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Sample records for biosphere model based

  1. Biosphere Model Report

    International Nuclear Information System (INIS)

    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)

  2. 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).

  3. 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

  4. Biosphere Process Model Report

    International Nuclear Information System (INIS)

    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

  5. 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.

  6. Characteristics of the Receptor for the Biosphere Model

    International Nuclear Information System (INIS)

    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

  7. 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

  8. 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.)

  9. Biosphere models for safety assessment of radioactive waste disposal

    International Nuclear Information System (INIS)

    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.)

  10. Characteristics of the Receptor for the Biosphere Model

    International Nuclear Information System (INIS)

    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])

  11. 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

  12. 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

  13. Inhalation Exposure Input Parameters for the Biosphere Model

    International Nuclear Information System (INIS)

    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

  14. 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.

  15. Environmental Transport Input Parameters for the Biosphere Model

    Energy Technology Data Exchange (ETDEWEB)

    M. A. Wasiolek

    2003-06-27

    ], Section 6.2). Parameter values developed in this report, and the related FEPs, are listed in Table 1-1. The relationship between the parameters and FEPs was based on a comparison of the parameter definition and the FEP descriptions as presented in BSC (2003 [160699], Section 6.2). The parameter values developed in this report support the biosphere model and are reflected in the TSPA through the biosphere dose conversion factors (BDCFs). Biosphere modeling focuses on radionuclides screened for the TSPA-LA (BSC 2002 [160059]). The same list of radionuclides is used in this analysis (Section 6.1.4). The analysis considers two human exposure scenarios (groundwater and volcanic ash) and climate change (Section 6.1.5). This analysis combines and revises two previous reports, ''Transfer Coefficient Analysis'' (CRWMS M&O 2000 [152435]) and ''Environmental Transport Parameter Analysis'' (CRWMS M&O 2001 [152434]), because the new ERMYN biosphere model requires a redefined set of input parameters. The scope of this analysis includes providing a technical basis for the selection of radionuclide- and element-specific biosphere parameters (except for Kd) that are important for calculating BDCFs based on the available radionuclide inventory abstraction data. The environmental transport parameter values were developed specifically for use in the biosphere model and may not be appropriate for other applications.

  16. Environmental Transport Input Parameters for the Biosphere Model

    International Nuclear Information System (INIS)

    developed in this report, and the related FEPs, are listed in Table 1-1. The relationship between the parameters and FEPs was based on a comparison of the parameter definition and the FEP descriptions as presented in BSC (2003 [160699], Section 6.2). The parameter values developed in this report support the biosphere model and are reflected in the TSPA through the biosphere dose conversion factors (BDCFs). Biosphere modeling focuses on radionuclides screened for the TSPA-LA (BSC 2002 [160059]). The same list of radionuclides is used in this analysis (Section 6.1.4). The analysis considers two human exposure scenarios (groundwater and volcanic ash) and climate change (Section 6.1.5). This analysis combines and revises two previous reports, ''Transfer Coefficient Analysis'' (CRWMS MandO 2000 [152435]) and ''Environmental Transport Parameter Analysis'' (CRWMS MandO 2001 [152434]), because the new ERMYN biosphere model requires a redefined set of input parameters. The scope of this analysis includes providing a technical basis for the selection of radionuclide- and element-specific biosphere parameters (except for Kd) that are important for calculating BDCFs based on the available radionuclide inventory abstraction data. The environmental transport parameter values were developed specifically for use in the biosphere model and may not be appropriate for other applications

  17. Characteristics of the Receptor for the Biosphere Model

    International Nuclear Information System (INIS)

    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

  18. 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

  19. BIOSPHERE MODELING AT YUCCA MOUNTAIN, NEVADA

    International Nuclear Information System (INIS)

    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

  20. Evaluation of terrestrial primary production using biosphere models and space-based measurements of fluorescence

    Science.gov (United States)

    Parazoo, N.; Bowman, K. W.; Frankenberg, C.; Sitch, S.; Fisher, J. B.; Jones, D. B.; Friedlingstein, P.; Poulter, B.

    2013-12-01

    Changes in the processes that control terrestrial carbon uptake are highly uncertain but likely to have a significant influence on future atmospheric CO2 levels. RECCAP aims to improve process understanding by reconciling fluxes from top-down CO2 inversions and bottom-up estimates from an ensemble of dynamical global vegetation models (DGVMs). As these models are typically used in projections of climate change a key part of this effort is evaluating drivers of net carbon exchange within the current climate. Of particular importance are the spatial distribution and time rate of change of gross primary productivity (GPP). Recent advances in the remote sensing of solar-induced chlorophyll fluorescence opens up a new possibility to directly measure planetary photosynthesis on spatially resolved scales. Here, we discuss a new methodology for estimating GPP from an optimal combination of an ensemble of DGVMs from the TRENDY project with satellite-based observations of chlorophyll fluorescence from GOSAT. We evaluate optimized fluxes against flux tower and semi-empirical data in N. America, Europe, and S. America, then examine the period 2009-2010 to identify critical regions (i.e., regions with high annual GPP) where optimized and model fluxes diverge.

  1. Constraining carbon budgets at a regional scale: fusing forest inventory data with a cohort-based biosphere model

    Science.gov (United States)

    Viskari, T.; Dietze, M.; Desai, A. R.

    2014-12-01

    Forest inventories play an essential role in carbon monitoring and REDD+, however they provide a sparse picture of the carbon cycle at a regional scale. Terrestrial Biosphere Models (TBMs) provide a complete picture of the carbon cycle, but efforts at combining inventory data with models have focused primarily on model calibration and purely model-based regional-scale carbon estimation, which ignore observed disturbances, management, and spatiotemporal variability in forest. Our approach is based on assimilating inventory observations in a size- and age-structured model, the Ecosystem Demography model (ED2). Assumptions of large homogenous areas in ecological models result in loss of details that hinder incorporation of observations. We address how to assimilate inventory data with model predictions in a practical way that is readily extensible to the simultaneous fusion of remote sensing and eddy covariance along with inventories. We updated ED2 predictions on forest growth with Forest Inventory and Analysis program (FIA) data. Data assimilation method was the Ensemble Adjustment Kalman Filter (EAKF) as implemented in Data Assimilation Research Testbed (DART) workflow. The study area is a 1° by 1° grid with the Willow Creek Ameriflux tower in Wisconsin at center. ED2 groups individual trees in cohorts so it captures the landscape-scale heterogeneity. Although this approach speeds up computations, it is not practical to estimate each FIA plot within a chosen area. We classified and averaged data for different plots according to their biomass based on number and size of trees within a plot, focusing on biomass changes over a measurement period. We separately calculated the average diameter at breast height (dbh) and stem density for plants over 5 cm for measured and modeled plots within a biomass class for different Plant Functional Types (PFTs). The results showed EAKF successfully adjusting the predicted changes in biomass according to observations. Variation in

  2. 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

  3. VALORA: data base system for storage significant information used in the behavior modelling in the biosphere

    International Nuclear Information System (INIS)

    The nuclear and radioactive facilities can emit to the environment effluents that contain radionuclides, which are dispersed and/or its accumulate in the atmosphere, the terrestrial surface and the surface waters. As part of the evaluations of radiological impact, it requires to be carried out qualitative and quantitative analysis. In many of the cases it doesn't have the real values of the parameters that are used in the modelling, neither it is possible to carry out their measure, for that to be able to carry out the evaluation it needs to be carried out an extensive search of that published in the literature about the possible values of each parameter, under similar conditions to the object of study, this work can be extensive. In this work the characteristics of the VALORA Database System developed with the purpose of organizing and to automate significant information that it appears in different sources (scientific or technique literature) of the parameters that are used in the modelling of the behavior of the pollutants in the environment and the values assigned to these parameters that are used in the evaluation of the radiological impact potential is described; VALORA allows the consultation and selection of the characteristic parametric data of different situations and processes that are required by the calculation pattern implemented. The software VALORA it is a component of a group of tools computer that have as objective to help to the resolution of dispersion models and transfer of pollutants. (Author)

  4. Agricultural and Environmental Input Parameters for the Biosphere Model

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  6. 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.

  7. Environmental Transport Input Parameters for the Biosphere Model

    International Nuclear Information System (INIS)

    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])

  8. 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

  9. Inhalation Exposure Input Parameters for the Biosphere Model

    International Nuclear Information System (INIS)

    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

  10. 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.

  11. 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.

  12. 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.

  13. Soil-Related Input Parameters for the Biosphere Model

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  15. Guide to the dynamic biosphere model DECOS (Ed. 1)

    International Nuclear Information System (INIS)

    A dynamic biosphere model, DECOS, has been developed by Associated Nuclear Sevices Ltd for the Department of the Environment. DECOS was written as a 'stand-alone' development code to be interfaced with other assessment models as part of a new probabilistic code, VANDAL. This report provides a guide to the 'stand-alone' version of DECOS. (author)

  16. 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...

  17. Interannual variability in the atmosphere-biosphere CO2 exchange as simulated by a process-based model for the last decades

    Science.gov (United States)

    Ito, A.

    2001-05-01

    Atmosphere-biosphere CO2 exchange induces not only seasonal oscillation but also interannual change in the atmospheric CO2 concentration. Actually, in 1998, atmospheric CO2 concentration increased at a remarkably high rate, while the growth rate was apparently depressed in 1992 and 1993. Elucidating whether these anomalies were attributable to the ocean or the terrestrial biosphere is an important challenge for carbon cycle researchers. In this study, a process-based model of terrestrial carbon dynamics (Sim-CYCLE) was constructed and used to simulate the terrestrial carbon balance for the period from 1953 to 1999. Climatic variables related to ecosystem processes were derived from the U.S NCEP/NCAR-reanalysis data (T62 spatial resolution), and the Matthews's biome map was adopted. The atmospheric CO2 fertilization effect during the experimental period was also considered in the simulation analysis. Sim-CYCLE includes five carbon compartments (leaves, stems, roots, litter, and humus), and calculates fluxes among them at a monthly step, with taking environmental regulations into account. Accordingly, I could obtain a time-series of net carbon budget, i.e. net ecosystem production (NEP), on the global scale. Through the experimental period, global annual NEP exhibited a considerable interannual variability ranging from +2.0 Pg C in 1971 to ?2.5 Pg C in 1998 (SD 1.1 Pg C yr-1). Tropical ecosystems were most responsible for the interannual variability, especially in such ENSO years as 1973, 1983, and 1998. The estimated NEP anomalies were negatively correlated with surface temperature anomaly, due to the high sensitivity of respiration and decomposition to temperature. Thus, it is inferred that higher temperatures induced by the strong 1997-98 ENSO event would lead to extra CO2 emission and consequently the largest negative NEP anomaly. The estimated responsiveness of terrestrial carbon budget seems enough large to cause anomalies in atmospheric CO2 concentration

  18. Radioactive waste disposal assessment - overview of biosphere processes and models

    International Nuclear Information System (INIS)

    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)

  19. Biosphere modelling for near surface disposal of wastes

    International Nuclear Information System (INIS)

    Shallow land burial has been used for many years as a method for disposal of many kinds of wastes, including less active types of radioactive waste, special and hazardous industrial wastes, sewage sludge, building construction and demolition wastes, domestic refuse and so on. For a number of reasons particular attention has been given to safety for radioactive wastes and the assessments of the post-disposal impact. Such radiological assessments include relatively detailed models for migration and accumulation of radionuclides through the biosphere, and models for the corresponding radiation exposure of man. These biosphere models form the quantitative link between our predictions for contaminant behaviour below ground and the way in which they affect the surface environment, including mankind. This paper examines the types of environmental impact which might arise post-disposal from any shallow facility, including those on man himself, and wider environmental effects on ecosystems. All these kinds of impact could be relevant to assessments to determine the appropriateness of proposed disposals, or to determine the Best Practicable Environmental Option. The biosphere modelling requirements necessary for the evaluation of such impacts are then considered. The features events and processes which should be taken into account in various circumstances are briefly examined, along with data requirements and data availability, and the status of biosphere modelling capability. Finally suggestions are made for where further effort could be concentrated, to provide for better quantitative assessments of solid waste disposal. (28 refs.)

  20. 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

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

    International Nuclear Information System (INIS)

    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

  2. Biosphere modelling for a HLW repository scenario and parameter variations

    International Nuclear Information System (INIS)

    In Switzerland high-level radioactive wastes have been considered for disposal in deep-lying crystalline formations. The individual doses to man resulting from radionuclides entering the biosphere via groundwater transport are calculated. The main recipient area modelled, which constitutes the base case, is a broad gravel terrace sited along the south bank of the river Rhine. An alternative recipient region, a small valley with a well, is also modelled. A number of parameter variations are performed in order to ascertain their impact on the doses. Finally two scenario changes are modelled somewhat simplistically, these consider different prevailing climates, namely tundra and a warmer climate than present. In the base case negligibly low doses to man in the long term, resulting from the existence of a HLW repository have been calculated. Cs-135 results in the largest dose (8.4x10-7 mrem/y at 6.1x106 y) while Np-237 gives the largest dose from the actinides (3.6x10-8 mrem/y). The response of the model to parameter variations cannot be easily predicted due to non-linear coupling of many of the parameters. However, the calculated doses were negligibly low in all cases as were those resulting from the two scenario variations. (author)

  3. Radionuclide transport and dose assessment modelling in biosphere assessment 2009

    International Nuclear Information System (INIS)

    Following the guidelines set forth by the Ministry of Trade and Industry (now Ministry of Employment and Economy), Posiva is preparing to submit a construction license application for the final disposal spent nuclear fuel at the Olkiluoto site, Finland, by the end of the year 2012. Disposal will take place in a geological repository implemented according to the KBS-3 method. The long-term safety section supporting the license application will be based on a safety case that, according to the internationally adopted definition, will be a compilation of the evidence, analyses and arguments that quantify and substantiate the safety and the level of expert confidence in the safety of the planned repository. This report documents in detail the conceptual and mathematical models and key data used in the landscape model set-up, radionuclide transport modelling, and radiological consequences analysis applied in the 2009 biosphere assessment. Resulting environmental activity concentrations in landscape model due to constant unit geosphere release rates, and the corresponding annual doses, are also calculated and presented in this report. This provides the basis for understanding the behaviour of the applied landscape model and subsequent dose calculations. (orig.)

  4. Models for dose assessments. Modules for various biosphere types

    International Nuclear Information System (INIS)

    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

  5. 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

  6. Frozen soil parameterization in a distributed biosphere hydrological model

    OpenAIRE

    Wang, L.; Koike, T; Yang, K.; Jin, R.; Li, H.

    2010-01-01

    In this study, a frozen soil parameterization has been modified and incorporated into a distributed biosphere hydrological model (WEB-DHM). The WEB-DHM with the frozen scheme was then rigorously evaluated in a small cold area, the Binngou watershed, against the in-situ observations from the WATER (Watershed Allied Telemetry Experimental Research). First, by using the original WEB-DHM without the frozen scheme, the land surface parameters and two van Genuchten parameters were optimized using t...

  7. 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)

    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)

  8. A computational framework for a database of terrestrial biosphere models

    Science.gov (United States)

    Metzler, Holger; Müller, Markus; Ceballos-Núñez, Verónika; Sierra, Carlos A.

    2016-04-01

    Most terrestrial biosphere models consist of a set of coupled ordinary first order differential equations. Each equation represents a pool containing carbon with a certain turnover rate. Although such models share some basic mathematical structures, they can have very different properties such as number of pools, cycling rates, and internal fluxes. We present a computational framework that helps analyze the structure and behavior of terrestrial biosphere models using as an example the process of soil organic matter decomposition. The same framework can also be used for other sub-processes such as carbon fixation or allocation. First, the models have to be fed into a database consisting of simple text files with a common structure. Then they are read in using Python and transformed into an internal 'Model Class' that can be used to automatically create an overview stating the model's structure, state variables, internal and external fluxes. SymPy, a Python library for symbolic mathematics, helps to also calculate the Jacobian matrix at possibly given steady states and the eigenvalues of this matrix. If complete parameter sets are available, the model can also be run using R to simulate its behavior under certain conditions and to support a deeper stability analysis. In this case, the framework is also able to provide phase-plane plots if appropriate. Furthermore, an overview of all the models in the database can be given to help identify their similarities and differences.

  9. 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

    to the water column, which may lead to significantly higher doses than indicated by the SKB models. It is recommended that alternative groundwater discharge and system evolution models should therefore be considered in future assessments. It is also recommended that care should be taken to ensure that releases from the geosphere to the biosphere are represented in a consistent manner, based on careful integration of processes at the interface.

  10. Analysis of Critical Issues in Biosphere Assessment Modelling and Site Investigation

    International Nuclear Information System (INIS)

    , which may lead to significantly higher doses than indicated by the SKB models. It is recommended that alternative groundwater discharge and system evolution models should therefore be considered in future assessments. It is also recommended that care should be taken to ensure that releases from the geosphere to the biosphere are represented in a consistent manner, based on careful integration of processes at the interface

  11. 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

  12. Influence of biosphere modelling on the results of performance assessments of deep geological disposal. Lessons learnt from the SPT project

    International Nuclear Information System (INIS)

    The proposed paper is based on the work achieved by the participants to the Spent fuel Performance Assessment (SPA) project under the co-ordination of IPSN. Devoted to performance analyses of geological disposal of spent fuel, the project had notably the objective to evaluate long-term radiological impacts and therefore required to identify hypothetical critical groups and model environment transfer. Because of the uncertainties linked with future human behaviour and biosphere long-term evolution but also because of natural variability, a wide range of assumptions and data are generally possible to model biosphere transfer. Accordingly biosphere modelling can greatly vary from one assessment to another and radiological impact assessment results can possibly be significantly affected. In order to clarify this aspect, a cross comparison of the different approaches used within the SPA project was made. The first step of the comparison consisted in a general description of the different biospheres used in the performance assessment calculations. This description included the identification of the source of contamination, the environmental transfer pathways and the exposed group. In a second step, a comparison of biosphere conversion factors derived from biosphere calculations by prescribing a constant unit input, was done for a selection of 13 fission and activation products and 19 transuranic isotopes. In order to trace back the origin of the existing discrepancies, a set of 6 simplified parameters was then defined by aggregating the many different and specific parameters used by each participant. These common set of parameters enabled to compare separately the behavior of each of the environmental compartments and exposure pathways usually involved in biosphere calculations (soil, plant, farm, animal, fish and external exposure). The main conclusion drawn from the first step is a clear distinction between an utmost simplified 'water drinking' biosphere modelling

  13. 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)

    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.)

  14. '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)

    International Nuclear Information System (INIS)

    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

  15. Frozen soil parameterization in a distributed biosphere hydrological model

    Directory of Open Access Journals (Sweden)

    L. Wang

    2009-11-01

    Full Text Available In this study, a frozen soil parameterization has been modified and incorporated into a distributed biosphere hydrological model (WEB-DHM. The WEB-DHM with the frozen scheme was then rigorously evaluated in a small cold area, the Binngou watershed, against the in-situ observations from the WATER (Watershed Allied Telemetry Experimental Research. In the summer 2008, land surface parameters were optimized using the observed surface radiation fluxes and the soil temperature profile at the Dadongshu-Yakou (DY station in July; and then soil hydraulic parameters were obtained by the calibration of the July soil moisture profile at the DY station and by the calibration of the discharges at the basin outlet in July and August that covers the annual largest flood peak of 2008. The calibrated WEB-DHM with the frozen scheme was then used for a yearlong simulation from 21 November 2007 to 20 November 2008, to check its performance in cold seasons. Results showed that the WEB-DHM with the frozen scheme has given much better performance than the WEB-DHM without the frozen scheme, in the simulations of soil moisture profile at the DY station and the discharges at the basin outlet in the yearlong simulation.

  16. Frozen soil parameterization in a distributed biosphere hydrological model

    Directory of Open Access Journals (Sweden)

    L. Wang

    2010-03-01

    Full Text Available In this study, a frozen soil parameterization has been modified and incorporated into a distributed biosphere hydrological model (WEB-DHM. The WEB-DHM with the frozen scheme was then rigorously evaluated in a small cold area, the Binngou watershed, against the in-situ observations from the WATER (Watershed Allied Telemetry Experimental Research. First, by using the original WEB-DHM without the frozen scheme, the land surface parameters and two van Genuchten parameters were optimized using the observed surface radiation fluxes and the soil moistures at upper layers (5, 10 and 20 cm depths at the DY station in July. Second, by using the WEB-DHM with the frozen scheme, two frozen soil parameters were calibrated using the observed soil temperature at 5 cm depth at the DY station from 21 November 2007 to 20 April 2008; while the other soil hydraulic parameters were optimized by the calibration of the discharges at the basin outlet in July and August that covers the annual largest flood peak in 2008. With these calibrated parameters, the WEB-DHM with the frozen scheme was then used for a yearlong validation from 21 November 2007 to 20 November 2008. Results showed that the WEB-DHM with the frozen scheme has given much better performance than the WEB-DHM without the frozen scheme, in the simulations of soil moisture profile at the cold regions catchment and the discharges at the basin outlet in the yearlong simulation.

  17. Multi-model analysis of terrestrial carbon cycles in Japan: reducing uncertainties in model outputs among different terrestrial biosphere models using flux observations

    Directory of Open Access Journals (Sweden)

    K. Ichii

    2009-08-01

    Full Text Available Terrestrial biosphere models show large uncertainties when simulating carbon and water cycles, and reducing these uncertainties is a priority for developing more accurate estimates of both terrestrial ecosystem statuses and future climate changes. To reduce uncertainties and improve the understanding of these carbon budgets, we investigated the ability of 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 flux sites in Japan and (2 spatial simulations for Japan with a default model (based on original settings and an improved model (based on calibration using flux observations. 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 flux observations (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, and model calibration using flux observations significantly improved the model outputs. These results show that to reduce uncertainties among terrestrial biosphere models, we need to conduct careful validation and calibration with available flux observations. Flux observation data significantly improved terrestrial biosphere models, not only on a point scale but also on spatial scales.

  18. Evaluating the Carbon Cycle of a Coupled Atmosphere-Biosphere Model

    Energy Technology Data Exchange (ETDEWEB)

    Delire, C; Foley, J A; Thompson, S

    2002-08-21

    We investigate how well a coupled biosphere-atmosphere model, CCM3-IBIS, can simulate the functioning of the terrestrial biosphere and the carbon cycling through it. The simulated climate is compared to observations, while the vegetation cover and the carbon cycle are compared to an offline version of the biosphere model IBIS forced with observed climatic variables. The simulated climate presents some local biases that strongly affect the vegetation (e.g., a misrepresentation of the African monsoon). Compared to the offline model, the coupled model simulates well the globally averaged carbon fluxes and vegetation pools. The zonal mean carbon fluxes and the zonal mean seasonal cycle are also well represented except between 0{sup o} and 20{sup o}N due to the misrepresentation of the African monsoon. These results suggest that, despite regional biases in climate and ecosystem simulations, this coupled atmosphere-biosphere model can be used to explore geographic and temporal variations in the global carbon cycle.

  19. Root structural and functional dynamics in terrestrial biosphere models--evaluation and recommendations.

    Science.gov (United States)

    Warren, Jeffrey M; Hanson, Paul J; Iversen, Colleen M; Kumar, Jitendra; Walker, Anthony P; Wullschleger, Stan D

    2015-01-01

    There is wide breadth of root function within ecosystems that should be considered when modeling the terrestrial biosphere. Root structure and function are closely associated with control of plant water and nutrient uptake from the soil, plant carbon (C) assimilation, partitioning and release to the soils, and control of biogeochemical cycles through interactions within the rhizosphere. Root function is extremely dynamic and dependent on internal plant signals, root traits and morphology, and the physical, chemical and biotic soil environment. While plant roots have significant structural and functional plasticity to changing environmental conditions, their dynamics are noticeably absent from the land component of process-based Earth system models used to simulate global biogeochemical cycling. Their dynamic representation in large-scale models should improve model veracity. Here, we describe current root inclusion in models across scales, ranging from mechanistic processes of single roots to parameterized root processes operating at the landscape scale. With this foundation we discuss how existing and future root functional knowledge, new data compilation efforts, and novel modeling platforms can be leveraged to enhance root functionality in large-scale terrestrial biosphere models by improving parameterization within models, and introducing new components such as dynamic root distribution and root functional traits linked to resource extraction.

  20. 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

  1. 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

  2. Biosphere modeling with climate changes for safety assessment of high-level radioactive waste geological isolation

    International Nuclear Information System (INIS)

    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 estimate the impacts, a biosphere model is developed by reasonably assuming radionuclide migration processes in the surface environment and relevant human lifestyles. Releases from the repository might not occur for many thousands of years after disposal. Over such timescales, it is anticipated that the considerable climatic change, for example, induced by the next glaciation period expected to occur in around ten thousand years from now, will have a significant influence on the near surface environment and associated human lifestyles. In case of taking these evolution effects into account in modeling, it is reasonable to develop several alternative models on biosphere evolution systems consistent with possible future conditions affected by expected climatic changes. In this study, alternative biosphere models were developed taking effects of possible climatic change into account. In the modeling, different climatic states existing in the world from the present climate condition in Japan are utilized as an analogy. Estimation of net effects of the climatic change on biosphere system was made by comparing these alternative biosphere models with a constant biosphere model consistent with the present climatic state through flux to dose conversion factors derived from each one. (author)

  3. Confronting terrestrial biosphere models with forest inventory data.

    Science.gov (United States)

    Lichstein, Jeremy W; Golaz, Ni-Zhang; Malyshev, Sergey; Shevliakova, Elena; Zhang, Tao; Sheffield, Justin; Birdsey, Richard A; Sarmiento, Jorge L; Pacala, Stephen W

    2014-06-01

    Efforts to test and improve terrestrial biosphere models (TBMs) using a variety of data sources have become increasingly common. Yet, geographically extensive forest inventories have been under-exploited in previous model-data fusion efforts. Inventory observations of forest growth, mortality, and biomass integrate processes across a range of timescales, including slow timescale processes such as species turnover, that are likely to have important effects on ecosystem responses to environmental variation. However, the large number (thousands) of inventory plots precludes detailed measurements at each location, so that uncertainty in climate, soil properties, and other environmental drivers may be large. Errors in driver variables, if ignored, introduce bias into model-data fusion. We estimated errors in climate and soil drivers at U.S. Forest Inventory and Analysis (FIA) plots, and we explored the effects of these errors on model-data fusion with the Geophysical Fluid Dynamics Laboratory LM3V dynamic global vegetation model. When driver errors were ignored or assumed small at FIA plots, responses of biomass production in LM3V to precipitation and soil available water capacity appeared steeper than the corresponding responses estimated from FIA data. These differences became nonsignificant if driver errors at FIA plots were assumed to be large. Ignoring driver errors when optimizing LM3V parameter values yielded estimates for fine-root allocation that were larger than biometric estimates, which is consistent with the expected direction of bias. To explore whether complications posed by driver errors could be circumvented by relying on intensive study sites where driver errors are small, we performed a power analysis. To accurately quantify the response of biomass production to spatial variation in mean annual precipitation within the eastern United States would require at least 40 intensive study sites, which is larger than the number of sites typically available

  4. Capturing Vegetation Diversity in the Ent Terrestrial Biosphere Model

    Science.gov (United States)

    Kiang, N. Y.; Haralick, R. M.; Cook, B.; Aleinov, I. D.

    2013-12-01

    We present preliminary results from data mining to develop parameter sets and global vegetation structure datasets to set boundary conditions for the Ent Terrestrial Biosphere Model (Ent TBM) for improved representation of diversity and to propagate uncertainty in simulations of land carbon dynamics in the 20th century and under future climate change. The Ent TBM is the only dynamic global vegetation model (DGVM) developed for coupling with general circulation models (GCMs) to account for the height structure of mixed canopies, including a canopy radiative transfer scheme that accounts for foliage clumping in dynamically changing canopies. It is flexibly programmed to incorporate any number of "plant functional types" (PFTs). It is now a coupled component of the ModelE2 version of the NASA Goddard Institute for Space Studies (GISS) general circulation model (GCM). We demonstrate a data mining method, linear manifold clustering, to be used with several very recently compiled large databases of plant traits and phenology combined with climate and satellite data, to identify new PFT groupings, and also conduct customized parameter fits of PFT traits already defined in Ent. These parameter sets are used together with satellite-derived global forest height structure and land cover derived from a combination of satellite and inventory sources and bioclimatic relations to provide a new estimate and uncertainty bounds on vegetation biomass carbon stocks. These parameter sets will also be used to reproduce atmospheric CO2 time series over the flask observational period, to evaluate the impact of improved representation of vegetation dynamics on soil carbon stocks, and finally to produce a projection of the land carbon sink under future climate change. This research is timely in taking advantage of new, globally ranging vegetation databases, satellite-derived forest heights, and the advanced framework of the Ent TBM. It will advance understanding of and reduce uncertainty in

  5. Confronting terrestrial biosphere models with forest inventory data.

    Science.gov (United States)

    Lichstein, Jeremy W; Golaz, Ni-Zhang; Malyshev, Sergey; Shevliakova, Elena; Zhang, Tao; Sheffield, Justin; Birdsey, Richard A; Sarmiento, Jorge L; Pacala, Stephen W

    2014-06-01

    Efforts to test and improve terrestrial biosphere models (TBMs) using a variety of data sources have become increasingly common. Yet, geographically extensive forest inventories have been under-exploited in previous model-data fusion efforts. Inventory observations of forest growth, mortality, and biomass integrate processes across a range of timescales, including slow timescale processes such as species turnover, that are likely to have important effects on ecosystem responses to environmental variation. However, the large number (thousands) of inventory plots precludes detailed measurements at each location, so that uncertainty in climate, soil properties, and other environmental drivers may be large. Errors in driver variables, if ignored, introduce bias into model-data fusion. We estimated errors in climate and soil drivers at U.S. Forest Inventory and Analysis (FIA) plots, and we explored the effects of these errors on model-data fusion with the Geophysical Fluid Dynamics Laboratory LM3V dynamic global vegetation model. When driver errors were ignored or assumed small at FIA plots, responses of biomass production in LM3V to precipitation and soil available water capacity appeared steeper than the corresponding responses estimated from FIA data. These differences became nonsignificant if driver errors at FIA plots were assumed to be large. Ignoring driver errors when optimizing LM3V parameter values yielded estimates for fine-root allocation that were larger than biometric estimates, which is consistent with the expected direction of bias. To explore whether complications posed by driver errors could be circumvented by relying on intensive study sites where driver errors are small, we performed a power analysis. To accurately quantify the response of biomass production to spatial variation in mean annual precipitation within the eastern United States would require at least 40 intensive study sites, which is larger than the number of sites typically available

  6. 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.

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

    Science.gov (United States)

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

    1992-01-01

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

  8. Illstrative probabilistic biosphere model for Yucca Mountain individual risk calculations

    International Nuclear Information System (INIS)

    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

  9. 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.

  10. Modeling the global society-biosphere-climate system. Part 2: computed scenarios

    International Nuclear Information System (INIS)

    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 concentrations of gases, temperature, precipitation, land cover and other indicators. Included are a 'Conventional Wisdom' scenario, and three variations of this scenario: (i) the Conventional Wisdom scenario is a reference case which is partly based on the input assumptions of the IPCC's IS92a scenario; (ii) the 'Biofuel Crops' scenario assumes that most biofuels will be derived from new cropland; (iii) the 'No Biofuels' scenario examines the sensitivity of the system to the use of biofuels; and (iv) the 'Ocean Realignment' scenario investigates the effect of a large-scale change in ocean circulation on the biosphere and climate. Results of the biofuel scenarios illustrate the importance of examining the impact of biofuels on the full range of greenhouse gases, rather than only CO2. These scenarios also indicate possible side effects of the land requirements for energy crops. The Ocean Realignment scenario shows that an unexpected, low probability event can both enhance the build-up of greenhouse gases, and at the same time cause a temporary cooling of surface air temperatures in the Northern Hemisphere. However, warming of the atmosphere is only delayed, not avoided. 26 refs., 16 figs., 7 tabs

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

    International Nuclear Information System (INIS)

    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

  12. Biosphere modeling for safety assessment of high-level radioactive waste geological disposal

    Energy Technology Data Exchange (ETDEWEB)

    Baba, T.; Ishihara, Y.; Ishiguro, K. [Japan Nuclear Cycle Development Inst., Waste Management and Fuel Cycle Research Center, Tokai Works, Tokai, Ibaraki (Japan); Suzuki, Y. [Nuclear Energy System Incorporated, Tokyo (Japan); Naito, M. [Japan Nuclear Cycle Development Inst., Geological Isolation Research Project, Tokai, Ibaraki (Japan); Ikeda, T. [Japan Gas Corporation, Tokyo (Japan); Little, R. [QuantiSci Ltd, Henley-on-Thames, Oxon (United Kingdom)

    1999-11-01

    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, some specific reference biospheres' are developed using an approach consistent with the BIOMOVS II reference biosphere methodology. The models represent the components of the surface environment using compartments between which fluxes of materials (solid/water) and radionuclides are defined by transfer factors. A range of exposure pathways via which such radionuclides enter the food-chain, along with uptake and concentration factors, are also defined. The response to a step function of unit flux from the geosphere is determined for each model. The results show that it is reasonable to use steady-state biosphere responses to a unit-input flux to define nuclide-dependent factors for converting fluxes from the geosphere to doses. This simplifies safety assessment calculations, which then require only look-up tables for such flux to dose conversion rather than fully coupled biosphere models. (author)

  13. The Effects of Recreation Experience, Environmental Attitude, and Biospheric Value on the Environmentally Responsible Behavior of Nature-Based Tourists

    Science.gov (United States)

    Lee, Tsung Hung; Jan, Fen-Hauh

    2015-07-01

    The scientific understanding of the recreation experience and the environmentally responsible behavior of nature-based tourists is limited. This study examines the relationship among the recreation experience, environmental attitude, biospheric value, and the general and site-specific environmentally responsible behavior of nature-based tourists in Taomi, Liuqiu Island, and Aowanda and Najenshan in Taiwan. A total of 1342 usable questionnaires were collected for this study. The empirical results indicate that the recreation experience influences biospheric value and environmental attitude; subsequently, it then indirectly influences the general and site-specific environmentally responsible behavior of nature-based tourists. Our theoretical behavioral model elucidates previously proposed but unexamined behavioral models among nature-based tourists, and it offers a theoretical framework for researchers, decision makers, managers, and tourists in the field of nature-based tourism. We conclude that when an individual participates in nature-based tourism as described here, these recreation experiences strengthen their environmental attitude and biospheric value, and consequently increase their engagement in both general and site-specific environmentally responsible behaviors.

  14. The effects of recreation experience, environmental attitude, and biospheric value on the environmentally responsible behavior of nature-based tourists.

    Science.gov (United States)

    Lee, Tsung Hung; Jan, Fen-Hauh

    2015-07-01

    The scientific understanding of the recreation experience and the environmentally responsible behavior of nature-based tourists is limited. This study examines the relationship among the recreation experience, environmental attitude, biospheric value, and the general and site-specific environmentally responsible behavior of nature-based tourists in Taomi, Liuqiu Island, and Aowanda and Najenshan in Taiwan. A total of 1342 usable questionnaires were collected for this study. The empirical results indicate that the recreation experience influences biospheric value and environmental attitude; subsequently, it then indirectly influences the general and site-specific environmentally responsible behavior of nature-based tourists. Our theoretical behavioral model elucidates previously proposed but unexamined behavioral models among nature-based tourists, and it offers a theoretical framework for researchers, decision makers, managers, and tourists in the field of nature-based tourism. We conclude that when an individual participates in nature-based tourism as described here, these recreation experiences strengthen their environmental attitude and biospheric value, and consequently increase their engagement in both general and site-specific environmentally responsible behaviors.

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

    Directory of Open Access Journals (Sweden)

    M. Krapp

    2011-06-01

    Full Text Available We present simulations with a coupled ocean-atmosphere-biosphere model for the Middle Miocene 15 million years ago. 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, thereby matching proxy-based Middle Miocene global temperature estimates of 3–6 K warming. Higher CO2 levels and the associated water vapour feedback enhance the greenhouse effect and lead to a polar amplification of the warming. Although oceanic and atmospheric poleward heat transport are individually altered by 10–30 % in the mid and high latitudes, changes of the total heat transport account only for 4–8 %, pointing toward a compensation between oceanic and atmospheric heat transport. Our model reproduces a denser vegetation in agreement with fossil records. These results suggest that higher than present-day CO2 levels are essential to drive the warm Middle Miocene climate.

  16. The Biosphere International Peer Review

    International Nuclear Information System (INIS)

    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

  17. 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

    degree of warming varied between 2.2 days °C−1 and 5.2 days °C−1 depending on model structure.

    We quantified the impact of uncertainties in bud-burst forecasts on simulated photosynthetic CO2 uptake and evapotranspiration (ET using a process-based terrestrial biosphere model. Uncertainty in phenology model structure led to uncertainty in the description of forest seasonality, which accumulated to uncertainty in annual model estimates of gross primary productivity (GPP and ET of 9.6% and 2.9%, respectively. A sensitivity analysis shows that a variation of ±10 days in bud-burst dates led to a variation of ±5.0% for annual GPP and about ±2.0% for ET.

    For phenology models, differences among future climate scenarios (i.e. driver represent the largest source of uncertainty, followed by uncertainties related to model structure, and finally, related to model parameterization. The uncertainties we have quantified will affect the description of the seasonality of ecosystem processes and in particular the simulation of carbon uptake by forest ecosystems, with a larger impact of uncertainties related to phenology model structure, followed by uncertainties related to phenological model parameterization.

  18. 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 concent

  19. 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

  20. Observation-based global biospheric excess radiocarbon inventory 1963-2005

    Science.gov (United States)

    Naegler, Tobias; Levin, Ingeborg

    2009-09-01

    For the very first time, we present an observation-based estimate of the temporal development of the biospheric excess radiocarbon (14C) inventory IB14,E, i.e., the change in the biospheric 14C inventory relative to prebomb times (1940s). IB14,E was calculated for the period 1963-2005 with a simple budget approach as the difference between the accumulated excess 14C production by atmospheric nuclear bomb tests and the nuclear industry and observation-based reconstructions of the excess 14C inventories in the atmosphere and the ocean. IB14,E increased from the late 1950s onward to maximum values between 126 and 177 × 1026 atoms 14C between 1981 and 1985. In the early 1980s, the biosphere turned from a sink to a source of excess 14C. Consequently, IB14,E decreased to values of 108-167 × 1026 atoms 14C in 2005. The uncertainty of IB14,E is dominated by uncertainties in the total bomb 14C production and the oceanic excess 14C inventory. Unfortunately, atmospheric Δ14CO2 from the early 1980s lack the necessary precision to reveal the expected small change in the amplitude and phase of atmospheric Δ14C seasonal cycle due to the sign flip in the biospheric net 14C flux during that time.

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

    International Nuclear Information System (INIS)

    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

  2. Additional Research Needs to Support the GENII Biosphere Models

    Energy Technology Data Exchange (ETDEWEB)

    Napier, Bruce A.; Snyder, Sandra F.; Arimescu, Carmen

    2013-11-30

    In the course of evaluating the current parameter needs for the GENII Version 2 code (Snyder et al. 2013), areas of possible improvement for both the data and the underlying models have been identified. As the data review was implemented, PNNL staff identified areas where the models can be improved both to accommodate the locally significant pathways identified and also to incorporate newer models. The areas are general data needs for the existing models and improved formulations for the pathway models. It is recommended that priorities be set by NRC staff to guide selection of the most useful improvements in a cost-effective manner. Suggestions are made based on relatively easy and inexpensive changes, and longer-term more costly studies. In the short term, there are several improved model formulations that could be applied to the GENII suite of codes to make them more generally useful. • Implementation of the separation of the translocation and weathering processes • Implementation of an improved model for carbon-14 from non-atmospheric sources • Implementation of radon exposure pathways models • Development of a KML processor for the output report generator module data that are calculated on a grid that could be superimposed upon digital maps for easier presentation and display • Implementation of marine mammal models (manatees, seals, walrus, whales, etc.). Data needs in the longer term require extensive (and potentially expensive) research. Before picking any one radionuclide or food type, NRC staff should perform an in-house review of current and anticipated environmental analyses to select “dominant” radionuclides of interest to allow setting of cost-effective priorities for radionuclide- and pathway-specific research. These include • soil-to-plant uptake studies for oranges and other citrus fruits, and • Development of models for evaluation of radionuclide concentration in highly-processed foods such as oils and sugars. Finally, renewed

  3. 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

  4. On the uncertainty of phenological responses to climate change and its implication for terrestrial biosphere models

    Directory of Open Access Journals (Sweden)

    M. Migliavacca

    2012-01-01

    Full Text Available Phenology, the timing of recurring life cycle events, controls numerous land surface feedbacks to the climate systems through the regulation of exchanges of carbon, water and energy between the biosphere and atmosphere. Land surface 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 analyzed the Harvard Forest phenology record to investigate and characterize the sources of uncertainty in phenological forecasts and the subsequent impacts on model forecasts of carbon and water cycling in the future. Using a model-data fusion approach, we combined information from 20 yr of phenological observations of 11 North American woody species with 12 phenological models of different complexity to predict leaf bud-burst.

    The evaluation of different phenological models indicated support for spring warming models with photoperiod limitations and, though to a lesser extent, to chilling models based on the alternating model structure.

    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% CI: 2.4 day century−1 for scenario B1 and 4.5 day century−1 for A1fi, whereas driver uncertainty was the largest (up to 8.4 day 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 somewhat among models (±7.7 day century−1 for A1fi, ±3.6 day century−1 for B1. The forecast sensitivity of bud-burst to

  5. Water Management in the Camargue Biosphere Reserve: Insights from Comparative Mental Models Analysis

    Directory of Open Access Journals (Sweden)

    Coralie Calvet

    2011-03-01

    Full Text Available Mental models are the cognitive representations of the world that frame how people interact with the world. Learning implies changing these mental models. The successful management of complex social-ecological systems requires the coordination of actions to achieve shared goals. The coordination of actions requires a level of shared understanding of the system or situation; a shared or common mental model. We first describe the elicitation and analysis of mental models of different stakeholder groups associated with water management in the Camargue Biosphere Reserve in the Rhône River delta on the French Mediterranean coast. We use cultural consensus analysis to explore the degree to which different groups shared mental models of the whole system, of stakeholders, of resources, of processes, and of interactions among these last three. The analysis of the elicited data from this group structure enabled us to tentatively explore the evidence for learning in the nonstatute Water Board; comprising important stakeholders related to the management of the central Rhône delta. The results indicate that learning does occur and results in richer mental models that are more likely to be shared among group members. However, the results also show lower than expected levels of agreement with these consensual mental models. Based on this result, we argue that a careful process and facilitation design can greatly enhance the functioning of the participatory process in the Water Board. We conclude that this methodology holds promise for eliciting and comparing mental models. It enriches group-model building and participatory approaches with a broader view of social learning and knowledge-sharing issues.

  6. 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)

    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 TerrMaxAgri Case (maximum extent of agricultural areas and

  7. The biosphere at Aberg, Beberg and Ceberg - a description based on literature concerning climate, physical geography, ecology, land use and environment

    Energy Technology Data Exchange (ETDEWEB)

    Lindborg, T.; Schueldt, R. [NaturRaadet, (Sweden)

    1998-12-01

    The current safety analysis, SR 97, compares three sites in Sweden. This report compares the biosphere for the three areas, Aespoe, Finnsjoen and Gideaa, which have been studied to describe the conditions at three hypothetical sites, Aberg, Beberg and Ceberg. Data from these sites will be used in analysis and to make realistic models of the biosphere development. The report is based on a literature study considering climate, physical geography, vegetation, ecology, land use, environment and population. Data from each site is presented separately and is compared for present conditions and from a future perspective. The locations of the sites along the south-north gradient influences the climate, temperature, vegetation period and precipitation. Aberg has a more humid climate with a longer vegetation period, a higher mean temperature, a higher diversity and a faster turn-over time than Beberg and Ceberg. There is also a difference in land use, where Beberg has the greatest potential for agriculture, because of the soil types and topography. Abergs location in the archipelago makes it very exposed to shore level displacement, compared to Beberg and Ceberg with a higher elevation. The highest population density is found in Aberg, but Beberg has the highest potential for increase. Simplified models made from present and future biosphere conditions, show that the sites have different prerequisite concerning biosphere factors. The parameters that may affect the ecosystem and the biosphere over time are more likely to change in Aberg due to position above sea level, climate, sea level displacement and land use. Biosphere changes are however in a long time perspective hard to predict. The models used in this report are a suggestion on how to evaluate biological data in a more thorough study. 99 refs, 14 figs, 31 tabs

  8. The biosphere at Aberg, Beberg and Ceberg - a description based on literature concerning climate, physical geography, ecology, land use and environment

    International Nuclear Information System (INIS)

    The current safety analysis, SR 97, compares three sites in Sweden. This report compares the biosphere for the three areas, Aespoe, Finnsjoen and Gideaa, which have been studied to describe the conditions at three hypothetical sites, Aberg, Beberg and Ceberg. Data from these sites will be used in analysis and to make realistic models of the biosphere development. The report is based on a literature study considering climate, physical geography, vegetation, ecology, land use, environment and population. Data from each site is presented separately and is compared for present conditions and from a future perspective. The locations of the sites along the south-north gradient influences the climate, temperature, vegetation period and precipitation. Aberg has a more humid climate with a longer vegetation period, a higher mean temperature, a higher diversity and a faster turn-over time than Beberg and Ceberg. There is also a difference in land use, where Beberg has the greatest potential for agriculture, because of the soil types and topography. Abergs location in the archipelago makes it very exposed to shore level displacement, compared to Beberg and Ceberg with a higher elevation. The highest population density is found in Aberg, but Beberg has the highest potential for increase. Simplified models made from present and future biosphere conditions, show that the sites have different prerequisite concerning biosphere factors. The parameters that may affect the ecosystem and the biosphere over time are more likely to change in Aberg due to position above sea level, climate, sea level displacement and land use. Biosphere changes are however in a long time perspective hard to predict. The models used in this report are a suggestion on how to evaluate biological data in a more thorough study

  9. 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.

