dopson, Mark

2017-03-23

Deep terrestrial biosphere waters are separated from the light-driven surface by the time required to percolate to the subsurface. Despite biofilms being the dominant form of microbial life in many natural environments, they have received little attention in the oligotrophic and anaerobic waters found in deep bedrock fractures. This study is the first to use community DNA sequencing to describe biofilm formation under in situ conditions in the deep terrestrial biosphere. In this study, flow cells were attached to boreholes containing either "modern marine" or "old saline" waters of different origin and degree of isolation from the light-driven surface of the earth. Using 16S rRNA gene sequencing, we showed that planktonic and attached populations were dissimilar while gene frequencies in the metagenomes suggested that hydrogen-fed, carbon dioxide- and nitrogen-fixing populations were responsible for biofilm formation across the two aquifers. Metagenome analyses further suggested that only a subset of the populations were able to attach and produce an extracellular polysaccharide matrix. Initial biofilm formation is thus likely to be mediated by a few bacterial populations which were similar to Epsilonproteobacteria, Deltaproteobacteria, Betaproteobacteria, Verrucomicrobia, and unclassified bacteria. Populations potentially capable of attaching to a surface and to produce extracellular polysaccharide matrix for attachment were identified in the terrestrial deep biosphere. Our results suggest that the biofilm populations were taxonomically distinct from the planktonic community and were enriched in populations with a chemolithoautotrophic and diazotrophic metabolism coupling hydrogen oxidation to energy conservation under oligotrophic conditions.

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.

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 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.

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

Modeling and estimation of a low degree geopotential model from terrestrial gravity data

Science.gov (United States)

Pavlis, Nikolaos K.

1988-01-01

The development of appropriate modeling and adjustment procedures for the estimation of harmonic coefficients of the geopotential, from surface gravity data was studied, in order to provide an optimum way of utilizing the terrestrial gravity information in combination solutions currently developed at NASA/Goddard Space Flight Center, for use in the TOPEX/POSEIDON mission. The mathematical modeling was based on the fundamental boundary condition of the linearized Molodensky boundary value problem. Atmospheric and ellipsoidal corrections were applied to the surface anomalies. Terrestrial gravity solutions were found to be in good agreement with the satellite ones over areas which are well surveyed (gravimetrically), such as North America or Australia. However, systematic differences between the terrestrial only models and GEMT1, over extended regions in Africa, the Soviet Union, and China were found. In Africa, gravity anomaly differences on the order of 20 mgals and undulation differences on the order of 15 meters, over regions extending 2000 km in diameter, occur. Comparisons of the GEMT1 implied undulations with 32 well distributed Doppler derived undulations gave an RMS difference of 2.6 m, while corresponding comparison with undulations implied by the terrestrial solution gave RMS difference on the order of 15 m, which implies that the terrestrial data in that region are substantially in error.

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)