  10. Experience in biosphere modelling and definition of exposed groups. Concerns on consideration of the long-term

    International Nuclear Information System (INIS)

    The long life of high level waste and their 'possible' releases, from the repository, in the far future during wide time frames, introduce difficulties on the ability of forecasting actual doses. Similar difficulties were found when trying to establish or recommend protection criteria for the environment and human health. The stochastic nature of the whole problem, from the causes that initiate radionuclides releases to the nature of the environmental conditions where impact is evaluated, made more complex the treatment of the radionuclide transport models and the analysis of radiological impact. The application of radiological protection principles to this management option, was also seen as different from other present-day practices. All this gave rise to the diversification of the research lines towards new areas that allow for the analysis of radionuclide transport, dose calculations and, criteria, in this new situation. The approach for the biosphere system based on the 'reference' concept, in essence the same idea as the one for the 'Reference man' concept, was promoted internationally, first within the BIOMOVS II Project and, afterwards, in the BIOMASS IAEA Programme. In parallel to the participation in these Projects and based on their conclusions, CIEMAT has been developing for ENRESA a methodology, which has to be updated and completed with recent developments from BIOMASS-Theme1. Notably, for the Justification and Identification step, the Description of Critical Groups and the use of the Data protocol. An application of this methodology was performed and published in 1998 and, its results and conclusions are summarised in the paper. Also, the paper includes main conclusions from the biosphere modelling applied in the last ENRESA2000 Spanish PA exercise and, difficulties found in the consistency between the scenario generation procedure, the treatment of the interface and the source term and, the use of the reference biosphere concept. (author)

  11. Consideration of climate changes in biosphere modelling for performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Semioshkina, Nathascha; Staudt, Christian; Kaiser, Christian [Helmholtz Zentrum Muenchen Deutsches Forschungszentrum fuer Gesundheit und Umwelt GmbH, Neuherberg (Germany); Proehl, Gerhard; Fahrenholz, Christine; Noseck, Ulrich [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koeln (Germany)

    2012-12-15

    The assessment of the long-term safety of a repository for radioactive or hazardous waste and therewith the development of a safety case requires a comprehensive system understanding, a continuous development of the methods of a safety case and capable and qualified numerical tools. The objective of the project ''Scientific basis for the assessment of the long-term safety of repositories'', identification number 02 E 10548, was to follow national and international developments in this area, to evaluate research projects, which contribute to knowledge, model approaches and data, and to perform specific investigations to improve the methodologies of the safety case and the long-term safety assessment.

  12. A Distributed Biosphere-Hydrological Model System for Continental Scale River Basins

    Science.gov (United States)

    Tang, Q.; Oki, T.; Kanae, S.; Hu, H.

    2006-12-01

    A new generation hydrological model, Distributed Biosphere-Hydrological (DBH) Model, is developed to connect hydrological cycle with biosphere, climate system and human society. The vegetated surface is calculated by a realistic land surface model SiB2. The hydrological part estimates the surface runoff and calculates the interlayer exchanges and interaction between soil water and groundwater. It physically represents hydrological cycle with the support of nontraditional datasets. With the new generation model, the scope of hydrology will broaden from rainfall-runoff relationship to climatology, biosphere, ecosystem, remote sensing, and human society. The model can demonstrate the effects of natural and anthropogenic heterogeneity on hydrological cycle. The effects on hydrological responses of precipitation variability and the variability on irrigation redistributing runoff, was investigated. Runoff is underestimated if the rainfall is spatially uniformly put on large grid cell. Runoff simulation could be improved by taking into account the precipitation heterogeneity. However, the negative runoff contribution cannot be simulated by only considering the natural heterogeneity. This constructive model shortcoming can be eliminated by taking into account anthropogenic heterogeneity. The model is used to interpret the Yellow River drying up phenomenon in China. Scenarios are performed from 1960 to 2000 to quantify the effect of human activity, and to distinguish it from the effect from climate change. The results show climate change is dominated in the upper and middle reaches, and human activity is dominated in the lower reaches. The river discharge nearly half is affected by climate change and half by human activities. Climate pattern change rather than linear change contributes to the decrease of stream flow in the Yellow River.

  13. A global model of carbon, nitrogen and phosphorus cycles for the terrestrial biosphere

    Directory of Open Access Journals (Sweden)

    Y. P. Wang

    2009-10-01

    Full Text Available Carbon storage by many terrestrial ecosystems can be limited by nutrients, predominantly nitrogen (N and phosphorous (P, in additional to other environmental constraints, water, light and temperature. However the spatial distribution and the extent of both N and P limitation at global scale have not been quantified. Here we have developed a global model of carbon (C, nitrogen (N and phosphorus (P cycles for the terrestrial biosphere. Model estimates of steady state C and N pool sizes and major fluxes between plant, litter and soil pools, under present climate conditions, agree well with various independent estimates. The total amount of C in the terrestrial biosphere is 2526 Gt C, and the C fractions in plant, litter and soil organic matter are 21, 6 and 73%. The total amount of N is 124 Gt N, with about 94% stored in the soil, 5% in the plant live biomass, and 1% in litter. We found that the estimates of total soil P and its partitioning into different pools in soil are quite sensitive to biochemical P mineralization that has not been included in any other global models previously. The total amount of P is 26 Gt P in the terrestrial biosphere, 17% of which is stored in the soil organic matter if biochemical P mineralization is modelled, or 40 Gt P, with 60% in soil organic matter, otherwise.

    This model was used to derive the global distribution of N or P limitation on the productivity of terrestrial ecosystems. Our model predicts that the net primary productivity of most tropical evergreen broadleaf forests and tropical savannahs is reduced by about 20% on average by P limitation, and most of the remaining biomes are N limited; N limitation is strongest in high latitude deciduous needle leaf forests, and reduces its net primary productivity by up to 40% under present conditions.

  14. A global model of carbon, nitrogen and phosphorus cycles for the terrestrial biosphere

    Directory of Open Access Journals (Sweden)

    Y. P. Wang

    2010-07-01

    Full Text Available Carbon storage by many terrestrial ecosystems can be limited by nutrients, predominantly nitrogen (N and phosphorus (P, in addition to other environmental constraints, water, light and temperature. However the spatial distribution and the extent of both N and P limitation at the global scale have not been quantified. Here we have developed a global model of carbon (C, nitrogen (N and phosphorus (P cycles for the terrestrial biosphere. Model estimates of steady state C and N pool sizes and major fluxes between plant, litter and soil pools, under present climate conditions, agree well with various independent estimates. The total amount of C in the terrestrial biosphere is 2767 Gt C, and the C fractions in plant, litter and soil organic matter are 19%, 4% and 77%. The total amount of N is 135 Gt N, with about 94% stored in the soil, 5% in the plant live biomass, and 1% in litter. We found that the estimates of total soil P and its partitioning into different pools in soil are quite sensitive to biochemical P mineralization. The total amount of P (plant biomass, litter and soil excluding occluded P in soil is 17 Gt P in the terrestrial biosphere, 33% of which is stored in the soil organic matter if biochemical P mineralization is modelled, or 31 Gt P with 67% in soil organic matter otherwise.

    This model was used to derive the global distribution and uncertainty of N or P limitation on the productivity of terrestrial ecosystems at steady state under present conditions. Our model estimates that the net primary productivity of most tropical evergreen broadleaf forests and tropical savannahs is reduced by about 20% on average by P limitation, and most of the remaining biomes are N limited; N limitation is strongest in high latitude deciduous needle leaf forests, and reduces its net primary productivity by up to 40% under present conditions.

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

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange

    Directory of Open Access Journals (Sweden)

    C. R. Flechard

    2013-07-01

    Full Text Available Atmospheric ammonia (NH3 dominates global emissions of total reactive nitrogen (Nr, while emissions from agricultural production systems contribute about two-thirds of global NH3 emissions; the remaining third emanates from oceans, natural vegetation, humans, wild animals and biomass burning. On land, NH3 emitted from the various sources eventually returns to the biosphere by dry deposition to sink areas, predominantly semi-natural vegetation, and by wet and dry deposition as ammonium (NH4+ to all surfaces. However, the land/atmosphere exchange of gaseous NH3 is in fact bi-directional over unfertilized as well as fertilized ecosystems, with periods and areas of emission and deposition alternating in time (diurnal, seasonal and space (patchwork landscapes. The exchange is controlled by a range of environmental factors, including meteorology, surface layer turbulence, thermodynamics, air and surface heterogeneous-phase chemistry, canopy geometry, plant development stage, leaf age, organic matter decomposition, soil microbial turnover, and, in agricultural systems, by fertilizer application rate, fertilizer type, soil type, crop type, and agricultural management practices. We review the range of processes controlling NH3 emission and uptake in the different parts of the soil-canopy-atmosphere continuum, with NH3 emission potentials defined at the substrate and leaf levels by different [NH4+] / [H+] ratios (Γ. Surface/atmosphere exchange models for NH3 are necessary to compute the temporal and spatial patterns of emissions and deposition at the soil, plant, field, landscape, regional and global scales, in order to assess the multiple environmental impacts of airborne and deposited NH3 and NH4+. Models of soil/vegetation/atmosphere NH3 exchange are reviewed from the substrate and leaf scales to the global scale. They range from simple steady-state, "big leaf" canopy resistance models, to dynamic, multi-layer, multi-process, multi

  18. Advances in understanding, models and parameterisations of biosphere-atmosphere ammonia exchange

    Science.gov (United States)

    Flechard, C. R.; Massad, R.-S.; Loubet, B.; Personne, E.; Simpson, D.; Bash, J. O.; Cooter, E. J.; Nemitz, E.; Sutton, M. A.

    2013-03-01

    Atmospheric ammonia (NH3) dominates global emissions of total reactive nitrogen (Nr), while emissions from agricultural production systems contribute about two thirds of global NH3 emissions; the remaining third emanates from oceans, natural vegetation, humans, wild animals and biomass burning. On land, NH3 emitted from the various sources eventually returns to the biosphere by dry deposition to sink areas, predominantly semi-natural vegetation, and by wet and dry deposition as ammonium (NH4+) to all surfaces. However, the land/atmosphere exchange of gaseous NH3 is in fact bi-directional over unfertilized as well as fertilized ecosystems, with periods and areas of emission and deposition alternating in time (diurnal, seasonal) and space (patchwork landscapes). The exchange is controlled by a range of environmental factors, including meteorology, surface layer turbulence, thermodynamics, air and surface heterogeneous-phase chemistry, canopy geometry, plant development stage, leaf age, organic matter decomposition, soil microbial turnover, and, in agricultural systems, by fertilizer application rate, fertilizer type, soil type, crop type, and agricultural management practices. We review the range of processes controlling NH3 emission and uptake in the different parts of the soil-canopy-atmosphere continuum, with NH3 emission potentials defined at the substrate and leaf levels by different [NH4+] / [H+] ratios (Γ). Surface/atmosphere exchange models for NH3 are necessary to compute the temporal and spatial patterns of emissions and deposition at the soil, plant, field, landscape, regional and global scales, in order to assess the multiple environmental impacts of air-borne and deposited NH3 and NH4+. Models of soil/vegetation/atmosphereem NH3 exchange are reviewed from the substrate and leaf scales to the global scale. They range from simple steady-state, "big leaf" canopy resistance models, to dynamic, multi-layer, multi-process, multi

  19. Advances in understanding, models and parameterisations of biosphere-atmosphere ammonia exchange

    Directory of Open Access Journals (Sweden)

    C. R. Flechard

    2013-03-01

    Full Text Available Atmospheric ammonia (NH3 dominates global emissions of total reactive nitrogen (Nr, while emissions from agricultural production systems contribute about two thirds of global NH3 emissions; the remaining third emanates from oceans, natural vegetation, humans, wild animals and biomass burning. On land, NH3 emitted from the various sources eventually returns to the biosphere by dry deposition to sink areas, predominantly semi-natural vegetation, and by wet and dry deposition as ammonium (NH4+ to all surfaces. However, the land/atmosphere exchange of gaseous NH3 is in fact bi-directional over unfertilized as well as fertilized ecosystems, with periods and areas of emission and deposition alternating in time (diurnal, seasonal and space (patchwork landscapes. The exchange is controlled by a range of environmental factors, including meteorology, surface layer turbulence, thermodynamics, air and surface heterogeneous-phase chemistry, canopy geometry, plant development stage, leaf age, organic matter decomposition, soil microbial turnover, and, in agricultural systems, by fertilizer application rate, fertilizer type, soil type, crop type, and agricultural management practices. We review the range of processes controlling NH3 emission and uptake in the different parts of the soil-canopy-atmosphere continuum, with NH3 emission potentials defined at the substrate and leaf levels by different [NH4+] / [H+] ratios (Γ. Surface/atmosphere exchange models for NH3 are necessary to compute the temporal and spatial patterns of emissions and deposition at the soil, plant, field, landscape, regional and global scales, in order to assess the multiple environmental impacts of air-borne and deposited NH3 and NH4+. Models of soil/vegetation/atmosphereem NH3 exchange are reviewed from the substrate and leaf scales to the global scale. They range from simple steady-state, "big leaf" canopy resistance models, to dynamic, multi-layer, multi

  20. Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange

    Science.gov (United States)

    Flechard, C. R.; Massad, R.-S.; Loubet, B.; Personne, E.; Simpson, D.; Bash, J. O.; Cooter, E. J.; Nemitz, E.; Sutton, M. A.

    2013-07-01

    Atmospheric ammonia (NH3) dominates global emissions of total reactive nitrogen (Nr), while emissions from agricultural production systems contribute about two-thirds of global NH3 emissions; the remaining third emanates from oceans, natural vegetation, humans, wild animals and biomass burning. On land, NH3 emitted from the various sources eventually returns to the biosphere by dry deposition to sink areas, predominantly semi-natural vegetation, and by wet and dry deposition as ammonium (NH4+) to all surfaces. However, the land/atmosphere exchange of gaseous NH3 is in fact bi-directional over unfertilized as well as fertilized ecosystems, with periods and areas of emission and deposition alternating in time (diurnal, seasonal) and space (patchwork landscapes). The exchange is controlled by a range of environmental factors, including meteorology, surface layer turbulence, thermodynamics, air and surface heterogeneous-phase chemistry, canopy geometry, plant development stage, leaf age, organic matter decomposition, soil microbial turnover, and, in agricultural systems, by fertilizer application rate, fertilizer type, soil type, crop type, and agricultural management practices. We review the range of processes controlling NH3 emission and uptake in the different parts of the soil-canopy-atmosphere continuum, with NH3 emission potentials defined at the substrate and leaf levels by different [NH4+] / [H+] ratios (Γ). Surface/atmosphere exchange models for NH3 are necessary to compute the temporal and spatial patterns of emissions and deposition at the soil, plant, field, landscape, regional and global scales, in order to assess the multiple environmental impacts of airborne and deposited NH3 and NH4+. Models of soil/vegetation/atmosphere NH3 exchange are reviewed from the substrate and leaf scales to the global scale. They range from simple steady-state, "big leaf" canopy resistance models, to dynamic, multi-layer, multi-process, multi-chemical species schemes

  1. Modeling the biophysical impacts of global change in mountain biosphere reserves

    Science.gov (United States)

    Bugmann, H.K.M.; Bjornsen, F. Ewert; Haeberli, W.; Guisan, A.; Fagre, Daniel B.; Kaab, A.

    2007-01-01

    Mountains and mountain societies provide a wide range of goods and services to humanity, but they are particularly sensitive to the effects of global environmental change. Thus, the definition of appropriate management regimes that maintain the multiple functions of mountain regions in a time of greatly changing climatic, economic, and societal drivers constitutes a significant challenge. Management decisions must be based on a sound understanding of the future dynamics of these systems. The present article reviews the elements required for an integrated effort to project the impacts of global change on mountain regions, and recommends tools that can be used at 3 scientific levels (essential, improved, and optimum). The proposed strategy is evaluated with respect to UNESCO's network of Mountain Biosphere Reserves (MBRs), with the intention of implementing it in other mountain regions as well. First, methods for generating scenarios of key drivers of global change are reviewed, including land use/land cover and climate change. This is followed by a brief review of the models available for projecting the impacts of these scenarios on (1) cryospheric systems, (2) ecosystem structure and diversity, and (3) ecosystem functions such as carbon and water relations. Finally, the cross-cutting role of remote sensing techniques is evaluated with respect to both monitoring and modeling efforts. We conclude that a broad range of techniques is available for both scenario generation and impact assessments, many of which can be implemented without much capacity building across many or even most MBRs. However, to foster implementation of the proposed strategy, further efforts are required to establish partnerships between scientists and resource managers in mountain areas.

  2. Modelling of the interface between the geosphere and the biosphere: discharge through a soil layer

    International Nuclear Information System (INIS)

    Radionuclides released from an underground repository can be transported by deep groundwater to the biosphere. The deep groundwater can be discharged to an agricultural area or a bog. In this report an evaluation is made of the resulting distribution of radionuclides in the upper soil and the release of radionuclides to a creek. From these environments, radionuclides can follow different exposure pathways to man. In order to evaluate the radionuclide movement to and retention in the soil surface, the hydrology in the superficial layers has been studied with the help of computer models. The chemical environment in soil was studied with special emphasis on radionuclide mobility. Examples of parameters which affect this mobility and which were studied are mineral composition, content of organic material, pH and redox potential. The chemical behaviour of the radionuclides iodine, cesium, radium, uranium, neptunium and americium was the topic of a literature survey. For the work in this report, radionuclide mobility in soils is represented by the equilibrium distribution coefficient, Kd. The radionuclide transport calculations showed that only those radionuclides which are sorbed strongly in the soil (i.e. radium, cesium and americium) have retention times longer than the expected lifetime of the soil layer itself. This would also be the case for neptunium and uranium if reducing conditions are found at the base of the soil column. For only slightly sorbing nuclides no important retention was found. The retarding effects of the soil layer is less than that of a sediment layer in a lake (the subject of a previous study). because of the greater water turnover in the soil. Several limitations to current knowledge and modelling techniques have been identified, and suggestion for possible improvement have been made. (85 refs.) (au)

  3. 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

  4. 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)

  5. 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

  6. A model of accumulation of radionuclides in biosphere originating from groundwater contamination

    International Nuclear Information System (INIS)

    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

  7. Testing the Simple Biosphere model (SiB) using point micrometeorological and biophysical data

    Science.gov (United States)

    Sellers, P. J.; Dorman, J. L.

    1987-01-01

    The suitability of the Simple Biosphere (SiB) model of Sellers et al. (1986) for calculation of the surface fluxes for use within general circulation models is assessed. The structure of the SiB model is described, and its performance is evaluated in terms of its ability to realistically and accurately simulate biophysical processes over a number of test sites, including Ruthe (Germany), South Carolina (U.S.), and Central Wales (UK), for which point biophysical and micrometeorological data were available. The model produced simulations of the energy balances of barley, wheat, maize, and Norway Spruce sites over periods ranging from 1 to 40 days. Generally, it was found that the model reproduced time series of latent, sensible, and ground-heat fluxes and surface radiative temperature comparable with the available data.

  8. The disposal of Canada's nuclear fuel waste: the biosphere model, BIOTRAC, for postclosure assessment

    International Nuclear Information System (INIS)

    The nuclear fuel waste management concept of Canada calls for disposal of the waste in a vault mined deep in plutonic rock of the Canadian Shield. The technical feasibility of this concept, and its impact on the environment and human health, will be documented in an Environmental Impact statement (EIS) by AECL. The present report is one of nine EIS primary references. The report describes the BIOTRAC model, which is used to trace nuclide movement from the geosphere through the biosphere and to calculate time-dependent environmental concentrations and radiological doses to humans and other biota for the postclosure phase. These concentrations and doses are crucial for evaluating the safety and environmental acceptability of the concept in terms of chemical and radiological toxicity. BIOTRAC was developed specifically to assess the impacts of a used-fuel disposal vault. It is a comprehensive, generic model with distributed or probabilistic parameter values to account for spatial and temporal variability and uncertainty. It is composed of four separate but closely linked submodels representing surface waters, soils, the atmosphere and the food chain. It also includes a unique model for predicting radiological doses to non-human biota, represented by generic target organisms. The mathematical formulation of each submodel is derived in detail and interpreted physically, and all the assumptions are fully evaluated and discussed. It is shown how the parameter values and distributions adopted for each submodel are derived from the available data. The interfaces between the submodels, and between BIOTRAC and the geosphere model, are presented in detail. Fluctuations in the physical state of the biosphere are accounted for through the parameter distributions. Major environmental changes, such as those caused by continental glaciation, are addressed quantitatively and through reasoned arguments, which indicate that radiological doses to humans will not increase suddenly or

  9. Exchange Processes at Geosphere-Biosphere Interface

    Energy Technology Data Exchange (ETDEWEB)

    Worman, A.; Sjogren, B. [Swedish University of Agricultural Sciences, Uppsala (Sweden); Dverstorp, B.; Xu, S. [Swedish Radiation Protection Authority, Stockholm (Sweden)

    2004-07-01

    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

  10. 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

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

    International Nuclear Information System (INIS)

    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. The parameters are 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, e.g. collecting missing site data, reanalysing site data, reviewing radionuclide specific data, reformulating ecosystem models and evaluating the results with further sensitivity analysis. The report presents descriptions and estimates not presented elsewhere, as well as summaries of important steps in the biosphere modelling that are presented in more detail in separate reports. The intention is to give the reader a coherent description of the steps taken to calculate doses to biota and humans, including a description of the data used, the rationale for a number of assumptions made during parameterisation, and of how the landscape context is applied in the modelling, and also to present the models used and the results obtained

  12. The biosphere at Forsmark. 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 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. The parameters are 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, e.g. collecting missing site data, reanalysing site data, reviewing radionuclide specific data, reformulating ecosystem models and evaluating the results with further sensitivity analysis. The report presents descriptions and estimates not presented elsewhere, as well as summaries of important steps in the biosphere modelling that are presented in more detail in separate reports. The intention is to give the reader a coherent description of the steps taken to calculate doses to biota and humans, including a description of the data used, the rationale for a number of assumptions made during parameterisation, and of how the landscape context is applied in the modelling, and also to present the models used and the results obtained.

  13. Towards global empirical upscaling of FLUXNET eddy covariance observations: validation of a model tree ensemble approach using a biosphere model

    Directory of Open Access Journals (Sweden)

    M. Jung

    2009-05-01

    Full Text Available Global, spatially and temporally explicit estimates of carbon and water fluxes derived from empirical up-scaling eddy covariance measurements would constitute a new and possibly powerful data stream to study the variability of the global terrestrial carbon and water cycle. This paper introduces and validates a machine learning approach dedicated to the upscaling of observations from the current global network of eddy covariance towers (FLUXNET. We present a new model TRee Induction ALgorithm (TRIAL that performs hierarchical stratification of the data set into units where particular multiple regressions for a target variable hold. We propose an ensemble approach (Evolving tRees with RandOm gRowth, ERROR where the base learning algorithm is perturbed in order to gain a diverse sequence of different model trees which evolves over time.

    We evaluate the efficiency of the model tree ensemble approach using an artificial data set derived from the the Lund-Potsdam-Jena managed Land (LPJmL biosphere model. We aim at reproducing global monthly gross primary production as simulated by LPJmL from 1998–2005 using only locations and months where high quality FLUXNET data exist for the training of the model trees. The model trees are trained with the LPJmL land cover and meteorological input data, climate data, and the fraction of absorbed photosynthetic active radiation simulated by LPJmL. Given that we know the "true result" in the form of global LPJmL simulations we can effectively study the performance of the model tree ensemble upscaling and associated problems of extrapolation capacity.

    We show that the model tree ensemble is able to explain 92% of the variability of the global LPJmL GPP simulations. The mean spatial pattern and the seasonal variability of GPP that constitute the largest sources of variance are very well reproduced (96% and 94% of variance explained respectively while the monthly interannual anomalies which occupy

  14. Modelling of present and future hydrology and solute transport at Forsmark. SR-Site Biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Bosson, Emma (Swedish Nuclear Fuel and Waste Management Co., Stocholm (Sweden)); Sassner, Mona; Sabel, Ulrika; Gustafsson, Lars-Goeran (DHI Sverige AB (Sweden))

    2010-10-15

    Radioactive waste from nuclear power plants in Sweden is managed by the Swedish Nuclear Fuel and Waste Management Co, SKB. SKB has performed site investigations at two different locations in Sweden, referred to as the Forsmark and Laxemar-Simpevarp areas, with the objective of siting a final repository for high-level radioactive waste. In 2009 a decision was made to focus on the Forsmark site. This decision was based on a large amount of empirical evidence suggesting Forsmark to be more suitable for a geological repository /SKB 2010b/. This report presents model results of numerical flow and transport modelling of surface water and near-surface groundwater at the Forsmark site for present and future conditions. Both temperate and periglacial climates have been simulated. Also different locations of the shoreline have been applied to the model, as well as different models of vegetation and Quaternary deposits. The modelling was performed using the modelling tool MIKE SHE and was based on the SDM-Site Forsmark MIKE SHE model (presented by Bosson et al. in SKB report R-08-09). The present work is a part of the biosphere modelling performed for the SR-Site safety assessment. The Forsmark area has a flat, small-scale topography. The study area is almost entirely below 20 m.a.s.l. (metres above sea level). There is a strong correlation between the topography of the ground surface and the ground water level in the Quaternary deposits (QD); thus, the surface water divides and the groundwater divides for the QD can be assumed to coincide. No major water courses flow through the catchment. Small brooks, which often dry out in the summer, connect the different sub-catchments with each other. The main lakes in the area, Lake Bolundsfjaerden, Lake Fiskarfjaerden, Lake Gaellsbotraesket and Lake Eckarfjaerden, all have sizes of less than one km2. The lakes are in general shallow. Approximately 70% of the catchment areas are covered by forest. Agricultural land is only present in

  15. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Terrain and ecosystems development modelling in the biosphere assessment BSA-2012

    International Nuclear Information System (INIS)

    This report is one of the four supporting reports for the three main biosphere reports in the safety case for the disposal of spent nuclear fuel at Olkiluoto, 'TURVA-2012'. The focus of this report is to detail the scenario analysis of terrain and ecosystems development at the Olkiluoto repository site within a time frame of 10 000 years, whereas the input data to this modelling is detailed in the Data Basis report. The results are used further especially in the surface and near-surface hydrological modelling and in the biosphere radionuclide transport and dose modelling, both part of the biosphere assessment 'BSA-2012' feeding into the safety case. Based on the results of the 18 cases simulated in the scenario analysis, it can be outlined that the most significant differences in respect of the dose implications of the repository arise from the inputs and settings affecting the rate of coastline retreat (i.e. land uplift and sea level) and determining whether there are croplands or not in the area. (orig.)

  16. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Terrain and ecosystems development modelling in the biosphere assessment BSA-2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-12-15

    This report is one of the four supporting reports for the three main biosphere reports in the safety case for the disposal of spent nuclear fuel at Olkiluoto, 'TURVA-2012'. The focus of this report is to detail the scenario analysis of terrain and ecosystems development at the Olkiluoto repository site within a time frame of 10 000 years, whereas the input data to this modelling is detailed in the Data Basis report. The results are used further especially in the surface and near-surface hydrological modelling and in the biosphere radionuclide transport and dose modelling, both part of the biosphere assessment 'BSA-2012' feeding into the safety case. Based on the results of the 18 cases simulated in the scenario analysis, it can be outlined that the most significant differences in respect of the dose implications of the repository arise from the inputs and settings affecting the rate of coastline retreat (i.e. land uplift and sea level) and determining whether there are croplands or not in the area. (orig.)

  17. A Better Representation of European Croplands into a Global Biosphere Model

    Science.gov (United States)

    Gervois, S.; de Noblet, N.; Viovy, N.; Ciais, P.; Brisson, N.; Seguin, B.

    2002-12-01

    Croplands cover a quarter of Europe's surface (about an hundred million hectares), their impact on carbon and water fluxes must therefore be estimated. Global biosphere models such as ORCHIDEE (http://www.ipsl.jussieu.fr/~ssipsl/) were conceived to simulate natural ecosystems only, so croplands are often described as grasslands. Not only cropland productivity depends on climate and soil conditions but also on irrigations, fertilisers impact, date of sowing... In addition crop species are usually selected genetically to shorten and accelerate their growth. Agronomic models such as STICS (Brisson et al. 1998) give a more realistic picture of croplands as they are especially designed to account for this human forcing. On the other hand they can be used at the local scale only. First we evaluate the ability of the two models to reproduce the seasonal behaviour the leaf area index (LAI), the aerial biomass, and the exchanges of water vapour and CO2 with the atmosphere. For that we compare the model outputs with measurements performed at five sites that are representative of most common European crops (wheat, corn, soybean). As expected the agronomic STICS better behaves than the generic model ORCHIDEE in representing the seasonal cycle of the above variables. In order to get a realistic representation of croplands areas at the regional scale, we decided to couple ORCHIDEE with STICS. First we present the main steps of the coupling procedure. The principle consists in forcing ORCHIDEE with five more realistic outputs of STICS: LAI, date of harvest, nitrogen stress, root profile, and vegetation height. On the other hand, ORCHIDEE computes its own carbon and water balance. The allocation scheme was also modified in ORCHIDEE in order to conserve the coherence between LAI and leaf biomass, and we added a harvest module into ORCHIDEE. The coupled model was validated against carbon and water fluxes observed respectively at two fields (wheat and corn) in the US. We also

  18. VALORA: data base system for storage significant information used in the behavior modelling in the biosphere; VALORA: sistema de base de datos para almacenar informacion significativa utilizada en la modelizacion del comportamiento en la biosfera

    Energy Technology Data Exchange (ETDEWEB)

    Valdes R, M. [CPHR, Calle 20, No. 4113 e/41 y 47, Playa, La Habana 11300 (Cuba); Aguero P, A.; Perez S, D.; Cancio P, D. [CIEMAT, Av. Complutense No. 22, 28040 Madrid (Spain)]. e-mail: zury@cphr.edu.cu

    2006-07-01

    The nuclear and radioactive facilities can emit to the environment effluents that contain radionuclides, which are dispersed and/or its accumulate in the atmosphere, the terrestrial surface and the surface waters. As part of the evaluations of radiological impact, it requires to be carried out qualitative and quantitative analysis. In many of the cases it doesn't have the real values of the parameters that are used in the modelling, neither it is possible to carry out their measure, for that to be able to carry out the evaluation it needs to be carried out an extensive search of that published in the literature about the possible values of each parameter, under similar conditions to the object of study, this work can be extensive. In this work the characteristics of the VALORA Database System developed with the purpose of organizing and to automate significant information that it appears in different sources (scientific or technique literature) of the parameters that are used in the modelling of the behavior of the pollutants in the environment and the values assigned to these parameters that are used in the evaluation of the radiological impact potential is described; VALORA allows the consultation and selection of the characteristic parametric data of different situations and processes that are required by the calculation pattern implemented. The software VALORA it is a component of a group of tools computer that have as objective to help to the resolution of dispersion models and transfer of pollutants. (Author)

  19. 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)

    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.

  20. Predicting ecosystem dynamics at regional scales: an evaluation of a terrestrial biosphere model for the forests of northeastern North America.

    Science.gov (United States)

    Medvigy, David; Moorcroft, Paul R

    2012-01-19

    Terrestrial biosphere models are important tools for diagnosing both the current state of the terrestrial carbon cycle and forecasting terrestrial ecosystem responses to global change. While there are a number of ongoing assessments of the short-term predictive capabilities of terrestrial biosphere models using flux-tower measurements, to date there have been relatively few assessments of their ability to predict longer term, decadal-scale biomass dynamics. Here, we present the results of a regional-scale evaluation of the Ecosystem Demography version 2 (ED2)-structured terrestrial biosphere model, evaluating the model's predictions against forest inventory measurements for the northeast USA and Quebec from 1985 to 1995. Simulations were conducted using a default parametrization, which used parameter values from the literature, and a constrained model parametrization, which had been developed by constraining the model's predictions against 2 years of measurements from a single site, Harvard Forest (42.5° N, 72.1° W). The analysis shows that the constrained model parametrization offered marked improvements over the default model formulation, capturing large-scale variation in patterns of biomass dynamics despite marked differences in climate forcing, land-use history and species-composition across the region. These results imply that data-constrained parametrizations of structured biosphere models such as ED2 can be successfully used for regional-scale ecosystem prediction and forecasting. We also assess the model's ability to capture sub-grid scale heterogeneity in the dynamics of biomass growth and mortality of different sizes and types of trees, and then discuss the implications of these analyses for further reducing the remaining biases in the model's predictions.

  1. 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)

    Seasonal and inter-annual variations of atmospheric CO2 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 CO2 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 CO2 time series simulated by Biome-BGC were compared to the global CO2 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 CO2 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 CO2, 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

  2. The Yale Interactive terrestrial Biosphere model version 1.0: description, evaluation and implementation into NASA GISS ModelE2

    Science.gov (United States)

    Yue, X.; Unger, N.

    2015-08-01

    The land biosphere, atmospheric chemistry and climate are intricately interconnected, yet the modeling of carbon-climate and chemistry-climate interactions have evolved as entirely separate research communities. We describe the Yale Interactive terrestrial Biosphere (YIBs) model version 1.0, a land carbon cycle model that has been developed for coupling to the NASA Goddard Institute for Space Studies (GISS) ModelE2 global chemistry-climate model. The YIBs model adapts routines from the mature TRIFFID (Top-down Representation of Interactive Foliage and Flora Including Dynamics) and CASA (Carnegie-Ames-Stanford Approach) models to simulate interactive carbon assimilation, allocation, and autotrophic and heterotrophic respiration. Dynamic daily leaf area index is simulated based on carbon allocation and temperature- and drought-dependent prognostic phenology. YIBs incorporates a semi-mechanistic ozone vegetation damage scheme. Here, we validate the present-day YIBs land carbon fluxes for three increasingly complex configurations: (i) offline local site level, (ii) offline global forced with WFDEI (WATCH Forcing Data methodology applied to ERA-Interim data) meteorology, and (iii) online coupled to the NASA ModelE2 (NASA ModelE2-YIBs). Offline YIBs has hourly and online YIBs has half-hourly temporal resolution. The large observational database used for validation includes carbon fluxes from 145 flux tower sites and multiple satellite products. At the site level, YIBs simulates reasonable seasonality (correlation coefficient R > 0.8) of gross primary productivity (GPP) at 121 out of 145 sites with biases in magnitude ranging from -19 to 7 % depending on plant functional type. On the global scale, the offline model simulates an annual GPP of 125 ± 3 Pg C and net ecosystem exchange (NEE) of -2.5 ± 0.7 Pg C for 1982-2011, with seasonality and spatial distribution consistent with the satellite observations. We assess present-day global ozone vegetation damage using the

  3. 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

  4. Assessment of Food Chain Pathway Parameters in Biosphere Models: Annual Progress Report for Fiscal Year 2004

    Energy Technology Data Exchange (ETDEWEB)

    Napier, Bruce A.; Krupka, Kenneth M.; Fellows, Robert J.; Cataldo, Dominic A.; Valenta, Michelle M.; Gilmore, Tyler J.

    2004-12-02

    This Annual Progress Report describes the work performed and summarizes some of the key observations to date on 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 describes activities undertaken to collect samples of soils from three regions of the United States, the Southeast, Northwest, and Southwest, and perform analyses to characterize their physical and chemical properties. Section 3 summarizes information gathered regarding agricultural practices and common and unusual crops grown in each of these three areas. Section 4 describes progress in studying radionuclide uptake in several representative crops from the three soil types in controlled laboratory conditions. Section 5 describes a range of international coordination activities undertaken by Project staff in order to support the underlying data needs of the Project. Section 6 provides a very brief summary of the status of the GENII Version 2 computer program, which is a “client” of the types of data being generated by the Project, and for which the Project will be providing training to the US NRC staff in the coming Fiscal Year. Several appendices provide additional supporting information.

  5. Landscape model configuration for biosphere analysis of selected cases in TILA-99 and in KBS-3H safety evaluation, 2007

    International Nuclear Information System (INIS)

    In this report, the configuration of a landscape model based on the Terrain and ecosystems development model of the Olkiluoto site, 2006, is presented in details. The landscape model is created especially for use in the simulations of release cases in the KBS-3H safety evaluation and for recalculating some older cases originally presented in the TILA-99 safety assessment. The report presents results for constant unit release rate on the landscape doses, and activity concentrations and radionuclide inventories in the various environmental media. Results on the specific release cases are left for subsequent reports. In this report, the discussion and presentation of the results is focused on a limited set of radionuclides (Cl-36, Tc-99, I-129, Ra-226, Th-230) of different behaviour in the environment. However, same results have been calculated also for a large variety of nuclides present in the release terms to the biosphere. In the sensitivity analysis the parameters most affecting to the results are identified. They are further evaluated using data quality index, reflecting to the confidence on the underlying data and knowledge base. These are then combined in the multi-dimensional uncertainty analysis, revealing water balance, the fraction of precipitation intercepted by the foliage, concentration ratios in forests, Kds in sediments, river width and wetland parameters in general as the most important factors, in respect of the unit release rate, calling for further research at the moment, together with some structural improvements to the biosphere object modules. Uncertainties related to the release locations are studied with a number of cases assuming various patterns of release distribution to several objects as well as the release term received by single objects. The maximum landscape doses per unit release rate vary between one and less than four orders of magnitude across the cases depending on the nuclide, or from more than two less to slightly more than one

  6. The biosphere: current status

    International Nuclear Information System (INIS)

    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)

  7. A generic analysis code of dynamic compartment model for evaluation of doses in terrestrial biosphere. GACOM user`s manual

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Tomoyuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-02-01

    A computer code GACOM (Generic Analysis code for dynamic COmpartment Model) has been developed to evaluate the behavior of radionuclides in terrestrial biosphere and the subsequent individual doses. In this code, the simultaneous ordinary differential equations are solved by using the sixth-step fifth-order Runge-Kutta method called Fehlberg formula. This principal characteristics of this code are shown as follows; (1) user definition of such as a number of compartments and transfer pathways of nuclides makes it possible to apply this code to various subjects of analysis, (2) various kinds of equations for evaluating doses in terrestrial biosphere are available for making input data of this code, (3) the units of time and nuclides can be defined flexibly, (4) probabilistic analysis by using the Monte-Carlo simulation is possible. This report describes the structure and user information for execution of GACOM code. (author)

  8. Biosphere model simulations of interannual variability in terrestrial 13C/12C exchange.

    NARCIS (Netherlands)

    Velde, van der I.R.; Miller, J.B.; Schaefer, K.; Masarie, K.A.; Denning, S.; White, J.W.C.; Krol, M.C.; Peters, W.; Tans, P.P.

    2013-01-01

    Previous studies suggest that a large part of the variability in the atmospheric ratio of (CO2)-C-13/(12)CO(2)originates from carbon exchange with the terrestrial biosphere rather than with the oceans. Since this variability is used to quantitatively partition the total carbon sink, we here investig

  9. 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.

  10. Transbios - a unified model for assessment of the effect of noxious materials in ground water to the biosphere. Compilation of the model

    International Nuclear Information System (INIS)

    This model of radionuclide propagation in the biosphere is part of the project 'Final Deposition of Low- and Medium- active Wastes from Hospitals, University Institutes and Industry'. The six parts are: a flow-and transport model in ground water, an evaporation-transpiration model, a transfer model soil-to-plant, a water cycle- and a food chain model. Solutions are designed and peculiarities of the program are outlined. Finally the individual parts are integrated into the overall model

  11. 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.

  12. Spanish methodological approach for biosphere assessment of radioactive waste disposal

    International Nuclear Information System (INIS)

    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

  13. Advances in understanding, models and parameterisations of biosphere-atmosphere ammonia exchange

    OpenAIRE

    C. R. Flechard; Massad, R.-S.; Loubet, B.; Personne, E.; Simpson, D.; Bash, J.O.; E. J. Cooter; Nemitz, E.; Sutton, M. A.

    2013-01-01

    Atmospheric ammonia (NH3) dominates global emissions of total reactive nitrogen (Nr), while emissions from agricultural production systems contribute about two-thirds of global NH3 emissions; the remaining third emanates from oceans, natural vegetation, humans, wild animals and biomass burning. On land, NH3 emitted from the various sources eventually returns to the biosphere by dry deposition to sink areas, predominantly semi-natural vegetation, and by wet and dry deposition...

  14. 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

  15. Towards understanding the variability in biospheric CO2 fluxes: using FTIR spectrometry and a chemical transport model to investigate the sources and sinks of carbonyl sulfide and its link to CO2

    Science.gov (United States)

    Wang, Yuting; Deutscher, Nicholas M.; Palm, Mathias; Warneke, Thorsten; Notholt, Justus; Baker, Ian; Berry, Joe; Suntharalingam, Parvadha; Jones, Nicholas; Mahieu, Emmanuel; Lejeune, Bernard; Hannigan, James; Conway, Stephanie; Mendonca, Joseph; Strong, Kimberly; Campbell, J. Elliott; Wolf, Adam; Kremser, Stefanie

    2016-02-01

    Understanding carbon dioxide (CO2) biospheric processes is of great importance because the terrestrial exchange drives the seasonal and interannual variability of CO2 in the atmosphere. Atmospheric inversions based on CO2 concentration measurements alone can only determine net biosphere fluxes, but not differentiate between photosynthesis (uptake) and respiration (production). Carbonyl sulfide (OCS) could provide an important additional constraint: it is also taken up by plants during photosynthesis but not emitted during respiration, and therefore is a potential means to differentiate between these processes. Solar absorption Fourier Transform InfraRed (FTIR) spectrometry allows for the retrievals of the atmospheric concentrations of both CO2 and OCS from measured solar absorption spectra. Here, we investigate co-located and quasi-simultaneous FTIR measurements of OCS and CO2 performed at five selected sites located in the Northern Hemisphere. These measurements are compared to simulations of OCS and CO2 using a chemical transport model (GEOS-Chem). The coupled biospheric fluxes of OCS and CO2 from the simple biosphere model (SiB) are used in the study. The CO2 simulation with SiB fluxes agrees with the measurements well, while the OCS simulation reproduced a weaker drawdown than FTIR measurements at selected sites, and a smaller latitudinal gradient in the Northern Hemisphere during growing season when comparing with HIPPO (HIAPER Pole-to-Pole Observations) data spanning both hemispheres. An offset in the timing of the seasonal cycle minimum between SiB simulation and measurements is also seen. Using OCS as a photosynthesis proxy can help to understand how the biospheric processes are reproduced in models and to further understand the carbon cycle in the real world.

  16. Causes and timing of future biosphere extinction

    OpenAIRE

    s Franck; Bounama, C.; Von Bloh, W.

    2005-01-01

    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 aggregated reservoir ocean and atmosphere. The model is specified by introducing three different types of biosphere: procaryotes, eucaryotes, and complex multicellular life. We find that from the Archaean to the future a procaryotic biosphere always exists. 2 Gyr ago eucaryotic life first appears. The emergence of comp...

  17. Causes and timing of future biosphere extinctions

    OpenAIRE

    s Franck; Bounama, C.; Bloh, W.

    2006-01-01

    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 multi...

  18. Increased biotic metabolism of the biosphere inferred from observed data and models

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A 35 year record of production and respiration in the Northern Hemisphere bas been derived from monthly records of atmospheric concentration, fossil fuel combustion, and oceanic absorption of carbon dioxide using a method developed by Hall et al. The original conclusion of Hall et al. that there was no significant change in biotic metabolism, is confirmed by measuring both production and respiration from 1958 to 1972. But the analysis of the subsequent record shows that both production and respiration have been enhanced since the early 1970s by some large scale global change, probably of human origin. Our results also show that high-latitude regions in the Northern Hemisphere are changing more than regions further south. Nevertheless, the ratio of production to respiration (P/R) remains unchanged during the time period examined. Thus, no argument can be made for net carbon storage of or release from the biosphere from this analysis, although the turnover rate of the biosphere appears to be enhanced.

  19. Increased biotic metabolism of the biosphere inferred from observed data and models

    Institute of Scientific and Technical Information of China (English)

    田汉勤[1; CharlesA.S.Hall[2; 叶琦[3

    2000-01-01

    A 35 year record ot production and respiration in tne Northern Hemisphere bas been derived from monthly records of atmospheric concentration, fossil fuel combustion, and oceanic absorption of carbon dioxide using a method developed by Hall et al. The original conclusion of Hall et al. that there was no significant change in biotic metabolism, is confirmed by measuring both production and respiration from 1958 to 1972. But the analysis of the subsequent record shows that both production and respiration have been enhanced since the early 1970s by some large scale global change, probably of human origin. Our results also show that high-latitude regions in the Northern Hemisphere are changing more than regions further south. Nevertheless, the ratio of production to respiration (P/R) remains unchanged during the time period examined. Thus, no argument can be made for net carbon storage of or release from the biosphere from this analysis, although the turnover rate of the biosphere appears to be enhanced.

  20. Latest developments on the modeling of the biosphere in the management of radioactive waste in Spain; Ultimos desarrollos sobre la modelizacion de la biosfera en la gestion de residuos radiactivos en Espana

    Energy Technology Data Exchange (ETDEWEB)

    Perez Sanchez, D.; Trueba Alonso, C.

    2013-07-01

    In recent years, the CIEMAT has developed for ENRESA a methodology and tools for safety assessment of the biosphere in the management of radioactive waste. This methodology includes modeling of migration and accumulation of radionuclides in the biosphere to allow the assessment of the radiological impact of the distribution of radionuclides in the environment. The working group is developing projects related to the safety assessment of the biosphere, which comprise several studies. In this paper the latest results obtained are described. (Author)

  1. FORest Canopy Atmosphere Transfer (FORCAsT) 1.0: a 1-D model of biosphere-atmosphere chemical exchange

    Science.gov (United States)

    Ashworth, K.; Chung, S. H.; Griffin, R. J.; Chen, J.; Forkel, R.; Bryan, A. M.; Steiner, A. L.

    2015-11-01

    Biosphere-atmosphere interactions play a critical role in governing atmospheric composition, mediating the concentrations of key species such as ozone and aerosol, thereby influencing air quality and climate. The exchange of reactive trace gases and their oxidation products (both gas and particle phase) is of particular importance in this process. The FORCAsT (FORest Canopy Atmosphere Transfer) 1-D model is developed to study the emission, deposition, chemistry and transport of volatile organic compounds (VOCs) and their oxidation products in the atmosphere within and above the forest canopy. We include an equilibrium partitioning scheme, making FORCAsT one of the few canopy models currently capable of simulating the formation of secondary organic aerosols (SOAs) from VOC oxidation in a forest environment. We evaluate the capability of FORCAsT to reproduce observed concentrations of key gas-phase species and report modeled SOA concentrations within and above a mixed forest at the University of Michigan Biological Station (UMBS) during the Community Atmosphere-Biosphere Interactions Experiment (CABINEX) field campaign in the summer of 2009. We examine the impact of two different gas-phase chemical mechanisms on modelled concentrations of short-lived primary emissions, such as isoprene and monoterpenes, and their oxidation products. While the two chemistry schemes perform similarly under high-NOx conditions, they diverge at the low levels of NOx at UMBS. We identify peroxy radical and alkyl nitrate chemistry as the key causes of the differences, highlighting the importance of this chemistry in understanding the fate of biogenic VOCs (bVOCs) for both the modelling and measurement communities.

  2. Interpretation of Biosphere Reserves.

    Science.gov (United States)

    Merriman, Tim

    1994-01-01

    Introduces the Man and the Biosphere Programme (MAB) to monitor the 193 biogeographical provinces of the Earth and the creation of biosphere reserves. Highlights the need for interpreters to become familiar or involved with MAB program activities. (LZ)

  3. Database for radionuclide transport in the biosphere

    International Nuclear Information System (INIS)

    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.)

  4. Probabilistic calculations and sensitivity analysis of parameters for a reference biosphere model assessing the potential exposure of a population to radionuclides from a deep geological repository

    Energy Technology Data Exchange (ETDEWEB)

    Staudt, Christian; Kaiser, Jan Christian [Helmholtz Zentrum Muenchen, Institute of Radiation Protection, Munich (Germany); Proehl, Gerhard [International Atomic Energy Agency, Division of Radiation, Transport and Waste Safety, Wagramerstrasse 5, 1400 Vienna (Austria)

    2014-07-01

    Radioecological models are used to assess the exposure of hypothetical populations to radionuclides. Potential radionuclide sources are deep geological repositories for high level radioactive waste. Assessment time frames are long since releases from those repositories are only expected in the far future, and radionuclide migration to the geosphere biosphere interface will take additional time. Due to the long time frames, climate conditions at the repository site will change, leading to changing exposure pathways and model parameters. To identify climate dependent changes in exposure in the far field of a deep geological repository a range of reference biosphere models representing climate analogues for potential future climate states at a German site were developed. In this approach, model scenarios are developed for different contemporary climate states. It is assumed that the exposure pathways and parameters of the contemporary biosphere in the far field of the repository will change to be similar to those at the analogue sites. Since current climate models cannot predict climate developments over the assessment time frame of 1 million years, analogues for a range of realistically possible future climate conditions were selected. These climate states range from steppe to permafrost climate. As model endpoint Biosphere Dose conversion factors (BDCF) are calculated. The radionuclide specific BDCF describe the exposure of a population to radionuclides entering the biosphere in near surface ground water. The BDCF are subject to uncertainties in the exposure pathways and model parameters. In the presented work, probabilistic and sensitivity analysis was used to assess the influence of model parameter uncertainties on the BDCF and the relevance of individual parameters for the model result. This was done for the long half-live radionuclides Cs-135, I-129 and U-238. In addition to this, BDCF distributions for nine climate reference regions and several scenarios were

  5. 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 (CO2) 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 = 1015 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 CO2 and nitrogen deposition over intact ecosystems increased SOC stocks—even though the responses varied significantly among models. Model

  6. Access: A Directory of Contacts, Environmental Data Bases, and Scientific Infrastructure on 175 Biosphere Reserves in 32 Countries.

    Science.gov (United States)

    Department of State, Washington, DC. Bureau of Oceans and International Environmental and Scientific Affairs.

    Following the EuroMAB meeting in Strasbourg, France (September 1991) and on an initiative of the Man and the Biosphere National Committee of the United States, a decision was made to create a research network from information available in biosphere reserves in 30 European countries, Canada and the United States. This Directory of EuroMAB Biosphere…

  7. Use of midlatitude soil moisture and meteorological observations to validate soil moisture simulations with biosphere and bucket models

    International Nuclear Information System (INIS)

    Soil moisture observations in sites with natural vegetation were made for several decades in the former Soviet Union at hundreds of stations. In this paper, the authors use data from six of these stations from different climatic regimes, along with ancillary meteorological and actinometric data, to demonstrate a method to validate soil moisture simulations with biosphere and bucket models. Some early and current general circulation models (GCMs) use bucket models for soil hydrology calculations. More recently, the Simple Biosphere Model (SiB) was developed to incorporate the effects of vegetation on fluxes of moisture, momentum, and energy at the earth's surface into soil hydrology models. Until now, the bucket and SiB have been verified by comparison with actual soil moisture data only on a limited basis. In this study, a Simplified SiB (SSiB) soil hydrology model and a 15-cm bucket model are forced by observed meteorological and actinometric data every 3 h for 6-yr simulations at the six stations. The model calculations of soil moisture are compared to observations of soil moisture, literally 'ground truth,' snow cover, surface albedo, and net radiation, and with each other. For three of the stations, the SSiB and 15-cm bucket models produce good simulations of seasonal cycles and interannual variations of soil moisture. For the other three stations, there are large errors in the simulations by both models. Inconsistencies in specification of field capacity may be partly responsible. There is no evidence that the SSiB simulations are superior in simulating soil moisture variations. In fact, the models are quite similar since SSiB implicitly has a bucket embedded in it. One of the main differences between the models is in the treatment of runoff due to melting snow in the spring-SSiB incorrectly puts all the snowmelt into runoff. While producing similar soil moisture simulations, the models produce very different surface latent and sensible heat

  8. Modeling climate change impacts on primary production by the terrestrial biosphere

    Science.gov (United States)

    Davis, T. W.; Prentice, I. C.; Evans, B. J.; Gilbert, X.

    2013-12-01

    A modelling system is under development for the global hindcasting and analysis of spatial and temporal patterns in terrestrial gross primary production (GPP). The aim is to produce the simplest possible model that makes good use of observational data (from flux towers, meteorological stations, and remote-sensing satellites) while defensibly representing the principal ecophysiological processes that govern GPP. The first modelling step consists of partitioning high time-resolution carbon dioxide flux data, using in situ photosynthetically active radiation (PAR) measurements. The second step estimates monthly light-use efficiency (LUE) from monthly aggregated GPP and gap-filled, monthly aggregated PAR, and analyses the empirical dependencies of LUE on vegetational and environmental factors in order to yield a simple predictive model for LUE. The third and final stage generates spatial fields of monthly GPP based on remotely sensed reflectances and predicted LUE. The basis of the system is an efficient database structure, which is the "tool chest" for modelling. The tool chest is designed to hold the variety of observational data necessary to complete each stage of the model including point measurements of CO2 fluxes and PAR, and gridded measurements of surface reflectances and downwelling radiation. The Python programming language is used to upload, retrieve and process data. Although the model as currently developed is a data-driven, 'diagnostic' model, the intention is to use its basic elements in the construction of a next-generation vegetation and land-surface model based on a new theoretical approach to predict the light use efficiency of ecosystems. The model will strive for clarity and uniformity so that it may be used by researchers across disciplines. The use of an open-source programming language allows for portability and transparency. The model will invite a range of applications to the analysis of climate and CO2 change impacts on ecosystem processes.

  9. Nuclide documentation. Element specific parameter values used in the biospheric models of the safety assessments SR 97 and SAFE

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Sara; Bergstroem, Ulla [Studsvik Eco and Safety AB, Nykoeping (Sweden)

    2002-05-01

    In this report the element and nuclide specific parameter values used in the biospheric models of the safety assessments SR 97 and SAFE are presented. The references used are presented and where necessary the process of estimation of data is described. The parameters treated in this report are distribution coefficients in soil, organic soil and suspended matter in freshwater and brackish water, root uptake factors for pasturage, cereals, root crops and vegetables, bioaccumulation factors for freshwater fish, brackish water fish, freshwater invertebrates and marine water plants, transfer coefficients for transfer to milk and meat, translocation factors and dose coefficients for external exposure, ingestion (age-dependent values) and inhalation (age-dependent values). The radionuclides treated are those which could be of interest in the two safety assessments. Physical data such as half-lives and type of decay are also presented.

  10. Nuclide documentation. Element specific parameter values used in the biospheric models of the safety assessments SR 97 and SAFE

    International Nuclear Information System (INIS)

    In this report the element and nuclide specific parameter values used in the biospheric models of the safety assessments SR 97 and SAFE are presented. The references used are presented and where necessary the process of estimation of data is described. The parameters treated in this report are distribution coefficients in soil, organic soil and suspended matter in freshwater and brackish water, root uptake factors for pasturage, cereals, root crops and vegetables, bioaccumulation factors for freshwater fish, brackish water fish, freshwater invertebrates and marine water plants, transfer coefficients for transfer to milk and meat, translocation factors and dose coefficients for external exposure, ingestion (age-dependent values) and inhalation (age-dependent values). The radionuclides treated are those which could be of interest in the two safety assessments. Physical data such as half-lives and type of decay are also presented

  11. BIOPROTA Key Issues in Biosphere Aspects of Assessment of the Long-term Impact of Contaminant Releases Associated with Radioactive Waste Management Theme 2: Task 7:Modelling Processes in the Geosphere Biosphere Interface Zone

    Energy Technology Data Exchange (ETDEWEB)

    Pinedo, P.; Smith, G.; Aguero, A.; Albrecht, A.; Bath, A.; Benhabderrahmane, H.; Van Dorp, F.; Kautsky, U.; Klos, R.; Laciok, A.; Milodowski, T.; Selroos, J.O.; Simon, I.; Texier, D.; Thorne, M.; Willans, M.

    2005-07-01

    This document reports on BIOPROTA Theme 2, task 7 which investigated modelling processes in the geosphere- biosphere interface zone (GBIZ) during performance assessments. Modelling issues in the treatment of the GBIZ are identified. A large proportion of the identified issues concern modelling radionuclide behaviour in near surface aquifers which are subject to relatively high gradients in chemical and other conditions. Other key issues concern transfer of radionuclides through the unsaturated zone above aquifers, bearing in mind the scope for erosion and variations in the level of the phreatic surface and also the consideration of environmental change. A number of research areas are highlighted that are aimed at addressing each of the identified issues in the treatment of GBIZ. These include (i) Developing of a current statement of continuing problems, and hence clarify and justify the need to do more; (ii) Conducting a review of site investigations as they have been done already, and determine whether they meet performance assessment requirements; (iii) Identifying scenarios and FEPs considered in current treatments; and, (iv) Conducting source-pathway-receptor analysis to demonstrate comprehensiveness of the overall scenario identification process. The objectives of these activities would be to determine the potential to reduce uncertainties and/or conservative assumptions in assessment of radionuclide transfer from the geosphere to biosphere domains, taking account of environmental change; and to develop guidance on site-characterisation needs at different types of site, as regards the near-surface features. (Author) 23 refs.

  12. BIOPROTA Key Issues in Biosphere Aspects of Assessment of the Long-term Impact of Contaminant Releases Associated with Radioactive Waste Management. Theme 2: Task 7: Modelling Processes in the Geosphere Biosphere Interface Zone

    International Nuclear Information System (INIS)

    This document reports on BIOPROTA Theme 2, task 7 which investigated modelling processes in the geosphere- biosphere interface zone (GBIZ) during performance assessments. Modelling issues in the treatment of the GBIZ are identified. A large proportion of the identified issues concern modelling radionuclide behaviour in near surface aquifers which are subject to relatively high gradients in chemical and other conditions. Other key issues concern transfer of radionuclides through the unsaturated zone above aquifers, bearing in mind the scope for erosion and variations in the level of the phreatic surface and also the consideration of environmental change. A number of research areas are highlighted that are aimed at addressing each of the identified issues in the treatment of GBIZ. These include (i) Developing of a current statement of continuing problems, and hence clarify and justify the need to do more; (ii) Conducting a review of site investigations as they have been done already, and determine whether they meet performance assessment requirements; (iii) Identifying scenarios and FEPs considered in current treatments; and, (iv) Conducting source-pathway-receptor analysis to demonstrate comprehensiveness of the overall scenario identification process. The objectives of these activities would be to determine the potential to reduce uncertainties and/or conservative assumptions in assessment of radionuclide transfer from the geosphere to biosphere domains, taking account of environmental change; and to develop guidance on site-characterisation needs at different types of site, as regards the near-surface features. (Author) 23 refs

  13. 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. PMID:18314639

  14. Database description for the biosphere code BIOMOD

    International Nuclear Information System (INIS)

    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)

  15. An international peer review of the biosphere modelling programme of the US Department of Energy's Yucca mountain site characterization project. Report of the IAEA International Review Team

    International Nuclear Information System (INIS)

    The United States Department of Energy (DOE) has a project for characterizing the site of a facility for disposing of radioactive waste located at Yucca Mountain Nevada, USA (the Yucca Mountain Site Characterization Project). This Project has developed an approach for assessing the future potential impact of any releases of radionuclides to the biosphere from a potential disposal facility sited at Yucca Mountain The DOE requested the International Atomic Energy Agency (IAEA) to organize an independent international expert review of the assessment methodology being used in its biosphere modelling programme. The IAEA accepted the request in the context of its statutory obligation to provide for the application of its established international standards of safety for the protection of health, at the request of a State, to any of that State's activities in the field of atomic energy. The terms of reference of the peer review were to review the biosphere assessment methodology being used for the total system performance assessment of the potential disposal facility. The main purpose was to analyze critically the proposed rationale and methodology and to identify consistencies and inconsistencies between methods being used in the frame of the Project and those established in international standards or in international programmes such as the IAEA's Biosphere Modelling and Assessment Programme (BIOMASS). This report presents the consensus view of the international experts convened by the IAEA for carrying out the review

  16. Higher Resolution Modeling of the Global Terrestrial Biosphere for the PETM

    Science.gov (United States)

    Cacciatore, C.; Breecker, D.

    2015-12-01

    The Paleocene-Eocene Thermal Maximum (PETM) was a rapid climactic warming event at ~55.5 Ma associated with abrupt warming of surface temperatures (5-8 °C), massive input of carbon into the ocean-atmosphere system, and negative carbon isotope excursions (CIE) across nearly every terrestrial and oceanic carbon pool. Whereas there is ubiquitous evidence for CIEs across sites, differences in magnitude and duration of these shifts among records highlight an incomplete characterization of initial carbon injections and of ecosystem feedbacks in response to such perturbations. Numerical modeling of global carbon cycling has thus been utilized to reconcile differences between isotope records, and to also check for agreement with other constraints like carbon release scenarios and oceanic acid-base chemistry. Here, we present a carbon cycle box model that addresses oversimplification in previous quantification of terrestrial carbon cycling by introducing a soil organic and inorganic soil carbon reservoirs. The new model calculates the carbon isotope compositions of both soil organic carbon and pedogenic carbonate and considers the seasonality of calcium carbonate formation, productivity/respiration rates. Coupling this more resolved terrestrial carbon model to a global carbon flux model with established oceanic-atmospheric interaction (LOSCAR) provides a compatibility check given recent paleosol CIE records in the Bighorn Basin (Wyoming, USA). Moreover, the more highly resolved model is used in an effort to address previously irreconcilable differences between organic carbon, surface oceanic, and pedogenic CIE records. Changes in ocean and atmospheric chemistry from such rapid carbon perturbations provided in the model output ultimately serves as an important analog for modern climate change.

  17. Causes and timing of future biosphere extinction

    Science.gov (United States)

    Franck, S.; Bounama, C.; von Bloh, W.

    2005-11-01

    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 aggregated reservoir ocean and atmosphere. The model is specified by introducing three different types of biosphere: procaryotes, eucaryotes, and complex multicellular life. We find that from the Archaean to the future a procaryotic biosphere always exists. 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. The ultimate life span of the biosphere is defined by the extinction of procaryotes in about 1.6 Gyr.

  18. The Sensitivity of Ground Surface Temperature Prediction to Soil Thermal Properties Using the Simple Biosphere Model (SiB2)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaohui; GAO Zhiqiu; WEI Dongping

    2012-01-01

    Using the Simple Biosphere Model (SiB2),soil thermal properties (STP) were examined in a Tibetan prairie during the monsoon period to investigate ground surface temperature prediction.We improved the SiB2 model by incorporating a revised force-restore method (FRM) to take the vertical heterogeneity of soil thermal diffusivity (k) into account.The results indicate that (1) the revised FRM alleviates daytime overestimation and nighttime underestimation in modeled ground surface temperature (Tg),and (2) its role in little rainfall events is significant because the vertical gradient of k increases with increasing surface evaporation.Since the original formula of thermal conductivity (λ) in the SiB2 greatly underestimates soil thermal conductivity,we compared five algorithms of λ involving soil moisture to investigate the cause of overestimation during the day and underestimation at night on the basis of the revised FRM.The results show that (1) the five algorithms significantly improve Tg prediction,especially in daytime,and (2) taking one of these five algorithms as an example,the simulated Tg values in the daytime are closer to the field measurements than those in the nighttime.The differences between modeled Tg and field measurements are mostly within the margin of error of ±2 K during 3 August to 4 September 1998.

  19. Mathematical modeling of diffuse flow in seafloor hydrothermal systems: The potential extent of the subsurface biosphere at mid-ocean ridges

    Science.gov (United States)

    Lowell, R. P.; Houghton, J. L.; Farough, A.; Craft, K. L.; Larson, B. I.; Meile, C. D.

    2015-09-01

    We describe a variety of one- and two-dimensional mathematical modeling approaches to characterizing diffuse flow circulation at mid-ocean ridge hydrothermal systems. The goal is to estimate the potential extent of the sub-seafloor microbial biosphere based on subsurface contours of the 120 °C isotherm as determined from the various models. The models suggest that the sub-seafloor depth for microbial life may range from less than 1 m in some places to the thickness of crustal layer 2A of ∼ 500 m in others. This depth depends primarily on how diffuse flow is driven. The 120 °C isotherm tends to be much deeper if diffuse flow is induced as boundary layer flow near high-temperature plumes, than if it results from conductive cooling or mixing near the seafloor. Because the heat flow alone may not allow identification of the flow regime in the subsurface, we highlight the use of chemical tracers as an additional constraint that sheds light into the flow and reaction patterns associated with vents. We use thermodynamic modeling, which connects the temperature of the diffuse fluid to its chemical composition. As the temperature-composition relationships differ for mixing versus conductive heating and cooling, the fluid geochemistry can shed light on subsurface transport. Using methane as an example, the geochemical models indicate subsurface microbial methane production and consumption in different regions of the vent field near EPR 9 °50‧ N.

  20. Solid phase evolution in the Biosphere 2 hillslope experiment as predicted by modeling of hydrologic and geochemical fluxes

    Directory of Open Access Journals (Sweden)

    K. Dontsova

    2009-12-01

    Full Text Available A reactive transport geochemical modeling study was conducted to help predict the mineral transformations occurring over a ten year time-scale that are expected to impact soil hydraulic properties in the Biosphere 2 (B2 synthetic hillslope experiment. The modeling sought to predict the rate and extent of weathering of a granular basalt (selected for hillslope construction as a function of climatic drivers, and to assess the feedback effects of such weathering processes on the hydraulic properties of the hillslope. Flow vectors were imported from HYDRUS into a reactive transport code, CrunchFlow2007, which was then used to model mineral weathering coupled to reactive solute transport. Associated particle size evolution was translated into changes in saturated hydraulic conductivity using Rosetta software. We found that flow characteristics, including velocity and saturation, strongly influenced the predicted extent of incongruent mineral weathering and neo-phase precipitation on the hillslope. Results were also highly sensitive to specific surface areas of the soil media, consistent with surface reaction controls on dissolution. Effects of fluid flow on weathering resulted in significant differences in the prediction of soil particle size distributions, which should feedback to alter hillslope hydraulic conductivities.

  1. Solid phase evolution in the Biosphere 2 hillslope experiment as predicted by modeling of hydrologic and geochemical fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Dontsova, K.; Steefel, C.I.; Desilets, S.; Thompson, A.; Chorover, J.

    2009-07-15

    A reactive transport geochemical modeling study was conducted to help predict the mineral transformations occurring over a ten year time-scale that are expected to impact soil hydraulic properties in the Biosphere 2 (B2) synthetic hillslope experiment. The modeling sought to predict the rate and extent of weathering of a granular basalt (selected for hillslope construction) as a function of climatic drivers, and to assess the feedback effects of such weathering processes on the hydraulic properties of the hillslope. Flow vectors were imported from HYDRUS into a reactive transport code, CrunchFlow2007, which was then used to model mineral weathering coupled to reactive solute transport. Associated particle size evolution was translated into changes in saturated hydraulic conductivity using Rosetta software. We found that flow characteristics, including velocity and saturation, strongly influenced the predicted extent of incongruent mineral weathering and neo-phase precipitation on the hillslope. Results were also highly sensitive to specific surface areas of the soil media, consistent with surface reaction controls on dissolution. Effects of fluid flow on weathering resulted in significant differences in the prediction of soil particle size distributions, which should feedback to alter hillslope hydraulic conductivities.

  2. Combining Ground-based and Satellite Observations to Reconstruct Changes in the Functioning of the Terrestrial Biosphere

    Science.gov (United States)

    Cox, P. M.; Groenendijk, M.

    2014-12-01

    Vegetation links the planet's water and carbon cycles. Stomata on plant leaves are the pores through which CO2 is fixed during photosynthesis, and also the pores through which water is returned to the atmosphere as the transpiration flux. Stomata therefore exert considerable control over both the water and carbon cycles. Unfortunately, the long-term responses of stomata to rising CO2 and changes in climate are still rather uncertain, despite their significance for future climate. In contrast, Plant Water Use Efficiency (WUE) which is the ratio of the carbon assimilated through photosynthesis to the water lost through transpiration, is a robust diagnostic of the functioning of the land biosphere that is not directly dependent on the uncertain long-term responses of stomata. We have recently shown that it is possible to get constrained estimates of fractional changes in WUE based purely on changes in atmospheric CO2 and near surface temperature and humidity. This is achieved by calibrating against eddy covariance flux measurements (that constrain the response of WUE to humidity deficit), and also d13C records from tree-rings (that constrain the CO2-sensitivity of WUE). This talk will show how these ground-based measurements imply very significant changes in WUE, both globally and regionally, from 1900 onwards. Furthermore, we will show how the combination of our reconstructed changes in WUE with satellite-based estimates of Gross Primary Productivity, enable recent changes in plant transpiration to be estimated.

  3. Implications of Biospheric Energization

    Science.gov (United States)

    Budding, Edd; Demircan, Osman; Gündüz, Güngör; Emin Özel, Mehmet

    2016-07-01

    Our physical model relating to the origin and development of lifelike processes from very simple beginnings is reviewed. This molecular ('ABC') process is compared with the chemoton model, noting the role of the autocatalytic tuning to the time-dependent source of energy. This substantiates a Darwinian character to evolution. The system evolves from very simple beginnings to a progressively more highly tuned, energized and complex responding biosphere, that grows exponentially; albeit with a very low net growth factor. Rates of growth and complexity in the evolution raise disturbing issues of inherent stability. Autocatalytic processes can include a fractal character to their development allowing recapitulative effects to be observed. This property, in allowing similarities of pattern to be recognized, can be useful in interpreting complex (lifelike) systems.

  4. Development of a generic analysis code of dynamic compartment model for evaluation of doses in terrestrial biosphere

    International Nuclear Information System (INIS)

    The release rate of a nuclide from a reactor or a radioactive waste disposal plant at the accident is not steady, but varies with time. The various parameters of a nuclide migration into environment vary also day after day, or with the seasons. In such cases, dynamic behavior of the nuclide in the environment must be taken into consideration. It is difficult for a mathematical model to involve all of mechanisms for the nuclide migration. The environment for evaluation of doses are usually divided into some of compartments in which a nuclide concentration is uniform. Time variations of the nuclide concentration in the compartment are described in simultaneous differential equations. The nuclide concentration can be solved as a time function, and the radiation doses, therefore, can be estimated as a time function. Generic analysis code for dynamic compartment model (GACOM) is developed for the nuclide migration and the evaluation of doses in terrestrial biosphere. The code contains many items, such as atmospheric release, vertical migration between surface soil layers, lake system, nuclide concentrations in the compartment, internal doses by inhalation, internal doses by ingestion of drinking water, crops, animal products, aquatic products, and external doses. The GACOM has been confirmed by the analysis of international cooperational research program (BIOMOVS II): long term contaminant migration and impacts from uranium mill tailing. (Suetake, M.)

  5. Coupled Climate–Economy–Biosphere (CoCEB model – Part 1: Abatement share and investment in low-carbon technologies

    Directory of Open Access Journals (Sweden)

    K. B. Z. Ogutu

    2015-04-01

    Full Text Available The Coupled Climate–Economy–Biosphere (CoCEB model described herein takes an integrated assessment approach to simulating global change. By using an endogenous economic growth module with physical and human capital accumulation, this paper considers the sustainability of economic growth, as economic activity intensifies greenhouse gas emissions that in turn cause economic damage due to climate change. Different types of fossil fuels and different technologies produce different volumes of carbon dioxide in combustion. The shares of different fuels and their future evolution are not known. We assume that the dynamics of hydrocarbon-based energy share and their replacement with renewable energy sources in the global energy balance can be modeled into the 21st century by use of logistic functions. Various climate change mitigation policy measures are considered. While many integrated assessment models treat abatement costs merely as an unproductive loss of income, we consider abatement activities also as an investment in overall energy efficiency of the economy and decrease of overall carbon intensity of the energy system. The paper shows that these efforts help to reduce the volume of industrial carbon dioxide emissions, lower temperature deviations, and lead to positive effects in economic growth.

  6. Global Land Data Assimilation System data assessment using a distributed biosphere hydrological model

    Science.gov (United States)

    Qi, Wei; Zhang, Chi; Fu, Guangtao; Zhou, Huicheng

    2015-09-01

    Observed water and energy fluxes are sparse in many regions of the world. The overall aim of this study is to demonstrate the applicability of Global Land Data Assimilation System-Noah (GLDAS/Noah) data for basin scale water and energy studies in terms of input, output, seasonal and spatial distributions. A Water and Energy Budget-based Distributed Hydrological Model (WEB-DHM) is employed to evaluate the output of GLDAS/Noah and the simulations of seasonal and spatial distributions of fluxes after calibration with discharges and MODIS land surface temperatures (LSTs) in a semiarid catchment. GLDAS/Noah air temperatures and humidity agree well with observations, but GLDAS/Noah overestimates downward solar radiation and wind speed. LSTs and upward long wave radiation from GLDAS/Noah and WEB-DHM are comparable, but GLDAS/Noah shows larger upward shortwave, net radiation, latent heat, sensible heat fluxes and smaller ground heat flux amplitude. Two correction functions are developed for downward solar radiation and wind speed. The accuracy of discharges and LSTs is improved after corrections. The simulated seasonal and spatial distributions of water and energy fluxes and states (LSTs, evapotranspiration, surface, root, deep soil wetness, ground heat flux, latent heat flux, sensible heat flux, upward long wave radiation and upward shortwave radiation) show high accuracy using corrected GLDAS/Noah data. The findings provide an insight into the applicability of GLDAS/Noah.

  7. Incorporation of crop phenology in Simple Biosphere Model (SiBcrop to improve land-atmosphere carbon exchanges from croplands

    Directory of Open Access Journals (Sweden)

    E. Lokupitiya

    2009-02-01

    Full Text Available Croplands are man-made ecosystems that have high net primary productivity during the growing season of crops, thus impacting carbon and other exchanges with the atmosphere. These exchanges play a~major role in nutrient cycling and climate change related issues. An accurate representation of crop phenology and physiology is important in land-atmosphere carbon models being used to predict these exchanges. To better estimate time-varying exchanges of carbon, water, and energy of croplands using the Simple Biosphere (SiB model, we developed crop-specific phenology models and coupled them to SiB. The coupled SiB-phenology model (SiBcrop replaces remotely-sensed NDVI information, on which SiB originally relied for deriving Leaf Area Index (LAI and the fraction of Photosynthetically Active Radiation (fPAR for estimating carbon dynamics. The use of the new phenology scheme within SiB substantially improved the prediction of LAI and carbon fluxes for maize, soybean, and wheat crops, as compared with the observed data at several AmeriFlux eddy covariance flux tower sites in the US mid continent region. SiBcrop better predicted the onset and end of the growing season, harvest, interannual variability associated with crop rotation, day time carbon uptake (especially for maize and day to day variability in carbon exchange. Biomass predicted by SiBcrop had good agreement with the observed biomass at field sites. In the future, we will predict fine resolution regional scale carbon and other exchanges by coupling SiBcrop with RAMS (the Regional Atmospheric Modeling System.

  8. Incorporation of crop phenology in Simple Biosphere Model (SiBcrop) to improve land-atmosphere carbon exchanges from croplands

    Science.gov (United States)

    Lokupitiya, E.; Denning, S.; Paustian, K.; Baker, I.; Schaefer, K.; Verma, S.; Meyers, T.; Bernacchi, C. J.; Suyker, A.; Fischer, M.

    2009-06-01

    Croplands are man-made ecosystems that have high net primary productivity during the growing season of crops, thus impacting carbon and other exchanges with the atmosphere. These exchanges play a major role in nutrient cycling and climate change related issues. An accurate representation of crop phenology and physiology is important in land-atmosphere carbon models being used to predict these exchanges. To better estimate time-varying exchanges of carbon, water, and energy of croplands using the Simple Biosphere (SiB) model, we developed crop-specific phenology models and coupled them to SiB. The coupled SiB-phenology model (SiBcrop) replaces remotely-sensed NDVI information, on which SiB originally relied for deriving Leaf Area Index (LAI) and the fraction of Photosynthetically Active Radiation (fPAR) for estimating carbon dynamics. The use of the new phenology scheme within SiB substantially improved the prediction of LAI and carbon fluxes for maize, soybean, and wheat crops, as compared with the observed data at several AmeriFlux eddy covariance flux tower sites in the US mid continent region. SiBcrop better predicted the onset and end of the growing season, harvest, interannual variability associated with crop rotation, day time carbon uptake (especially for maize) and day to day variability in carbon exchange. Biomass predicted by SiBcrop had good agreement with the observed biomass at field sites. In the future, we will predict fine resolution regional scale carbon and other exchanges by coupling SiBcrop with RAMS (the Regional Atmospheric Modeling System).

  9. Incorporation of crop phenology in Simple Biosphere Model (SiBcrop to improve land-atmosphere carbon exchanges from croplands

    Directory of Open Access Journals (Sweden)

    E. Lokupitiya

    2009-06-01

    Full Text Available Croplands are man-made ecosystems that have high net primary productivity during the growing season of crops, thus impacting carbon and other exchanges with the atmosphere. These exchanges play a major role in nutrient cycling and climate change related issues. An accurate representation of crop phenology and physiology is important in land-atmosphere carbon models being used to predict these exchanges. To better estimate time-varying exchanges of carbon, water, and energy of croplands using the Simple Biosphere (SiB model, we developed crop-specific phenology models and coupled them to SiB. The coupled SiB-phenology model (SiBcrop replaces remotely-sensed NDVI information, on which SiB originally relied for deriving Leaf Area Index (LAI and the fraction of Photosynthetically Active Radiation (fPAR for estimating carbon dynamics. The use of the new phenology scheme within SiB substantially improved the prediction of LAI and carbon fluxes for maize, soybean, and wheat crops, as compared with the observed data at several AmeriFlux eddy covariance flux tower sites in the US mid continent region. SiBcrop better predicted the onset and end of the growing season, harvest, interannual variability associated with crop rotation, day time carbon uptake (especially for maize and day to day variability in carbon exchange. Biomass predicted by SiBcrop had good agreement with the observed biomass at field sites. In the future, we will predict fine resolution regional scale carbon and other exchanges by coupling SiBcrop with RAMS (the Regional Atmospheric Modeling System.

  10. Nominal Performance Biosphere Dose Conversion Factor Analysis

    International Nuclear Information System (INIS)

    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

  11. Coupled Climate–Economy–Biosphere (CoCEB) model – Part 2: Deforestation control and investment in carbon capture and storage technologies

    OpenAIRE

    K. B. Z. Ogutu; F. D'Andrea; M. Ghil; C. Nyandwi; M. M. Manene; J. N. Muthama

    2015-01-01

    This study uses the global climate–economy–biosphere (CoCEB) model developed in Part 1 to investigate economic aspects of deforestation control and carbon sequestration in forests, as well as the efficiency of carbon capture and storage (CCS) technologies as policy measures for climate change mitigation. We assume – as in Part 1 – that replacement of one technology with another occurs in terms of a logistic law, so that the same law also governs the dynamics...

  12. Coupled Climate–Economy–Biosphere (CoCEB) model – Part 1: Abatement share and investment in low-carbon technologies

    OpenAIRE

    K. B. Z. Ogutu; F. D'Andrea; M. Ghil; C. Nyandwi; M. M. Manene; J. N. Muthama

    2015-01-01

    The Coupled Climate–Economy–Biosphere (CoCEB) model described herein takes an integrated assessment approach to simulating global change. By using an endogenous economic growth module with physical and human capital accumulation, this paper considers the sustainability of economic growth, as economic activity intensifies greenhouse gas emissions that in turn cause economic damage due to climate change. Different types of fossil fuels and different technologi...

  13. 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

  14. Technical note: 3-hourly temporal downscaling of monthly global terrestrial biosphere model net ecosystem exchange

    Science.gov (United States)

    Fisher, Joshua B.; Sikka, Munish; Huntzinger, Deborah N.; Schwalm, Christopher; Liu, Junjie

    2016-07-01

    The land surface provides a boundary condition to atmospheric forward and flux inversion models. These models require prior estimates of CO2 fluxes at relatively high temporal resolutions (e.g., 3-hourly) because of the high frequency of atmospheric mixing and wind heterogeneity. However, land surface model CO2 fluxes are often provided at monthly time steps, typically because the land surface modeling community focuses more on time steps associated with plant phenology (e.g., seasonal) than on sub-daily phenomena. Here, we describe a new dataset created from 15 global land surface models and 4 ensemble products in the Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP), temporally downscaled from monthly to 3-hourly output. We provide 3-hourly output for each individual model over 7 years (2004-2010), as well as an ensemble mean, a weighted ensemble mean, and the multi-model standard deviation. Output is provided in three different spatial resolutions for user preferences: 0.5° × 0.5°, 2.0° × 2.5°, and 4.0° × 5.0° (latitude × longitude). These data are publicly available from doi:10.3334/ORNLDAAC/1315.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-02-01

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

  16. An intercomparison of measured and modeled canopy parameters during the variable water-stressed period of FIFE 1989 using an hybrid biosphere-remote sensing model

    Science.gov (United States)

    Cooper, H. J.; Crosson, W. L.; Smith, E. A.

    1992-01-01

    The measured atmospheric parameters and the fluxes of latent and sensible heat across the biosphere-atmosphere interface collected during the water-stressed period of the First ISLSCP Field Experiment (FIFE) were compared with those calculated by an experimental version of the Biosphere-Atmosphere Transfer Scheme (Ex-BATS). It is shown that the brightness temperature (T(B)) values observed near the surface during FIFE 1987 are closely correlated to in-canopy temperatures calculated by Ex-BATS. The 1987 near-surface observations of T(B) are also well correlated to AVHHR channels 4 and 5 measurements. An inverted form of Ex-BATS was applied to determine the associated required in-canopy temperatures, T(icr), and regressions between T(icr) and T(B) found from the 1987 data were applied to the 1989 observed T(B) at a different site. The T(icr) so estimated showed excellent correlation to the 1989 model calculated T(icr).

  17. Transport of radionuclides in the biosphere

    International Nuclear Information System (INIS)

    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.)

  18. Response of a One-Biosphere Nutrient Modeling System to Regional Land Use and Management Change

    Science.gov (United States)

    A multi-media system of nitrogen and co-pollutant models describing critical physical and chemical processes that cascade synergistically and competitively through the environment, the economy and society has been developed at the USEPA Office of Research and Development (see fig...

  19. 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

  20. Final report on "Modeling Diurnal Variations of California Land Biosphere CO2 Fluxes"

    Energy Technology Data Exchange (ETDEWEB)

    Fung, Inez

    2014-07-28

    In Mediterranean climates, the season of water availability (winter) is out of phase with the season of light availability and atmospheric demand for moisture (summer). Multi-year half-hourly observations of sap flow velocities in 26 evergreen trees in a small watershed in Northern California show that different species of evergreen trees have different seasonalities of transpiration: Douglas-firs respond immediately to the first winter rain, while Pacific madrones have peak transpiration in the dry summer. Using these observations, we have derived species-specific parameterization of normalized sap flow velocities in terms of insolation, vapor pressure deficit and near-surface soil moisture. A simple 1-D boundary layer model showed that afternoon temperatures may be higher by 1 degree Celsius in an area with Douglas-firs than with Pacific madrones. The results point to the need to develop a new representation of subsurface moisture, in particular pools beneath the organic soil mantle and the vadose zone. Our ongoing and future work includes coupling our new parameterization of transpiration with new representation of sub-surface moisture in saprolite and weathered bedrock. The results will be implemented in a regional climate model to explore vegetation-climate feedbacks, especially in the dry season.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-08-01

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

  2. The Photochemical Oxidation of Siderite That Drove Hydrogen Based Microbial Redox Reactions in The Archean Biosphere

    Science.gov (United States)

    Kim, J. D.; Yee, N.; Falkowski, P. G.

    2012-12-01

    Hydrogen is the most abundant element in the universe and molecular hydrogen (H2) is a rich source of electron in a mildly reducing environment for microbial redox reactions, such as anoxygenic photosynthesis and methanogenesis. Subaerial volcanoes, ocean crust serpentinization and mid-ocean ridge volcanoes have been believed to be the major source of the hydrogen flux to the atmosphere. Although ferrous ion (Fe2+) photooxidation has been proposed as an alternative mechanism by which hydrogen gas was produced, ferruginous water in contact with a CO2-bearing atmosphere is supersaturated with respect to FeCO3 (siderite), thus the precipitation of siderite would have been thermodynamically favored in the Archean environment. Siderite is the critical mineral component of the oldest fossilized microbial mat. It has also been inferred as a component of chemical sedimentary protolith in the >3750 Ma Nuvvuagittuq supracrustal belt, Canada and the presence of siderite in the protolith suggests the occurrence of siderite extends to Hadean time. Analyses of photooxidation of siderite suggest a significant flux of hydrogen in the early atmosphere. Our estimate of the hydrogen production rate under Archean solar flux is approximately 50 times greater than the estimated hydrogen production rate by the volcanic activity based on a previous report (Tian et al. Science 2005). Our analyses on siderite photooxidation also suggest a mechanism by which banded iron formation (BIF) was formed. The photooxidation transforms siderite to magnetite/maghemite (spinnel iron oxide), while oxygenic oxidation of siderite leads to goethite, and subsequently to hematite (Fe3+2O3) upon dehydration. We will discuss the photochemical reaction, which was once one of the most ubiquitous photochemical reactions before the rise of oxygen in the atmosphere. Photooxidation of siderite over time by UV light From left to right: UV oxidized siderite, pristine siderite, oxidized siderite by oxygen

  3. Drivers and patterns of land biosphere carbon balance reversal

    Science.gov (United States)

    Müller, Christoph; Stehfest, Elke; van Minnen, Jelle G.; Strengers, Bart; von Bloh, Werner; Beusen, Arthur H. W.; Schaphoff, Sibyll; Kram, Tom; Lucht, Wolfgang

    2016-04-01

    The carbon balance of the land biosphere is the result of complex interactions between land, atmosphere and oceans, including climatic change, carbon dioxide fertilization and land-use change. While the land biosphere currently absorbs carbon dioxide from the atmosphere, this carbon balance might be reversed under climate and land-use change (‘carbon balance reversal’). A carbon balance reversal would render climate mitigation much more difficult, as net negative emissions would be needed to even stabilize atmospheric carbon dioxide concentrations. We investigate the robustness of the land biosphere carbon sink under different socio-economic pathways by systematically varying climate sensitivity, spatial patterns of climate change and resulting land-use changes. For this, we employ a modelling framework designed to account for all relevant feedback mechanisms by coupling the integrated assessment model IMAGE with the process-based dynamic vegetation, hydrology and crop growth model LPJmL. We find that carbon balance reversal can occur under a broad range of forcings and is connected to changes in tree cover and soil carbon mainly in northern latitudes. These changes are largely a consequence of vegetation responses to varying climate and only partially of land-use change and the rate of climate change. Spatial patterns of climate change as deduced from different climate models, substantially determine how much pressure in terms of global warming and land-use change the land biosphere will tolerate before the carbon balance is reversed. A reversal of the land biosphere carbon balance can occur as early as 2030, although at very low probability, and should be considered in the design of so-called peak-and-decline strategies.

  4. Sustainable Development of the Biosphere

    OpenAIRE

    Clark, W C; Munn, R.E.

    1986-01-01

    The future management of the world's resources depends upon reconciling the needs of socio-economic development with the conservation of the world's environment. This book provides a strategic framework for understanding and managing the long-term and large-scale interactions between these two requirements, based upon the sustainable development of the natural resources of the biosphere. It represents the first results of an on-going collaborative study organized by the International Institut...

  5. Testing of environmental transfer models using data from the atmospheric release of Iodine-131 from the Hanford site, USA, in 1963. Report of the Dose Reconstruction Working Group of the Biosphere Modelling and Assessment (BIOMASS) Programme, Theme 2

    International Nuclear Information System (INIS)

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

  6. Farmers' Perceptions of a Mountain Biosphere Reserve in Austria

    Directory of Open Access Journals (Sweden)

    Adelheid Humer-Gruber

    2016-05-01

    Full Text Available This study explored farmers’ perceptions of a biosphere reserve in the Austrian Alps with the goal of promoting better understanding among different stakeholders involved in the agricultural sector in a biosphere reserve. Biosphere reserves have a variety of functions and serve as models of sustainable regional development and involve stakeholders in decision-making on and development of protected areas. In the Alpine biosphere reserve selected for this study, the conservation of cultural landscapes plays a major role; therefore, farmers feature prominently, and this study focuses on their points of view. Farmers rely heavily on natural resources, but structural changes in agriculture determine their work to a large degree, and they often refuse to support protected area management. This situation calls for a closer integration of social-scientific knowledge in regional development programs. Qualitative research methods based on grounded theory can help identify sources of conflict and social strengths. The study found substantial support for the reserve but also a noticeable lessening of the original excitement about it, pointing to the need for further outreach and to the importance, when establishing future reserves, of handling the start-up phase with heightened sensitivity.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Hanqin [Auburn Univ., AL (United States); Lu, Chaoqun [Auburn Univ., AL (United States); Yang, Jia [Auburn Univ., AL (United States); Banger, Kamaljit [Auburn Univ., AL (United States); Huntzinger, Deborah N. [Northern Arizona Univ., Flagstaff, AZ (United States); Schwalm, Christopher R. [Northern Arizona Univ., Flagstaff, AZ (United States); Michalak, A. M. [Carnegie Inst. for Science, Stanford, CA (United States); Cook, Robert B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ciais, Philippe [Climate and Environment Sciences Lab. (LSCE) (France); Hayes, Daniel J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Huang, Maoyi [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ito, Akihiko [National Inst. for Environmental Studies, Tsukuba (Japan); Jain, Atul K. [Univ. of Illinois, Urbana-Champaign, IL (United States); Lei, Huimin [Tsinghua Univ., Beijing (China); Mao, Jiafu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pan, Shufen [Auburn Univ., AL (United States); Post, W. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peng, Shushi [Climate and Environment Sciences Lab. (LSCE) (France); Poulter, Benjamin [Montana State Univ., Bozeman, MT (United States); Ren, Wei [Auburn Univ., AL (United States); Ricciuto, Daniel M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Schaefer, Kevin [National Snow and Ice Data Center, Boulder, CO (United States); Shi, Xiaoying [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tao, Bo [Auburn Univ., AL (United States); Wang, Weile [National Aeronautics and Space Administration, Mountain View, CA (United States); Wei, Yaxing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yang, Qichun [Auburn Univ., AL (United States); Zhang, Bowen [Auburn Univ., AL (United States); Zeng, Ning [Univ. of Maryland, College Park, MD (United States)

    2015-06-05

    Soil is the largest organic carbon (C) pool of terrestrial ecosystems, and loss from soil accounts for a large pro portion of land-atmosphere C exchange. Due to large pool size and variable residence time from years to millennia, even small changes in soil organic C(SOC) have substantial effects on the terrestrial C budget, thereby affecting atmospheric carbon dioxide (CO2)concentration and climate change. In the past decades, a wide variety of studies have been conducted to quantify global SOC stocks and soil 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 storage and fluxes remains a key research challenge his study has compiled century-long (1901-2010)estimates of SOC storage and heterotrophic respiration (Rh) from ten terrestrial biosphere models (TBMs) in the Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) and two observation based datasets. The ten-TBM ensemble shows that global SOC estimate range from 4 to 2111 Pg C (1 Pg = 1015g) with a median value of 1158 Pg C33 in 2010. Modeling approach estimates a broad range of Rh from 35 to 69 Pg C yr-1 with a median value of 51Pg C yr-1 during 200–2010. The largest uncertainty in SOC stocks exists in the 40–65°N latitude band while Rh differences are the largest in the tropics. All the models agreed that climate and land use changes have decreased SOC stocks while elevated CO2 and atmospheric nitrogen deposition have increased SOC stocks though the response varied significantly among models. Model representations of temperature and moisture sensitivity,nutrient limitation and land use partially explain the divergent estimates of global SOC stocks and soil fluxes in this study. In addition, major sources of uncertainty from model estimation include exclusion of SOC storage in

  8. The EC BIOCLIM Project (2000-2003), 5. Euratom Framework Programme - Modelling sequential biosphere systems under climate change for radioactive waste disposal

    International Nuclear Information System (INIS)

    Marianne Calvez (ANDRA, France) presented the new EC BIOCLIM project that started in 2001. Its main objective is to provide a scientific basis and practical methodology for assessing the possible long-term impacts on the safety of radioactive waste repositories in deep formations due to climate driven changes. She explained that BIOCLIM objective is not to predict what will be the future but will correspond to an illustration of how people could use the knowledge. The BIOCLIM project will use the outcomes from the Biomass project. Where Biomass considered discrete biospheres, the BIOCLIM project will consider the evolution of climate with a focus on the European climate for three regions in the United Kingdom, France and Spain. The consortium of BIOCLIM participants consists of various experts in climate modelling and various experts and organisations in performance assessment. The intent is to build an integrated dynamic climate model that represents all the important mechanisms for long-term climate evolution. The modelling will primarily address the next 200000 years. The final outcome will be an enhancement of the state-of-the-art treatment of biosphere system change over long periods of time through the use of a number of innovative climate modelling approaches and the application of the climate model outputs in performance assessments

  9. Conch, Cooperatives, and Conflict: Conservation and Resistance in the Banco Chinchorro Biosphere Reserve

    Directory of Open Access Journals (Sweden)

    David M Hoffman

    2014-01-01

    Full Text Available In theory, biosphere reserves link biodiversity conservation with development, primarily through sustainable resource utilisation, and alternative, conservation-compatible economies in the buffer and transition zones outside the core area. Successful management should reduce pressure on natural resources within its core area as well as enable local communities to participate in the management of buffer zone resources in a sustainable manner. The Banco Chinchorro Biosphere Reserve was declared in 1996 to protect coral reefs and marine biodiversity, while also enabling fishing cooperatives to maintain their livelihoods based upon the sustainable extraction of lobster, conch, and scalefish. In 2004, eight years after the Reserve′s declaration, Mexican authorities struggled to control marine resource use in the reserve, especially the extraction of queen conch (Strombus gigas. This article provides an overview of the long struggle to conserve queen conch populations in the area. Particular attention is paid to describing the various forms of resistance fishermen employed to counter the increasing regulation and vigilance that accompanied the creation of the Banco Chinchorro Biosphere Reserve. This case chronicles the resistance to regulation and interpersonal violence that erupts when entrenched attitudes and practices are confronted with increasing surveillance. Thus, what was observed in the Banco Chinchorro Biosphere Reserve parallels other research that depicts the forms of resistance to conservation that local people enact when confronted with conservation interventions. Finally, the plight of queen conch in the Banco Chinchorro Biosphere Reserve clearly reflects the conflicts and difficulties found across Mexico in the implementation of the biosphere reserve model.

  10. Conceptual and numerical modelling of radionuclide transport in near-surface systems at Forsmark. SR-Site Biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Pique, Angels; Grandia, Fidel; Sena, Clara; Arcos, David; Molinero, Jorge; Duro, Lara; Bruno, Jordi (Amphos21 Consulting S.L., Barcelona (Spain))

    2010-11-15

    In the framework of the SR-Site safety assessment, a conceptual and numerical modelling of radionuclide reactive transport in near-surface systems (including till and clay systems) at Forsmark has been carried out. The objective was to evaluate the retention capacity of the near-surface systems, composed of Quaternary deposits, which would be the last natural barrier for an eventual radionuclide release from the deep repository prior to reaching the biosphere. The studied radionuclides are 14C, 129I, 36Cl, 94Nb, 59Ni, 93Mo, 79Se, 99Tc, 230Th, 90Sr, 226Ra, 135Cs and U. Conceptual description and numerical simulations of radionuclide reactive transport show that cation exchange and surface complexation on illite are active processes for the retention of several radionuclides (U, Th, Ni, Cs, Sr, Ra). Surface complexation on iron hydroxide is an active process in the till system, able to effectively retain U and Ni. Another retention process of importance is the incorporation of the radionuclides into mineral phases, either by the precipitation of pure phases or solid solutions. Quantitative modelling has been useful to illustrate the incorporation of C and Sr in the carbonate solid solution in the considered model domains (till and clay), as well as the precipitation of uraninite in the clay sediments and the precipitation of native selenium and radiobarite in the till. Other mineral phases that could, a priori, retain U, Se, Nb and Tc do not precipitate in the simulations, either due to the pH-Eh conditions and/or because the dissolved concentration of the element is not high enough under the considered simulation conditions. It is important to keep in mind that changes in these parameters and in the boundary conditions could modify the predicted behaviour of these elements. The radionuclides that are most significantly retarded are Th, Ni and Cs, mainly through sorption onto illite. Therefore, if the amount of illite (or available sorption sites) decreases, the

  11. Conceptual and numerical modelling of radionuclide transport in near-surface systems at Forsmark. SR-Site Biosphere

    International Nuclear Information System (INIS)

    In the framework of the SR-Site safety assessment, a conceptual and numerical modelling of radionuclide reactive transport in near-surface systems (including till and clay systems) at Forsmark has been carried out. The objective was to evaluate the retention capacity of the near-surface systems, composed of Quaternary deposits, which would be the last natural barrier for an eventual radionuclide release from the deep repository prior to reaching the biosphere. The studied radionuclides are 14C, 129I, 36Cl, 94Nb, 59Ni, 93Mo, 79Se, 99Tc, 230Th, 90Sr, 226Ra, 135Cs and U. Conceptual description and numerical simulations of radionuclide reactive transport show that cation exchange and surface complexation on illite are active processes for the retention of several radionuclides (U, Th, Ni, Cs, Sr, Ra). Surface complexation on iron hydroxide is an active process in the till system, able to effectively retain U and Ni. Another retention process of importance is the incorporation of the radionuclides into mineral phases, either by the precipitation of pure phases or solid solutions. Quantitative modelling has been useful to illustrate the incorporation of C and Sr in the carbonate solid solution in the considered model domains (till and clay), as well as the precipitation of uraninite in the clay sediments and the precipitation of native selenium and radiobarite in the till. Other mineral phases that could, a priori, retain U, Se, Nb and Tc do not precipitate in the simulations, either due to the pH-Eh conditions and/or because the dissolved concentration of the element is not high enough under the considered simulation conditions. It is important to keep in mind that changes in these parameters and in the boundary conditions could modify the predicted behaviour of these elements. The radionuclides that are most significantly retarded are Th, Ni and Cs, mainly through sorption onto illite. Therefore, if the amount of illite (or available sorption sites) decreases, the

  12. Disaggregating Fossil Fuel Emissions from Biospheric Fluxes: Methodological Improvements for Inverse Methods

    Science.gov (United States)

    Yadav, V.; Shiga, Y. P.; Michalak, A. M.

    2012-12-01

    The accurate spatio-temporal quantification of fossil fuel emissions is a scientific challenge. Atmospheric inverse models have the capability to overcome this challenge and provide estimates of fossil fuel emissions. Observational and computational limitations limit current analyses to the estimations of a combined "biospheric flux and fossil-fuel emissions" carbon dioxide (CO2) signal, at coarse spatial and temporal resolution. Even in these coarse resolution inverse models, the disaggregation of a strong biospheric signal form a weaker fossil-fuel signal has proven difficult. The use of multiple tracers (delta 14C, CO, CH4, etc.) has provided a potential path forward, but challenges remain. In this study, we attempt to disaggregate biospheric fluxes and fossil-fuel emissions on the basis of error covariance models rather through tracer based CO2 inversions. The goal is to more accurately define the underlying structure of the two processes by using a stationary exponential covariance model for the biospheric fluxes, in conjunction with a semi-stationary covariance model derived from nightlights for fossil fuel emissions. A non-negativity constraint on fossil fuel emissions is imposed using a data transformation approach embedded in an iterative quasi-linear inverse modeling algorithm. The study is performed for January and June 2008, using the ground-based CO2 measurement network over North America. The quality of disaggregation is examined by comparing the inferred spatial distribution of biospheric fluxes and fossil-fuel emissions in a synthetic-data inversion. In addition to disaggregation of fluxes, the ability of the covariance models derived from nightlights to explain the fossil-fuel emissions over North America is also examined. The simple covariance model proposed in this study is found to improve estimation and disaggregation of fossil-fuel emissions from biospheric fluxes in the tracer-based inverse models.

  13. 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

  14. Forecasting carbon budget under climate change and CO2 fertilization for subtropical region in China using integrated biosphere simulator (IBIS) model

    Science.gov (United States)

    Zhu, Q.; Jiang, H.; Liu, J.; Peng, C.; Fang, X.; Yu, S.; Zhou, G.; Wei, X.; Ju, W.

    2011-01-01

    The regional carbon budget of the climatic transition zone may be very sensitive to climate change and increasing atmospheric CO2 concentrations. This study simulated the carbon cycles under these changes using process-based ecosystem models. The Integrated Biosphere Simulator (IBIS), a Dynamic Global Vegetation Model (DGVM), was used to evaluate the impacts of climate change and CO2 fertilization on net primary production (NPP), net ecosystem production (NEP), and the vegetation structure of terrestrial ecosystems in Zhejiang province (area 101,800 km2, mainly covered by subtropical evergreen forest and warm-temperate evergreen broadleaf forest) which is located in the subtropical climate area of China. Two general circulation models (HADCM3 and CGCM3) representing four IPCC climate change scenarios (HC3AA, HC3GG, CGCM-sresa2, and CGCM-sresb1) were used as climate inputs for IBIS. Results show that simulated historical biomass and NPP are consistent with field and other modelled data, which makes the analysis of future carbon budget reliable. The results indicate that NPP over the entire Zhejiang province was about 55 Mt C yr-1 during the last half of the 21st century. An NPP increase of about 24 Mt C by the end of the 21st century was estimated with the combined effects of increasing CO2 and climate change. A slight NPP increase of about 5 Mt C was estimated under the climate change alone scenario. Forests in Zhejiang are currently acting as a carbon sink with an average NEP of about 2.5 Mt C yr-1. NEP will increase to about 5 Mt C yr-1 by the end of the 21st century with the increasing atmospheric CO2 concentration and climate change. However, climate change alone will reduce the forest carbon sequestration of Zhejiang's forests. Future climate warming will substantially change the vegetation cover types; warm-temperate evergreen broadleaf forest will be gradually substituted by subtropical evergreen forest. An increasing CO2 concentration will have little

  15. Forecasting carbon budget under climate change and CO 2 fertilization for subtropical region in China using integrated biosphere simulator (IBIS) model

    Science.gov (United States)

    Zhu, Q.; Jiang, H.; Liu, J.; Peng, C.; Fang, X.; Yu, S.; Zhou, G.; Wei, X.; Ju, W.

    2011-01-01

    The regional carbon budget of the climatic transition zone may be very sensitive to climate change and increasing atmospheric CO 2 concentrations. This study simulated the carbon cycles under these changes using process-based ecosystem models. The Integrated Biosphere Simulator (IBIS), a Dynamic Global Vegetation Model (DGVM), was used to evaluate the impacts of climate change and CO 2 fertilization on net primary production (NPP), net ecosystem production (NEP), and the vegetation structure of terrestrial ecosystems in Zhejiang province (area 101,800 km 2, mainly covered by subtropical evergreen forest and warm-temperate evergreen broadleaf forest) which is located in the subtropical climate area of China. Two general circulation models (HADCM3 and CGCM3) representing four IPCC climate change scenarios (HC3AA, HC3GG, CGCM-sresa2, and CGCM-sresb1) were used as climate inputs for IBIS. Results show that simulated historical biomass and NPP are consistent with field and other modelled data, which makes the analysis of future carbon budget reliable. The results indicate that NPP over the entire Zhejiang province was about 55 Mt C yr -1 during the last half of the 21 st century. An NPP increase of about 24 Mt C by the end of the 21 st century was estimated with the combined effects of increasing CO 2 and climate change. A slight NPP increase of about 5 Mt C was estimated under the climate change alone scenario. Forests in Zhejiang are currently acting as a carbon sink with an average NEP of about 2.5 Mt C yr -1. NEP will increase to about 5 Mt C yr -1 by the end of the 21 st century with the increasing atmospheric CO 2 concentration and climate change. However, climate change alone will reduce the forest carbon sequestration of Zhejiang's forests. Future climate warming will substantially change the vegetation cover types; warm-temperate evergreen broadleaf forest will be gradually substituted by subtropical evergreen forest. An increasing CO 2 concentration will have

  16. Causes and timing of future biosphere extinction

    Directory of Open Access Journals (Sweden)

    S. Franck

    2005-11-01

    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 aggregated reservoir ocean and atmosphere. The model is specified by introducing three different types of biosphere: procaryotes, eucaryotes, and complex multicellular life. We find that from the Archaean to the future a procaryotic biosphere always exists. 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. The ultimate life span of the biosphere is defined by the extinction of procaryotes in about 1.6 Gyr.

  17. 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.

  18. Causes and timing of future biosphere extinctions

    Science.gov (United States)

    Franck, S.; Bounama, C.; von Bloh, W.

    2006-03-01

    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.

  19. 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

  20. User's guide to the biosphere code ECOS

    International Nuclear Information System (INIS)

    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)

  1. 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.

  2. 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. PMID:23701641

  3. Factual biosphere database for Sellafield and the surrounding area

    International Nuclear Information System (INIS)

    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)

  4. Reconnecting to the biosphere.

    Science.gov (United States)

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

    2011-11-01

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

  5. 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

  6. Linking Metabolism, Elemental Cycles, and Environmental Conditions in the Deep Biosphere: Growth of a Model Extremophile, Archaeoglobus fulgidus, Under High-Pressure Conditions

    Science.gov (United States)

    Oliver, G. C. M.; Cario, A.; Rogers, K. L.

    2015-12-01

    A majority of Earth's biosphere is hosted in subsurface environments where global-scale biogeochemical and energy cycles are driven by diverse microbial communities that operate on and are influenced by micro-scale environmental variables. While the subsurface hosts a variety of geochemical and geothermal conditions, elevated pressures are common to all subsurface ecosystems. Understanding how microbes adapt to and thrive in high-pressure environments is essential to linking microbial subsurface processes with global-scale cycles. Here we are using a model extremophile, Archaeoglobus fulgidus, to determine how elevated pressures affect the growth, metabolism, and physiology of subsurface microorganisms. A. fulgidus cycles carbon and sulfur via heterotrophic and autotrophic sulfate reduction in various high temperature and high-pressure niches including shallow marine vents, deep-sea hydrothermal vents, and deep oil reservoirs. Here we report the results of A. fulgidus growth experiments at optimum temperature, 83°C, and pressures up to 600 bars. Exponential growth was observed over the entire pressure range, though growth rates were diminished at 500 and 600 bars compared to ambient pressure experimental controls. At pressures up to 400 bars, cell density yields and growth rates were at least as high as ambient pressure controls. Elevated pressures and extended incubation times stimulated cell flocculation, a common stress response in this strain, and cellular morphology was affected at pressures exceeding 400 bars. These results suggest that A. fulgidus continues carbon, sulfur and energy cycling unaffected by elevated pressures up to 400 bars, representing a variety of subsurface environments. The ability of subsurface organisms to drive biogeochemical cycles at elevated pressures is a critical link between the surface and subsurface biospheres and understanding how species-scale processes operate under these conditions is a vital part of global

  7. In situ Detection of Microbial Life in the Deep Biosphere in Igneous Ocean Crust.

    Science.gov (United States)

    Salas, Everett C; Bhartia, Rohit; Anderson, Louise; Hug, William F; Reid, Ray D; Iturrino, Gerardo; Edwards, Katrina J

    2015-01-01

    The deep biosphere is a major frontier to science. Recent studies have shown the presence and activity of cells in deep marine sediments and in the continental deep biosphere. Volcanic lavas in the deep ocean subsurface, through which substantial fluid flow occurs, present another potentially massive deep biosphere. We present results from the deployment of a novel in situ logging tool designed to detect microbial life harbored in a deep, native, borehole environment within igneous oceanic crust, using deep ultraviolet native fluorescence spectroscopy. Results demonstrate the predominance of microbial-like signatures within the borehole environment, with densities in the range of 10(5) cells/mL. Based on transport and flux models, we estimate that such a concentration of microbial cells could not be supported by transport through the crust, suggesting in situ growth of these communities.

  8. In-situ detection of microbial life in the deep biosphere in igneous ocean crust

    Directory of Open Access Journals (Sweden)

    Everett Cosio Salas

    2015-11-01

    Full Text Available The deep biosphere is a major frontier to science. Recent studies have shown the presence and activity of cells in deep marine sediments and in the continental deep biosphere. Volcanic lavas in the deep ocean subsurface, through which substantial fluid flow occurs, present another potentially massive deep biosphere. We present results from the deployment of a novel in-situ logging tool designed to detect microbial life harbored in a deep, native, borehole environment within igneous oceanic crust, using deep ultraviolet native fluorescence spectroscopy. Results demonstrate the predominance of microbial-like signatures within the borehole environment, with densities in the range of 105 cells/mL. Based on transport and flux models, we estimate that such a concentration of microbial cells could not be supported by transport through the crust, suggesting in situ growth of these communities.

  9. In situ Detection of Microbial Life in the Deep Biosphere in Igneous Ocean Crust

    Science.gov (United States)

    Salas, Everett C.; Bhartia, Rohit; Anderson, Louise; Hug, William F.; Reid, Ray D.; Iturrino, Gerardo; Edwards, Katrina J.

    2015-01-01

    The deep biosphere is a major frontier to science. Recent studies have shown the presence and activity of cells in deep marine sediments and in the continental deep biosphere. Volcanic lavas in the deep ocean subsurface, through which substantial fluid flow occurs, present another potentially massive deep biosphere. We present results from the deployment of a novel in situ logging tool designed to detect microbial life harbored in a deep, native, borehole environment within igneous oceanic crust, using deep ultraviolet native fluorescence spectroscopy. Results demonstrate the predominance of microbial-like signatures within the borehole environment, with densities in the range of 105 cells/mL. Based on transport and flux models, we estimate that such a concentration of microbial cells could not be supported by transport through the crust, suggesting in situ growth of these communities. PMID:26617595

  10. Developing Starlight connections with UNESCO sites through the Biosphere Smart

    Science.gov (United States)

    Marin, Cipriano

    2015-08-01

    The large number of UNESCO Sites around the world, in outstanding sites ranging from small islands to cities, makes it possible to build and share a comprehensive knowledge base on good practices and policies on the preservation of the night skies consistent with the protection of the associated scientific, natural and cultural values. In this context, the Starlight Initiative and other organizations such as IDA play a catalytic role in an essential international process to promote comprehensive, holistic approaches on dark sky preservation, astronomical observation, environmental protection, responsible lighting, sustainable energy, climate change and global sustainability.Many of these places have the potential to become models of excellence to foster the recovery of the dark skies and its defence against light pollution, included some case studies mentioned in the Portal to the Heritage of Astronomy.Fighting light pollution and recovering starry sky are already elements of a new emerging culture in biosphere reserves and world heritage sites committed to acting on climate change and sustainable development. Over thirty territories, including biosphere reserves and world heritage sites, have been developed successful initiatives to ensure night sky quality and promote sustainable lighting. Clear night skies also provide sustainable income opportunities as tourists and visitors are eagerly looking for sites with impressive night skies.Taking into account the high visibility and the ability of UNESCO sites to replicate network experiences, the Starlight Initiative has launched an action In cooperation with Biosphere Smart, aimed at promoting the Benchmark sites.Biosphere Smart is a global observatory created in partnership with UNESCO MaB Programme to share good practices, and experiences among UNESCO sites. The Benchmark sites window allows access to all the information of the most relevant astronomical heritage sites, dark sky protected areas and other places

  11. Methodology for the biosphere analysis in the evaluation of deep geological repositories for high radioactive waste

    International Nuclear Information System (INIS)

    This report summarizes the work done and the achievements reached within the R and D Project that IMA/CIEMAT has had with ENRESA during 1993-1995. The overal R and D Project has a wide radiological protection context, but the work reported here relates only to the development of a Methodology for considering the Biosphere sub-system in the assessments of deep geological repositories for high radioactive wastes (HLW). The main areas concerned within the Methodology have to do with Biosphere structure and morphology in the long-term relevant to deep disposal of HLW: in the contexts of the assessment of these systems, and appropiate modelling of the behaviour of radionuclides released to the biosphere system and with the associated human exposure. This document first provides a review of the past and present international and national concerns about the biosphere modelling and its importance in relation to the definition of safety criteria. A joint ENRESA/ANDRA/IPSN/CIEMAT study about the definition and proactical descriptions of the biosphere systems under different climatic states is then summarized. The Methodology developed by IMA/CIEMAT is outlined with an illustration of the way it works. Different steps and procedures are included for a better proactical understanding of the software tools developed within the project to support the application of the Methologoy. This Methodology is widely based on an international working group on Reference Biospheres part national work for ENRESA has been supported under a collaborative agreement with QuantiSci Ltd. Specific software development have been carried out in collaboration with QuantiSci Ltd and with the Polytechnical University of Madrid. Most of the items included within the Methodology and moreover the Methodology as a whole, follows a continuos progressive development. It is increasinaly recognized that assessment capabilities, establisment of safety criteria and regulatory framework and the steps in a

  12. 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)

  13. Recent developments in assessment of long-term radionuclide behavior in the geosphere-biosphere subsystem.

    Science.gov (United States)

    Smith, G M; Smith, K L; Kowe, R; Pérez-Sánchez, D; Thorne, M; Thiry, Y; Read, D; Molinero, J

    2014-05-01

    Decisions on permitting, controlling and monitoring releases of radioactivity into the environment rely on a great variety of factors. Important among these is the prospective assessment of radionuclide behavior in the environment, including migration and accumulation among and within specific environmental media, and the resulting environmental and human health impacts. Models and techniques to undertake such assessments have been developed over several decades based on knowledge of the ecosystems involved, as well as monitoring of previous radionuclide releases to the environment, laboratory experiments and other related research. This paper presents developments in the assessment of radiation doses and related research for some of the key radionuclides identified as of potential significance in the context of releases to the biosphere from disposal facilities for solid radioactive waste. Since releases to the biosphere from disposal facilities involve transfers from the geosphere to the biosphere, an important aspect is the combined effects of surface hydrology, near-surface hydrogeology and chemical gradients on speciation and radionuclide mobility in the zone in which the geosphere and biosphere overlap (herein described as the geosphere-biosphere subsystem). In turn, these aspects of the environment can be modified as a result of environmental change over the thousands of years that have to be considered in radioactive waste disposal safety assessments. Building on the experience from improved understanding of the behavior of the key radionuclides, this paper proceeds to describe development of a generic methodology for representing the processes and environmental changes that are characteristic of the interface between the geosphere and the biosphere. The information that is provided and the methodology that is described are based on international collaborative work implemented through the BIOPROTA forum, www.bioprota.org.

  14. Pre-industrial-potential and Last Glacial Maximum global vegetation simulated with a coupled climate-biosphere model: diagnosis of bioclimatic relationships

    Science.gov (United States)

    Crucifix, Michel; Betts, Richard A.; Hewitt, Christopher D.

    2005-03-01

    The global climate-vegetation model HadSM3_TRIFFID has been used to estimate the equilibrium states of climate and vegetation with pre-industrial and last glacial boundary conditions. The present study focuses on the evaluation of the terrestrial biosphere component (TRIFFID) and its response to changes in climate and CO 2 concentration. We also show how, by means of a diagnosis of the distribution of plant functional types according to climate parameters (soil temperature, winter temperature, growing-degree days, precipitation), it is possible to get better insights into the strengths and weaknesses of the biosphere model by reference to field knowledge of ecosystems. The model exhibits profound changes between the vegetation distribution at the Last Glacial Maximum and today that are generally consistent with palaeoclimate data, such as the disappearance of the Siberian boreal forest (taiga), an increase in shrub cover in Europe and an increase of the subtropical desert area. The effective equatorial and sub-tropical tree area is reduced by 18%. There is also an increase in cover of wooded species in North-Western Africa and in Mexico. The analysis of bioclimatic relationships turns out to be an efficient method to infer the contributions of different climatic factors to vegetation changes, both at high latitudes, where the position of the boreal treeline appears in this model to be more directly constrained by the water stress than by summer temperature, and in semi-humid areas where the contributions of temperature and precipitation changes may partly compensate each other. Our study also confirms the major contribution of the decrease in CO 2 to environmental changes and carbon storage through its selective impact on gross primary productivity of C3 and C4 plants and a reduction by 25% of water-use efficiency. Specifically, the reduction in CO 2 concentration increases the amount of precipitation necessary to sustain at least 20% of grass fraction by 50 mm

  15. A Regional-Scale Groundwater Model Supporting Management of the Sian Ka'an Biosphere Reserve and its Catchment, Quintana Roo, Mexico

    Science.gov (United States)

    Neuman, B. R.; Merediz Alonso, G.; Rebolledo Vieyra, M.; Marin, L.; Supper, R.; Bauer-Gottwein, P.

    2007-05-01

    The Caribbean Coast of the Yucatan Peninsula is a rapidly developing area featuring a booming tourism industry. The number of hotel rooms in the Riviera Maya has increased from 2600 in 1996 to 26,000 in 2005, while the total population in the Mexican federal state of Quintana Roo has grown from 500,000 in 1990 to 1,115,000 in 2005. This explosive growth threatens the region's water resources, which primarily consist of a less than 50m thick freshwater lens residing in the regional karst aquifer underlying the entire Yucatan Peninsula. The Sian Ka'an Biosphere Reserve, a 6400 km2 combined marine/terrestrial nature protection area is situated south of Tulum (approx. 87.3° - 88° W, 19° - 20° N). The site is listed as a UNESCO world heritage site and is protected under the Ramsar Convention. It includes extensive freshwater wetlands, saline/brackish mangrove swamps, tropical rainforests and parts of the world's second largest coral reef. The freshwater supply to the system occurs primarily via subsurface inflow. Large freshwater springs emerge through vertical sinkholes (cenotes) in the lagoons of Sian Ka'an. Management of this unique ecosystem in view of the rapid development and urbanization of the surrounding areas requires detailed knowledge on the groundwater flow paths in and around the reserve. Moreover, mapping and delineation of its groundwater catchment zone and groundwater traveling time zones is essential. To this end, a regional-scale steady-state groundwater flow model of the Sian Ka'an Biosphere reserve and its catchment was developed. The model is implemented in MIKE SHE with a finite-difference cell size of 1 km2 and is driven with temporally averaged climate forcings. The karst aquifer is treated as an equivalent porous medium. Darcy's law is assumed to be valid over regional scales and the main structural elements of the karst aquifer are included in the model as zones of varying hydraulic conductivity. High conductivity zones in the Sian Ka

  16. 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'.

  17. Developing a global mixed-canopy, height-variable vegetation structure dataset for estimating global vegetation albedo and biomass in the NASA Ent Terrestrial Biosphere Model and GISS GCM

    Science.gov (United States)

    Montes, C.; Kiang, N. Y.; Yang, W.; Ni-Meister, W.; Schaaf, C.; Aleinov, I. D.; Jonas, J.; Zhao, F. A.; Yao, T.; Wang, Z.; Sun, Q.

    2015-12-01

    Processes determining biosphere-atmosphere coupling are strongly influenced by vegetation structure. Thus, ecosystem carbon sequestration and evapotranspiration affecting global carbon and water balances will depend upon the spatial extent of vegetation, its vertical structure, and its physiological variability. To represent this globally, Dynamic Global Vegetation Models (DGVMs) coupled to General Circulation Models (GCMs) make use of satellite and/or model-based vegetation classifications often composed by homogeneous communities. This work aims at developing a new Global Vegetation Structure Dataset (GVSD) by incorporating varying vegetation heights for mixed plant communities to be used as input to the Ent Terrestrial Biosphere Model (TBM), the DGVM coupled to the NASA Goddard Institute for Space Studies (GISS) GCM. Information sources include the Moderate Resolution Imaging Spectroradiometer (MODIS) land cover and plant functional types (PFTs) (Friedl et al., 2010), vegetation height from the Geoscience Laser Altimeter System (GLAS) on board ICESat (Ice, Cloud, and land Elevation Satellite) (Simard et al., 2011; Tang et al., 2014) along with the Global Data Sets of Vegetation Leaf Area Index (LAI)3g (Zhu et al. 2013). Further PFT partitioning is performed according to a climate classification utilizing the Climate Research Unit (CRU) and the NOAA Global Precipitation Climatology Centre (GPCC) data. Final products are a GVSD consisting of mixed plant communities (e.g. mixed forests, savannas, mixed PFTs) following the Ecosystem Demography model (Moorcroft et al., 2001) approach represented by multi-cohort community patches at the sub-grid level of the GCM, which are ensembles of identical individuals whose differences are represented by PFTs, canopy height, density and vegetation structure sensitivity to allometric parameters. To assess the sensitivity of the GISS GCM to vegetation structure, we produce a range of estimates of Ent TBM biomass and plant

  18. Developing a global mixed-canopy, height-variable vegetation structure dataset for estimating global vegetation albedo by a clumped canopy radiative transfer scheme in the NASA Ent Terrestrial Biosphere Model and GISS GCM

    Science.gov (United States)

    Montes, Carlo; Kiang, Nancy Y.; Ni-Meister, Wenge; Yang, Wenze; Schaaf, Crystal; Aleinov, Igor; Jonas, Jeffrey A.; Zhao, Feng; Yao, Tian; Wang, Zhuosen; Sun, Qingsong; Carrer, Dominique

    2016-04-01

    Processes determining biosphere-atmosphere coupling are strongly influenced by vegetation structure. Thus, ecosystem carbon sequestration and evapotranspiration affecting global carbon and water balances will depend upon the spatial extent of vegetation, its vertical structure, and its physiological variability. To represent this globally, Dynamic Global Vegetation Models (DGVMs) coupled to General Circulation Models (GCMs) make use of satellite and/or model-based vegetation classifications often composed by homogeneous communities. This work aims at developing a new Global Vegetation Structure Dataset (GVSD) by incorporating varying vegetation heights for mixed plant communities to be used as boundary conditions to the Analytical Clumped Two-Stream (ACTS) canopy radiative transfer scheme (Ni-Meister et al., 2010) incorporated into the NASA Ent Terrestrial Biosphere Model (TBM), the DGVM coupled to the NASA Goddard Institute for Space Studies (GISS) GCM. Information sources about land surface and vegetation characteristics obtained from a number of earth observation platforms and algorithms include the Moderate Resolution Imaging Spectroradiometer (MODIS) land cover and plant functional types (PFTs) (Friedl et al., 2010), soil albedo derived from MODIS (Carrer et al., 2014), along with vegetation height from the Geoscience Laser Altimeter System (GLAS) on board ICESat (Ice, Cloud, and land Elevation Satellite) (Simard et al., 2011; Tang et al., 2014). Three widely used Leaf Area Index (LAI) products are compared as input to the GVSD and ACTS forcing in terms of vegetation albedo: Global Data Sets of Vegetation (LAI)3g (Zhu et al. 2013), Beijing Normal University LAI (Yuan et al., 2011), and MODIS MOD15A2H product (Yang et al., 2006). Further PFT partitioning is performed according to a climate classification utilizing the Climate Research Unit (CRU; Harris et al., 2013) and the NOAA Global Precipitation Climatology Centre (GPCC; Scheider et al., 2014) data. Final

  19. Recent developments in assessment of long-term radionuclide behavior in the geosphere-biosphere subsystem

    International Nuclear Information System (INIS)

    Decisions on permitting, controlling and monitoring releases of radioactivity into the environment rely on a great variety of factors. Important among these is the prospective assessment of radionuclide behavior in the environment, including migration and accumulation among and within specific environmental media, and the resulting environmental and human health impacts. Models and techniques to undertake such assessments have been developed over several decades based on knowledge of the ecosystems involved, as well as monitoring of previous radionuclide releases to the environment, laboratory experiments and other related research. This paper presents developments in the assessment of radiation doses and related research for some of the key radionuclides identified as of potential significance in the context of releases to the biosphere from disposal facilities for solid radioactive waste. Since releases to the biosphere from disposal facilities involve transfers from the geosphere to the biosphere, an important aspect is the combined effects of surface hydrology, near-surface hydrogeology and chemical gradients on speciation and radionuclide mobility in the zone in which the geosphere and biosphere overlap (herein described as the geosphere-biosphere subsystem). In turn, these aspects of the environment can be modified as a result of environmental change over the thousands of years that have to be considered in radioactive waste disposal safety assessments. Building on the experience from improved understanding of the behavior of the key radionuclides, this paper proceeds to describe development of a generic methodology for representing the processes and environmental changes that are characteristic of the interface between the geosphere and the biosphere. The information that is provided and the methodology that is described are based on international collaborative work implemented through the BIOPROTA forum, (www.bioprota.org). - Highlights: • Geological

  20. Testing of environmental transfer models using Chernobyl fallout data from the Iput River catchment area, Bryansk Region, Russian Federation. Report of the Dose Reconstruction Working Group of BIOMASS Theme 2. Part of the IAEA Co-ordinated Research Project on Biosphere Modelling and Assessment (BIOMASS)

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    We develop a simple, globally uniform model of CO2 exchange between the atmosphere and the terrestrial biosphere by coupling the model with a three-dimensional atmospheric tracer transport model using observed winds, and checking results against observed concentrations of CO2 at various monitoring sites. CO2 fluxes are derived from observed greenness using satellite-derived Global Vegetation Index data, combined with observations of temperature, radiation, and precipitation. We explore a range of CO2 flux formulations together with some modifications of the modelled atmospheric transport. We find that while some formulations can be excluded, it cannot be decided whether or not to make CO2 uptake and release dependent on water stress. It appears that the seasonality of net CO2 fluxes in the tropics, which would be expected to be driven by water availability, is small and is therefore not visible in the seasonal cycle of atmospheric CO2. The latter is dominated largely by northern temperate and boreal vegetation, where seasonality is mostly temperature determined. We find some evidence that there is still considerable CO2 release from soils during northern-hemisphere winter. An exponential air temperature dependence of soil release with a Q10 of 1.5 is found to be most appropriate, with no cutoff at low freezing temperatures. This result is independent of the year from which observed winds were taken. This is remarkable insofar as year-to-year changes in modelled CO2 concentrations caused by changes in the wind data clearly outweigh those caused by year-to-year variability in the climate and vegetation index data. (orig.)

  2. 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.

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

    International Nuclear Information System (INIS)

    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

  4. 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

  5. User's guide to the biosphere code BIOMOD

    International Nuclear Information System (INIS)

    BIOMOD has been designed to interface with SYVAC, the function of which is to perform generic risk assessments on hypothetical repository-geosphere-biosphere combinations. The user's guide contains the detailed specifications for the models used, a description of the interim user-interface, a specification for required input and definition of output. Sources of error are indicated and reference is made to the database description and other documents issued relating to BIOMOD. (author)

  6. A summary of biospheric research 1975-1997

    International Nuclear Information System (INIS)

    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

  7. 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

  8. Assessing biosphere feedbacks on Earth System Processes

    Science.gov (United States)

    McElwain, Jennifer

    2016-04-01

    The evolution and ecology of plant life has been shaped by the direct and indirect influence of plate tectonics. Climatic change and environmental upheaval associated with the emplacement of large igneous provinces have triggered biosphere level ecological change, physiological modification and pulses of both extinction and origination. This talk will investigate the influence of large scale changes in atmospheric composition on plant ecophysiology at key intervals of the Phanerozoic. Furthermore, I will assess the extent to which plant ecophysiological response can in turn feedback on earth system processes such as the global hydrological cycle and biogeochemical cycling of nitrogen and carbon. Palaeo-atmosphere simulation experiments, palaeobotanical data and recent historical (last 50 years) data-model comparison will be used to address the extent to which plant physiological responses to atmospheric CO2 can modulate global climate change via biosphere level feedback.

  9. Estimating the seasonal carbon source-sink geography of a natural, steady-state terrestrial biosphere

    Science.gov (United States)

    Box, Elgene O.

    1988-01-01

    The estimation of the seasonal dynamics of biospheric-carbon sources and sinks to be used as an input to global atmospheric CO2 studies and models is discussed. An ecological biosphere model is given and the advantages of the model are examined. Monthly maps of estimated biospheric carbon source and sink regions and estimates of total carbon fluxes are presented for an equilibrium terrestrial biosphere. The results are compared with those from other models. It is suggested that, despite maximum variations of atmospheric CO2 in boreal latitudes, the enormous contributions of tropical wet-dry regions to global atmospheric CO2 seasonality can not be ignored.

  10. How close are we to a predictive science of the biosphere?

    Science.gov (United States)

    Moorcroft, Paul R

    2006-07-01

    In just 20 years, the field of biosphere-atmosphere interactions has gone from a nascent discipline to a central area of modern climate change research. The development of terrestrial biosphere models that predict the responses of ecosystems to climate and increasing CO2 levels has highlighted several mechanisms by which changes in ecosystem composition and function might alter regional and global climate. However, results from empirical studies suggest that ecosystem responses can differ markedly from the predictions of terrestrial biosphere models. As I discuss here, the challenge now is to connect terrestrial biosphere models to empirical ecosystem measurements. Only by systematically evaluating the predictions of terrestrial biosphere models against suites of ecosystem observations and experiments measurements will a true predictive science of the biosphere be achieved.

  11. Coupled Climate-Economy-Biosphere (CoCEB) model - Part 2: Deforestation control and investment in carbon capture and storage technologies

    Science.gov (United States)

    Ogutu, K. B. Z.; D'Andrea, F.; Ghil, M.; Nyandwi, C.; Manene, M. M.; Muthama, J. N.

    2015-04-01

    This study uses the global climate-economy-biosphere (CoCEB) model developed in Part 1 to investigate economic aspects of deforestation control and carbon sequestration in forests, as well as the efficiency of carbon capture and storage (CCS) technologies as policy measures for climate change mitigation. We assume - as in Part 1 - that replacement of one technology with another occurs in terms of a logistic law, so that the same law also governs the dynamics of reduction in carbon dioxide emission using CCS technologies. In order to take into account the effect of deforestation control, a slightly more complex description of the carbon cycle than in Part 1 is needed. Consequently, we add a biomass equation into the CoCEB model and analyze the ensuing feedbacks and their effects on per capita gross domestic product (GDP) growth. Integrating biomass into the CoCEB and applying deforestation control as well as CCS technologies has the following results: (i) low investment in CCS contributes to reducing industrial carbon emissions and to increasing GDP, but further investment leads to a smaller reduction in emissions, as well as in the incremental GDP growth; and (ii) enhanced deforestation control contributes to a reduction in both deforestation emissions and in atmospheric carbon dioxide concentration, thus reducing the impacts of climate change and contributing to a slight appreciation of GDP growth. This effect is however very small compared to that of low-carbon technologies or CCS. We also find that the result in (i) is very sensitive to the formulation of CCS costs, while to the contrary, the results for deforestation control are less sensitive.

  12. Coupled Climate–Economy–Biosphere (CoCEB model – Part 2: Deforestation control and investment in carbon capture and storage technologies

    Directory of Open Access Journals (Sweden)

    K. B. Z. Ogutu

    2015-04-01

    Full Text Available This study uses the global climate–economy–biosphere (CoCEB model developed in Part 1 to investigate economic aspects of deforestation control and carbon sequestration in forests, as well as the efficiency of carbon capture and storage (CCS technologies as policy measures for climate change mitigation. We assume – as in Part 1 – that replacement of one technology with another occurs in terms of a logistic law, so that the same law also governs the dynamics of reduction in carbon dioxide emission using CCS technologies. In order to take into account the effect of deforestation control, a slightly more complex description of the carbon cycle than in Part 1 is needed. Consequently, we add a biomass equation into the CoCEB model and analyze the ensuing feedbacks and their effects on per capita gross domestic product (GDP growth. Integrating biomass into the CoCEB and applying deforestation control as well as CCS technologies has the following results: (i low investment in CCS contributes to reducing industrial carbon emissions and to increasing GDP, but further investment leads to a smaller reduction in emissions, as well as in the incremental GDP growth; and (ii enhanced deforestation control contributes to a reduction in both deforestation emissions and in atmospheric carbon dioxide concentration, thus reducing the impacts of climate change and contributing to a slight appreciation of GDP growth. This effect is however very small compared to that of low-carbon technologies or CCS. We also find that the result in (i is very sensitive to the formulation of CCS costs, while to the contrary, the results for deforestation control are less sensitive.

  13. The water cycle in closed ecological systems: perspectives from the Biosphere 2 and Laboratory Biosphere systems

    Science.gov (United States)

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

    To achieve sustainable and healthy closed ecological systems requires successful solutions to the challenge of closing the water cycle - recycling wastewater/soil leachate and evaporateed 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, total footprint of the airtight area is 12,700 m2 with a combined volume of 200,000 m3 with a total water capacity of some 6 x 106 liters of water presented a complex challenge because it included human inhabitants, their agricultural and technical systems, as well as a range of analogue ecosystems ranging from rainforest to desert, freshwater ecologies to mini-ocean coral reef ecosystems. By contrast, the Laboratory Biosphere - a small (40m3 volume) soil-based plant growth facility with a footprint of 15m3 - is a very simplified system, but with some similar issues such as salinity management and the provision of water quality sufficient 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, adequately freshwater was needed for terrestrial ecosystems and maintaining appropriate salinity and pH in aquatic/marine ecosystems. The largest reservoirs in Biosphere 2 were the ocean/marsh with some 4x106 liters, soil with 2 x 106 liters, primary storage tanks with a capacity for up to 8 x 105 liters and storage tanks for condensate collection and mixing tanks with 1.5 x 105 liters to supply irrigation for farm and wilderness ecosystems. Other reservoirs were far smaller - humidity in the atmosphere (2 x 103 liters), streams in the rainforest and savannah, and seasonal pools in the desert were orders of magnitude smaller (8 x 103 liters). Key technologies included condensation from humidity in the airhandlers and from the glass

  14. Decadal trends in the seasonal-cycle amplitude of terrestrial CO 2 exchange resulting from the ensemble of terrestrial biosphere models

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Akihiko; Inatomi, Motoko; Huntzinger, Deborah N.; Schwalm, Christopher; Michalak, Anna M.; Cook, Robert; King, Anthony W.; Mao, Jiafu; Wei, Yaxing; Post, W. Mac; Wang, Weile; Arain, M. Altaf; Huang, Suo; Hayes, Daniel J.; Ricciuto, Daniel M.; Shi, Xiaoying; Huang, Maoyi; Lei, Huimin; Tian, Hanqin; Lu, Chaoqun; Yang, Jia; Tao, Bo; Jain, Atul; Poulter, Benjamin; Peng, Shushi; Ciais, Philippe; Fisher, Joshua B.; Parazoo, Nicholas; Schaefer, Kevin; Peng, Changhui; Zeng, Ning; Zhao, Fang

    2016-05-12

    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

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

    Science.gov (United States)

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

    2016-04-01

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

  16. Incorporation of crop phenology in Simple Biosphere Model (SiBcrop) to improve land-atmosphere carbon exchanges from croplands

    OpenAIRE

    E. Lokupitiya; S. Denning; K. Paustian; Baker, I; K. Schaefer; Verma, S.; Meyers, T; C. J. Bernacchi; Suyker, A.; Fischer, M.

    2009-01-01

    Croplands are man-made ecosystems that have high net primary productivity during the growing season of crops, thus impacting carbon and other exchanges with the atmosphere. These exchanges play a~major role in nutrient cycling and climate change related issues. An accurate representation of crop phenology and physiology is important in land-atmosphere carbon models being used to predict these exchanges. To better estimate time-varying exchanges of carbon, water, and energy of croplands...

  17. Monitoring Hydrological Patterns of Temporary Lakes Using Remote Sensing and Machine Learning Models: Case Study of La Mancha Húmeda Biosphere Reserve in Central Spain

    Directory of Open Access Journals (Sweden)

    Carolina Doña

    2016-07-01

    Full Text Available The Biosphere Reserve of La Mancha Húmeda is a wetland-rich area located in central Spain. This reserve comprises a set of temporary lakes, often saline, where water level fluctuates seasonally. Water inflows come mainly from direct precipitation and runoff of small lake watersheds. Most of these lakes lack surface outlets and behave as endorheic systems, where water withdrawal is mainly due to evaporation, causing salt accumulation in the lake beds. Remote sensing was used to estimate the temporal variation of the flooded area in these lakes and their associated hydrological patterns related to the seasonality of precipitation and evapotranspiration. Landsat 7 ETM+ satellite images for the reference period 2013–2015 were jointly used with ground-truth datasets. Several inverse modeling methods, such as two-band and multispectral indices, single-band threshold, classification methods, artificial neural network, support vector machine and genetic programming, were applied to retrieve information on the variation of the flooded areas. Results were compared to ground-truth data, and the classification errors were evaluated by means of the kappa coefficient. Comparative analyses demonstrated that the genetic programming approach yielded the best results, with a kappa value of 0.98 and a total error of omission-commission of 2%. The dependence of the variations in the water-covered area on precipitation and evaporation was also investigated. The results show the potential of the tested techniques to monitor the hydrological patterns of temporary lakes in semiarid areas, which might be useful for management strategy-linked lake conservation and specifically to accomplish the goals of both the European Water Framework Directive and the Habitats Directive.

  18. 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.

  19. An open-access software platform for modeling turbulent heat and moisture fluxes as well as surface soil moisture from the Synergy of VNIR/TIR EO Data and a Land Biosphere Model

    Science.gov (United States)

    Petropoulos, George; Anagnostopoulos, Vasileios

    2015-04-01

    Today, in the face of climate change, it has been recognised by the global scientific community as a topic requiring further attention and investigation. Use of simulation process models combined with Earth Observation (EO) data provides a promising direction towards deriving accurately spatiotemporal estimates of key parameters characterising land surface interactions such as latent (LE) and sensible (H) heat fluxes as well as soil surface moisture (SSM). Herein a software tool developed in Java for deriving regional estimates of LE and H fluxes (sensible and latent heat) as well as surface soil moisture from the implementation of the so-called "triangle" method is presented. The method is based on a contextual interpretation of a satellite-derived scatterplot of land surface temperature (Ts) versus a Fractional Vegetation Cover (Fr) combined with a land biosphere model. The tool offers a graphical user interface (GUI) to the user, with the aim to allow customisation of the noise removal of the dataset. Upper and lower edges of the trapezoid in the Fr versus normalized Ts diagram are automatically derived and visualised. The user can also enter various parameters to the SimSphere engine through a convenient form and visualisation of trapezoid matching for various simulation scenarios is also provided. Computationally it can handle one million scatter points with acceptable lag in the user interface. It is also multi-core friendly by using Java 8 parallel streams for conversions and prediction. The predictor training and histogram computation are the main serialisation bottlenecks. In contrast to other methods the trapezoid derivation and matching is automatic requiring little more than a customisation of noise removal and scenario definition. The tool is written in Java 8 and Java FX 8 for best performance, reduced maintenance and easy interaction. The practical usefulness of the software tool is demonstrated using a variety of examples exploiting EO data from

  20. 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

  1. Biospheric Aspects of the Hydrological Cycle

    Science.gov (United States)

    Hutjes, R. W. A.; Kabat, P.; Running, S. W.; Shuttleworth, W. J.; Field, C.; Bass, B.; da Silva Dias, M. F.; Avissar, R.; Becker, A.; Claussen, M.; Dolman, A. J.; Feddes, R. A.; Fosberg, M.; Fukushima, Y.; Gash, J. H. C.; Guenni, L.; Hoff, H.; Jarvis, P. G.; Kayane, I.; Krenke, A. N.; Liu, Changming; Meybeck, M.; Nobre, C. A.; Oyebande, L.; Pitman, A.; Pielke, R. A., Sr.; Raupach, M.; Saugier, B.; Schulze, E. D.; Sellers, P. J.; Tenhunen, J. D.; Valentini, R.; Victoria, R. L.; Vörösmarty, C. J.

    1998-12-01

    The Core Project Biospheric Aspects of the Hydrological Cycle (BAHC) of the International Geosphere Biosphere Programme (IGBP) addresses the biospheric aspects of the hydrological cycle through experiments and modelling of energy, water, carbon dioxide and sediment fluxes in the soil- vegetation-atmosphere system at a variety of spatial and temporal scales. Active regulation of water, energy and carbon dioxide fluxes by the vegetation make it an important factor in regulating the Earth's hydrological cycle and in the formation of the climate. Consequently, human induced conversion of vegetation cover is an important driver for climate change. A number of recent studies, discussed in this paper, emphasise the importance of the terrestrial biosphere for the climate system. Initially, these studies demonstrate the influence of the land surface on tropical weather and climate, revealing the mechanisms, acting at various scales, that connect increasing temperatures and decreasing rainfall to large-scale deforestation and other forms of land degradation. More recently, the significance of the land surface processes for water cycle and for weather and climate in temperate and boreal zones was demonstrated. In addition the terrestrial biosphere plays a significant role in the carbon dioxide fluxes and in global carbon balance. Recent work suggests that many ecosystems both in the tropics and in temperate zones may act as a substantial sink for carbon dioxide, though the temporal variability of this sink strength is yet unclear. Further, carbon dioxide uptake and evaporation by vegetation are intrinsically coupled, leading to links and feedbacks between land surface and climate that are hardly explored yet. Earth's vegetation cover and its changes owing to human impact have a profound influence on a lateral redistribution of water and transported constituents, such as nutrients and sediments, and acts therefore as an important moderator of Earth's biogeochemical cycles. In

  2. Exchanges of Atmospheric CO2 and 13CO2 with the Terrestrial Biosphere and Oceans from 1978 to 2000. II. A Three-Dimensional Tracer Inversion Model to Deduce Regional Fluxes

    OpenAIRE

    Piper, Stephen C; Keeling, Charles D.; HEIMANN Martin; Stewart, Elisabeth F

    2001-01-01

    A three-dimensional tracer inversion model is described that couples atmospheric CO2 transport with prescribed and adjustable source/sink components of the global car- bon cycle to predict atmospheric CO2 concentration and 13C/12C isotopic ratio taking account of exchange fluxes of atmospheric CO2 with the terrestrial biosphere and the oceans. Industrial CO2 emissions are prescribed from fuel production data. Transport of CO2 is prescribed by a model, TM2, that employs 9 vertical levels from ...

  3. Biosphere dose conversion Factor Importance and Sensitivity Analysis

    Energy Technology Data Exchange (ETDEWEB)

    M. Wasiolek

    2004-10-15

    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.

  4. Biosphere dose conversion Factor Importance and Sensitivity Analysis

    International Nuclear Information System (INIS)

    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

  5. What impact does ionising radiation have on humans and the environment? Use of SCK-CEN biosphere models in international studies

    International Nuclear Information System (INIS)

    Certain nuclear activities may have an impact on man and the environment. To understand the precise magnitude of the effect, one must first understand the distribution and behaviour of radioactive substances in the environment. This knowledge is also necessary in order to take appropriate measures to reduce radiation exposure. analysing the environmental effects of MYRRHA and of waste disposal facilities are just some of the applications of SCK-CEN biosphere impact studies.

  6. Satellite image based quantification of invasion and patch dynamics of mesquite (Prosopis juliflora) in Great Rann of Kachchh, Kachchh Biosphere Reserve, Gujarat, India

    Indian Academy of Sciences (India)

    S Vazeed Pasha; K V Satish; C Sudhakar Reddy; P V V Prasada Rao; C S Jha

    2014-10-01

    The invasion of alien species is a significant threat to global biodiversity and the top driver of climate change. The present study was conducted in the Great Rann of Kachchh, part of Kachchh Biosphere Reserve, Gujarat, India, which has been severely affected by invasion of Prosopis juliflora. The invasive weed infestation has been identified using multi-temporal remote sensing datasets of 1977, 1990, 1999, 2005 and 2011. Spatial analyses of the transition matrix, extent of invasive colonies, patchiness, coalescence and rate of spread were carried out. During the study period of three and half decades, almost 295 km2 of the natural land cover was converted into Prosopis cover. This study has shown an increment of 42.9% of area under Prosopis cover in the Great Rann of Kachchh, part of the Kachchh Biosphere Reserve during 1977 to 2011. Spatial analysis indicates high occupancy of Prosopis cover with most of the invasion (95.9%) occurring in the grasslands and only 4.1% in other land cover types. The process of Prosopis invasion shows high patch initiation, followed by coalescence, indicating aggressive colonization of species. The number of patches within an area of > 1 km2 increased from 1977 to 2011, indicating the formation of new Prosopis habitats by replacing the grasslands. The largest patch of Prosopis cover increased from 144 km2 in 1977 to 430 km2 in 2011. The estimated mean patch size was 7.8 km2 in 1977. The mean patch size was largest during 2011, i.e., 9 km2. The annual spread rate for Prosopis has been estimated as 2.1% during 2005–2011. The present work has investigated the long term changes in Prosopis cover in the Great Rann of Kachchh, part of Kachchh Biosphere Reserve. The spatial database generated will be useful in preparing strategies for the management of Prosopis juliflora.

  7. Satellite image based quantification of invasion and patch dynamics of mesquite ( Prosopis juliflora) in Great Rann of Kachchh, Kachchh Biosphere Reserve, Gujarat, India

    Science.gov (United States)

    Pasha, S. Vazeed; Satish, K. V.; Reddy, C. Sudhakar; Prasada Rao, P. V. V.; Jha, C. S.

    2014-10-01

    The invasion of alien species is a significant threat to global biodiversity and the top driver of climate change. The present study was conducted in the Great Rann of Kachchh, part of Kachchh Biosphere Reserve, Gujarat, India, which has been severely affected by invasion of Prosopis juliflora. The invasive weed infestation has been identified using multi-temporal remote sensing datasets of 1977, 1990, 1999, 2005 and 2011. Spatial analyses of the transition matrix, extent of invasive colonies, patchiness, coalescence and rate of spread were carried out. During the study period of three and half decades, almost 295 km2 of the natural land cover was converted into Prosopis cover. This study has shown an increment of 42.9% of area under Prosopis cover in the Great Rann of Kachchh, part of the Kachchh Biosphere Reserve during 1977 to 2011. Spatial analysis indicates high occupancy of Prosopis cover with most of the invasion (95.9%) occurring in the grasslands and only 4.1% in other land cover types. The process of Prosopis invasion shows high patch initiation, followed by coalescence, indicating aggressive colonization of species. The number of patches within an area of Prosopis habitats by replacing the grasslands. The largest patch of Prosopis cover increased from 144 km2 in 1977 to 430 km2 in 2011. The estimated mean patch size was 7.8 km2 in 1977. The mean patch size was largest during 2011, i.e., 9 km2. The annual spread rate for Prosopis has been estimated as 2.1% during 2005-2011. The present work has investigated the long term changes in Prosopis cover in the Great Rann of Kachchh, part of Kachchh Biosphere Reserve. The spatial database generated will be useful in preparing strategies for the management of Prosopis juliflora.

  8. Turnover of microbial lipids in the deep biosphere and growth of benthic archaeal populations.

    Science.gov (United States)

    Xie, Sitan; Lipp, Julius S; Wegener, Gunter; Ferdelman, Timothy G; Hinrichs, Kai-Uwe

    2013-04-01

    Deep subseafloor sediments host a microbial biosphere with unknown impact on global biogeochemical cycles. This study tests previous evidence based on microbial intact polar lipids (IPLs) as proxies of live biomass, suggesting that Archaea dominate the marine sedimentary biosphere. We devised a sensitive radiotracer assay to measure the decay rate of ([(14)C]glucosyl)-diphytanylglyceroldiether (GlcDGD) as an analog of archaeal IPLs in continental margin sediments. The degradation kinetics were incorporated in model simulations that constrained the fossil fraction of subseafloor IPLs and rates of archaeal turnover. Simulating the top 1 km in a generic continental margin sediment column, we estimated degradation rate constants of GlcDGD being one to two orders of magnitude lower than those of bacterial IPLs, with half-lives of GlcDGD increasing with depth to 310 ky. Given estimated microbial community turnover times of 1.6-73 ky in sediments deeper than 1 m, 50-96% of archaeal IPLs represent fossil signals. Consequently, previous lipid-based estimates of global subseafloor biomass probably are too high, and the widely observed dominance of archaeal IPLs does not rule out a deep biosphere dominated by Bacteria. Reverse modeling of existing concentration profiles suggest that archaeal IPL synthesis rates decline from around 1,000 pg⋅mL(-1) sediment⋅y(-1) at the surface to 0.2 pg⋅mL(-1)⋅y(-1) at 1 km depth, equivalent to production of 7 × 10(5) to 140 archaeal cells⋅mL(-1) sediment⋅y(-1), respectively. These constraints on microbial growth are an important step toward understanding the relationship between the deep biosphere and the carbon cycle.

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

    International Nuclear Information System (INIS)

    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)

  10. Exposing the Dark Microbial Biosphere

    OpenAIRE

    Hubalek, Valerie

    2015-01-01

    Dark biosphere research has been widely neglected, although by volume this biome comprises the lion’s share of habitats on our planet. In these systems the main metabolic strategies are of chemotrophic nature, leading to gradual depletion of redox gradients essential for sustaining life. Thus these environments are regarded more or less close to chemical equilibrium. Here, we use sequence data of whole community metagenomes and taxonomic marker approaches to study the ecology of environments ...

  11. 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

  12. The terrestrial biosphere in the SFR region

    International Nuclear Information System (INIS)

    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/m2 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

  13. The biosphere today and tomorrow in the SFR area

    International Nuclear Information System (INIS)

    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

  14. 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.

  15. An Estimate of the Total DNA in the Biosphere.

    Science.gov (United States)

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

    2015-06-01

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

  16. The disposal of Canada's nuclear fuel waste: a study of postclosure safety of in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock. Volume 4: biosphere model

    International Nuclear Information System (INIS)

    AECL (Atomic Energy of Canada Limited) has developed a disposal concept for Canada's nuclear fuel waste, which calls for a vault deep in plutonic rock of the Canadian Shield. The concept has been fully, documented in an environmental impact statement (EIS) for review by a panel under the Canadian Environmental Assessment Agency. The EIS includes the results of the EIS postclosure assessment case study to address the long term safety of the disposal concept. To more fully demonstrate the flexibility of the disposal concept and our assessment methodology, we are now carrying out another postclosure assessment study, which involves different assumptions and engineering options than those used in the EIS. In response to these changes, we have updated the BIOTRAC (BIOsphere Transport and Assessment Code) model developed for the EIS postclosure assessment case study. The main changes made to the BIOTRAC model are the inclusion of 36Cl, 137Cs, 239Np and 243Am; animals inhalation pathway; International Commission on Radiological Protection 60/61 human internal dose conversion factors; all the postclosure assessment nuclides in the dose calculations for non-human biota; and groundwater dose limits for 14C, 16C1 and 129I for non-human biota to parallel these limits for humans. We have also reviewed and changed several parameter values, including evasion rates of gaseous nuclides from soil and release fractions of various nuclides from domestic water, and indicated changes that affect the geosphere/biosphere interface model. These changes make the BIOTRAC model more flexible. As a result of all of these changes, the BIOTRAC model has been significantly expanded and improved, although the changes do not greatly affect model predictions. The modified model for the present study is called BIOTRAC2 (BIOTRAC - Version 2). The full documentation of the BIOTRAC2 model includes the report by Davis et al. (1993a) and this report. (author). 105 refs., 13 tabs., 8 figs

  17. 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.

  18. Fungal and Prokaryotic Activities in the Marine Subsurface Biosphere at Peru Margin and Canterbury Basin Inferred from RNA-Based Analyses and Microscopy.

    Science.gov (United States)

    Pachiadaki, Maria G; Rédou, Vanessa; Beaudoin, David J; Burgaud, Gaëtan; Edgcomb, Virginia P

    2016-01-01

    The deep sedimentary biosphere, extending 100s of meters below the seafloor harbors unexpected diversity of Bacteria, Archaea, and microbial eukaryotes. Far less is known about microbial eukaryotes in subsurface habitats, albeit several studies have indicated that fungi dominate microbial eukaryotic communities and fungal molecular signatures (of both yeasts and filamentous forms) have been detected in samples as deep as 1740 mbsf. Here, we compare and contrast fungal ribosomal RNA gene signatures and whole community metatranscriptomes present in sediment core samples from 6 and 95 mbsf from Peru Margin site 1229A and from samples from 12 and 345 mbsf from Canterbury Basin site U1352. The metatranscriptome analyses reveal higher relative expression of amino acid and peptide transporters in the less nutrient rich Canterbury Basin sediments compared to the nutrient rich Peru Margin, and higher expression of motility genes in the Peru Margin samples. Higher expression of genes associated with metals transporters and antibiotic resistance and production was detected in Canterbury Basin sediments. A poly-A focused metatranscriptome produced for the Canterbury Basin sample from 345 mbsf provides further evidence for active fungal communities in the subsurface in the form of fungal-associated transcripts for metabolic and cellular processes, cell and membrane functions, and catalytic activities. Fungal communities at comparable depths at the two geographically separated locations appear dominated by distinct taxa. Differences in taxonomic composition and expression of genes associated with particular metabolic activities may be a function of sediment organic content as well as oceanic province. Microscopic analysis of Canterbury Basin sediment samples from 4 and 403 mbsf produced visualizations of septate fungal filaments, branching fungi, conidiogenesis, and spores. These images provide another important line of evidence supporting the occurrence and activity of fungi in

  19. Hillslope hydrology under glass: confronting fundamental questions of soil-water-biota co-evolution at Biosphere 2

    Directory of Open Access Journals (Sweden)

    L. Hopp

    2009-06-01

    Full Text Available Recent studies have called for a new unifying hydrological theory at the hillslope and watershed scale, emphasizing the importance of coupled process understanding of the interactions between hydrology, ecology, pedology, geochemistry and geomorphology. The Biosphere 2 Hillslope Experiment aims at exploring how climate, soil and vegetation interact and drive the evolution of the hydrologic hillslope behavior using a set of three large-scale hillslopes (18 m by 33 m each that will be built in the climate-controlled experimental biome of the Biosphere 2 facility near Tucson, Arizona, USA. By minimizing the initial physical complexity of these hillslopes, the spontaneous formation of flow pathways, soil spatial heterogeneity, surface morphology and vegetation patterns can be observed over time. This paper documents the hydrologic design process for the Biosphere 2 Hillslope Experiment, which was based on design principles agreed upon among the Biosphere 2 science community. Main design principles were that the hillslopes should promote spatiotemporal variability of hydrological states and fluxes, facilitate transient lateral subsurface flow without inducing overland flow and be capable of supporting vegetation. Hydrologic modeling was used to identify a hillslope configuration (geometry, soil texture, soil depth that meets the design objectives. The recommended design for the hillslopes consists of a zero-order basin shape with a 10 degree overall slope, a uniform soil depth of 1 m and a loamy sand soil texture. The sensitivity of the hydrologic response of this design to different semi-arid climate scenarios was subsequently tested. Modeling results show that the timing of rainfall in relation to the timing of radiation input controls the spatiotemporal variability of moisture within the hillslope and the generation of lateral subsurface flow. The Biosphere 2 Hillslope Experiment will provide an excellent opportunity to test hypotheses, observe

  20. Overall strategy for management of parameters and data in the biosphere assessment portfolio

    International Nuclear Information System (INIS)

    Throughout the biosphere assessment, the parameters selected to represent the present and future biosphere and choices of data values are crucial issues, greatly affecting the end result. The necessity of clear strategy for managing parameters and data is obvious; how to handle the variability of parameters as such, the selection from different sources, the derivation of values of model parameters not readily available, storage of the data in a proper manner, and assuring the quality throughout the whole assessment programme. In this working report a proposed set of broad guidelines for the overall strategy for the management of parameters and data in the biosphere assessment strategy is first presented. Thereafter, a scheme is proposed for assuring the knowledge quality of data. Finally, a proposal for requirements and management of the biosphere assessment database and the current status of the on-going work building the biosphere assessment database and interfaces to other tools are presented. (orig.)

  1. Initial experimental results from the Laboratory Biosphere closed ecological system facility

    Science.gov (United States)

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

    Results from the closure and initial closed ecological system research in the "Laboratory Biosphere" facility in Santa Fe, New Mexico (USA) will be presented. The facility was initially sealed in April 2002; and the first crop experiments with soybeans commenced in May 2002. The Laboratory Biosphere was created by the team which invented, built and operated Biosphere 2 during its years of closed ecological system functioning (1991-94) and is a testbed to build upon the lessons learned. It is an opportunity to continue experiments with a sustainable soil based agriculture system unlike most bioregenerative systems which use hydroponic systems dependent on a supply of nutrient solution. Because of the small volume of the system (34-45 m3), developing mechanisms to keep parameters like carbon dioxide within acceptable limits will be critical. Recycle of nutrients within the system to maintain soil fertility; and the ability of the inherent complex ecology of soils and a soil bed reactor to handle trace gas buildups are primary research goals. Other research goals are determination of short and long-term exchanges between soil, plants and atmosphere, especially for carbon dioxide, oxygen, nitrogen, NOX, and methane, impact of cultivation (tillage) on soil/atmospheric exchanges., investigation and development of strategies to return nutrients to the soil to maintain fertility, e.g. shredding biomass vs. composting, impact on soil chemistry of returning leachate water to the soil as irrigation water. The microbiological status of soils prior to experiments and over time will allow measurement of changes in microbial diversity and the determination of the role of soil microbes in biogeochemical cycles. Integration of automated sensor and control in the system with real-time modeling has importance for operation, research and educational outreach programs. The Laboratory Biosphere is intended to test and develop a "cybersphere" (network of shared intelligence) that may be

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

    International Nuclear Information System (INIS)

    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

  3. Review on Eco-tourism Development Modes of Biosphere Reserves in China

    Institute of Scientific and Technical Information of China (English)

    CUI Xianghui; CHU Jianmin; ZHU Xueling

    2006-01-01

    Based on the analysis of the current situation and existing problems in the development of eco-tourism carried out by biosphere reserves in China, this paper discussed the development of global biosphere reserve and a set of development criteria about eco-tourism. According to the current tourism development of Baotianman Biosphere Reserve, a development mode for eco-tourism was gotten , in which such aspects as the function division, development process, establishment of facility, constitution of organization, community participation and sustainable management of biosphere reserve were taken into account, and the establishment of public education and environmental protection facility were considered as a vital characteristic of eco-tourism of biosphere reserves.

  4. Posiva's Strategy for Biosphere Studies

    International Nuclear Information System (INIS)

    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

  5. Nominal Performance Biosphere Dose Conversion Factor Analysis

    International Nuclear Information System (INIS)

    The purpose of this report was to document the process leading to development of the Biosphere Dose Conversion Factors (BDCFs) for the postclosure nominal performance of the potential repository at Yucca Mountain. BDCF calculations concerned twenty-four radionuclides. This selection included sixteen radionuclides that may be significant nominal performance dose contributors during the compliance period of up to 10,000 years, five additional radionuclides of importance for up to 1 million years postclosure, and three relatively short-lived radionuclides important for the human intrusion scenario. Consideration of radionuclide buildup in soil caused by previous irrigation with contaminated groundwater was taken into account in the BDCF development. The effect of climate evolution, from the current arid conditions to a wetter and cooler climate, on the BDCF values was evaluated. The analysis included consideration of different exposure pathway's contribution to the BDCFs. Calculations of nominal performance BDCFs used the GENII-S computer code in a series of probabilistic realizations to propagate the uncertainties of input parameters into the output. BDCFs for the nominal performance, when combined with the concentrations of radionuclides in groundwater allow calculation of potential radiation doses to the receptor of interest. Calculated estimates of radionuclide concentration in groundwater result from the saturated zone modeling. The integration of the biosphere modeling results (BDCFs) with the outcomes of the other component models is accomplished in the Total System Performance Assessment (TSPA) to calculate doses to the receptor of interest from radionuclides postulated to be released to the environment from the potential repository at Yucca Mountain

  6. Nominal Performance Biosphere Dose Conversion Factor Analysis

    Energy Technology Data Exchange (ETDEWEB)

    M. Wasiolek

    2000-12-21

    The purpose of this report was to document the process leading to development of the Biosphere Dose Conversion Factors (BDCFs) for the postclosure nominal performance of the potential repository at Yucca Mountain. BDCF calculations concerned twenty-four radionuclides. This selection included sixteen radionuclides that may be significant nominal performance dose contributors during the compliance period of up to 10,000 years, five additional radionuclides of importance for up to 1 million years postclosure, and three relatively short-lived radionuclides important for the human intrusion scenario. Consideration of radionuclide buildup in soil caused by previous irrigation with contaminated groundwater was taken into account in the BDCF development. The effect of climate evolution, from the current arid conditions to a wetter and cooler climate, on the BDCF values was evaluated. The analysis included consideration of different exposure pathway's contribution to the BDCFs. Calculations of nominal performance BDCFs used the GENII-S computer code in a series of probabilistic realizations to propagate the uncertainties of input parameters into the output. BDCFs for the nominal performance, when combined with the concentrations of radionuclides in groundwater allow calculation of potential radiation doses to the receptor of interest. Calculated estimates of radionuclide concentration in groundwater result from the saturated zone modeling. The integration of the biosphere modeling results (BDCFs) with the outcomes of the other component models is accomplished in the Total System Performance Assessment (TSPA) to calculate doses to the receptor of interest from radionuclides postulated to be released to the environment from the potential repository at Yucca Mountain.

  7. Microbial metagenomes from three aquifers in the Fennoscandian shield terrestrial deep biosphere reveal metabolic partitioning among populations.

    Science.gov (United States)

    Wu, Xiaofen; Holmfeldt, Karin; Hubalek, Valerie; Lundin, Daniel; Åström, Mats; Bertilsson, Stefan; Dopson, Mark

    2016-05-01

    Microorganisms in the terrestrial deep biosphere host up to 20% of the earth's biomass and are suggested to be sustained by the gases hydrogen and carbon dioxide. A metagenome analysis of three deep subsurface water types of contrasting age (from 86% coverage. The populations were dominated by Proteobacteria, Candidate divisions, unclassified archaea and unclassified bacteria. The estimated genome sizes of the biosphere. The data were finally used to create a combined metabolic model of the deep terrestrial biosphere microbial community.

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

    International Nuclear Information System (INIS)

    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.)

  9. Disruptive Event Biosphere Doser Conversion Factor Analysis

    Energy Technology Data Exchange (ETDEWEB)

    M. Wasiolek

    2000-12-28

    The purpose of this report was to document the process leading to, and the results of, development of radionuclide-, exposure scenario-, and ash thickness-specific Biosphere Dose Conversion Factors (BDCFs) for the postulated postclosure extrusive igneous event (volcanic eruption) at Yucca Mountain. BDCF calculations were done for seventeen radionuclides. The selection of radionuclides included those that may be significant dose contributors during the compliance period of up to 10,000 years, as well as radionuclides of importance for up to 1 million years postclosure. The approach documented in this report takes into account human exposure during three different phases at the time of, and after, volcanic eruption. Calculations of disruptive event BDCFs used the GENII-S computer code in a series of probabilistic realizations to propagate the uncertainties of input parameters into the output. The pathway analysis included consideration of different exposure pathway's contribution to the BDCFs. BDCFs for volcanic eruption, when combined with the concentration of radioactivity deposited by eruption on the soil surface, allow calculation of potential radiation doses to the receptor of interest. Calculation of radioactivity deposition is outside the scope of this report and so is the transport of contaminated ash from the volcano to the location of the receptor. The integration of the biosphere modeling results (BDCFs) with the outcomes of the other component models is accomplished in the Total System Performance Assessment (TSPA), in which doses are calculated to the receptor of interest from radionuclides postulated to be released to the environment from the potential repository at Yucca Mountain.

  10. Disruptive Event Biosphere Doser Conversion Factor Analysis

    International Nuclear Information System (INIS)

    The purpose of this report was to document the process leading to, and the results of, development of radionuclide-, exposure scenario-, and ash thickness-specific Biosphere Dose Conversion Factors (BDCFs) for the postulated postclosure extrusive igneous event (volcanic eruption) at Yucca Mountain. BDCF calculations were done for seventeen radionuclides. The selection of radionuclides included those that may be significant dose contributors during the compliance period of up to 10,000 years, as well as radionuclides of importance for up to 1 million years postclosure. The approach documented in this report takes into account human exposure during three different phases at the time of, and after, volcanic eruption. Calculations of disruptive event BDCFs used the GENII-S computer code in a series of probabilistic realizations to propagate the uncertainties of input parameters into the output. The pathway analysis included consideration of different exposure pathway's contribution to the BDCFs. BDCFs for volcanic eruption, when combined with the concentration of radioactivity deposited by eruption on the soil surface, allow calculation of potential radiation doses to the receptor of interest. Calculation of radioactivity deposition is outside the scope of this report and so is the transport of contaminated ash from the volcano to the location of the receptor. The integration of the biosphere modeling results (BDCFs) with the outcomes of the other component models is accomplished in the Total System Performance Assessment (TSPA), in which doses are calculated to the receptor of interest from radionuclides postulated to be released to the environment from the potential repository at Yucca Mountain

  11. Estimating agricultural N2O emissions in France: comparison of a spatialized agro-ecosytem model (CERES-EGC) and a terrestrial biosphere model (O-CN)

    Science.gov (United States)

    Massad, R. S.; Prieur, V.; Boukari, E.; Lehuger, S.; Chaumartin, F.; Schultz, M.; Gabrielle, B.

    2012-04-01

    Nitrous oxide (N2O) is a major greenhouse gas and air pollutant. Considered over a 100 year period, it has 298 times more impact 'per unit weight' (Global warming potential) than carbon dioxide. The parties to the United Nations Framework Convention on Climate Change (UNFCCC), including France, are committed to estimate their national nitrous oxide (N2O) budgets and to establish regional programmes of N2O emissions reductions. Agricultural activities are gradually coming into focus as a major GHG emission sector; precise regional estimates of current N2O emissions from arable land are being needed, along with possible means for mitigating emissions. The use of biogeochemical simulation models to estimate N2O fluxes from agricultural soils has obvious benefits. These models provide a unique potential to mechanistically predict N2O emissions from arable soils on both the plot-scale and the regional/national scale on daily time resolutions. In this study we apply two biogeochemical simulation models: CERES-EGC and O-CN all over France for the year 2007 in the perspective of producing an inventory of N2O emissions from croplands. Simulated total N2O emissions from agricultural soils sum up to 20.4 Gg N-N2O/yr with the CERES-EGC model and to 95.1 Gg N-N2O/yr with the O-CN model. Even though the total emissions are largely different between the two models, the temporal and spatial distributions are comparable. When compared to the EDGAR 4.2 emission database we note that O-CN overestimates the annual emissions by approximately a factor of two, whereas CERES-EGC underestimates those emissions. These differences can be explained to a certain extent by the difference in land-use types considered in each of the models and the inventories.

  12. Ecology of the rare microbial biosphere of the Arctic Ocean.

    Science.gov (United States)

    Galand, Pierre E; Casamayor, Emilio O; Kirchman, David L; Lovejoy, Connie

    2009-12-29

    Understanding the role of microbes in the oceans has focused on taxa that occur in high abundance; yet most of the marine microbial diversity is largely determined by a long tail of low-abundance taxa. This rare biosphere may have a cosmopolitan distribution because of high dispersal and low loss rates, and possibly represents a source of phylotypes that become abundant when environmental conditions change. However, the true ecological role of rare marine microorganisms is still not known. Here, we use pyrosequencing to describe the structure and composition of the rare biosphere and to test whether it represents cosmopolitan taxa or whether, similar to abundant phylotypes, the rare community has a biogeography. Our examination of 740,353 16S rRNA gene sequences from 32 bacterial and archaeal communities from various locations of the Arctic Ocean showed that rare phylotypes did not have a cosmopolitan distribution but, rather, followed patterns similar to those of the most abundant members of the community and of the entire community. The abundance distributions of rare and abundant phylotypes were different, following a log-series and log-normal model, respectively, and the taxonomic composition of the rare biosphere was similar to the composition of the abundant phylotypes. We conclude that the rare biosphere has a biogeography and that its tremendous diversity is most likely subjected to ecological processes such as selection, speciation, and extinction.

  13. Boundaries of life: estimating the life span of the biosphere

    Science.gov (United States)

    Franck, S.; Bounama, C.; von Bloh, W.

    We present a minimal model for the global carbon cycle of the Earth containing the reservoirs mantle ocean floor continental crust continental biosphere and the Kerogen as well as the aggregated reservoir ocean and atmosphere and obtain reasonable values for the present distribution of carbon in the surface reservoirs of the Earth The Earth system model for the long-term carbon cycle is specified by introducing three different types of biosphere prokaryotes eucaryotes and complex multicellular life They are characterized by different global temperature tolerance windows prokaryotes 2oC 100oC eucaryotes 5oC 45oC complex multicellular life 0oC 30oC From the Archaean to the future there always exists a prokaryotic biosphere 2 Gyr ago eucaryotic life first appears because the global surface temperature reaches the tolerance window for eucaryotes 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 For realistic values of the biotic enhancement of weathering there is no bistability in the future solutions for complex life Therefore complex organisms will not extinct by an implosion in comparison to the Cambrian explosion Eucaryotes and complex life become extinct because of too high surface temperatures in the future The ultimate life span of the biosphere is defined by the extinction of procaryotes in about 1 6 Gyr

  14. 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.

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

    International Nuclear Information System (INIS)

    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

  16. A regional-scale groundwater model supporting management of the Sian Ka'an Biosphere Reserve and its catchment, Quintana Roo, Mexico

    DEFF Research Database (Denmark)

    Gondwe, Bibi Ruth Neuman; Merediz Alonso, G.; Rebolledo Vieyra, M.;

    2007-01-01

    /terrestrial nature protection area is situated south of Tulum (approx. 87.3° - 88° W, 19° - 20° N). The site is listed as a UNESCO world heritage site and is protected under the Ramsar Convention. It includes extensive freshwater wetlands, saline/brackish mangrove swamps, tropical rainforests and parts of the world......The Caribbean Coast of the Yucatan Peninsula is a rapidly developing area featuring a booming tourism industry. The number of hotel rooms in the Riviera Maya has increased from 2600 in 1996 to 26,000 in 2005, while the total population in the Mexican federal state of Quintana Roo has grown from 500......,000 in 1990 to 1,115,000 in 2005. This explosive growth threatens the region's water resources, which primarily consist of a less than 50m thick freshwater lens residing in the regional karst aquifer underlying the entire Yucatan Peninsula. The Sian Ka'an Biosphere Reserve, a 6400 km2 combined marine...

  17. Development of a reference biospheres methodology for radioactive waste disposal. Final report

    International Nuclear Information System (INIS)

    the Working Group assumes a requirement to calculate annual individual doses arising from long term release of radionuclides in groundwater at an inland site. Though to a degree limited, this context is broadly relevant to many assessments and so the FEP List may be useful as a generic starting point for new model development or for auditing existing biosphere assessments. An example illustration of how to apply the methodology has been provided, based on the case description of the Complementary Studies Working Group of BIOMOVS II. (The results of the Complementary Studies exercise are provided in a separate BIOMOVS II Technical Report.) The application of the International FEP List to the Complementary Studies case description has been examined. A major component of the methodology is the development of a conceptual model from the available information about processes and the related data. Several approaches are discussed, including 'process influence diagrams', 'event trees', and the Rock Engineering System (RES) Interaction Matrix Methodology. The latter was tested in some depth by the Working Group and found to be effective at helping to distinguish the more and less important FEPs, and in identifying the important interactions between components of the system being modelled. An interesting feature of the interaction matrix methodology is that the FEP List applied to the matrix construction process can be developed independently from the matrix. If the matrix were to be developed by the same people as the FEP List then there could be legitimate criticism that the matrix, and hence the conceptual models, had been designed in a closed loop of assessment modelers. However, any issue can be introduced by any interested party through the FEP List. The auditing step allows these other issues to be introduced in model development and so forces the assessment team to explain how the issues are to be dealt with. At the same time, previous experience within the assessment

  18. 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

  19. Will the tropical land biosphere dominate the climate-carbon cycle feedback during the twenty-first century?

    Science.gov (United States)

    Raddatz, T. J.; Reick, C. H.; Knorr, W.; Kattge, J.; Roeckner, E.; Schnur, R.; Schnitzler, K.-G.; Wetzel, P.; Jungclaus, J.

    2007-11-01

    Global warming caused by anthropogenic CO2 emissions is expected to reduce the capability of the ocean and the land biosphere to take up carbon. This will enlarge the fraction of the CO2 emissions remaining in the atmosphere, which in turn will reinforce future climate change. Recent model studies agree in the existence of such a positive climate-carbon cycle feedback, but the estimates of its amplitude differ by an order of magnitude, which considerably increases the uncertainty in future climate projections. Therefore we discuss, in how far a particular process or component of the carbon cycle can be identified, that potentially contributes most to the positive feedback. The discussion is based on simulations with a carbon cycle model, which is embedded in the atmosphere/ocean general circulation model ECHAM5/MPI-OM. Two simulations covering the period 1860-2100 are conducted to determine the impact of global warming on the carbon cycle. Forced by historical and future carbon dioxide emissions (following the scenario A2 of the Intergovernmental Panel on Climate Change), they reveal a noticeable positive climate-carbon cycle feedback, which is mainly driven by the tropical land biosphere. The oceans contribute much less to the positive feedback and the temperate/boreal terrestrial biosphere induces a minor negative feedback. The contrasting behavior of the tropical and temperate/boreal land biosphere is mostly attributed to opposite trends in their net primary productivity (NPP) under global warming conditions. As these findings depend on the model employed they are compared with results derived from other climate-carbon cycle models, which participated in the Coupled Climate-Carbon Cycle Model Intercomparison Project (C4MIP).

  20. New prognostic phenology in the Yale Interactive Terrestrial Biosphere Model: implications for plant volatile emissions and surface air pollution in the temperate zone between 1980s and 2010s

    Science.gov (United States)

    Yue, X.; Unger, N.

    2014-12-01

    We describe the implementation of an improved prognostic phenology scheme in the Yale Interactive Terrestrial Biosphere Model (YIBs). The spring phenology of deciduous broadleaf forest (DBF) is predicted using the cumulative thermal summation with chilling requirements, and the autumn phenology is jointly regulated by temperature and photoperiod. The phenology of shrubland and grassland is sensitive to temperature, except for sites with climatological soil temperature > 12 °C, where plant phenology is controlled by water availability. The model represents frost hardening in evergreen needleleaf forest. An off-line version of the model is evaluated against carbon flux measurements at 145 FLUXNET sites across a wide range of ecosystem types. The simulated seasonality of the gross primary productivity (GPP) has high correlations R > 0.95 with observations at 15 out 20 deciduous broadleaf sites. The updated vegetation model has been embedded on-line inside the NASA ModelE2 global chemistry-climate model. We apply this framework to quantify the phenology changes between the 1980s and 2010s and compare those changes to satellite observations for this period. We isolate the impacts of the phenology changes on plant volatile emissions (isoprene and monoterpenes) and examine the consequences for surface ozone and PM2.5 pollution in the United States and Europe.

  1. Use of the food-chain model FOOD III and the soil model SCEMR to assess irrigation as a biosphere pathway

    International Nuclear Information System (INIS)

    Irrigation of contaminated water onto crop land is a relatively direct pathway for radionuclides to deliver a radiation dose to man. Irrigation was not originally included in the SYVAC assessment model for the Precambrian Shield because no irrigation is currently practised in the region. This report re-evaluates this decision. An analysis of meteorological data shows that crop yield in northern Ontario would benefit from irrigation. Thus, incentives are present for subsistence-scale, and perhaps commercial-scale, irrigation of surface or well water. A food-chain analysis indicated that irrigation with contaminated water could deliver a dose comparable to direct consumption (drinking) of the same water, for some radionuclides. Long-term contamination of soil through irrigation was predicted to be a substantial hazard, even when soil leaching was incorporated into the food-chain model. This report presents parameter estimates that could be used to incorporate irrigation as a pathway in the SYVAC code and will constitute the basis for further decisions concerning this pathway

  2. Development of a reference biospheres methodology for radioactive waste disposal. Final report

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-09-01

    detail by the Working Group assumes a requirement to calculate annual individual doses arising from long term release of radionuclides in groundwater at an inland site. Though to a degree limited, this context is broadly relevant to many assessments and so the FEP List may be useful as a generic starting point for new model development or for auditing existing biosphere assessments. An example illustration of how to apply the methodology has been provided, based on the case description of the Complementary Studies Working Group of BIOMOVS II. (The results of the Complementary Studies exercise are provided in a separate BIOMOVS II Technical Report.) The application of the International FEP List to the Complementary Studies case description has been examined. A major component of the methodology is the development of a conceptual model from the available information about processes and the related data. Several approaches are discussed, including 'process influence diagrams', 'event trees', and the Rock Engineering System (RES) Interaction Matrix Methodology. The latter was tested in some depth by the Working Group and found to be effective at helping to distinguish the more and less important FEPs, and in identifying the important interactions between components of the system being modelled. An interesting feature of the interaction matrix methodology is that the FEP List applied to the matrix construction process can be developed independently from the matrix. If the matrix were to be developed by the same people as the FEP List then there could be legitimate criticism that the matrix, and hence the conceptual models, had been designed in a closed loop of assessment modelers. However, any issue can be introduced by any interested party through the FEP List. The auditing step allows these other issues to be introduced in model development and so forces the assessment team to explain how the issues are to be dealt with. At the same time, previous

  3. Anthropogenic transformation of the terrestrial biosphere.

    Science.gov (United States)

    Ellis, Erle C

    2011-03-13

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

  4. Estimation of Mangrove Net Primary Production and Carbon Sequestration service using Light Use Efficiency model in the Sunderban Biosphere region, India

    Science.gov (United States)

    Sannigrahi, Srikanta; Sen, Somnath; Paul, Saikat

    2016-04-01

    Net Primary Production (NPP) of mangrove ecosystem and its capacity to sequester carbon from the atmosphere may be used to quantify the regulatory ecosystem services. Three major group of parameters has been set up as BioClimatic Parameters (BCP): (Photosynthetically Active Radiation (PAR), Absorbed PAR (APAR), Fraction of PAR (FPAR), Photochemical Reflectance Index (PRI), Light Use Efficiency (LUE)), BioPhysical Parameters (BPP) :(Normalize Difference Vegetation Index (NDVI), scaled NDVI, Enhanced Vegetation Index (EVI), scaled EVI, Optimised and Modified Soil Adjusted Vegetation Index (OSAVI, MSAVI), Leaf Area Index (LAI)), and Environmental Limiting Parameters (ELP) (Temperature Stress (TS), Land Surface Water Index (LSWI), Normalize Soil Water Index (NSWI), Water Stress Scalar (WS), Inversed WS (iWS) Land Surface Temperature (LST), scaled LST, Vapor Pressure Deficit (VPD), scaled VPD, and Soil Water Deficit Index (SWDI)). Several LUE models namely Carnegie Ames Stanford Approach (CASA), Eddy Covariance - LUE (EC-LUE), Global Production Efficiency Model (GloPEM), Vegetation Photosynthesis Model (VPM), MOD NPP model, Temperature and Greenness Model (TG), Greenness and Radiation model (GR) and MOD17 was adopted in this study to assess the spatiotemporal nature of carbon fluxes. Above and Below Ground Biomass (AGB & BGB) was calculated using field based estimation of OSAVI and NDVI. Microclimatic zonation has been set up to assess the impact of coastal climate on environmental limiting factors. MODerate Resolution Imaging Spectroradiometer (MODIS) based yearly Gross Primary Production (GPP) and NPP product MOD17 was also tested with LUE based results with standard model validation statistics: Root Mean Square of Error (RMSE), Mean Absolute Error (MEA), Bias, Coefficient of Variation (CV) and Coefficient of Determination (R2). The performance of CASA NPP was tested with the ground based NPP with R2 = 0.89 RMSE = 3.28 P = 0.01. Among the all adopted models, EC

  5. Insights into the Deep Biosphere from Petroleum Geology

    Science.gov (United States)

    Larter, S.; Adams, J. J.; Huang, H.; Bennett, B.

    2008-12-01

    Petroleum reservoirs provide a unique and direct portal into the deep biosphere enabling microbiological and geochemical studies of microorganisms, carbon cycling processes, microbial reaction kinetics and the spatial distribution of the organisms. Detailed mapping of oil fluid property and chemical composition shows that microbially and geologically induced oil compositional gradients are ubiquitous at regional to sub-reservoir scales (1 m to 105 m) in heavy and super heavy oil deposits of the Alberta basin. Some oil columns shows a cascading series of gradients in one through three ring alkylaromatic hydrocarbons with increasingly deeper locations of complete compound removal related to increasing resistance of degrading hydrocarbon component to biodegradation and decreasing component diffusivity. Similar compositional profiles have been seen in other heavy oilfields around the globe. Vertical 1D compositional diffusion models coupling oil charge, diffusive mixing and the effects of geological barriers can match observed gradients when the active biodegradation zone extends across the oil-water transition zone and well into the oil column. We observe steepening compositional gradients at the base of the oil column coincident with up to 10-15 m thick, downward increasing water saturation zones, thicker than a capillary pressure controlled oil-water transition zone. These "burnout zones" possess the hallmarks of a vertically extensive bio-reactor with increased concentrations of biogeochemical parameters of microbial processes and commonly an immobile and probably discontinuous oil phase. In this zone and across an oilfield, the relative biodegradation susceptibility of different hydrocarbon components varies greatly, indicating a suite of biodegradation reaction pathways dependent in part on local mass transport controls. 1D models show that the top of the degradation zone is coincident with complete depletion of reactive components, when oil charge is active

  6. 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.

  7. 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

    Directory of Open Access Journals (Sweden)

    Y. Kim

    2015-07-01

    Full Text Available 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 leafout 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.

  8. 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.

  9. Nuclear fuel waste management - biosphere program highlights - 1978 to 1996

    International Nuclear Information System (INIS)

    The biosphere program in support of the development of the disposal concept for Canadian nuclear fuel waste since 1978 is scheduled for close-out. AECL's Environmental Science Branch (ESB) was mainly responsible for work in this program. In order to preserve as much information as possible, this report highlights many of the key achievements of the program, particularly those related to the development of the BIOTRAC biosphere model and its supporting research. This model was used for the assessment and review of the disposal concept in an environmental impact statement (EIS). The report also treats highlights related to alternative models, external scientific/technical reviews, EIS feedback, and the international BIOMOVS model validation program. Furthermore, it highlights basic aspects of future modelling and research needs in relation to siting a disposal facility. In this, feedback from the various reviews and the EIS is taken into account. Appendices of the report include listings of key ESB staff involved in the program, all the scientific/technical reports and papers produced under the program, contracts let to outside agencies, and issues raised by various participants or intervenors during the EIS review. Although the report is concerned with close-out of the biosphere program, it also provides valuable information for a continuing program concerned with siting a disposal facility. One of the conclusions of the report is that such a program is essential for successfully siting such a facility. (author)

  10. The development of biosphere codes for use in assessment of the radiological impact of geological repositories for radioactive waste

    International Nuclear Information System (INIS)

    A statement of radiological protection criteria and measures of dose, forms the preface to a review of extant biosphere codes. Consideration is given to the implementation of the codes FOODII and NEPTUN for use with SYVAC. The selection of nuclides for consideration in SYVAC is discussed. Detailed specifications are provided for biosphere model developments desirable in the longer term. (author)

  11. 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.

  12. Ciliates and the rare biosphere: a review.

    Science.gov (United States)

    Dunthorn, Micah; Stoeck, Thorsten; Clamp, John; Warren, Alan; Mahé, Frédéric

    2014-01-01

    Here we provide a brief review of the rare biosphere from the perspective of ciliates and other microbial eukaryotes. We trace research on rarity from its lack of much in-depth focus in morphological and Sanger sequencing projects, to its central importance in analyses using high throughput sequencing strategies. The problem that the rare biosphere is potentially comprised of mostly errors is then discussed in the light of asking community-comparative, novel-diversity, and ecosystem-functioning questions.

  13. Cambrian explosion triggered by geosphere-biosphere feedbacks

    Science.gov (United States)

    von Bloh, Werner; Bounama, Christine; Franck, Siegfried

    2003-09-01

    A new hypothesis for the cause of the Cambrian explosion is presented. For that the evolution of the planet Earth is described by the co-evolution of the geosphere-biosphere system. Here we specify our previously published Earth system model for the long-term carbon cycle by introducing three different types of biosphere: procaryotes, eucaryotes, and complex multicellular life. They are characterized by different global temperature tolerance windows. The biotic enhancement of silicate weathering by complex multicellular life adds an additional feedback to the system and triggers the Cambrian explosion. The Cambrian explosion is characterized by a sudden increase of biomass and a rapid cooling, which amplified the spread of complex multicellular life. Cooling events in the Neoproterozoic, however, could force a premature appearance of complex multicellular life.

  14. Information in the Biosphere: Biological and Digital Worlds.

    Science.gov (United States)

    Gillings, Michael R; Hilbert, Martin; Kemp, Darrell J

    2016-03-01

    Evolution has transformed life through key innovations in information storage and replication, including RNA, DNA, multicellularity, and culture and language. We argue that the carbon-based biosphere has generated a cognitive system (humans) capable of creating technology that will result in a comparable evolutionary transition. Digital information has reached a similar magnitude to information in the biosphere. It increases exponentially, exhibits high-fidelity replication, evolves through differential fitness, is expressed through artificial intelligence (AI), and has facility for virtually limitless recombination. Like previous evolutionary transitions, the potential symbiosis between biological and digital information will reach a critical point where these codes could compete via natural selection. Alternatively, this fusion could create a higher-level superorganism employing a low-conflict division of labor in performing informational tasks.

  15. Information in the Biosphere: Biological and Digital Worlds.

    Science.gov (United States)

    Gillings, Michael R; Hilbert, Martin; Kemp, Darrell J

    2016-03-01

    Evolution has transformed life through key innovations in information storage and replication, including RNA, DNA, multicellularity, and culture and language. We argue that the carbon-based biosphere has generated a cognitive system (humans) capable of creating technology that will result in a comparable evolutionary transition. Digital information has reached a similar magnitude to information in the biosphere. It increases exponentially, exhibits high-fidelity replication, evolves through differential fitness, is expressed through artificial intelligence (AI), and has facility for virtually limitless recombination. Like previous evolutionary transitions, the potential symbiosis between biological and digital information will reach a critical point where these codes could compete via natural selection. Alternatively, this fusion could create a higher-level superorganism employing a low-conflict division of labor in performing informational tasks. PMID:26777788

  16. Commonness and rarity in the marine biosphere.

    Science.gov (United States)

    Connolly, Sean R; MacNeil, M Aaron; Caley, M Julian; Knowlton, Nancy; Cripps, Ed; Hisano, Mizue; Thibaut, Loïc M; Bhattacharya, Bhaskar D; Benedetti-Cecchi, Lisandro; Brainard, Russell E; Brandt, Angelika; Bulleri, Fabio; Ellingsen, Kari E; Kaiser, Stefanie; Kröncke, Ingrid; Linse, Katrin; Maggi, Elena; O'Hara, Timothy D; Plaisance, Laetitia; Poore, Gary C B; Sarkar, Santosh K; Satpathy, Kamala K; Schückel, Ulrike; Williams, Alan; Wilson, Robin S

    2014-06-10

    Explaining patterns of commonness and rarity is fundamental for understanding and managing biodiversity. Consequently, a key test of biodiversity theory has been how well ecological models reproduce empirical distributions of species abundances. However, ecological models with very different assumptions can predict similar species abundance distributions, whereas models with similar assumptions may generate very different predictions. This complicates inferring processes driving community structure from model fits to data. Here, we use an approximation that captures common features of "neutral" biodiversity models--which assume ecological equivalence of species--to test whether neutrality is consistent with patterns of commonness and rarity in the marine biosphere. We do this by analyzing 1,185 species abundance distributions from 14 marine ecosystems ranging from intertidal habitats to abyssal depths, and from the tropics to polar regions. Neutrality performs substantially worse than a classical nonneutral alternative: empirical data consistently show greater heterogeneity of species abundances than expected under neutrality. Poor performance of neutral theory is driven by its consistent inability to capture the dominance of the communities' most-abundant species. Previous tests showing poor performance of a neutral model for a particular system often have been followed by controversy about whether an alternative formulation of neutral theory could explain the data after all. However, our approach focuses on common features of neutral models, revealing discrepancies with a broad range of empirical abundance distributions. These findings highlight the need for biodiversity theory in which ecological differences among species, such as niche differences and demographic trade-offs, play a central role.

  17. Risk of severe climate change impact on the terrestrial biosphere

    International Nuclear Information System (INIS)

    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 CO2 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.

  18. Model-based geostatistics

    CERN Document Server

    Diggle, Peter J

    2007-01-01

    Model-based geostatistics refers to the application of general statistical principles of modeling and inference to geostatistical problems. This volume provides a treatment of model-based geostatistics and emphasizes on statistical methods and applications. It also features analyses of datasets from a range of scientific contexts.

  19. Nonlinear geosphere-biosphere interactions and the Cambrian explosion

    Science.gov (United States)

    von Bloh, W.; Bounama, C.; Franck, S.

    2003-04-01

    A conceptual model for the global carbon cycle of the Earth containing the reservoirs mantle, ocean floor, continental crust, continental biosphere, the kerogen , as well as the aggregated reservoir ocean and atmosphere is presented. In this study the evolution of the mean global surface temperature, the biomass, and reservoir sizes over the whole history and future of the Earth under a maturing Sun is investigated. Reasonable values for the present distribution of carbon in the surface reservoirs of the Earth are obtained and a pronounced global minimum of mean surface temperature at the present state of the Earth is found. Furthermore, three different biosphere types are introduced: procaryotes, eucaryotes, and higher metazoa. They all differ in their temperature tolerance interval and their biogenic enhancement of silicate rock weathering. Around 500 Myr in the past we find a rise of higher metazoa caused by the nonlinear feedback between biosphere and climate. Biotic amplifying of weathering provides and maintains the environment of higher life forms. Such a mechanism may explain the so-called Cambrian explosion.

  20. Swansong Biospheres II: The final signs of life on terrestrial planets near the end of their habitable lifetimes

    CERN Document Server

    O'Malley-James, Jack T; Greaves, Jane S; Raven, John A

    2013-01-01

    The biosignatures of life on Earth do not remain static, but change considerably over the planet's habitable lifetime. Earth's future biosphere, much like that of the early Earth, will consist of predominantly unicellular microorganisms due to the increased hostility of environmental conditions caused by the Sun as it enters the late stage of its main sequence evolution. Building on previous work, the productivity of the biosphere is evaluated during different stages of biosphere decline between 1 Gyr and 2.8 Gyr from present. A simple atmosphere-biosphere interaction model is used to estimate the atmospheric biomarker gas abundances at each stage and to assess the likelihood of remotely detecting the presence of life in low-productivity, microbial biospheres, putting an upper limit on the lifetime of Earth's remotely detectable biosignatures. Other potential biosignatures such as leaf reflectance and cloud cover are discussed.

  1. Variability of projected terrestrial biosphere responses to elevated levels of atmospheric CO2 due to uncertainty in biological nitrogen fixation

    Science.gov (United States)

    Meyerholt, Johannes; Zaehle, Sönke; Smith, Matthew J.

    2016-03-01

    Including a terrestrial nitrogen (N) cycle in Earth system models has led to substantial attenuation of predicted biosphere-climate feedbacks. However, the magnitude of this attenuation remains uncertain. A particularly important but highly uncertain process is biological nitrogen fixation (BNF), which is the largest natural input of N to land ecosystems globally. In order to quantify this uncertainty and estimate likely effects on terrestrial biosphere dynamics, we applied six alternative formulations of BNF spanning the range of process formulations in current state-of-the-art biosphere models within a common framework, the O-CN model: a global map of static BNF rates, two empirical relationships between BNF and other ecosystem variables (net primary productivity and evapotranspiration), two process-oriented formulations based on plant N status, and an optimality-based approach. We examined the resulting differences in model predictions under ambient and elevated atmospheric [CO2] and found that the predicted global BNF rates and their spatial distribution for contemporary conditions were broadly comparable, ranging from 108 to 148 Tg N yr-1 (median: 128 Tg N yr-1), despite distinct regional patterns associated with the assumptions of each approach. Notwithstanding, model responses in BNF rates to elevated levels of atmospheric [CO2] (+200 ppm) ranged between -4 Tg N yr-1 (-3 %) and 56 Tg N yr-1 (+42 %) (median: 7 Tg N yr-1 (+8 %)). As a consequence, future projections of global ecosystem carbon (C) storage (+281 to +353 Pg C, or +13 to +16 %) as well as N2O emission (-1.6 to +0.5 Tg N yr-1, or -19 to +7 %) differed significantly across the different model formulations. Our results emphasize the importance of better understanding the nature and magnitude of BNF responses to change-induced perturbations, particularly through new empirical perturbation experiments and improved model representation.

  2. Effects of Gamma Ray Bursts in Earth Biosphere

    CERN Document Server

    Martin, Osmel; Guimaraes, Mayrene; Penate, Liuba; Horvath, Jorge; Galante, Douglas

    2009-01-01

    We continue former work on the modeling of potential effects of Gamma Ray Bursts on Phanerozoic Earth. We focus on global biospheric effects of ozone depletion and show a first modeling of the spectral reduction of light by NO2 formed in the stratosphere. We also illustrate the current complexities involved in the prediction of how terrestrial ecosystems would respond to this kind of burst. We conclude that more biological field and laboratory data are needed to reach even moderate accuracy in this modeling

  3. Swansong Biospheres: Refuges for life and novel microbial biospheres on terrestrial planets near the end of their habitable lifetimes

    CERN Document Server

    O'Malley-James, J T; Raven, J A; Cockell, C S

    2012-01-01

    The future biosphere on Earth (as with its past) will be made up predominantly of unicellular microorganisms. Unicellular life was probably present for at least 2.5 Gyr before multicellular life appeared and will likely be the only form of life capable of surviving on the planet in the far future, when the ageing Sun causes environmental conditions to become more hostile to more complex forms of life. Therefore, it is statistically more likely that habitable Earth-like exoplanets we discover will be at a stage in their habitable lifetime more conducive to supporting unicellular, rather than multicellular life. The end stage of habitability on Earth is the focus of this work. A simple, latitude-based climate model incorporating eccentricity and obliquity variations is used as a guide to the temperature evolution of the Earth over the next 3 Gyr. This allows inferences to be made about potential refuges for life, particularly in mountains and cold-trap (ice) caves and what forms of life could live in these envi...

  4. Review of geosphere-biosphere interface processes and their handling in the safety case of Posiva

    International Nuclear Information System (INIS)

    The report describes list of databases of the Features, Events and Processes (FEPs) on the basis of the current knowledge and ranks them for their potential importance of radionuclide transport in the Safety Case. Due to vast amount of FEPs, only those assessed as potentially significant for the geosphere-biosphere interface zone (GBIZ) are described in detail. However, for scientific understanding also general main FEPs in the GBIZ are incorporated whether they affect directly radionuclide transport or not. The geosphere-biosphere interface zone, or the boundaries between the geosphere and biosphere modelling domains of the safety assessment, has been raised to an important issue but, according to the reports, it has so far taken into account rather poorly or not at all. Thus, it is acknowledged that a genuine site-specific treatment and incorporation of (deeper) overburden and aquifers into the biosphere models are needed to cover all relevant FEPs and to treat properly the zone in the modeling chain of groundwater flow and geosphere and biosphere transport of radionuclides. The principal variability in the GBIZ, especially in the biosphere, is driven by climatic change. The change from bedrock groundwater to bioavailable region takes place without gaps in the top bedrock to the overburden. However, it is important to recognise that there are regions in GBIZ that overlap the geosphere and biosphere model domains problems envisaged with the treatment of the GBIZ are associated with defining the boundary conditions for both far field and biosphere models. The GBIZ is not a separate modelling domain and the processes and events affecting the transport of radionuclides within the GBIZ should not be considered to be unidirectional. The biosphere is a diverse system under continuous development and impossible to model accurately. Thus, some inherent uncertainty already in the conceptual level of modelling has to be accepted. In addition of needs to handle spatial and

  5. Components, processes and interactions in the biosphere

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-15

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

  6. Components, processes and interactions in the biosphere

    International Nuclear Information System (INIS)

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

  7. Modelling the transfer of radionuclides to fruit. Report of the Fruits Working Group of BIOMASS Theme 3. Part of the IAEA Co-ordinated Research Project on Biosphere Modelling and Assessment (BIOMASS)

    International Nuclear Information System (INIS)

    This report contains a description of the activities carried out by the Fruits Working Group and presents the main results such as conceptual advances, quantitative data and models on the transfer of radionuclides to fruit in the context of the overall objective of BIOMASS Theme 3. The aim of the study was to improve understanding of the processes affecting the migration of radionuclides in the fruit system and to identify the uncertainties associated with modelling the transfer of radionuclides to fruit. The overall objective was to improve the accuracy of risk assessment that should translate to improved health safety for the population and associated cost savings. The significance of fruit, intended as that particular component of the human diet generally consumed as a dessert item, derives from its high economic value, the agricultural area devoted to its cultivation, and its consumption rates. These are important factors for some countries and groups of population. Fruits may become contaminated with radioactive material from nuclear facilities during routine operation, as a consequence of nuclear accidents, or due to migration through the biosphere of radionuclides from radioactive waste disposal facilities. Relevant radionuclides when considering transfer to fruit from atmospheric deposition were identified as 3H, 14C, 35S, 36Cl, 90Sr, 129I, 134Cs and 137Cs. The transfer of radionuclides to fruit is complex and involves many interactions between biotic and abiotic components. Edible fruit is borne by different plant species, such as herbaceous plants, shrubs and trees, that can grow under different climatic conditions and may be found in agricultural or natural ecosystems. A review of experimental, field and modelling information on the transfer of radionuclides to fruit was carried out at the inception of the activities of the Group, taking into account results from a Questionnaire circulated to radioecologists. Results on current experimental studies have

  8. Hydrogeologic Controls on the Deep Terrestrial Biosphere - Chemolithotrophic Energy for Subsurface Life on Earth and Mars

    Science.gov (United States)

    Sherwood Lollar, B.; Moran, J.; Tille, S.; Voglesonger, K.; Lacrampe-Couloume, G.; Onstott, T.; Pratt, L.; Slater, G.

    2009-05-01

    As exploration for gold, diamonds and base metals expand mine workings to depths of almost 3 km below the Earth's surface, the mines of the Canadian Shield provide a window into the deep biosphere as diverse, but to date less well-explored than the South African Gold Mines. To date investigations of the deep biosphere have, in most cases, focused on the marine subsurface, including deep sea sediments, hydrothermal vents, off-axis spreading centers and cold seeps. Yet the deep terrestrial subsurface hosted in the fracture waters of Archean Shield rocks provides an important analog and counterpoint to studies of the deep marine biosphere. Depending on the particular geologic and hydrogeologic setting, sites vary from those dominated by paleometeoric waters and microbial hydrocarbon production, to those in which H2 and hydrocarbon gases have been suggested to be a function of long-term accumulation of the products of water-rock interaction in the deepest, most saline fracture waters with residence times on the order of tens of millions of years. The hydrogeologically isolated fracture-controlled ground water system periodically generates steep redox gradients and chemical disequilibrium due to fracture opening, and episodic release of mM levels of H2 that support a redox driven microbial community of H2-utilizing sulfate reducers and methanogens. Exploration of these systems may provide information about the limits of the deep terrestrial biosphere, controls on the distribution of deep subsurface life, and the diversity of geochemical reactions that produce substrates on which microbiological communities at great depths survive. The geologically stable Precambrian cratons of Earth are arguably the closest analogs available to single-plate planets such as Mars. Studies of these Earth analogs imply that the habitability of the Martian crust might similarly not be restricted to sites of localized hydrothermal activity. While the presence of the Martian cryosphere and

  9. Ecology and exploration of the rare biosphere.

    Science.gov (United States)

    Lynch, Michael D J; Neufeld, Josh D

    2015-04-01

    The profound influence of microorganisms on human life and global biogeochemical cycles underlines the value of studying the biogeography of microorganisms, exploring microbial genomes and expanding our understanding of most microbial species on Earth: that is, those present at low relative abundance. The detection and subsequent analysis of low-abundance microbial populations—the 'rare biosphere'—have demonstrated the persistence, population dynamics, dispersion and predation of these microbial species. We discuss the ecology of rare microbial populations, and highlight molecular and computational methods for targeting taxonomic 'blind spots' within the rare biosphere of complex microbial communities.

  10. Quantifying Uncertainty in the Predictions of the SimSphere Land Biosphere Model in Simulating Key Parameters Characterising Earth's Energy Balance

    Science.gov (United States)

    North, Matthew; Petropoulos, George

    2014-05-01

    Soil Vegetation Atmosphere Transfer (SVAT) models are becoming the preferred scientific tool to assess land surface energy fluxes due to their computational efficiency, accuracy and ability to provide results at fine temporal scales. An all-inclusive validation of those models is a fundamental step before those can be confidently used for any practical application or research purpose alike. SimSphere is an example of a SVAT model, simulating a large array of parameters characterising various land surface interactions over a 24 hour cycle at a 1-D vertical profile. Being able to appreciate the uncertainty of SimSphere predictions, is of vital importance towards increasing confidence in the models' overall use and ability to represent accurate land surface interactions. This is particularly important, given that its use either as a stand-alone tool or synergistically with Earth Observation (EO) data is currently expanding worldwide. In the present study, uncertainty in the SimSphere's predictions is evaluated at seven European sites, representative of a range of ecosystem conditions and biomes types for which in-situ data from the CarboEurope IP operational network acquired during 2011 were available. Selected sites are characterised by varying topographical characteristics, which further allow developing a comprehensive understanding on how topography can affect the models' ability to reproduce the variables which are evaluated. Model simulations are compared to in-situ data collected on cloud free days and on days with high Energy Balance Ratio. We focused here specifically on evaluating SimSphere capability in predicting selected variables of the energy balance, namely the Latent Heat (LE), Sensible heat (H) and Net Radiation (Rn) fluxes. An evaluation of the uncertainty in the model predictions was evaluated on the basis of extensive statistical analysis that was carried out by computing a series of relevant statistical measures. Results obtained confirmed the

  11. Biospheric Health and Integrity: The Top Priority for Humankind

    OpenAIRE

    Cairns, John

    2009-01-01

    All life on Earth depends on the biospheric life support system to provide both natural capital, or resources, and ecosystem services. Why, then, is the human economy, a subset of the biosphere, given the highest priority by both politicians and the general public? If humans do not make the biosphere s health the top priority, the effects of global warming will change the biosphere into a vastly different, unlivable system.

  12. QND – DESIGNING A PARTICIPATORY SCENARIO MODELING TOOL TO INTEGRATE TECHNOLOGY, ECOLOGY, AND SOCIOLOGY IN GUATEMALA’S MAYA BIOSPHERE RESERVE AND BEYOND

    Science.gov (United States)

    Participatory scenario modeling – an interactive method for visualizing the future – is one of the most promising tools for achieving sustainable land use agreements amongst diverse stakeholder groups. The method has the potential to bridge the gap between the high...

  13. The World Campaign for the Biosphere.

    Science.gov (United States)

    Barman, Charles R.

    1984-01-01

    Lists and discusses goals of The World Campaign for the Biosphere and strategies designed to achieve these goals. Also lists eight suggestions for science teachers to help incorporate the goals into school curricula and programs. These include organizing assemblies which present information about environmental problems and presenting environmental…

  14. Biosphere 2's Marsh Biome

    Science.gov (United States)

    Molnar, Jennifer; Goodridge, Kelven

    1997-01-01

    The Marsh Biome, which was modeled after the mangroves and marshes of southwest Florida, has an area of 441.2 sq m separated into three hydrologically independent sections: the Freshwater, Oligohaline and Salt Marshes. The divisions are made based on their salinity (approximately 0, 4, and 34 ppt. respectively), but they also contain different biological communities. The Freshwater and Oligohaline Marshes are mostly filled with various grasses and several trees, while the Salt Marsh houses regions of red, black, and white mangroves (Rhizophora mangle, Avicennia germinans, and Languncularia racemosa respectively). Overall, there are an estimated 80 species of plants within the biome. Water in the Salt Marsh follows a meandering stream from the algal turf scrubbers (apparatuses that clean the water of its nutrients and heavy metals while increasing dissolved oxygen levels) which have an outlet in the Salt Marsh section near sites 4 and 5 to the Fringing Red Mangrove section. The sections of the Salt Marsh are separated by walls of concrete with openings to allow the stream to flow through. Throughout this study, conducted through the months of June and July, many conditions within the biome remained fairly constant. The temperature was within a degree or two of 25 C, mostly depending on whether the sample site was in direct sunlight or shaded. The pH throughout the Salt Marsh was 8.0 +/- 0.2, and the lower salinity waters only dropped below this soon after rains. The water rdepth and dissolved oxygen varied, however, between sites.

  15. Living microbial ecosystems within the active zone of catagenesis: Implications for feeding the deep biosphere

    Science.gov (United States)

    Horsfield, B.; Schenk, H. J.; Zink, K.; Ondrak, R.; Dieckmann, V.; Kallmeyer, J.; Mangelsdorf, K.; di Primio, R.; Wilkes, H.; Parkes, R. J.; Fry, J.; Cragg, B.

    2006-06-01

    Earth's largest reactive carbon pool, marine sedimentary organic matter, becomes increasingly recalcitrant during burial, making it almost inaccessible as a substrate for microorganisms, and thereby limiting metabolic activity in the deep biosphere. Because elevated temperature acting over geological time leads to the massive thermal breakdown of the organic matter into volatiles, including petroleum, the question arises whether microorganisms can directly utilize these maturation products as a substrate. While migrated thermogenic fluids are known to sustain microbial consortia in shallow sediments, an in situ coupling of abiotic generation and microbial utilization has not been demonstrated. Here we show, using a combination of basin modelling, kinetic modelling, geomicrobiology and biogeochemistry, that microorganisms inhabit the active generation zone in the Nankai Trough, offshore Japan. Three sites from ODP Leg 190 have been evaluated, namely 1173, 1174 and 1177, drilled in nearly undeformed Quaternary and Tertiary sedimentary sequences seaward of the Nankai Trough itself. Paleotemperatures were reconstructed based on subsidence profiles, compaction modelling, present-day heat flow, downhole temperature measurements and organic maturity parameters. Today's heat flow distribution can be considered mainly conductive, and is extremely high in places, reaching 180 mW/m 2. The kinetic parameters describing total hydrocarbon generation, determined by laboratory pyrolysis experiments, were utilized by the model in order to predict the timing of generation in time and space. The model predicts that the onset of present day generation lies between 300 and 500 m below sea floor (5100-5300 m below mean sea level), depending on well location. In the case of Site 1174, 5-10% conversion has taken place by a present day temperature of ca. 85 °C. Predictions were largely validated by on-site hydrocarbon gas measurements. Viable organisms in the same depth range have been

  16. Biosphere assessment due to radionuclide release in waste disposal repository through food chain pathways

    International Nuclear Information System (INIS)

    The long-term safety of radioactive waste disposal is assessed by the consequence analysis of radionuclides release, of which the final step is carried out by the biosphere assessment. the radiation dose is calculated from the food chain modeling which especially necessitates site-specific input database and exposure pathways. A biosphere model in consideration of new exposure pathways has been analyzed, and a program for food chain calculation has been developed. The up-to-data input data are reflected and the new exposure pathways are considered in the program, so the code shows more realistic and reliable results

  17. 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

    Full Text Available The main purpose of this second essay the “biospherology” is to streamline and formalize the existing knowledge about the biosphere, to develop the theoretical basis of the theory of evolution of the biosphere. Despite the vast amount of research on ways of origin and development of life, yet there is no generally accepted theory of evolution of life on Earth, which would not only contain the phenomenology of this process, but also an understanding of the mechanism of functioning of the biosphere as a self-regulating living organism. In the first essay, the necessity of such an understanding to preserve life-supporting functions of the biosphere under increasing anthropogenic pressure. As solution it has been proposed in the form of transition to the managed (controlled evolution of the biosphere – to process of maintenance of life-supporting ability of the biosphere by management of Humankind activity. This essay is an attempt to create a consistent picture of the structure and functioning of the Earth life, the main achievements of the evolution of life, led to the almost completely closed (to the Anthropocene self-sustaining biosphere cycling of substance and energy, the growth of "sum of life" and evolve the social form of matter from biological one. The proposed view of the multidimensional picture of life on Earth consists of the determination of necessary and sufficient properties of a life matter, formulate functioning principles of the life, and determind of the different levels of organization of life. Among the main features of living: discreetness, integritiness, self-reproducibility, dissymmetriness, cooperativeness, mortality, orderness, energy saturation, informational content. Among the main principles of the functioning of the life: the unity of the biological structure (phenotype and the program for its construction (genotype, transmitted in generations; matrix way of transmission of the programs of development

  18. Does aspartic acid racemization constrain the depth limit of the subsurface biosphere?

    Energy Technology Data Exchange (ETDEWEB)

    Onstott, T. C. [Princeton University; Aubrey, A.D. [Jet Propulsion Laboratory, Pasadena, CA; Kieft, T L [New Mexico Institute of Mining and Technology; Silver, B J [Jet Propulsion Laboratory, Pasadena, CA; Phelps, Tommy Joe [ORNL; Van Heerden, E. [University of the Free State; Opperman, D. J. [University of the Free State; Bada, J L. [Geosciences Research Division, Scripps Instition of Oceanography, Univesity of California San Diego,

    2014-01-01

    Previous studies of the subsurface biosphere have deduced average cellular doubling times of hundreds to thousands of years based upon geochemical models. We have directly constrained the in situ average cellular protein turnover or doubling times for metabolically active micro-organisms based on cellular amino acid abundances, D/L values of cellular aspartic acid, and the in vivo aspartic acid racemization rate. Application of this method to planktonic microbial communities collected from deep fractures in South Africa yielded maximum cellular amino acid turnover times of ~89 years for 1 km depth and 27 C and 1 2 years for 3 km depth and 54 C. The latter turnover times are much shorter than previously estimated cellular turnover times based upon geochemical arguments. The aspartic acid racemization rate at higher temperatures yields cellular protein doubling times that are consistent with the survival times of hyperthermophilic strains and predicts that at temperatures of 85 C, cells must replace proteins every couple of days to maintain enzymatic activity. Such a high maintenance requirement may be the principal limit on the abundance of living micro-organisms in the deep, hot subsurface biosphere, as well as a potential limit on their activity. The measurement of the D/L of aspartic acid in biological samples is a potentially powerful tool for deep, fractured continental and oceanic crustal settings where geochemical models of carbon turnover times are poorly constrained. Experimental observations on the racemization rates of aspartic acid in living thermophiles and hyperthermophiles could test this hypothesis. The development of corrections for cell wall peptides and spores will be required, however, to improve the accuracy of these estimates for environmental samples.

  19. Does aspartic acid racemization constrain the depth limit of the subsurface biosphere?

    Science.gov (United States)

    Onstott, T C; Magnabosco, C; Aubrey, A D; Burton, A S; Dworkin, J P; Elsila, J E; Grunsfeld, S; Cao, B H; Hein, J E; Glavin, D P; Kieft, T L; Silver, B J; Phelps, T J; van Heerden, E; Opperman, D J; Bada, J L

    2014-01-01

    Previous studies of the subsurface biosphere have deduced average cellular doubling times of hundreds to thousands of years based upon geochemical models. We have directly constrained the in situ average cellular protein turnover or doubling times for metabolically active micro-organisms based on cellular amino acid abundances, D/L values of cellular aspartic acid, and the in vivo aspartic acid racemization rate. Application of this method to planktonic microbial communities collected from deep fractures in South Africa yielded maximum cellular amino acid turnover times of ~89 years for 1 km depth and 27 °C and 1-2 years for 3 km depth and 54 °C. The latter turnover times are much shorter than previously estimated cellular turnover times based upon geochemical arguments. The aspartic acid racemization rate at higher temperatures yields cellular protein doubling times that are consistent with the survival times of hyperthermophilic strains and predicts that at temperatures of 85 °C, cells must replace proteins every couple of days to maintain enzymatic activity. Such a high maintenance requirement may be the principal limit on the abundance of living micro-organisms in the deep, hot subsurface biosphere, as well as a potential limit on their activity. The measurement of the D/L of aspartic acid in biological samples is a potentially powerful tool for deep, fractured continental and oceanic crustal settings where geochemical models of carbon turnover times are poorly constrained. Experimental observations on the racemization rates of aspartic acid in living thermophiles and hyperthermophiles could test this hypothesis. The development of corrections for cell wall peptides and spores will be required, however, to improve the accuracy of these estimates for environmental samples. PMID:24289240

  20. Does aspartic acid racemization constrain the depth limit of the subsurface biosphere?

    Science.gov (United States)

    Onstott, T C; Magnabosco, C; Aubrey, A D; Burton, A S; Dworkin, J P; Elsila, J E; Grunsfeld, S; Cao, B H; Hein, J E; Glavin, D P; Kieft, T L; Silver, B J; Phelps, T J; van Heerden, E; Opperman, D J; Bada, J L

    2014-01-01

    Previous studies of the subsurface biosphere have deduced average cellular doubling times of hundreds to thousands of years based upon geochemical models. We have directly constrained the in situ average cellular protein turnover or doubling times for metabolically active micro-organisms based on cellular amino acid abundances, D/L values of cellular aspartic acid, and the in vivo aspartic acid racemization rate. Application of this method to planktonic microbial communities collected from deep fractures in South Africa yielded maximum cellular amino acid turnover times of ~89 years for 1 km depth and 27 °C and 1-2 years for 3 km depth and 54 °C. The latter turnover times are much shorter than previously estimated cellular turnover times based upon geochemical arguments. The aspartic acid racemization rate at higher temperatures yields cellular protein doubling times that are consistent with the survival times of hyperthermophilic strains and predicts that at temperatures of 85 °C, cells must replace proteins every couple of days to maintain enzymatic activity. Such a high maintenance requirement may be the principal limit on the abundance of living micro-organisms in the deep, hot subsurface biosphere, as well as a potential limit on their activity. The measurement of the D/L of aspartic acid in biological samples is a potentially powerful tool for deep, fractured continental and oceanic crustal settings where geochemical models of carbon turnover times are poorly constrained. Experimental observations on the racemization rates of aspartic acid in living thermophiles and hyperthermophiles could test this hypothesis. The development of corrections for cell wall peptides and spores will be required, however, to improve the accuracy of these estimates for environmental samples.

  1. Does Aspartic Acid Racemization Constrain the Depth Limit of the Subsurface Biosphere?

    Science.gov (United States)

    Onstott, T C.; Magnabosco, C.; Aubrey, A. D.; Burton, A. S.; Dworkin, J. P.; Elsila, J. E.; Grunsfeld, S.; Cao, B. H.; Hein, J. E.; Glavin, D. P.; Kieft, T. L.; Silver, B. J.; Phelps, T. J.; Heerden, E. Van; Opperman, D. J.; Bada, J. L.

    2013-01-01

    Previous studies of the subsurface biosphere have deduced average cellular doubling times of hundreds to thousands of years based upon geochemical models. We have directly constrained the in situ average cellular protein turnover or doubling times for metabolically active micro-organisms based on cellular amino acid abundances, D/L values of cellular aspartic acid, and the in vivo aspartic acid racemization rate. Application of this method to planktonic microbial communities collected from deep fractures in South Africa yielded maximum cellular amino acid turnover times of approximately 89 years for 1 km depth and 27 C and 1-2 years for 3 km depth and 54 C. The latter turnover times are much shorter than previously estimated cellular turnover times based upon geochemical arguments. The aspartic acid racemization rate at higher temperatures yields cellular protein doubling times that are consistent with the survival times of hyperthermophilic strains and predicts that at temperatures of 85 C, cells must replace proteins every couple of days to maintain enzymatic activity. Such a high maintenance requirement may be the principal limit on the abundance of living micro-organisms in the deep, hot subsurface biosphere, as well as a potential limit on their activity. The measurement of the D/L of aspartic acid in biological samples is a potentially powerful tool for deep, fractured continental and oceanic crustal settings where geochemical models of carbon turnover times are poorly constrained. Experimental observations on the racemization rates of aspartic acid in living thermophiles and hyperthermophiles could test this hypothesis. The development of corrections for cell wall peptides and spores will be required, however, to improve the accuracy of these estimates for environmental samples.

  2. Evolving Phytoplankton Stoichiometry Fueled Diversification of the Marine Biosphere

    Directory of Open Access Journals (Sweden)

    Antonietta Quigg

    2012-05-01

    Full Text Available The availability of nutrients and the quantity and quality of food at the base of food webs have largely been ignored in discussions of the Phanerozoic record of biodiversity. We examine the role of nutrient availability and phytoplankton stoichiometry (the relative proportions of inorganic nutrients to carbon in the diversification of the marine biosphere. Nutrient availability and phytoplankton stoichiometry played a critical role in the initial diversification of the marine biosphere during the Neoproterozoic. Initial biosphere expansion during this time resulted in the massive sequestration of nutrients into biomass which, along with the geologically slow input of nutrients from land, set the stage for severe nutrient limitation and relatively constant marine biodiversity during the rest of the Paleozoic. Given the slow nutrient inputs from land and low recycling rates, the growth of early-to-middle Paleozoic metazoans remained limited by their having to expend energy to first “burn off” (respire excess carbon in food before the associated nutrients could be utilized for growth and reproduction; the relative equilibrium in marine biodiversity during the Paleozoic therefore appears to be real. Limited nutrient availability and the consequent nutrient imbalance may have delayed the appearance of more advanced carnivores until the Permo-Carboniferous, when widespread orogeny, falling sea level, the spread of forests, greater weathering rates, enhanced ocean circulation, oxygenation, and upwelling all combined to increase nutrient availability. During the Meso-Cenozoic, rising oxygen levels, the continued nutrient input from land, and, especially, increasing rates of bioturbation, enhanced nutrient availability, increasing the nutrient content of phytoplankton that fueled the diversification of the Modern Fauna.

  3. Deep-sea smokers: windows to a subsurface biosphere?

    Science.gov (United States)

    Deming, J W; Baross, J A

    1993-07-01

    Since the discovery of hyperthermophilic microbial activity in hydrothermal fluids recovered from "smoker" vents on the East Pacific Rise, the widely accepted upper temperature limit for life (based on pure culture data) has risen from below the boiling point of water at atmospheric pressure to approximately 115 degrees C. Many microbiologists seem willing to speculate that the maximum may be closer to 150 degrees C. We have postulated not only higher temperatures than these (under deep-sea hydrostatic pressures), but also the existence of a biosphere subsurface to accessible seafloor vents. New geochemical information from the Endeavour Segment of the Juan de Fuca Ridge indicative of subsurface organic material caused us to re-examine both the literature on hyperthermophilic microorganisms cultured from deep-sea smoker environments and recent results of microbial sampling efforts at actively discharging smokers on the Endeavour Segment. Here we offer the case for a subsurface biosphere based on an interdisciplinary view of microbial and geochemical analyses of Endeavour smoker fluids, a case in keeping with rapidly evolving geophysical understanding of organic stability under deep-sea hydrothermal conditions. PMID:11538298

  4. Transfer into the biosphere of radionuclides released from deep storage of radioactive wastes. Bibliographical study

    International Nuclear Information System (INIS)

    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, however, does not preclude the essential need for in-depth knowledge of the phenomena and of the physico-chemical characteristics of radionuclides. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-09-01

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

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

    International Nuclear Information System (INIS)

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

  7. Biodiversity of soil invertebrates of Bel’gard International Prysamars’ky Biosphere Station

    OpenAIRE

    Y. B. Smirnov

    2006-01-01

    Biodiversity of soil invertebrates on the model plots of Bel’gard International Prysamars’ky Biosphere Station of the Dnipropetrovsk National University is under consideration. Number, biomass and distribution of the invertebrates on the right-bank of Samara River were ascertained in 2003–2005.

  8. Safety case for the disposal of spent nuclear fuel at Olkiluoto - Biosphere assessment 2012

    International Nuclear Information System (INIS)

    Biosphere Assessment sits within Posiva Oy's safety case 'TURVA-2012' report portfolio and has the objectives of presenting the assessment methodology, a summary of the surface environment at the Olkiluoto site and an assessment of the surface environment scenarios that have been identified in Formulation of Radionuclide Release Scenarios. A base scenario, variant scenarios and disturbance scenarios are considered. For the base scenario, a Reference Case has been identified and analysed. For the other scenarios, a range of biosphere calculation cases has been identified and analysed. All calculation cases, except cases addressing inadvertent human intrusion, are based on repository calculation cases, assessed in Assessment of Radionuclide Release Scenarios, in which failure of a single spent fuel canister gives radionuclide releases to the biosphere within the dose assessment time window of ten millennia. The biosphere calculation cases take into account uncertainties in the development of the terrain and the ecosystems, land use, location of the releases to the surface environment, radionuclide transport properties and dietary profiles. The resulting annual doses to humans for all calculation cases for the base and variant scenarios are below the radiation dose constraints for most exposed people and other people, as set out by the Finnish regulator, generally by more than two orders of magnitude. The resulting absorbed doses rates to plants and animals for all calculation cases imply that any radiological impacts of these releases will be negligible (orig.)

  9. 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

    . Nonetheless, the extreme ionisation could force atmospheric chemistry that may perturb a venusian biosphere in other ways. The energy deposition profiles presented here are also applicable to modelling efforts to understand how fundamental planetary atmospheric processes such as atmospheric chemistry, cloud microphysics and atmospheric electrical systems are affected by extreme solar particle events. The companion paper to this study, Constraints on a potential aerial biosphere on Venus: II. Solar ultraviolet radiation (Patel et al., in preparation), considers the threat posed by penetration of solar UV radiation. The results of these twin studies are based on Venus but are also applicable to extrasolar terrestrial planets near the inner edge of the circumstellar habitable zone.

  10. Geochemical ways of artificial radionuclide migration in biosphere

    International Nuclear Information System (INIS)

    This collection presents abstracts of papers on the following subjects: organization and methodology of research and developments on creation of combined medium- and largescale landscape-geochemical and radioecological maps for territories contaminated by radionuclides; typological and space features of distribution of artificial radionuclides and regularities of their migration, the radionuclides being entered the biosphere during accidents at NPPs; forms of artificial radionuclides in biosphere after the NPP accidents; simulation of primary entering and secondary migration of radionuclides in biosphere; methodology of organization and conducting radiogeochemical monitoring of biosphere; new methods and means for radiation monitoring of the environment

  11. Model Based Definition

    Science.gov (United States)

    Rowe, Sidney E.

    2010-01-01

    In September 2007, the Engineering Directorate at the Marshall Space Flight Center (MSFC) created the Design System Focus Team (DSFT). MSFC was responsible for the in-house design and development of the Ares 1 Upper Stage and the Engineering Directorate was preparing to deploy a new electronic Configuration Management and Data Management System with the Design Data Management System (DDMS) based upon a Commercial Off The Shelf (COTS) Product Data Management (PDM) System. The DSFT was to establish standardized CAD practices and a new data life cycle for design data. Of special interest here, the design teams were to implement Model Based Definition (MBD) in support of the Upper Stage manufacturing contract. It is noted that this MBD does use partially dimensioned drawings for auxiliary information to the model. The design data lifecycle implemented several new release states to be used prior to formal release that allowed the models to move through a flow of progressive maturity. The DSFT identified some 17 Lessons Learned as outcomes of the standards development, pathfinder deployments and initial application to the Upper Stage design completion. Some of the high value examples are reviewed.

  12. The natural radioactivity of the biosphere

    International Nuclear Information System (INIS)

    Of the approximately 1200 isotopes presently known more than 900 are radioactive. The nuclei of these isotopes are unstable and decay spontaneously emitting ionizing gamma-, alpha- or beta-radiation. The overwhelming majority of known radioactive isotopes have been obtained artificially; only a few are natural. Numerous investigations have shown that many of the natural radioactive isotopes can be grouped into three radioactive families. Each such family is characterized by the existence of one long-lived isotope - the family parent, one gaseous isotope of radon, intermediate radioactive decay products and final stable isotopes of atomic weights 206, 207 and 208. No such generic relationship has been established among the remaining natural radioactive isotopes. The purpose of the book, in contrast to some recent review works, is to present, in addition to a summary of reference data characterizing the radioactivity levels of various components of the biosphere, a description of those phenomena and regularities which will apparently make it possible to understand more completely the basic dynamics of the natural radioactivity of the biosphere and, consequently, contribute to a more correct interpretation of radiation-hygiene in each specific case

  13. MODELS OF THE CITIES OF THE FUTURE - FROM TECHNOPOLIS TO ECOSITY

    OpenAIRE

    Pryadko Igor Petrovich

    2014-01-01

    This paper is devoted to the models of future cities and evaluating their suitability in terms of biosphere compatible human environment. The following two models of cities are analyzed: technopolis (techno-park) and ecocity (garden city). Ecological aspects of the urban life are considered. The author demonstrates how the solutions based on the biosphere-compatible urban planning can serve to optimize the development of the cities. In the first part of the article the examples illustrating t...

  14. Biospheric and petrogenic organic carbon flux along southeast Alaska

    Science.gov (United States)

    Cui, Xingqian; Bianchi, Thomas S.; Jaeger, John M.; Smith, Richard W.

    2016-10-01

    Holocene fjords store ca. 11-12% of the total organic carbon (OC) buried in marine sediments with fjords along southeast (SE) Alaska possibly storing half of this OC (Smith et al., 2015). However, the respective burial of biospheric (OCbio) and petrogenic OC (OCpetro) remains poorly constrained, particularly across glaciated versus non-glaciated systems. Here, we use surface sediment samples to quantify the sources and burial of sedimentary OC along SE Alaska fjord-coastal systems, and conduct a latitudinal comparison across a suite of fjords and river-coastal systems with distinctive OC sources. Our results for SE Alaska show that surface sediments in northern fjords (north of Icy Strait) with headwater glaciers are dominated by OCpetro, in contrast to marine and terrestrially-derived fresh OC in non-glaciated southern fjords. Along the continental shelf of the Gulf of Alaska, terrestrial OC is exported from rivers. Using end-member mixing models, we determine that glaciated fjords have significantly higher burial rates of OCpetro (∼ 1.1 ×103 gOC m-2yr-1) than non-glaciated fjords and other coastal systems, making SE Alaska potentially the largest sink of OCpetro in North America. In contrast, non-glaciated fjords in SE Alaska are effective in burying marine OC (OCbio-mari) (13-82 g OC m-2yr-1). Globally, OC in fjord sediments are comprised of a mixture of OCpetro and fresh OCbio, in contrast to the pre-aged OC from floodplain river-coastal systems. We find that there may be a general latitudinal trend in the role of fjords in processing OC, where high-latitude temperate glacial fjords (e.g., Yakutat Bay, SE Alaska) rebury OCpetro and non-glacial mid-latitude fjords (e.g., Doubtful Sound, Fiordland) sequester CO2 from phytoplankton and/or temperate forests. Overall, we propose that fjords are effective in sequestering OCbio and re-burying OCpetro. Based on our study, we hypothesize that climate change will have a semi-predictable impact on fjords' OC cycling in

  15. Application of the Spanish methodological approach for biosphere assessment to a generic high-level waste disposal site.

    Science.gov (United States)

    Agüero, A; Pinedo, P; Simón, I; Cancio, D; Moraleda, M; Trueba, C; Pérez-Sánchez, D

    2008-09-15

    A methodological approach which includes conceptual developments, methodological aspects and software tools have been developed in the Spanish context, based on the BIOMASS "Reference Biospheres Methodology". The biosphere assessments have to be undertaken with the aim of demonstrating compliance with principles and regulations established to limit the possible radiological impact of radioactive waste disposals on human health and on the environment, and to ensure that future generations will not be exposed to higher radiation levels than those that would be acceptable today. The biosphere in the context of high-level waste disposal is defined as the collection of various radionuclide transfer pathways that may result in releases into the surface environment, transport within and between the biosphere receptors, exposure of humans and biota, and the doses/risks associated with such exposures. The assessments need to take into account the complexity of the biosphere, the nature of the radionuclides released and the long timescales considered. It is also necessary to make assumptions related to the habits and lifestyle of the exposed population, human activities in the long term and possible modifications of the biosphere. A summary on the Spanish methodological approach for biosphere assessment are presented here as well as its application in a Spanish generic case study. A reference scenario has been developed based on current conditions at a site located in Central-West Spain, to indicate the potential impact to the actual population. In addition, environmental change has been considered qualitatively through the use of interaction matrices and transition diagrams. Unit source terms of (36)Cl, (79)Se, (99)Tc, (129)I, (135)Cs, (226)Ra, (231)Pa, (238)U, (237)Np and (239)Pu have been taken. Two exposure groups of infants and adults have been chosen for dose calculations. Results are presented and their robustness is evaluated through the use of uncertainty and

  16. Application of the Spanish methodological approach for biosphere assessment to a generic high-level waste disposal site.

    Science.gov (United States)

    Agüero, A; Pinedo, P; Simón, I; Cancio, D; Moraleda, M; Trueba, C; Pérez-Sánchez, D

    2008-09-15

    A methodological approach which includes conceptual developments, methodological aspects and software tools have been developed in the Spanish context, based on the BIOMASS "Reference Biospheres Methodology". The biosphere assessments have to be undertaken with the aim of demonstrating compliance with principles and regulations established to limit the possible radiological impact of radioactive waste disposals on human health and on the environment, and to ensure that future generations will not be exposed to higher radiation levels than those that would be acceptable today. The biosphere in the context of high-level waste disposal is defined as the collection of various radionuclide transfer pathways that may result in releases into the surface environment, transport within and between the biosphere receptors, exposure of humans and biota, and the doses/risks associated with such exposures. The assessments need to take into account the complexity of the biosphere, the nature of the radionuclides released and the long timescales considered. It is also necessary to make assumptions related to the habits and lifestyle of the exposed population, human activities in the long term and possible modifications of the biosphere. A summary on the Spanish methodological approach for biosphere assessment are presented here as well as its application in a Spanish generic case study. A reference scenario has been developed based on current conditions at a site located in Central-West Spain, to indicate the potential impact to the actual population. In addition, environmental change has been considered qualitatively through the use of interaction matrices and transition diagrams. Unit source terms of (36)Cl, (79)Se, (99)Tc, (129)I, (135)Cs, (226)Ra, (231)Pa, (238)U, (237)Np and (239)Pu have been taken. Two exposure groups of infants and adults have been chosen for dose calculations. Results are presented and their robustness is evaluated through the use of uncertainty and

  17. Atmospheric and biospheric effects of cosmic

    International Nuclear Information System (INIS)

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

  18. Precambrian paleontology and acrochrons of the biosphere evolution: On the theory of the expanding biosphere

    Science.gov (United States)

    Sokolov, B. S.

    2012-04-01

    What is pre-life? We have no idea, since it is hidden in chemical molecules that conceal its future genetic potential. From the biological standpoint, a prokaryotic cyanobacteria cell represents a culmination of biochemical evolution. Its appearance on the Earth marked the starting point of the formation of the first biogeocoenosis on the planet, i.e., the onset of its biosphere. After having started, approximately 4.0-3.7 Ga ago, biosphere evolution has continued uninterrupted on the Earth. Its whole course is reflected in the geochronological record of the stratisphere, the stratified shell of the Earth. In the stratigraphic sense, this record comprises the Archean, Proterozoic (i.e., Karelian and Riphean), and Phanerozoic (i.e., Paleozoic, Mesozoic, and Cenozoic). They correspond to acrochrons, i.e., the main stages in biosphere evolution. According to the Precambrian paleontology, the first three acrochrons represent a pre-Vendian stage in the evolution of unicellular prokaryotic and eukaryotic organisms that terminated in the Riphean with the appearance of their colonial communities. The true metacellular structure of tissue Metaphyta and Metazoa started forming only in the Late Neoproterozoic (Late Riphean). The Vendian Period was marked by a radiation of macrotaxonomic diversity with the appearance of the main multicellular types of the Phanerozoic organization level. Therefore, the last acrochron (lasting from approximately 650 Ma ago) should be considered as corresponding to the Vendian-Phanerozoic period. The Cambrian explosion corresponds to the mass expansion of skeletal Metazoa.

  19. 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.

  20. Global and Regional Constraints on Exchanges of CO2 Between the Atmosphere and Terrestrial Biosphere

    Science.gov (United States)

    Piper, S. C.

    2001-12-01

    , respectively. Both the O2 and 13C/12C methods have complications and limitations that will be discussed. To partition the global biospheric flux further to zonal or regional detail or to shorter time steps, atmospheric models are required to simulate the transport of tracer from source regions to individual stations where air is sampled. An ongoing collaborative project to compare atmospheric models has highlighted significant differences in transport characteristics, mainly owing to differences in how the boundary layer is modeled. Accordingly, a recent compilation of model calculations showed a wide range of estimates for the tropical biosphere, from a significant release of CO2 to an uptake over recent decades; however, the calculations showed reasonable agreement on a significant northern biospheric sink. Fluxes of biospheric CO2 can be determined accurately at the global scale as well as at individual sites. An ingenious blend of observations and models will be required to bridge the gap between these two extreme spatial scales, and thereby gain an understanding sufficient to predict the influence of the terrestrial biosphere on variations in atmospheric CO2.

  1. Instrumental Learning and Sustainability Indicators: Outputs from Co-Construction Experiments in West African Biosphere Reserves

    OpenAIRE

    Meriem Bouamrane; Harold Levrel

    2008-01-01

    Co-adaptive management of biodiversity is largely based on a collective learning process. This collective learning concerns "instrumental policy learning," "social policy learning," and "political learning." This paper focuses on instrumental policy learning that has been launched in four West African biosphere reserves. It is based on a MAB-UNESCO/UNEP-GEF programme concerning the co-construction of interaction indicators (between development and conservation), ...

  2. Method for gesture based modeling

    DEFF Research Database (Denmark)

    2006-01-01

    A computer program based method is described for creating models using gestures. On an input device, such as an electronic whiteboard, a user draws a gesture which is recognized by a computer program and interpreted relative to a predetermined meta-model. Based on the interpretation, an algorithm...... is assigned to the gesture drawn by the user. The executed algorithm may, for example, consist in creating a new model element, modifying an existing model element, or deleting an existing model element....

  3. Geosphere-Biosphere Feedbacks as a Trigger for the Cambrian explosion

    Science.gov (United States)

    von Bloh, W.; Bounama, C.; Franck, S.

    2003-12-01

    A new hypothesis for the cause of the Cambrian explosion is presented. The Cambrian explosion 542 Myr ago is characterized by a sudden increase of biomass and a rapid cooling, which amplified the spread of complex multicellular life. The evolution of the planet Earth is described by the co-evolution of the geosphere-biosphere system. A conceptual model for the global carbon cycle of the Earth containing the reservoirs mantle, ocean floor, continental crust, continental biosphere, the kerogen, as well as the aggregated reservoir ocean and atmosphere is presented. In this study the evolution of the mean global surface temperature, the biomass, and reservoir sizes over the whole history and future of the Earth under a maturing Sun is investigated. Here we specify our previously published Earth system model (Franck et al., 2002) by introducing three different types of biosphere: procaryotes, eucaryotes, and complex multicellular life. They are characterized by different temperature tolerance windows and biotic amplification factors of silicate weathering. The biotic enhancement of weathering by complex multicellular life adds an additional feedback to the system and triggers the Cambrian explosion. The Cambrian explosion was mainly driven by extrinsic environmental causes, i.e. a gradual cooling of the Earth. The Cambrian explosion was so rapid because of a positive feedback between the spread of biosphere, increased silicate weathering, and a consequent cooling of the climate. The environment itself has been actively changed by the biosphere maintaining the temperature conditions for its existence. Furthermore, it can be shown that the coupled geosphere-biosphere system exhibit s bistability: there exist two stable model solutions for a certain interval of the biotic enhancement factor, one solution with and one without complex multicellular life. In particular, cooling events in the Neoproterozoic, could force a premature appearance of complex multicellular life

  4. Model Construct Based Enterprise Model Architecture and Its Modeling Approach

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to support enterprise integration, a kind of model construct based enterprise model architecture and its modeling approach are studied in this paper. First, the structural makeup and internal relationships of enterprise model architecture are discussed. Then, the concept of reusable model construct (MC) which belongs to the control view and can help to derive other views is proposed. The modeling approach based on model construct consists of three steps, reference model architecture synthesis, enterprise model customization, system design and implementation. According to MC based modeling approach a case study with the background of one-kind-product machinery manufacturing enterprises is illustrated. It is shown that proposal model construct based enterprise model architecture and modeling approach are practical and efficient.

  5. Model-based software design

    Science.gov (United States)

    Iscoe, Neil; Liu, Zheng-Yang; Feng, Guohui; Yenne, Britt; Vansickle, Larry; Ballantyne, Michael

    1992-01-01

    Domain-specific knowledge is required to create specifications, generate code, and understand existing systems. Our approach to automating software design is based on instantiating an application domain model with industry-specific knowledge and then using that model to achieve the operational goals of specification elicitation and verification, reverse engineering, and code generation. Although many different specification models can be created from any particular domain model, each specification model is consistent and correct with respect to the domain model.

  6. Model-Based Reasoning

    Science.gov (United States)

    Ifenthaler, Dirk; Seel, Norbert M.

    2013-01-01

    In this paper, there will be a particular focus on mental models and their application to inductive reasoning within the realm of instruction. A basic assumption of this study is the observation that the construction of mental models and related reasoning is a slowly developing capability of cognitive systems that emerges effectively with proper…

  7. Marine biosphere reserves - Need of the 21st century

    Digital Repository Service at National Institute of Oceanography (India)

    Dhargalkar, V.K.; Untawale, A.G.

    Worldwide awareness for the creation of Marine Biosphere Reserves has increased considerably due to the human depredation in many coastal areas and natural changes. Many important and unique plant and animal species have been extinct and whatever...

  8. Model-based Software Engineering

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2010-01-01

    The vision of model-based software engineering is to make models the main focus of software development and to automatically generate software from these models. Part of that idea works already today. But, there are still difficulties when it comes to behaviour. Actually, there is no lack in models...

  9. Principles of models based engineering

    Energy Technology Data Exchange (ETDEWEB)

    Dolin, R.M.; Hefele, J.

    1996-11-01

    This report describes a Models Based Engineering (MBE) philosophy and implementation strategy that has been developed at Los Alamos National Laboratory`s Center for Advanced Engineering Technology. A major theme in this discussion is that models based engineering is an information management technology enabling the development of information driven engineering. Unlike other information management technologies, models based engineering encompasses the breadth of engineering information, from design intent through product definition to consumer application.

  10. 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.

  11. Global carbon export from the terrestrial biosphere controlled by erosion

    Science.gov (United States)

    Galy, Valier; Peucker-Ehrenbrink, Bernhard; Eglinton, Timothy

    2015-05-01

    Riverine export of particulate organic carbon (POC) to the ocean affects the atmospheric carbon inventory over a broad range of timescales. On geological timescales, the balance between sequestration of POC from the terrestrial biosphere and oxidation of rock-derived (petrogenic) organic carbon sets the magnitude of the atmospheric carbon and oxygen reservoirs. Over shorter timescales, variations in the rate of exchange between carbon reservoirs, such as soils and marine sediments, also modulate atmospheric carbon dioxide levels. The respective fluxes of biospheric and petrogenic organic carbon are poorly constrained, however, and mechanisms controlling POC export have remained elusive, limiting our ability to predict POC fluxes quantitatively as a result of climatic or tectonic changes. Here we estimate biospheric and petrogenic POC fluxes for a suite of river systems representative of the natural variability in catchment properties. We show that export yields of both biospheric and petrogenic POC are positively related to the yield of suspended sediment, revealing that POC export is mostly controlled by physical erosion. Using a global compilation of gauged suspended sediment flux, we derive separate estimates of global biospheric and petrogenic POC fluxes of and megatonnes of carbon per year, respectively. We find that biospheric POC export is primarily controlled by the capacity of rivers to mobilize and transport POC, and is largely insensitive to the magnitude of terrestrial primary production. Globally, physical erosion rates affect the rate of biospheric POC burial in marine sediments more strongly than carbon sequestration through silicate weathering. We conclude that burial of biospheric POC in marine sediments becomes the dominant long-term atmospheric carbon dioxide sink under enhanced physical erosion.

  12. Evolution of Photosynthesis and Biospheric Oxygenation Contingent Upon Nitrogen Fixation?

    OpenAIRE

    Grula, John W.

    2006-01-01

    How photosynthesis by Precambrian cyanobacteria oxygenated Earth's biosphere remains incompletely understood. Here it is argued that the oxic transition, which took place between approximately 2.3 and 0.5 Gyr ago, required a great proliferation of cyanobacteria, and this in turn depended on their ability to fix nitrogen via the nitrogenase enzyme system. However, the ability to fix nitrogen was not a panacea, and the rate of biospheric oxygenation may still have been affected by nitrogen cons...

  13. Global carbon export from the terrestrial biosphere controlled by erosion.

    Science.gov (United States)

    Galy, Valier; Peucker-Ehrenbrink, Bernhard; Eglinton, Timothy

    2015-05-14

    Riverine export of particulate organic carbon (POC) to the ocean affects the atmospheric carbon inventory over a broad range of timescales. On geological timescales, the balance between sequestration of POC from the terrestrial biosphere and oxidation of rock-derived (petrogenic) organic carbon sets the magnitude of the atmospheric carbon and oxygen reservoirs. Over shorter timescales, variations in the rate of exchange between carbon reservoirs, such as soils and marine sediments, also modulate atmospheric carbon dioxide levels. The respective fluxes of biospheric and petrogenic organic carbon are poorly constrained, however, and mechanisms controlling POC export have remained elusive, limiting our ability to predict POC fluxes quantitatively as a result of climatic or tectonic changes. Here we estimate biospheric and petrogenic POC fluxes for a suite of river systems representative of the natural variability in catchment properties. We show that export yields of both biospheric and petrogenic POC are positively related to the yield of suspended sediment, revealing that POC export is mostly controlled by physical erosion. Using a global compilation of gauged suspended sediment flux, we derive separate estimates of global biospheric and petrogenic POC fluxes of 157(+74)(-50) and 43(+61)(-25) megatonnes of carbon per year, respectively. We find that biospheric POC export is primarily controlled by the capacity of rivers to mobilize and transport POC, and is largely insensitive to the magnitude of terrestrial primary production. Globally, physical erosion rates affect the rate of biospheric POC burial in marine sediments more strongly than carbon sequestration through silicate weathering. We conclude that burial of biospheric POC in marine sediments becomes the dominant long-term atmospheric carbon dioxide sink under enhanced physical erosion.

  14. Graph Model Based Indoor Tracking

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Lu, Hua; Yang, Bin

    2009-01-01

    infrastructure for different symbolic positioning technologies, e.g., Bluetooth and RFID. More specifically, the paper proposes a model of indoor space that comprises a base graph and mappings that represent the topology of indoor space at different levels. The resulting model can be used for one or several...... indoor positioning technologies. Focusing on RFID-based positioning, an RFID specific reader deployment graph model is built from the base graph model. This model is then used in several algorithms for constructing and refining trajectories from raw RFID readings. Empirical studies with implementations...

  15. The Role of the Biosphere in a Safety Case. IGSC topical session at the third IGSC Meeting

    International Nuclear Information System (INIS)

    . It also included one presentation on a peer review as a tool to build confidence in a safety case through an improvement of the comprehension on the biosphere and its role in a safety case. 48 participants represented several national waste management organisations and regulatory authorities from 15 OECD member's countries and the IAEA. The Topical Session was split in three parts: - Part one related to the scientific bases on the biosphere; - Part two was concerned with the regulators requirements; and - Part three aimed to present some examples as regards the implementers strategies. The current synthesis presented in Part A is aimed at briefly reflecting the material presented at this Topical Session and providing a short overview of its main outcomes. The written contributions are compiled without further elaboration from the Secretariat, in Part B of the document. Part C gives the list of participants at this Topical Session

  16. Instrumental Learning and Sustainability Indicators: Outputs from Co-Construction Experiments in West African Biosphere Reserves

    Directory of Open Access Journals (Sweden)

    Meriem Bouamrane

    2008-06-01

    Full Text Available Co-adaptive management of biodiversity is largely based on a collective learning process. This collective learning concerns "instrumental policy learning," "social policy learning," and "political learning." This paper focuses on instrumental policy learning that has been launched in four West African biosphere reserves. It is based on a MAB-UNESCO/UNEP-GEF programme concerning the co-construction of interaction indicators (between development and conservation, inspired by the Integrated Natural Resource Management (INRM methodology. Using this process, we were able to test conventional Pressure-State-Response indicators, highlight their limitations, and develop new indicators starting from stakeholders' stories and perceptions. These new indicators can also be tested through collective restitutions and simulations. We also discuss: a proposed framework for producing interaction indicators that are relevant to all stakeholders and enjoy a certain legitimacy; the importance of an ecosystem services approach to support discussions on biodiversity conservation; opportunities for using the indicators in an interactive, decentralized way at the ecosystem scale through simulation models; the costs of collecting, processing, and maintaining these interaction indicators, and how these costs may be offset using local knowledge.

  17. Terrestrial biosphere changes over the last 120 kyr and their impact on ocean δ 13C

    Directory of Open Access Journals (Sweden)

    B. A. A. Hoogakker

    2015-03-01

    Full Text Available A new global synthesis and biomization of long (>40 kyr pollen-data records is presented, and used with simulations from the HadCM3 and FAMOUS climate models to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial–interglacial cycle. Global modelled (BIOME4 biome distributions over time generally agree well with those inferred from pollen data. The two climate models show good agreement in global net primary productivity (NPP. NPP is strongly influenced by atmospheric carbon dioxide (CO2 concentrations through CO2 fertilization. The combined effects of modelled changes in vegetation and (via a simple model soil carbon result in a global terrestrial carbon storage at the Last Glacial Maximum that is 210–470 Pg C less than in pre-industrial time. Without the contribution from exposed glacial continental shelves the reduction would be larger, 330–960 Pg C. Other intervals of low terrestrial carbon storage include stadial intervals at 108 and 85 ka BP, and between 60 and 65 ka BP during Marine Isotope Stage 4. Terrestrial carbon storage, determined by the balance of global NPP and decomposition, influences the stable carbon isotope composition (δ13C of seawater because terrestrial organic carbon is depleted in 13C. Using a simple carbon-isotope mass balance equation we find agreement in trends between modelled ocean δ13C based on modelled land carbon storage, and palaeo-archives of ocean δ13C, confirming that terrestrial carbon storage variations may be important drivers of ocean δ13C changes.

  18. Model-based consensus

    NARCIS (Netherlands)

    Boumans, Marcel

    2014-01-01

    The aim of the rational-consensus method is to produce “rational consensus”, that is, “mathematical aggregation”, by weighing the performance of each expert on the basis of his or her knowledge and ability to judge relevant uncertainties. The measurement of the performance of the experts is based on

  19. Model-based consensus

    NARCIS (Netherlands)

    M. Boumans

    2014-01-01

    The aim of the rational-consensus method is to produce "rational consensus", that is, "mathematical aggregation", by weighing the performance of each expert on the basis of his or her knowledge and ability to judge relevant uncertainties. The measurement of the performance of the experts is based on

  20. Biosphere reserves in action: Case studies of the American experience

    Energy Technology Data Exchange (ETDEWEB)

    None

    1995-06-26

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

  1. Cluster Based Text Classification Model

    DEFF Research Database (Denmark)

    Nizamani, Sarwat; Memon, Nasrullah; Wiil, Uffe Kock

    2011-01-01

    We propose a cluster based classification model for suspicious email detection and other text classification tasks. The text classification tasks comprise many training examples that require a complex classification model. Using clusters for classification makes the model simpler and increases......, the classifier is trained on each cluster having reduced dimensionality and less number of examples. The experimental results show that the proposed model outperforms the existing classification models for the task of suspicious email detection and topic categorization on the Reuters-21578 and 20 Newsgroups...... datasets. Our model also outperforms A Decision Cluster Classification (ADCC) and the Decision Cluster Forest Classification (DCFC) models on the Reuters-21578 dataset....

  2. BIOPROTA: Key issues in biosphere aspects of assessment of the long-term impact of contaminant releases associated with radioactive waste management. Theme 2 Task 1: Model review and comparison for spray irrigation pathway

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, U.; Albrecht, A.; Kanyar, B.; Smith, G.; Thorne, M.C.; Yoshida, H.; Wasiolek, M.

    2006-04-15

    depend on the relative significance of the pathway for contamination considered here with results for the effects of long term accumulation in soil, and exposures due to: root uptake; inhalation of suspended activity; and external irradiation. The first two of these three have been considered in Tasks 2 and 4 of Theme 2 of BIOPROTA, within which correspondingly similar model descriptions and data compilations have been prepared, as well as assessment results based on similar system descriptions. External irradiation is a relatively simple exposure pathway to address, once the activity level in the soil has been evaluated.

  3. Impact of sensor failure on the observability of flow dynamics at the Biosphere 2 LEO hillslopes

    Science.gov (United States)

    Pasetto, Damiano; Niu, Guo-Yue; Pangle, Luke; Paniconi, Claudio; Putti, Mario; Troch, Peter A.

    2015-12-01

    The Biosphere 2 Landscape Evolution Observatory (LEO) has been developed to investigate hydrological, chemical, biological, and geological processes in a large-scale, controlled infrastructure. The experimental hillslopes at LEO are instrumented with a large number of different sensors that allow detailed monitoring of local and global dynamics and changes in the hydrological state and structure of the landscapes. Sensor failure, i.e., a progressive reduction in the number of active or working sensors, in such an evolving system can have a dramatic impact on observability of flow dynamics and estimation of the model parameters that characterize the soil properties. In this study we assess the retrieval of the spatial distributions of soil water content and saturated hydraulic conductivity under different scenarios of heterogeneity (different values of correlation length of the random field describing the hydraulic conductivity) and a variable number of active sensors. To avoid the influence of model structural errors and measurement bias, the analysis is based on a synthetic representation of the first hydrological experiment at LEO simulated with the physically-based hydrological model CATHY. We assume that the true hydraulic conductivity is a particular random realization of a stochastic field with lognormal distribution and exponential correlation length. During the true run, we collect volumetric water content measurements at an hourly interval. Perturbed observations are then used to estimate the total water storage via linear interpolation and to retrieve the conductivity field via the ensemble Kalman filter technique. The results show that when less than 100 out of 496 total sensors are active, the reconstruction of volumetric water content may introduce large errors in the estimation of total water storage. In contrast, retrieval of the saturated hydraulic conductivity distribution allows the CATHY model to reproduce the integrated hydrological response of

  4. Redefining fine roots improves understanding of below-ground contributions to terrestrial biosphere processes.

    Science.gov (United States)

    McCormack, M Luke; Dickie, Ian A; Eissenstat, David M; Fahey, Timothy J; Fernandez, Christopher W; Guo, Dali; Helmisaari, Heljä-Sisko; Hobbie, Erik A; Iversen, Colleen M; Jackson, Robert B; Leppälammi-Kujansuu, Jaana; Norby, Richard J; Phillips, Richard P; Pregitzer, Kurt S; Pritchard, Seth G; Rewald, Boris; Zadworny, Marcin

    2015-08-01

    Fine roots acquire essential soil resources and mediate biogeochemical cycling in terrestrial ecosystems. Estimates of carbon and nutrient allocation to build and maintain these structures remain uncertain because of the challenges of consistently measuring and interpreting fine-root systems. Traditionally, fine roots have been defined as all roots ≤ 2 mm in diameter, yet it is now recognized that this approach fails to capture the diversity of form and function observed among fine-root orders. Here, we demonstrate how order-based and functional classification frameworks improve our understanding of dynamic root processes in ecosystems dominated by perennial plants. In these frameworks, fine roots are either separated into individual root orders or functionally defined into a shorter-lived absorptive pool and a longer-lived transport fine-root pool. Using these frameworks, we estimate that fine-root production and turnover represent 22% of terrestrial net primary production globally - a c. 30% reduction from previous estimates assuming a single fine-root pool. Future work developing tools to rapidly differentiate functional fine-root classes, explicit incorporation of mycorrhizal fungi into fine-root studies, and wider adoption of a two-pool approach to model fine roots provide opportunities to better understand below-ground processes in the terrestrial biosphere.

  5. Event-Based Conceptual Modeling

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    The paper demonstrates that a wide variety of event-based modeling approaches are based on special cases of the same general event concept, and that the general event concept can be used to unify the otherwise unrelated fields of information modeling and process modeling. A set of event......-based modeling approaches are analyzed and the results are used to formulate a general event concept that can be used for unifying the seemingly unrelated event concepts. Events are characterized as short-duration processes that have participants, consequences, and properties, and that may be modeled in terms...... of information structures. The general event concept can be used to guide systems analysis and design and to improve modeling approaches....

  6. Quaternary climate - Terrestrial Biosphere Interaction: amplifying or stabilizing?

    Science.gov (United States)

    Claussen, Martin

    2016-04-01

    According to the Gaia hypothesis, interaction between climate and biological processes tend to homeostatically maintain, on a global scale, conditions favourable for life. Does the idea of homeostatic interaction between terrestrial biosphere and climate hold for the Quaternary glacial - interglacial changes? Interpretation of palaeoclimate and palaeobotanic evidence by using climate and Earth system models yields an interesting picture. The synergy between the sea-ice albedo - climate feedback and the taiga-tundra - climate feedback is suggested to amplify the orbitally forced climatic precession. This effect seems to be strong at regional scale, but small at global scale. Various simulations indicate that biogeophysical processes amplify the difference of some 4 to 6 K in global mean temperature between glacial and interglacial climate by some 10 percent. The combined effect of biogeophysical and biogeochemical processes, i.e. processes with involve carbon stored in biomass and soil, is less clear. Theoretical studies suggest that in pre-industrial, interglacial climate, a reduction in boreal and extratropical forests tend to cool the climate and a reduction in tropical forest, to warm the climate. Recent estimates in changes in organic carbon stored under ice sheets and in permafrost point at the possibility that the sum of all terrestrial biogeochemical processes might almost "carbon neutral" to the climate system. If corroborated, this observation would favour the assumption of a dominance of biogeophysical processes amplifying orbitally forced Quaternary climate variations.

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

    Science.gov (United States)

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

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

  8. 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.

  9. Pharmaceutical Residues Affecting the UNESCO Biosphere Reserve Kristianstads Vattenrike Wetlands: Sources and Sinks.

    Science.gov (United States)

    Björklund, Erland; Svahn, Ola; Bak, Søren; Bekoe, Samuel Oppong; Hansen, Martin

    2016-10-01

    This study is the first to investigate the pharmaceutical burden from point sources affecting the UNESCO Biosphere Reserve Kristianstads Vattenrike, Sweden. The investigated Biosphere Reserve is a >1000 km(2) wetland system with inflows from lakes, rivers, leachate from landfill, and wastewater-treatment plants (WWTPs). We analysed influent and treated wastewater, leachate water, lake, river, and wetland water alongside sediment for six model pharmaceuticals. The two WWTPs investigated released pharmaceutical residues at levels close to those previously observed in Swedish monitoring exercises. Compound-dependent WWTP removal efficiencies ranging from 12 to 100 % for bendroflumethiazide, oxazepam, atenolol, carbamazepine, and diclofenac were observed. Surface-water concentrations in the most affected lake were ≥100 ng/L for the various pharmaceuticals with atenolol showing the highest levels (>300 ng/L). A small risk assessment showed that adverse single-substance toxicity on aquatic organisms within the UNESCO Biosphere Reserve is unlikely. However, the effects of combinations of a large number of known and unknown pharmaceuticals, metals, and nutrients are still unknown.

  10. The radiological situation at the atolls of Mururoa and Fangataufa. Technical report. V. 4. Releases to the biosphere of radionuclides from underground nuclear weapon tests at the atolls

    International Nuclear Information System (INIS)

    This report is Volume 4 in the series of 6 volumes of the Technical Report on the radiological situation at the atolls of Mururoa and the Fangataufa. It is the second of the three volumes dealing with the evaluation of the long term radiological situation as a consequence of radionuclide migration from underground sources, which is the responsibility of Task Group B. This volume is based on the activities of Working Group 4 and uses, as its primary input on radionuclide inventories the report of Working Group 3, which is Vol. 3 in this series of Technical Report. Nuclear testing in the atmosphere, outer space and under open ocean was prohibited by the Limited Test Ban Treaty of 5 August 1963 and signed by UK, USA and USSR. France ceased atmospheric testing in September 1974. Isolation from the biosphere in geological formations, or containment in geological formations, became the preferred alternative. The explosion of 137 underground nuclear devices in Mururoa and Fangataufa over the testing period 1975-1996, together with 10 safety trials and the burial of radioactively contaminated material gathered from the atoll surfaces, has resulted in a substantial accumulation of radionuclides in the rock beneath the two atolls. Assessment of the rate at which these radionuclides move from the cavities to the environment accessible to humans, or biosphere and the total radionuclide release to the biosphere over time is the central effort of this Study. The rock mass within which the radionuclides are initially deposited, and which serves to contain or delay release of the radionuclides, will be referred to as the geosphere to distinguish it from the biosphere, where the radionuclides would be accessible either directly or through the food chain to the living environment. This assessment of geosphere transport has been divided into the following four interrelated tasks: (a) Geological Pathways; (b) Hydrological Modelling; (c) Solution Source Term; and (d) Geosphere

  11. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Data basis for the Biosphere Assessment BSA-2012. Part 1-2, Appendices

    International Nuclear Information System (INIS)

    The purpose of the report is to document and justify the input data used in the models of the biosphere assessment. Methodology similar to that presented in the Models and Data for the Repository System report has been followed. After more introductory parts, chapter 3 lays the foundation of data selection by describing typical properties of the soil and sediment types and biotopes, and summarises the representative plants and animals selected in the Biosphere Description report. The conceptual models on pools and fluxes of elements in the ecosystems are presented in chapter 4. These, together with the more qualitative descriptions of the succession lines in the Biosphere Description report, are simplified into the actual assessment models (summarised in chapter 5) in an iterative manner. Chapter 6 briefly presents the scenarios and calculation cases of the biosphere assessment, detailed in the Formulation of Radionuclide Releases Scenarios report. The account of the actual input data to the assessment models begins in chapter 7 with the data needed to identify the biotopes and compartments common to all assessment models. Chapters 8 to 13, grouped by the sub-models, address the input data to the terrain and ecosystems development modelling (detailed in the Terrain and Ecosystems Development Modelling report), and chapter 14 those to the surface and near-surface hydrological model (the Surface and Near-Surface Hydrological Modelling report). Chapters 15 to 18 address the data to the radionuclide transport modelling in the biosphere, and chapter 19 those needed for the dose assessment for humans (the Biosphere Radionuclide Transport and Dose Assessment report). Finally, before conclusions in chapter 21, the input data specific to the dose assessment for plants and animals (the Dose Assessment for the Plants and Animals report) are addressed in chapter 20. However, several parameters are common to the assessment models and are presented in connection to the model

  12. Searching for a shadow biosphere on Earth as a test of the 'cosmic imperative'.

    Science.gov (United States)

    Davies, P C W

    2011-02-13

    Estimates for the number of communicating civilizations in the galaxy, based on the so-called Drake equation, are meaningless without a plausible estimate for the probability that life will emerge on an Earth-like planet. In the absence of a theory of the origin of life, that number can be anywhere from 0 to 1. Distinguished scientists have been known to argue that life on Earth is a freak accident, unique in the observable universe and, conversely, that life is almost bound to arise in the course of time, given Earth-like conditions. De Duve, adopting the latter position, coined the phrase that 'life is a cosmic imperative'. De Duve's position would be immediately verified if we were to discover a second sample of life that we could be sure arose from scratch independently of known life. Given the current absence of evidence for life beyond Earth, the best way to test the hypothesis of the cosmic imperative is to see whether terrestrial life began more than once. If it did, it is possible that descendants of a second genesis might be extant, forming a sort of 'shadow biosphere' existing alongside, or perhaps interpenetrating, the known biosphere. I outline a strategy to detect the existence of such a shadow biosphere.

  13. Modeling Guru: Knowledge Base for NASA Modelers

    Science.gov (United States)

    Seablom, M. S.; Wojcik, G. S.; van Aartsen, B. H.

    2009-05-01

    Modeling Guru is an on-line knowledge-sharing resource for anyone involved with or interested in NASA's scientific models or High End Computing (HEC) systems. Developed and maintained by the NASA's Software Integration and Visualization Office (SIVO) and the NASA Center for Computational Sciences (NCCS), Modeling Guru's combined forums and knowledge base for research and collaboration is becoming a repository for the accumulated expertise of NASA's scientific modeling and HEC communities. All NASA modelers and associates are encouraged to participate and provide knowledge about the models and systems so that other users may benefit from their experience. Modeling Guru is divided into a hierarchy of communities, each with its own set forums and knowledge base documents. Current modeling communities include those for space science, land and atmospheric dynamics, atmospheric chemistry, and oceanography. In addition, there are communities focused on NCCS systems, HEC tools and libraries, and programming and scripting languages. Anyone may view most of the content on Modeling Guru (available at http://modelingguru.nasa.gov/), but you must log in to post messages and subscribe to community postings. The site offers a full range of "Web 2.0" features, including discussion forums, "wiki" document generation, document uploading, RSS feeds, search tools, blogs, email notification, and "breadcrumb" links. A discussion (a.k.a. forum "thread") is used to post comments, solicit feedback, or ask questions. If marked as a question, SIVO will monitor the thread, and normally respond within a day. Discussions can include embedded images, tables, and formatting through the use of the Rich Text Editor. Also, the user can add "Tags" to their thread to facilitate later searches. The "knowledge base" is comprised of documents that are used to capture and share expertise with others. The default "wiki" document lets users edit within the browser so others can easily collaborate on the

  14. Base Flow Model Validation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The program focuses on turbulence modeling enhancements for predicting high-speed rocket base flows. A key component of the effort is the collection of...

  15. Constraint Based Modeling Going Multicellular.

    Science.gov (United States)

    Martins Conde, Patricia do Rosario; Sauter, Thomas; Pfau, Thomas

    2016-01-01

    Constraint based modeling has seen applications in many microorganisms. For example, there are now established methods to determine potential genetic modifications and external interventions to increase the efficiency of microbial strains in chemical production pipelines. In addition, multiple models of multicellular organisms have been created including plants and humans. While initially the focus here was on modeling individual cell types of the multicellular organism, this focus recently started to switch. Models of microbial communities, as well as multi-tissue models of higher organisms have been constructed. These models thereby can include different parts of a plant, like root, stem, or different tissue types in the same organ. Such models can elucidate details of the interplay between symbiotic organisms, as well as the concerted efforts of multiple tissues and can be applied to analyse the effects of drugs or mutations on a more systemic level. In this review we give an overview of the recent development of multi-tissue models using constraint based techniques and the methods employed when investigating these models. We further highlight advances in combining constraint based models with dynamic and regulatory information and give an overview of these types of hybrid or multi-level approaches.

  16. Event-Based Conceptual Modeling

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    2009-01-01

    The purpose of the paper is to obtain insight into and provide practical advice for event-based conceptual modeling. We analyze a set of event concepts and use the results to formulate a conceptual event model that is used to identify guidelines for creation of dynamic process models and static...... information models. We characterize events as short-duration processes that have participants, consequences, and properties, and that may be modeled in terms of information structures. The conceptual event model is used to characterize a variety of event concepts and it is used to illustrate how events can...... be used to integrate dynamic modeling of processes and static modeling of information structures. The results are unique in the sense that no other general event concept has been used to unify a similar broad variety of seemingly incompatible event concepts. The general event concept can be used...

  17. Event-Based Activity Modeling

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    2004-01-01

    We present and discuss a modeling approach that supports event-based modeling of information and activity in information systems. Interacting human actors and IT-actors may carry out such activity. We use events to create meaningful relations between information structures and the related activit...

  18. Evolution of Photosynthesis and Biospheric Oxygenation Contingent Upon Nitrogen Fixation?

    CERN Document Server

    Grula, J W

    2006-01-01

    How photosynthesis by Precambrian cyanobacteria oxygenated Earth's biosphere remains incompletely understood. Here it is argued that the oxic transition, which took place between approximately 2.3 and 0.5 Gyr ago, required a great proliferation of cyanobacteria, and this in turn depended on their ability to fix nitrogen via the nitrogenase enzyme system. However, the ability to fix nitrogen was not a panacea, and the rate of biospheric oxygenation may still have been affected by nitrogen constraints on cyanobacterial expansion. Evidence is presented for why cyanobacteria probably have a great need for fixed nitrogen than other prokaryotes, underscoring the importance of their ability to fix nitrogen. The connection between nitrogen fixation and the evolution of photosynthesis is demonstrated by the similarities between nitrogenase and enzymes critical for the biosynthesis of (bacterio)chlorophyll. It is hypothesized that biospheric oxygenation would not have occurred if the emergence of cyanobacteria had not ...

  19. Culturing captures members of the soil rare biosphere.

    Science.gov (United States)

    Shade, Ashley; Hogan, Clifford S; Klimowicz, Amy K; Linske, Matthew; McManus, Patricia S; Handelsman, Jo

    2012-09-01

    The ecological significance of rare microorganisms within microbial communities remains an important, unanswered question. Microorganisms of extremely low abundance (the 'rare biosphere') are believed to be largely inaccessible and unknown. To understand the structure of complex environmental microbial communities, including the representation of rare and prevalent community members, we coupled traditional cultivation with pyrosequencing. We compared cultured and uncultured bacterial members of the same agricultural soil, including eight locations within one apple orchard and four time points. Our analysis revealed that soil bacteria captured by culturing were in very low abundance or absent in the culture-independent community, demonstrating unexpected accessibility of the rare biosphere by culturing.

  20. Modelling Gesture Based Ubiquitous Applications

    CERN Document Server

    Zacharia, Kurien; Varghese, Surekha Mariam

    2011-01-01

    A cost effective, gesture based modelling technique called Virtual Interactive Prototyping (VIP) is described in this paper. Prototyping is implemented by projecting a virtual model of the equipment to be prototyped. Users can interact with the virtual model like the original working equipment. For capturing and tracking the user interactions with the model image and sound processing techniques are used. VIP is a flexible and interactive prototyping method that has much application in ubiquitous computing environments. Different commercial as well as socio-economic applications and extension to interactive advertising of VIP are also discussed.

  1. Biosphere structure, carbon sequestering potential and the atmospheric C-14 carbon record

    Energy Technology Data Exchange (ETDEWEB)

    Goudriaan, J.

    1992-08-01

    The behaviour of a numerical model for the global carbon cycle is elucidated by a simple analytical model for the biosphere. In the period 1980-1990 the ocean is estimated to have absorbed 33% of the total CO{sub 2} emission to the atmosphere in that same period. Net deforestation was responsible for 12-17% of this total emission rate, whereas the CO{sub 2}-fertilization effect caused a re-absorption of 20-25%. Aggregation of the above-ground biosphere into a single pool in the model caused an overestimation of the CO{sub 2}-fertilization effect. Also, the estimate of this rate increased when the fraction of carbon assumed to remain after the transformation of litter into humus was increased, but the rate was little influenced by the model structure for soil organic carbon. A larger estimate for carbon uptake in the biosphere (Tans, Fung, and Takahashi, 1990) must be compensated by a reduced uptake in the ocean to arrive at a carbon balance. To do this, either the exchange rate between the upper mixed ocean layer and deep sea, or between ocean surface and atmosphere, should be reduced. In addition, a good match to the observed time-course of C-14 carbon in the atmosphere must be preserved by the model. The C-14 time-course did not remain well-matched if the atmosphere-ocean surface exchange was reduced, but it was hardly disturbed at all if the exchange rate with the deep sea was reduced.

  2. Selection of biosphere reserves for the Californian Biogeographical Province : Final report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Completion of the biosphere reserve network within the United States is a major objective of the United States Man and the Biosphere Program (US MAS). Toward this...

  3. Building institutional capacity for environmental governance through social entrepreneurship: lessons from Canadian biosphere reserves

    Directory of Open Access Journals (Sweden)

    Colleen George

    2016-03-01

    Full Text Available Sustainability-oriented organizations have typically adopted governance approaches that undertake community participation and collaboration through multistakeholder arrangements. Documented challenges of this model are associated with collaboration and institutional capacity, and include reactive accountability structures, inability to reach consensus, funding limitations, and lack of innovation. Social entrepreneurship is a model used successfully in other social sectors; yet, it has rarely been explored by sustainability-oriented organizations. Nevertheless, research in other sectors has found that social entrepreneurship models of governance can encourage diverse participation from a wide range of social groups. In this paper we consider the value of social entrepreneurship for sustainability-oriented organizations by examining whether it can help address governance-related challenges associated with collaboration and institutional capacity. Analysis of organizational documents and participant interviews in three biosphere reserves in Atlantic Canada revealed that, over time, these organizations have struggled to maintain their mission objectives, retain productivity, and respond to economic stress. By examining social entrepreneurship theory and its practice in a biosphere reserve in northern Quebec, we learned that social entrepreneurship strategies more effectively target values and expertise, encourage meaningful engagement, foster strategic direction, and promote diversified and stable funding models than the stakeholder models explored. We determined there are opportunities to develop hybrid governance models that offer the benefits of social entrepreneurship while addressing the procedural concerns outlined by the stakeholder model.

  4. Sketch-based geologic modeling

    Science.gov (United States)

    Rood, M. P.; Jackson, M.; Hampson, G.; Brazil, E. V.; de Carvalho, F.; Coda, C.; Sousa, M. C.; Zhang, Z.; Geiger, S.

    2015-12-01

    Two-dimensional (2D) maps and cross-sections, and 3D conceptual models, are fundamental tools for understanding, communicating and modeling geology. Yet geologists lack dedicated and intuitive tools that allow rapid creation of such figures and models. Standard drawing packages produce only 2D figures that are not suitable for quantitative analysis. Geologic modeling packages can produce 3D models and are widely used in the groundwater and petroleum communities, but are often slow and non-intuitive to use, requiring the creation of a grid early in the modeling workflow and the use of geostatistical methods to populate the grid blocks with geologic information. We present an alternative approach to rapidly create figures and models using sketch-based interface and modelling (SBIM). We leverage methods widely adopted in other industries to prototype complex geometries and designs. The SBIM tool contains built-in geologic rules that constrain how sketched lines and surfaces interact. These rules are based on the logic of superposition and cross-cutting relationships that follow from rock-forming processes, including deposition, deformation, intrusion and modification by diagenesis or metamorphism. The approach allows rapid creation of multiple, geologically realistic, figures and models in 2D and 3D using a simple, intuitive interface. The user can sketch in plan- or cross-section view. Geologic rules are used to extrapolate sketched lines in real time to create 3D surfaces. Quantitative analysis can be carried our directly on the models. Alternatively, they can be output as simple figures or imported directly into other modeling tools. The software runs on a tablet PC and can be used in a variety of settings including the office, classroom and field. The speed and ease of use of SBIM enables multiple interpretations to be developed from limited data, uncertainty to be readily appraised, and figures and models to be rapidly updated to incorporate new data or concepts.

  5. Community Forest Management and Policy implication for the Biosphere Reserve of Luki, Democratic Republic of Congo

    OpenAIRE

    Shange, Bosaze Rufinga

    2013-01-01

    This research focused on sustainable community forest management and policy implications for the biosphere reserve of Luki in the DR- Congo. The purpose of this research was to find out opportunities and options to develop sustainable community forest management at the biosphere reserve of Luki. The research was conducted in the biosphere reserve of Luki located in the southwest of DR- Congo. The human activities threat the biosphere reserve of Luki to be under significant pressure of unsusta...

  6. Agent Based Multiviews Requirements Model

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on the current researches of viewpoints oriented requirements engineering and intelligent agent, we present the concept of viewpoint agent and its abstract model based on a meta-language for multiviews requirements engineering. It provided a basis for consistency checking and integration of different viewpoint requirements, at the same time, these checking and integration works can automatically realized in virtue of intelligent agent's autonomy, proactiveness and social ability. Finally, we introduce the practical application of the model by the case study of data flow diagram.

  7. Terrestrial acidification during the end-Permian biosphere crisis?

    NARCIS (Netherlands)

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

    2015-01-01

    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 dete

  8. Acetogenesis in the energy-starved deep biosphere - a paradox?

    DEFF Research Database (Denmark)

    Lever, Mark

    2012-01-01

    Under anoxic conditions in sediments, acetogens are often thought to be outcompeted by microorganisms performing energetically more favorable metabolic pathways, such as sulfate reduction or methanogenesis. Recent evidence from deep subseafloor sediments suggesting acetogenesis in the presence of...... to be taken into account to understand microbial survival in the energy-depleted deep biosphere....

  9. Evidence for an active rare biosphere within freshwater protists community.

    Science.gov (United States)

    Debroas, Didier; Hugoni, Mylène; Domaizon, Isabelle

    2015-03-01

    Studies on the active rare biosphere at the RNA level are mainly focused on Bacteria and Archaea and fail to include the protists, which are involved in the main biogeochemical cycles of the earth. In this study, the richness, composition and activity of the rare protistan biosphere were determined from a temporal survey of two lakes by pyrosequencing. In these ecosystems, the always rare OTUs represented 77.2% of the total OTUs and 76.6% of the phylogenetic diversity. From the various phylogenetic indices computed, the phylogenetic units (PUs) constituted exclusively by always rare OTUs were discriminated from the other PUs. Therefore, the rare biosphere included mainly taxa that are distant from the reference databases compared to the dominant ones. In addition, the rarest OTUs represented 59.8% of the active biosphere depicted by rRNA and the activity (rRNA:rDNA ratio) increased with the rarity. The high rRNA:rDNA ratio determined in the rare fraction highlights that some protists were active at low abundances and contribute to ecosystem functioning. Interestingly, the always rare and active OTUs were characterized by seasonal changes in relation with the main environmental parameters measured. In conclusion, the rare eukaryotes represent an active, dynamic and overlooked fraction in the lacustrine ecosystems.

  10. The biosphere-reserve concept: Needs for a network design

    International Nuclear Information System (INIS)

    The biosphere-reserve concept is considered to be a major achievement in environmental management. Why then has it not helped to solve major ecological problems? This article addresses a few of the past difficulties of the concept, then gives recommendations on needed revisions. New programmatic developments in coastal-marine environments along part of the Atlantic seaboard of North America are described

  11. HMM-based Trust Model

    DEFF Research Database (Denmark)

    ElSalamouny, Ehab; Nielsen, Mogens; Sassone, Vladimiro

    2010-01-01

    Probabilistic trust has been adopted as an approach to taking security sensitive decisions in modern global computing environments. Existing probabilistic trust frameworks either assume fixed behaviour for the principals or incorporate the notion of ‘decay' as an ad hoc approach to cope with thei...... the major limitation of existing Beta trust model. We show the consistency of the HMM-based trust model and contrast it against the well known Beta trust model with the decay principle in terms of the estimation precision....

  12. Implementation of the Biosphere Compatibility Principle in Urban Planning: How to Train Next-Generation Specialists

    Science.gov (United States)

    Ivanova, Zinaida Ilyinichna; Yudenkova, Olga Valeryevna; Ishkov, Aleksandr Dmitrievich; Shnyrenkov, Evgeny Anatolyevich

    2015-01-01

    The co-authors address the relevant issues concerning the need to implement the principle of the biosphere compatibility as the core prerequisite for the symbiotic co-existence of man and nature. Caring treatment of the biosphere, termination of its excessive exploitation, analysis of the ratio between the biospheric potential of specific areas…

  13. 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.

  14. 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.

  15. 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.

    2016-03-01

    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.

  16. 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. PMID:26961656

  17. 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.

  18. Model-Based Security Testing

    CERN Document Server

    Schieferdecker, Ina; Schneider, Martin; 10.4204/EPTCS.80.1

    2012-01-01

    Security testing aims at validating software system requirements related to security properties like confidentiality, integrity, authentication, authorization, availability, and non-repudiation. Although security testing techniques are available for many years, there has been little approaches that allow for specification of test cases at a higher level of abstraction, for enabling guidance on test identification and specification as well as for automated test generation. Model-based security testing (MBST) is a relatively new field and especially dedicated to the systematic and efficient specification and documentation of security test objectives, security test cases and test suites, as well as to their automated or semi-automated generation. In particular, the combination of security modelling and test generation approaches is still a challenge in research and of high interest for industrial applications. MBST includes e.g. security functional testing, model-based fuzzing, risk- and threat-oriented testing,...

  19. Model-based sensor diagnosis

    International Nuclear Information System (INIS)

    Running a nuclear power plant involves monitoring data provided by the installation's sensors. Operators and computerized systems then use these data to establish a diagnostic of the plant. However, the instrumentation system is complex, and is not immune to faults and failures. This paper presents a system for detecting sensor failures using a topological description of the installation and a set of component models. This model of the plant implicitly contains relations between sensor data. These relations must always be checked if all the components are functioning correctly. The failure detection task thus consists of checking these constraints. The constraints are extracted in two stages. Firstly, a qualitative model of their existence is built using structural analysis. Secondly, the models are formally handled according to the results of the structural analysis, in order to establish the constraints on the sensor data. This work constitutes an initial step in extending model-based diagnosis, as the information on which it is based is suspect. This work will be followed by surveillance of the detection system. When the instrumentation is assumed to be sound, the unverified constraints indicate errors on the plant model. (authors). 8 refs., 4 figs

  20. Kernel model-based diagnosis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The methods for computing the kemel consistency-based diagnoses and the kernel abductive diagnoses are only suited for the situation where part of the fault behavioral modes of the components are known. The characterization of the kernel model-based diagnosis based on the general causal theory is proposed, which can break through the limitation of the above methods when all behavioral modes of each component are known. Using this method, when observation subsets deduced logically are respectively assigned to the empty or the whole observation set, the kernel consistency-based diagnoses and the kernel abductive diagnoses can deal with all situations. The direct relationship between this diagnostic procedure and the prime implicants/implicates is proved, thus linking theoretical result with implementation.

  1. Model-based requirements engineering

    CERN Document Server

    Holt, Jon

    2012-01-01

    This book provides a hands-on introduction to model-based requirementsengineering and management by describing a set of views that form the basisfor the approach. These views take into account each individual requirement interms of its description, but then also provide each requirement with meaning byputting it into the correct 'context'. A requirement that has been put into a contextis known as a 'use case' and may be based upon either stakeholders or levelsof hierarchy in a system. Each use case must then be analysed and validated bydefining a combination of scenarios and formal mathematica

  2. Model-based tomographic reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, David H.; Lehman, Sean K.; Goodman, Dennis M.

    2012-06-26

    A model-based approach to estimating wall positions for a building is developed and tested using simulated data. It borrows two techniques from geophysical inversion problems, layer stripping and stacking, and combines them with a model-based estimation algorithm that minimizes the mean-square error between the predicted signal and the data. The technique is designed to process multiple looks from an ultra wideband radar array. The processed signal is time-gated and each section processed to detect the presence of a wall and estimate its position, thickness, and material parameters. The floor plan of a building is determined by moving the array around the outside of the building. In this paper we describe how the stacking and layer stripping algorithms are combined and show the results from a simple numerical example of three parallel walls.

  3. Energy based hybrid turbulence modeling

    Science.gov (United States)

    Haering, Sigfried; Moser, Robert

    2015-11-01

    Traditional hybrid approaches exhibit deficiencies when used for fluctuating smooth-wall separation and reattachment necessitating ad-hoc delaying functions and model tuning making them no longer useful as a predictive tool. Additionally, complex geometries and flows often require high cell aspect-ratios and large grid gradients as a compromise between resolution and cost. Such transitions and inconsistencies in resolution detrimentally effect the fidelity of the simulation. We present the continued development of a new hybrid RANS/LES modeling approach specifically developed to address these challenges. In general, modeled turbulence is returned to resolved scales by reduced or negative model viscosity until a balance between theoretical and actual modeled turbulent kinetic energy is attained provided the available resolution. Anisotropy in the grid and resolved field are directly integrated into this balance. A viscosity-based correction is proposed to account for resolution inhomogeneities. Both the hybrid framework and resolution gradient corrections are energy conserving through an exchange of resolved and modeled turbulence.

  4. The Effect of Drought on Stomatal Conductance in the Biosphere 2 Rainforest

    Science.gov (United States)

    Gay, J. D.; Van Haren, J. L. M.

    2015-12-01

    Drought is a major climate change concern for the Earth's rainforests; however little is currently known about how these forests and individual plants will respond to water stress. At the individual level, the ability of plants to regulate their stomatal conductance is an important preservation mechanism that helps to cool leaves, regulate water loss, and uptake carbon dioxide. At the ecosystem level, transpiration in rainforests is a major contributor to the positive feedback loop that returns moisture to the atmosphere for continued precipitation cycles. Nearly 60% of atmospheric moisture in the Amazon rain forests has been traced back to origins of transpiration from its plants. In relation to current climatic conditions, stomatal conductance rates are highly variable across rainforest species and environmental conditions. It is still unknown to what extent these rates will decrease at leaf and forest level in response to periods of drought. The University of Arizona's Biosphere 2 (B2) served as the study site for a simulated 4-week long drought because of its ability to mimic the micrometeorology of an Amazonian rainforest. Three species of plants were chosen at various levels in the canopy: Clitoria racemosa, Cissus sicyoides, and Hibiscus elatus. These plants were selected based on their relative abundance and distribution in the B2 forest. It was revealed that two out of the three species exhibited decreases in H20 efflux at each elevation, while one species (C. racemosa) proved much more resistant, at each elevation, to H20 loss. These results may be useful for future integrative modeling of how individual leaf level responses extend to entire ecosystem scales. It will be important to better understand how rainforests conserve, recycle, and lose water to gauge their response to warming climate, and increased periods of drought in the tropics.

  5. Wrinkles in the rare biosphere: Pyrosequencing errors can lead to artificial inflation of diversity estimates

    Energy Technology Data Exchange (ETDEWEB)

    Kunin, Victor; Engelbrektson, Anna; Ochman, Howard; Hugenholtz, Philip

    2009-08-01

    Massively parallel pyrosequencing of the small subunit (16S) ribosomal RNA gene has revealed that the extent of rare microbial populations in several environments, the 'rare biosphere', is orders of magnitude higher than previously thought. One important caveat with this method is that sequencing error could artificially inflate diversity estimates. Although the per-base error of 16S rDNA amplicon pyrosequencing has been shown to be as good as or lower than Sanger sequencing, no direct assessments of pyrosequencing errors on diversity estimates have been reported. Using only Escherichia coli MG1655 as a reference template, we find that 16S rDNA diversity is grossly overestimated unless relatively stringent read quality filtering and low clustering thresholds are applied. In particular, the common practice of removing reads with unresolved bases and anomalous read lengths is insufficient to ensure accurate estimates of microbial diversity. Furthermore, common and reproducible homopolymer length errors can result in relatively abundant spurious phylotypes further confounding data interpretation. We suggest that stringent quality-based trimming of 16S pyrotags and clustering thresholds no greater than 97% identity should be used to avoid overestimates of the rare biosphere.

  6. Historical development and evolution of EPRI's post-closure dose assessment of potential releases to the biosphere from the proposed HLW repository at Yucca Mountain.

    Science.gov (United States)

    Smith, Graham; Kozak, Matthew W

    2011-12-01

    This paper describes the development and evolution of the Electric Power Research Institute's (EPRI) post-closure dose assessment for potential releases of radionuclides from the proposed High Level Waste repository at Yucca Mountain. The starting point for this work was the 1995 publication of Technical Bases for Yucca Mountain Standards by the Commission on Geosciences, Environment and Resources of the National Research Council. This report proposed the development and application of an individual risk-based standard for releases from the repository to replace the existing one, which was based on radionuclide release limits. This in turn implied the development and application of methods to assess radiation doses to humans. Accordingly, EPRI produced a methodology for such dose assessment as part of its Total System Performance Assessment program for the proposed Yucca Mountain repository site. The methodology initially addressed releases via groundwater and then releases associated with extrusive igneous events. The methodology was updated and applied over the following years to take account of regulatory developments, changes in estimates of the source term to the biosphere, peer review through international model comparison exercises, new site generic data, and new data concerning conditions at the point of compliance in Amargosa Valley. The main outputs were Biosphere Dose Conversion Factors, which relate radionuclide levels in environmental media to the annual individual doses to a member of a hypothetical critical group and to the regulator-defined Reasonably Maximally Exposed Individual. Most recently, consideration has been given to uncertainty in the dose estimates based on a probabilistic analysis. The paper provides a perspective on the evolution of the dose assessments in response to the developments listed above. PMID:22048489

  7. Development of the biosphere code BIOMOD: final report

    International Nuclear Information System (INIS)

    Final report to DoE on the development of the biosphere code BIOMOD. The work carried out under the contract is itemised. Reference is made to the six documents issued along with the final report. These consist of two technical notes issued as interim consultative documents, a user's guide and a programmer's guide to BIOMOD, a database description, program test document and a technical note entitled ''BIOMOD - preliminary findings''. (author)

  8. On detecting biospheres from chemical thermodynamic disequilibrium in planetary atmospheres

    OpenAIRE

    Krissansen-Totton, Joshua; Bergsman, David S.; Catling, David C.

    2015-01-01

    Atmospheric chemical disequilibrium has been proposed as a method for detecting extraterrestrial biospheres from exoplanet observations. Chemical disequilibrium is potentially a generalized biosignature since it makes no assumptions about particular biogenic gases or metabolisms. Here, we present the first rigorous calculations of the thermodynamic chemical disequilibrium in Solar System atmospheres, in which we quantify the available Gibbs energy: the Gibbs free energy of an observed atmosph...

  9. Impact disruption and recovery of the deep subsurface biosphere

    DEFF Research Database (Denmark)

    Cockell, Charles S.; Voytek, Mary A.; Gronstal, Aaaron L;

    2012-01-01

    , by fracturing subsurface rocks, impacts can extend the depth of the biosphere. This phenomenon would have provided deep refugia for life on the more heavily bombarded early Earth, and it shows that the deeply fractured regions of impact craters are promising targets to study the past and present habitability...... of Mars. Key Words: Asteroid—Impacts—Subsurface biosphere—Subterranean environment—Geobiology. Astrobiology 12, 231–246....

  10. An Agent Based Classification Model

    CERN Document Server

    Gu, Feng; Greensmith, Julie

    2009-01-01

    The major function of this model is to access the UCI Wisconsin Breast Can- cer data-set[1] and classify the data items into two categories, which are normal and anomalous. This kind of classifi cation can be referred as anomaly detection, which discriminates anomalous behaviour from normal behaviour in computer systems. One popular solution for anomaly detection is Artifi cial Immune Sys- tems (AIS). AIS are adaptive systems inspired by theoretical immunology and observed immune functions, principles and models which are applied to prob- lem solving. The Dendritic Cell Algorithm (DCA)[2] is an AIS algorithm that is developed specifi cally for anomaly detection. It has been successfully applied to intrusion detection in computer security. It is believed that agent-based mod- elling is an ideal approach for implementing AIS, as intelligent agents could be the perfect representations of immune entities in AIS. This model evaluates the feasibility of re-implementing the DCA in an agent-based simulation environ- ...

  11. Crowdsourcing Based 3d Modeling

    Science.gov (United States)

    Somogyi, A.; Barsi, A.; Molnar, B.; Lovas, T.

    2016-06-01

    Web-based photo albums that support organizing and viewing the users' images are widely used. These services provide a convenient solution for storing, editing and sharing images. In many cases, the users attach geotags to the images in order to enable using them e.g. in location based applications on social networks. Our paper discusses a procedure that collects open access images from a site frequently visited by tourists. Geotagged pictures showing the image of a sight or tourist attraction are selected and processed in photogrammetric processing software that produces the 3D model of the captured object. For the particular investigation we selected three attractions in Budapest. To assess the geometrical accuracy, we used laser scanner and DSLR as well as smart phone photography to derive reference values to enable verifying the spatial model obtained from the web-album images. The investigation shows how detailed and accurate models could be derived applying photogrammetric processing software, simply by using images of the community, without visiting the site.

  12. The Austrian Biosphere Reserves. A (connoisseur’s) world beyond the cookery book. eco.mont (Journal on Protected Mountain Areas Research)|eco.mont Vol. 5 No. 2 5 2|

    OpenAIRE

    Diry, Christian; Köck, Günter (Hrsg.); Umhack, Martha

    2013-01-01

    In many instances the Austrian UNESCO Biosphere Reserves as model regions of sustainable development are outshone by other conservation categories, such as national parks or world heritage sites, and are largely unknown to the wider population. This shadowy existence is ill deserved. The modern concept of biosphere reserves (BRs) is more important today than it ever was if we want to maintain valuable cultural landscapes for later generations. The Austrian MAB National Committee therefore mad...

  13. Global redox cycle of biospheric carbon: Interaction of photosynthesis and earth crust processes.

    Science.gov (United States)

    Ivlev, Alexander A

    2015-11-01

    A model of the natural global redox cycle of biospheric carbon is introduced. According to this model, carbon transfer between biosphere and geospheres is accompanied by a conversion of the oxidative forms, presented by CO2, bicarbonate and carbonate ions, into the reduced forms, produced in photosynthesis. The mechanism of carbon transfer is associated with two phases of movement of lithospheric plates. In the short-term orogenic phase, CO2 from the subduction (plates' collisions) zones fills the "atmosphere-hydrosphere" system, resulting in climate warming. In the long-term quiet (geosynclynal) phase, weathering and photosynthesis become dominant depleting the oxidative forms of carbon. The above asymmetric periodicity exerts an impact on climate, biodiversity, distribution of organic matter in sedimentary deposits, etc. Along with photosynthesis expansion, the redox carbon cycle undergoes its development until it reaches the ecological compensation point, at which CO2 is depleted to the level critical to support the growth and reproduction of plants. This occurred in the Permo-Carboniferous time and in the Neogene. Shorter-term perturbations of the global carbon cycle in the form of glacial-interglacial oscillations appear near the ecological compensation point. PMID:26477601

  14. Global redox cycle of biospheric carbon: Interaction of photosynthesis and earth crust processes.

    Science.gov (United States)

    Ivlev, Alexander A

    2015-11-01

    A model of the natural global redox cycle of biospheric carbon is introduced. According to this model, carbon transfer between biosphere and geospheres is accompanied by a conversion of the oxidative forms, presented by CO2, bicarbonate and carbonate ions, into the reduced forms, produced in photosynthesis. The mechanism of carbon transfer is associated with two phases of movement of lithospheric plates. In the short-term orogenic phase, CO2 from the subduction (plates' collisions) zones fills the "atmosphere-hydrosphere" system, resulting in climate warming. In the long-term quiet (geosynclynal) phase, weathering and photosynthesis become dominant depleting the oxidative forms of carbon. The above asymmetric periodicity exerts an impact on climate, biodiversity, distribution of organic matter in sedimentary deposits, etc. Along with photosynthesis expansion, the redox carbon cycle undergoes its development until it reaches the ecological compensation point, at which CO2 is depleted to the level critical to support the growth and reproduction of plants. This occurred in the Permo-Carboniferous time and in the Neogene. Shorter-term perturbations of the global carbon cycle in the form of glacial-interglacial oscillations appear near the ecological compensation point.

  15. Mapping Topoclimate and Microclimate in the Monarch Butterfly Biosphere Reserve, Mexico

    Science.gov (United States)

    Weiss, S. B.

    2006-12-01

    Overwintering monarch butterflies in Mexico select areas of the high elevation Oyamel fir -pine forest providing a canopy that protects them from extremes of cold, heat, sun, and wind. These exacting microclimatic conditions are found in relatively small areas of forest with appropriate topography and canopy cover. The major goal of this investigation is to map topoclimatic and microclimatic conditions within the Monarch Butterfly Biosphere Reserve by combining temperature monitoring (iButton Thermochrons), hemispherical canopy photography, multiple regression, and GIS modeling. Temperature measurements included base weather stations and arrays of Thermochrons (on the north-side of trees at 2m height) across local topographic and canopy cover gradients. Topoclimatic models of minimum temperatures included topographic position, slope, and elevation, and predicted that thermal belts on slopes and cold air drainage into canyons create local minimum temperature gradients of 2°C. Topoclimatic models of maximum temperatures models included elevation, topographic position, and relative solar exposure, with local gradients of 3°C. These models, which are independent of forest canopy structure, were then projected across the entire region. Forest canopy structure, including direct and diffuse solar radiation, was assessed with hemispherical photography at each Thermochron site. Canopy cover affected minimum temperatures primarily on the calmest, coldest nights. Maximum temperatures were predicted by direct radiation below the canopy. Fine- scale grids (25 m spacing) at three overwintering sites characterized effects of canopy gaps and edges on temperature and wind exposure. The effects of temperature variation were considered for lipid loss rates, ability to take flight, and freezing mortality. Lipid loss rates were estimated by measured hourly temperatures. Many of the closed canopy sites allowed for substantial lipid reserves at the end of the season (March 15), but

  16. Peat swamp forest types and their regeneration in Giam Siak Kecil-Bukit Batu Biosphere Reserve, Riau, East Sumatra, Indonesia

    OpenAIRE

    H. Gunawan; Kobayashi, S.; Mizuno, K; Kono, Y

    2012-01-01

    Although the ecology of tropical peat swamp forests is only now becoming understood, they are already under severe threat of conversion and degradation. Based on studies of the peat swamp forest of the Giam Siak Kecil–Bukit Batu Biosphere Reserve carried out between 2009 and 2010, this paper discusses forest types and regeneration processes in terms of promoting biodiversity conservation and sustainable management of the remaining peat swamp forest. Permanent plots covering a total area of th...

  17. Radioecological measurements of plutonium in the biosphere

    International Nuclear Information System (INIS)

    For the registration of the model soil/plant/air the following measurements were executed: 1) determination of Pu in the soil (soil profiles, resuspension factors). 2) Determination of Pu in the air (seasonal dependence, vertical distribution, Pu on aerosols of different size, deposition of Pu). 3) Determination of Pu in/on plants (seasonal dependences, washing tests with different solvents for determining the fraction of Pu which is bound on plants by adsorption). Some of the measurements were carried out in several successive years in order to register also longer-term changes. Furthermore further elements were determined parallel to Pu in order to find out in how far other elements could serve as models for the behaviour of Pu. (orig./MG)

  18. Systems to prevent nuclear material from re-entering the biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Buden, D. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Angelo, J.A. Jr. (Science Applications International Corp., Melbourne, FL (United States)); Lapin, S. (POD Associates, Inc., Albuquerque, NM (United States))

    1992-01-01

    Nuclear systems are key to the success of many space missions as we have witness in the Apollo science packages, Viking Mars landers, and Pioneer and Voyager planetary exploration missions. There is always a concern that nuclear materials will re-enter the biosphere from a mission abort. In fact, this has happened for radioisotope and reactor power systems. Until now, the emphasize has been an incorporating on-board means to protect the biosphere. With possible increased use of nuclear power and propulsion systems in space, Project SIREN (Search, Intercept, Retrieve, Expulsion, Nuclear) has determined that external means can be used as a back up to current on-board systems to provide assured prevention of nuclear materials from re-entry once in space. The technology base to implement a SIREN vehicle has been assessed and a data base and mission analysis program prepared (called THOR) to evaluate various missions. The degree of hazard from existing nuclear power systems in space has been assessed and found to be significant.

  19. Systems to prevent nuclear material from re-entering the biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Buden, D. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Angelo, J.A. Jr. [Science Applications International Corp., Melbourne, FL (United States); Lapin, S. [POD Associates, Inc., Albuquerque, NM (United States)

    1992-09-01

    Nuclear systems are key to the success of many space missions as we have witness in the Apollo science packages, Viking Mars landers, and Pioneer and Voyager planetary exploration missions. There is always a concern that nuclear materials will re-enter the biosphere from a mission abort. In fact, this has happened for radioisotope and reactor power systems. Until now, the emphasize has been an incorporating on-board means to protect the biosphere. With possible increased use of nuclear power and propulsion systems in space, Project SIREN (Search, Intercept, Retrieve, Expulsion, Nuclear) has determined that external means can be used as a back up to current on-board systems to provide assured prevention of nuclear materials from re-entry once in space. The technology base to implement a SIREN vehicle has been assessed and a data base and mission analysis program prepared (called THOR) to evaluate various missions. The degree of hazard from existing nuclear power systems in space has been assessed and found to be significant.

  20. Reference biospheres for post-closure performance assessment: inter-comparison of SHETRAN simulations and BIOMASS results

    International Nuclear Information System (INIS)

    Example Reference Biosphere 2B (ERB2B) is a hypothetical river catchment, described in the IAEA-sponsored BIOMASS study on biosphere aspects of post-closure radiological safety assessments for repositories for solid radioactive wastes. In ERB2B, a radioactively contaminated aquifer interacts with the soils and sediments of the river catchment. A 'semi-distributed', lumped-parameter model (SDLP) was set up for the site as part of the BIOMASS study. In the model, empirically derived transfer functions are used to reduce the complexity of real hydrological transport systems to readily calculable mass-balance accounting routines. In this work, a physically based, spatially distributed modelling system SHETRAN was set up for the site and comparison made with the existing SDLP model. The work has shown that, using standard soil properties in SHETRAN, the soil rapidly saturates and much of the hydrologically effective rainfall (precipitation less evapotranspiration) is lost as saturation-excess surface runoff. This is contrary to the assumptions in the SDLP model. The difficulty arose from the original formulation of catchment characteristics in BIOMASS. Specifically, there was a large water volume entering the soils from precipitation together with an upward flux of groundwater across the lower boundary of a substantial part of the catchment. This water had to be lost from the catchment in some way and the thinness of the soil zone precluded dominance of subsurface, lateral flow over surface runoff. Increasing the saturated conductivity from 1 to 20 m d-1 reduced the surface flows to similar values to those assumed in the SDLP model (this could also have been achieved by increasing the soil depth). Even with the high saturated conductivity there were still major differences between the two representations. In the woodland on the upper slopes of the valley, the SHETRAN simulation was slightly wetter than the SDLP model, whereas in the shrubland and marshland near the

  1. [A phylogenetic analysis of plant communities of Teberda Biosphere Reserve].

    Science.gov (United States)

    Shulakov, A A; Egorov, A V; Onipchenko, V G

    2016-01-01

    Phylogenetic analysis of communities is based on the comparison of distances on the phylogenetic tree between species of a community under study and those distances in random samples taken out of local flora. It makes it possible to determine to what extent a community composition is formed by more closely related species (i.e., "clustered") or, on the opposite, it is more even and includes species that are less related with each other. The first case is usually interpreted as a result of strong influence caused by abiotic factors, due to which species with similar ecology, a priori more closely related, would remain: In the second case, biotic factors, such as competition, may come to the fore and lead to forming a community out of distant clades due to divergence of their ecological niches: The aim of this' study Was Ad explore the phylogenetic structure in communities of the northwestern Caucasus at two spatial scales - the scale of area from 4 to 100 m2 and the smaller scale within a community. The list of local flora of the alpine belt has been composed using the database of geobotanic descriptions carried out in Teberda Biosphere Reserve at true altitudes exceeding.1800 m. It includes 585 species of flowering plants belonging to 57 families. Basal groups of flowering plants are.not represented in the list. At the scale of communities of three classes, namely Thlaspietea rotundifolii - commumties formed on screes and pebbles, Calluno-Ulicetea - alpine meadow, and Mulgedio-Aconitetea subalpine meadows, have not demonstrated significant distinction of phylogenetic structure. At intra level, for alpine meadows the larger share of closely related species. (clustered community) is detected. Significantly clustered happen to be those communities developing on rocks (class Asplenietea trichomanis) and alpine (class Juncetea trifidi). At the same time, alpine lichen proved to have even phylogenetic structure at the small scale. Alpine (class Salicetea herbaceae) that

  2. Earth's Early Biosphere and the Biogeochemical Carbon Cycle

    Science.gov (United States)

    DesMarais, David

    2004-01-01

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

  3. Trace-Based Code Generation for Model-Based Testing

    OpenAIRE

    Kanstrén, T.; Piel, E.; Gross, H.-G.

    2009-01-01

    Paper Submitted for review at the Eighth International Conference on Generative Programming and Component Engineering. Model-based testing can be a powerful means to generate test cases for the system under test. However, creating a useful model for model-based testing requires expertise in the (formal) modeling language of the used tool and the general concept of modeling the system under test for effective test generation. A commonly used modeling notation is to describe the model through a...

  4. Earth's earliest biosphere: Its origin and evolution

    International Nuclear Information System (INIS)

    Some of the subjects discussed are related to the early biogeologic history, the nature of the earth prior to the oldest known rock record, the early earth and the Archean rock record, the prebiotic organic syntheses and the origin of life, Precambrian organic geochemistry, the biochemical evolution of anaerobic energy conversion, the isotopic inferences of ancient biochemistries, Archean stromatolites providing evidence of the earth's earliest benthos, Archean microfossils, the geologic evolution of the Archean-Early Proterozoic earth, and the environmental evolution of the Archean-Early Proterozoic earth. Other topics examined are concerned with geochemical evidence bearing on the origin of aerobiosis, biological and biochemical effects of the development of an aerobic environment, Early Proterozoic microfossils, the evolution of earth's earliest ecosystems, and geographic and geologic data for processed rock samples. Attention is given to a processing procedure for abiotic samples and calculation of model atmospheric compositions, and procedures of organic geochemical analysis

  5. Business value modeling based on BPMN models

    OpenAIRE

    Masoumigoudarzi, Farahnaz

    2014-01-01

    In this study we will try to clarify the explanation of modeling and measuring 'Business Values', as it is defined in business context, in the business processes of a company and introduce different methods and select the one which is best for modeling the company's business values. These methods have been used by researchers in business analytics and senior managers of many companies. The focus in this project is business value detection and modeling. The basis of this research is on BPM...

  6. Patterns of new versus recycled primary production in the terrestrial biosphere.

    Science.gov (United States)

    Cleveland, Cory C; Houlton, Benjamin Z; Smith, W Kolby; Marklein, Alison R; Reed, Sasha C; Parton, William; Del Grosso, Stephen J; Running, Steven W

    2013-07-30

    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 and are recycled to varying degrees through the plant-soil-microbe system via organic matter decay processes. However, the proportion of global NPP that can be attributed to new nutrient inputs versus recycled nutrients is unresolved, as are the large-scale patterns of variation across terrestrial ecosystems. Here, we combined satellite imagery, biogeochemical modeling, and empirical observations to identify previously unrecognized patterns of new versus recycled nutrient (N and P) productivity on land. Our analysis points to tropical forests as a hotspot of new NPP fueled by new N (accounting for 45% of total new NPP globally), much higher than previous estimates from temperate and high-latitude regions. The large fraction of tropical forest NPP resulting from new N is driven by the high capacity for N fixation, although this varies considerably within this diverse biome; N deposition explains a much smaller proportion of new NPP. By contrast, the contribution of new N to primary productivity is lower outside the tropics, and worldwide, new P inputs are uniformly low relative to plant demands. These results imply that new N inputs have the greatest capacity to fuel additional NPP by terrestrial plants, whereas low P availability may ultimately constrain NPP across much of the terrestrial biosphere.

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

    International Nuclear Information System (INIS)

    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)

  8. Intelligent model-based OPC

    Science.gov (United States)

    Huang, W. C.; Lai, C. M.; Luo, B.; Tsai, C. K.; Chih, M. H.; Lai, C. W.; Kuo, C. C.; Liu, R. G.; Lin, H. T.

    2006-03-01

    Optical proximity correction is the technique of pre-distorting mask layouts so that the printed patterns are as close to the desired shapes as possible. For model-based optical proximity correction, a lithographic model to predict the edge position (contour) of patterns on the wafer after lithographic processing is needed. Generally, segmentation of edges is performed prior to the correction. Pattern edges are dissected into several small segments with corresponding target points. During the correction, the edges are moved back and forth from the initial drawn position, assisted by the lithographic model, to finally settle on the proper positions. When the correction converges, the intensity predicted by the model in every target points hits the model-specific threshold value. Several iterations are required to achieve the convergence and the computation time increases with the increase of the required iterations. An artificial neural network is an information-processing paradigm inspired by biological nervous systems, such as how the brain processes information. It is composed of a large number of highly interconnected processing elements (neurons) working in unison to solve specific problems. A neural network can be a powerful data-modeling tool that is able to capture and represent complex input/output relationships. The network can accurately predict the behavior of a system via the learning procedure. A radial basis function network, a variant of artificial neural network, is an efficient function approximator. In this paper, a radial basis function network was used to build a mapping from the segment characteristics to the edge shift from the drawn position. This network can provide a good initial guess for each segment that OPC has carried out. The good initial guess reduces the required iterations. Consequently, cycle time can be shortened effectively. The optimization of the radial basis function network for this system was practiced by genetic algorithm

  9. Comparative assessment of public opinion on the landscape quality of two biosphere reserves in Europe.

    Science.gov (United States)

    Sowińska-Świerkosz, Barbara; Chmielewski, Tadeusz J

    2014-09-01

    The European Landscape Convention (2000) obligates European Union countries to identify and implement landscape quality objectives (LQOs) understood as the specification of public expectations and preferences concerning the landscape of a given area, expressed by competent public authorities. The convention emphasizes the important role of local community representatives in this field. In Poland, the implementation of the LQO concept was first undertaken in two regions with radically different landscape characteristics: (1) the West Polesie Biosphere Reserve and (2) the selected protected areas of the Roztocze-Solska Forest, nominated to the rank of a biosphere reserve. The first stage of the presented study was the recognition of public opinion on the quality of key features of landscape, based on a questionnaire (n = 470). The primary objective of the study was to provide an answer to the following questions: (1) Whether similar social expectations regarding landscape quality exist in spite of radically different landscape characteristics of the regions investigated (landscape quality is understood as spatial arrangement, scenic beauty, and lack of environmental pollution); (2) which landscape features are considered to be most preservation worthy by the representatives of both local communities; and (3) What processes or development impacts pose the greatest threat to the landscape quality of both regions according to the public opinion? The conducted comparative assessment revealed that it is possible to define a set of features fundamental to the quality of both areas and that representatives of local communities pointed out the same threats to the natural and cultural values of both regions investigated.

  10. 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

  11. Prokaryotic silicon utilizing microorganisms in the biosphere

    Science.gov (United States)

    Gupta, D.; Das, S.

    2012-12-01

    Although a little study has been done to determine the silicon utilizing prokaryotes, our previous experiments indicated that almost all Gram-positive bacteria are silicon utilizing; one of them, Streptococci survived exposure on the lunar surface for a long period in experiment done by others. Our initial experiments with these Gram positive microorganisms showed that there were limited growths of these microorganisms on carbon free silicate medium probably with the help of some carry over carbon and nitrogen during cultivation procedures. However, increase in growth rate after repeated subcultures could not be explained at present. The main groups of prokaryotes which were found silicon utilizing microorganisms were Mycobacterium, Bacillus, Nocardia, Streptomyces, Staphylococcus, Streptococcus, Lactobacillus, and Clostridium. In a another previous study by us when silicon level was studied in such grown up cells on carbon "free" silicate medium by electron prove microanalyser, it was found that silicon in cells grown on carbon "free" silicate medium was much higher (24.9%) than those grown on conventional carbon based medium (0.84%). However, these initial findings are encouraging for our future application of this group of organisms on extraterrestrial surfaces for artificial micro-ecosystem formation. It was found that when electropositive elements are less in extraterrestrial situation, then polymerization of silicon-oxygen profusion may occur easily, particularly in carbon and nitrogen paucity in the rocky worlds of the Universe.

  12. Sensor-based interior modeling

    International Nuclear Information System (INIS)

    Robots and remote systems will play crucial roles in future decontamination and decommissioning (D ampersand D) of nuclear facilities. Many of these facilities, such as uranium enrichment plants, weapons assembly plants, research and production reactors, and fuel recycling facilities, are dormant; there is also an increasing number of commercial reactors whose useful lifetime is nearly over. To reduce worker exposure to radiation, occupational and other hazards associated with D ampersand D tasks, robots will execute much of the work agenda. Traditional teleoperated systems rely on human understanding (based on information gathered by remote viewing cameras) of the work environment to safely control the remote equipment. However, removing the operator from the work site substantially reduces his efficiency and effectiveness. To approach the productivity of a human worker, tasks will be performed telerobotically, in which many aspects of task execution are delegated to robot controllers and other software. This paper describes a system that semi-automatically builds a virtual world for remote D ampersand D operations by constructing 3-D models of a robot's work environment. Planar and quadric surface representations of objects typically found in nuclear facilities are generated from laser rangefinder data with a minimum of human interaction. The surface representations are then incorporated into a task space model that can be viewed and analyzed by the operator, accessed by motion planning and robot safeguarding algorithms, and ultimately used by the operator to instruct the robot at a level much higher than teleoperation

  13. Optimal pricing decision model based on activity-based costing

    Institute of Scientific and Technical Information of China (English)

    王福胜; 常庆芳

    2003-01-01

    In order to find out the applicability of the optimal pricing decision model based on conventional costbehavior model after activity-based costing has given strong shock to the conventional cost behavior model andits assumptions, detailed analyses have been made using the activity-based cost behavior and cost-volume-profitanalysis model, and it is concluded from these analyses that the theory behind the construction of optimal pri-cing decision model is still tenable under activity-based costing, but the conventional optimal pricing decisionmodel must be modified as appropriate to the activity-based costing based cost behavior model and cost-volume-profit analysis model, and an optimal pricing decision model is really a product pricing decision model construc-ted by following the economic principle of maximizing profit.

  14. Differential geometry based multiscale models.

    Science.gov (United States)

    Wei, Guo-Wei

    2010-08-01

    Large chemical and biological systems such as fuel cells, ion channels, molecular motors, and viruses are of great importance to the scientific community and public health. Typically, these complex systems in conjunction with their aquatic environment pose a fabulous challenge to theoretical description, simulation, and prediction. In this work, we propose a differential geometry based multiscale paradigm to model complex macromolecular systems, and to put macroscopic and microscopic descriptions on an equal footing. In our approach, the differential geometry theory of surfaces and geometric measure theory are employed as a natural means to couple the macroscopic continuum mechanical description of the aquatic environment with the microscopic discrete atomistic description of the macromolecule. Multiscale free energy functionals, or multiscale action functionals are constructed as a unified framework to derive the governing equations for the dynamics of different scales and different descriptions. Two types of aqueous macromolecular complexes, ones that are near equilibrium and others that are far from equilibrium, are considered in our formulations. We show that generalized Navier-Stokes equations for the fluid dynamics, generalized Poisson equations or generalized Poisson-Boltzmann equations for electrostatic interactions, and Newton's equation for the molecular dynamics can be derived by the least action principle. These equations are coupled through the continuum-discrete interface whose dynamics is governed by potential driven geometric flows. Comparison is given to classical descriptions of the fluid and electrostatic interactions without geometric flow based micro-macro interfaces. The detailed balance of forces is emphasized in the present work. We further extend the proposed multiscale paradigm to micro-macro analysis of electrohydrodynamics, electrophoresis, fuel cells, and ion channels. We derive generalized Poisson-Nernst-Planck equations that are

  15. Memristor model based on fuzzy window function

    OpenAIRE

    Abdel-Kader, Rabab Farouk; Abuelenin, Sherif M.

    2016-01-01

    Memristor (memory-resistor) is the fourth passive circuit element. We introduce a memristor model based on a fuzzy logic window function. Fuzzy models are flexible, which enables the capture of the pinched hysteresis behavior of the memristor. The introduced fuzzy model avoids common problems associated with window-function based memristor models, such as the terminal state problem, and the symmetry issues. The model captures the memristor behavior with a simple rule-base which gives an insig...

  16. Microbial metagenomes from three aquifers in the Fennoscandian shield terrestrial deep biosphere reveal metabolic partitioning among populations

    Science.gov (United States)

    Wu, Xiaofen; Holmfeldt, Karin; Hubalek, Valerie; Lundin, Daniel; Åström, Mats; Bertilsson, Stefan; Dopson, Mark

    2016-01-01

    Microorganisms in the terrestrial deep biosphere host up to 20% of the earth's biomass and are suggested to be sustained by the gases hydrogen and carbon dioxide. A metagenome analysis of three deep subsurface water types of contrasting age (from Metagenomes from the three water types were used for reconstruction of 69 distinct microbial genomes, each with >86% coverage. The populations were dominated by Proteobacteria, Candidate divisions, unclassified archaea and unclassified bacteria. The estimated genome sizes of the <0.22 μm populations were generally smaller than their phylogenetically closest relatives, suggesting that small dimensions along with a reduced genome size may be adaptations to oligotrophy. Shallow ‘modern marine' water showed community members with a predominantly heterotrophic lifestyle. In contrast, the deeper, ‘old saline' water adhered more closely to the current paradigm of a hydrogen-driven deep biosphere. The data were finally used to create a combined metabolic model of the deep terrestrial biosphere microbial community. PMID:26484735

  17. Planning, architecture, seismic, construction and energy-related criteria for sustainable spatial development in the Danube Delta Biosphere Reserve area

    Directory of Open Access Journals (Sweden)

    Vasile Meiţă

    2014-09-01

    Full Text Available The Danube Delta Biosphere Reserve represents a complex of ecosystems embedding a biome that had been included on UNESCO World Heritage list due to its global environmental importance. The outstanding natural diversity, including ecosystems, habitats and species situated at the top of European and International conservation lists, is mixed with an equally rich and important cultural (ethnic and religious diversity of the human communities inhabiting the area. According to the guidelines of the Man and the Biosphere Programme of UNESCO, the biosphere reserves including human settlements should be managed such that they could constitute an example for what sustainable development means. Starting from the spatial dimension added to the traditional socioeconomic, ecological and cultural pillars of sustainable development, the paper examines planning, architecture, seismic, construction and energy-related criteria that could substantiate a sustainable development model applicable to the Danube Delta, and counter the effects of clime change in the area. The results suggest that the traditional practices of the inhabitants could offer sustainable solutions and help preserving the natural and cultural diversity of the region.

  18. Guide to APA-Based Models

    Science.gov (United States)

    Robins, Robert E.; Delisi, Donald P.

    2008-01-01

    In Robins and Delisi (2008), a linear decay model, a new IGE model by Sarpkaya (2006), and a series of APA-Based models were scored using data from three airports. This report is a guide to the APA-based models.

  19. CEAI: CCM based Email Authorship Identification Model

    DEFF Research Database (Denmark)

    Nizamani, Sarwat; Memon, Nasrullah

    2013-01-01

    reveal that the proposed CCM-based email authorship identification model, along with the proposed feature set, outperforms the state-of-the-art support vector machine (SVM)-based models, as well as the models proposed by Iqbal et al. [1, 2]. The proposed model attains an accuracy rate of 94% for 10...

  20. Advancing subsurface biosphere and paleoclimate research: ECORD-ICDP-DCO-J-DESC-MagellanPlus Workshop Series Program Report

    Science.gov (United States)

    Mills, H. J.; de Leeuw, J.; Hinrichs, K.-U.; Inagaki, F.; Kallmeyer, J.

    2015-12-01

    The proper pre-drilling preparation, on-site acquisition and post-drilling preservation of high-quality subsurface samples are crucial to ensure significant progress in the scientifically and societally important areas of subsurface biosphere and paleoclimate research. Two of the four research themes of IODP and ICDP and one of the four research areas of the Deep Carbon Observatory (DCO) focus on the subsurface biosphere. Increasing understanding of paleoclimate is a central goal of IODP and incorporated within the scope of the IMPRESS program, the successor of the IMAGES program. Therefore, the goal of our IODP-ICDP-DCO-J-DESC-MagellanPlus-sponsored workshop was to help advance deep biosphere and paleoclimate research by identifying needed improvements in scientific drilling planning and available technology, sample collection and initial analysis, and long-term storage of subsurface samples and data. Success in these areas will (a) avoid biological and other contamination during drilling, sampling, storage and shipboard/shore-based experiments; (b) build a repository and database of high-quality subsurface samples for microbiological and paleoclimate research available for the scientific community world-wide over the next decades; and (c) standardize, as much as possible, microbiological and paleoclimate drilling, sampling and storage workflows to allow results and data to be comparable across both space and time. A result of this workshop is the development and suggested implementation of new advanced methods and technologies to collect high-quality samples and data for the deep biosphere and paleoclimate scientific communities to optimize expected substantial progress in these fields. The members of this workshop will enhance communication within the scientific drilling community by crafting a handbook focused on pre-drilling, drilling and post-drilling operations.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-06-01

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

  2. Cosmic rays and the biosphere over 4 billion years

    DEFF Research Database (Denmark)

    Svensmark, Henrik

    2006-01-01

    Variations in the flux of cosmic rays (CR) at Earth during the last 4.6 billion years are constructed from information about the star formation rate in the Milky Way and the evolution of the solar activity. The constructed CR signal is compared with variations in the Earths biological productivit...... as recorded in the isotope delta C-13, which spans more than 3 billion years. CR and fluctuations in biological productivity show a remarkable correlation and indicate that the evolution of climate and the biosphere on the Earth is closely linked to the evolution of the Milky Way....

  3. Comets, carbonaceous meteorites, and the origin of the biosphere

    Directory of Open Access Journals (Sweden)

    r. b. Hoover

    2006-01-01

    Full Text Available The Biosphere is considered to represent the Earth's crust, atmosphere, oceans, and ice caps and the living organisms that survive within this habitat. This paper considers the significance of comets and carbonaceous meteorites to the origin and evolution of the Biosphere and presents new Field Emission Scanning Electron Microscope (FESEM images of indigenous microfossils in the Orgueil and Murchison meteorites. The discovery of microbial extremophiles in deep crustal rocks, hydrothermal vents and ancient ice has established that the biosphere is far more extensive than previously recognized. Chemical and molecular biomarkers and microfossils in Archaean rocks indicate that life appeared very early on the primitive Earth and the origin of the biosphere is closely linked with the emergence of life. The role of comets, carbonaceous meteorites, interstellar dust and asteroids in the delivery of water, organics and prebiotic chemicals to Earth during the Hadean (4.5–3.8 Ga period of heavy bombardment has become more widely recognized. Spacecraft observations of the chemical compositions and characteristics of the nuclei of several comets (Halley, Borrelly, Wild 2, and Tempel 1 have established that comets contain complex organic chemicals; that water is the predominant volatile; and that high temperatures (~400 K can be reached on the black (albedo~0.03 nuclei when near perihelion. The microscopic dust particles in the Tempel 1 ejecta are similar in size to the particulates of the Orgueil meteorite and evidence is mounting that comets may represent the parent bodies of the CI meteorites. Impact craters and pinnacles on comet Wild 2 suggest a thick crust. Episodic outbursts and jets of Halley, Borrelly, Wild 2 and Tempel 1 near perihelion indicate that localized regimes of liquid water may periodically exist beneath the thick crust of many comets. This increases the possibility that microbial life might survive in comets and therefore the

  4. User's manual for biosphere and dose simulation program (Biodose)

    International Nuclear Information System (INIS)

    This user's manual describes the BIOsphere Transport and DOSE program (BIODOSE) prepared for, and delivered to, Lawrence Livermore Laboratory (LLL) by the Analytic Sciences Corporation (TASC). BIODOSE simulates the transport of radionuclides in surface water systems and the resulting concentration of nuclides in the food chain. It includes the prediction of human dosage risks for individuals and for populations resulting from release of radionuclides into surface water or well water. The BIODOSE program was designed for easy use, including standard defaults and a flexible input scheme

  5. Europa the ocean moon : search for an alien biosphere

    CERN Document Server

    Greenburg, Richard

    2009-01-01

    Europa - The Ocean Moon tells the story of the Galileo spacecraft probe to Jupiter's moon, Europa. It provides a detailed description of the physical processes, including the dominating tidal forces that operate on Europa, and includes a comprehensive tour of Europa using images taken by Galileo's camera. The book reviews and evaluates the interpretative work carried out to date, providing a philosophical discussion of the scientific process of analyzing results and the pitfalls that accompany it. It also examines the astrobiological constraints on this possible biosphere, and implications for

  6. Tracing the microbial biosphere into the Messinian Salinity Crisis

    Science.gov (United States)

    Natalicchio, Marcello; Dela Pierre, Francesco; Birgel, Daniel; Lozar, Francesca; Peckmann, Jörn

    2016-04-01

    The Messinian salinity crisis (MSC), one of the largest environmental crises in Earth history, occurred in the Mediterranean Basin about 6 Ma ago. The isolation of the Mediterranean from the Atlantic Ocean caused the transformation of the Mediterranean sea into a giant salina. The establishment of harsh conditions (hypersalinity and anoxia) in the water mass had a strong impact on the aquatic biosphere, resulting in the apparent disappearance of many marine biota. This aspect is however controversial, mostly because of the finding of fossils of biota that actually survived the onset of the MSC. To trace the response of life to this catastrophic event, we studied the microbial biosphere (both body fossils and molecular fossils) archived in the sediments straddling the MSC onset (shales, carbonates and sulphates) from marginal subbasins (Piedmont Basin, northern Italy, and Nijar Basin, southern Spain). Despite the significant reduction of calcareous plankton, the progressive rise of other microorganisms (prokaryotes and eukaryotes) is documented in the studied sediments at the MSC onset. These microorganisms include remains of euryhaline and stenohaline diatoms and filamentous microfossils interpreted as vacuolated sulphide-oxidizing bacteria. This fossil assemblage, which typifies both marginal (gypsum) and more distal (carbonates and shale) deposits, indicates conditions of high primary productivity in the surface waters, favoured by increased nutrient influx in the course of high riverine runoff. Molecular fossils allow tracing of the microbial biosphere into the geological past. The rise of algal compounds (e.g. dinosterol) in the basal MSC deposits (gypsum, carbonate and shales), accompanied by the simultaneous increase of terrigenous organic material (n-alkanes), agree with the eutrophication of the basin. In addition, the MSC deposits show an instant and significant increase of archaeal biomarkers, including the archaeal membrane lipids archaeol and extended

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

    Science.gov (United States)

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

    2015-12-01

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

  8. Towards a universal trait-based model of terrestrial primary production

    Science.gov (United States)

    Wang, H.; Prentice, I. C.; Cornwell, W.; Keenan, T. F.; Davis, T.; Wright, I. J.; Evans, B. J.; Peng, C.

    2015-12-01

    Systematic variations of plant traits along environmental gradients have been observed for decades. For example, the tendencies of leaf nitrogen per unit area to increase, and of the leaf-internal to ambient CO2 concentration ratio (ci:ca) to decrease, with aridity are well established. But ecosystem models typically represent trait variation based purely on empirical relationships, or on untested conjectures, or not at all. Neglect of quantitative trait variation and its adapative significance probably contributes to the persistent large uncertainties among models in predicting the response of the carbon cycle to environmental change. However, advances in ecological theory and the accumulation of extensive data sets during recent decades suggest that theoretically based and testable predictions of trait variation could be achieved. Based on well-established ecophysiological principles and consideration of the adaptive significance of traits, we propose universal relationships between photosynthetic traits (ci:ca, carbon fixation capacity, and the ratio of electron transport capacity to carbon fixation capacity) and primary environmental variables, which capture observed trait variations both within and between plant functional types. Moreover, incorporating these traits into the standard model of C3photosynthesis allows gross primary production (GPP) of natural vegetation to be predicted by a single equation with just two free parameters, which can be estimated from independent observations. The resulting model performs as well as much more complex models. Our results provide a fresh perspective with potentially high reward: the possibility of a deeper understanding of the relationships between plant traits and environment, simpler and more robust and reliable representation of land processes in Earth system models, and thus improved predictability for biosphere-atmosphere interactions and climate feedbacks.

  9. Trace-Based Code Generation for Model-Based Testing

    NARCIS (Netherlands)

    Kanstrén, T.; Piel, E.; Gross, H.-G.

    2009-01-01

    Paper Submitted for review at the Eighth International Conference on Generative Programming and Component Engineering. Model-based testing can be a powerful means to generate test cases for the system under test. However, creating a useful model for model-based testing requires expertise in the (fo

  10. Prospects for the study of evolution in the deep biosphere

    Directory of Open Access Journals (Sweden)

    Jennifer F Biddle

    2012-01-01

    Full Text Available Since the days of Darwin, scientists have used the framework of the theory of evolution to explore the interconnectedness of life on Earth and adaptation of organisms to the ever-changing environment. The advent of molecular biology has advanced and accelerated the study of evolution by allowing direct examination of the genetic material that ultimately determines the phenotypes upon which selection acts. The study of evolution has been furthered through examination of microbial evolution, with large population numbers, short generation times and easily extractable DNA. Such work has spawned the study of microbial biogeography, with the realization that concepts developed in population genetics may be applicable to microbial genomes (Manhes et al. 2011, Martiny et al. 2006. Microbial biogeography and adaptation has been examined in many different environments. Here we argue that the deep biosphere is a unique environment for the study of evolution and list specific factors that can be considered and where the studies may be performed. This publication is the result of the NSF-funded Center for Dark Energy Biosphere Investigations (C-DEBI theme team on Evolution (www.darkenergybiosphere.org.

  11. 1999 KUIPER PRIZE LECTURE. Cometary Origin of the Biosphere

    Science.gov (United States)

    Delsemme, Armand H.

    2000-08-01

    Most of the biosphere was brought on the primitive Earth by an intense bombardment of comets. This included the atmosphere, the seawater and those volatile carbon compounds needed for the emergence of life. Comets were thrown into the inner Solar System by the strong perturbation induced by the growth of the giant planets' cores. The bulk of the Earth's bombardment came from those comets that accreted in Jupiter's zone, where the original deuterium enrichment had been diminished by steam coming from the hot, inner parts of the Solar System. This steam had condensed into icy chunks before their accretion into larger cometary nuclei. In contrast, comets that accreted in the zones of the outer giant planets kept their interstellar isotopic enrichments. Those comets contributed to the Earth's bombardment for a small amount only; they were mostly ejected into the Oort cloud and are the major source of the long-period comets observed today. The short-period comets, which come from the Kuiper Belt, should also have the same interstellar enrichment. The deuterium enrichment of seawater, accurately predicted by the previous scenario, has become one of the best telltales for the cometary origin of our biosphere. This cometary origin may have far-reaching cosmological consequences, in particular for the origin of life in other planetary systems.

  12. Impact disruption and recovery of the deep subsurface biosphere

    Science.gov (United States)

    Cockell, Charles S.; Voytek, Mary A.; Gronstal, Aaron L.; Finster, Kai; Kirshtein, Julie D.; Howard, Kieren; Reitner, Joachim; Gohn, Gregory S.; Sanford, Ward E.; Horton, J. Wright; Kallmeyer, Jens; Kelly, Laura; Powars, David S.

    2012-01-01

    Although a large fraction of the world's biomass resides in the subsurface, there has been no study of the effects of catastrophic disturbance on the deep biosphere and the rate of its subsequent recovery. We carried out an investigation of the microbiology of a 1.76 km drill core obtained from the ~35 million-year-old Chesapeake Bay impact structure, USA, with robust contamination control. Microbial enumerations displayed a logarithmic downward decline, but the different gradient, when compared to previously studied sites, and the scatter of the data are consistent with a microbiota influenced by the geological disturbances caused by the impact. Microbial abundance is low in buried crater-fill, ocean-resurge, and avalanche deposits despite the presence of redox couples for growth. Coupled with the low hydraulic conductivity, the data suggest the microbial community has not yet recovered from the impact ~35 million years ago. Microbial enumerations, molecular analysis of microbia