Development of a global land cover characteristics database and IGBP DISCover from 1 km AVHRR data

USGS Publications Warehouse

Loveland, Thomas R.; Reed, B.C.; Brown, Jesslyn F.; Ohlen, D.O.; Zhu, Z.; Yang, L.; Merchant, J.W.

2000-01-01

Researchers from the U.S. Geological Survey, University of Nebraska-Lincoln and the European Commission's Joint Research Centre, Ispra, Italy produced a 1 km resolution global land cover characteristics database for use in a wide range of continental-to global-scale environmental studies. This database provides a unique view of the broad patterns of the biogeographical and ecoclimatic diversity of the global land surface, and presents a detailed interpretation of the extent of human development. The project was carried out as an International Geosphere-Biosphere Programme, Data and Information Systems (IGBP-DIS) initiative. The IGBP DISCover global land cover product is an integral component of the global land cover database. DISCover includes 17 general land cover classes defined to meet the needs of IGBP core science projects. A formal accuracy assessment of the DISCover data layer will be completed in 1998. The 1 km global land cover database was developed through a continent-by-continent unsupervised classification of 1 km monthly Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI) composites covering 1992-1993. Extensive post-classification stratification was necessary to resolve spectral/temporal confusion between disparate land cover types. The complete global database consists of 961 seasonal land cover regions that capture patterns of land cover, seasonality and relative primary productivity. The seasonal land cover regions were aggregated to produce seven separate land cover data sets used for global environmental modelling and assessment. The data sets include IGBP DISCover, U.S. Geological Survey Anderson System, Simple Biosphere Model, Simple Biosphere Model 2, Biosphere-Atmosphere Transfer Scheme, Olson Ecosystems and Running Global Remote Sensing Land Cover. The database also includes all digital sources that were used in the classification. The complete database can be sourced from the website: http://edcwww.cr.usgs.gov/landdaac/glcc/glcc.html.

Implementing the Simple Biosphere Model (SiB) in a general circulation model: Methodologies and results

NASA Technical Reports Server (NTRS)

Sato, N.; Sellers, P. J.; Randall, D. A.; Schneider, E. K.; Shukla, J.; Kinter, J. L., III; Hou, Y.-T.; Albertazzi, E.

1989-01-01

The Simple Biosphere MOdel (SiB) of Sellers et al., (1986) was designed to simulate the interactions between the Earth's land surface and the atmosphere by treating the vegetation explicitly and relistically, thereby incorporating biophysical controls on the exchanges of radiation, momentum, sensible and latent heat between the two systems. The steps taken to implement SiB in a modified version of the National Meteorological Center's spectral GCM are described. The coupled model (SiB-GCM) was used with a conventional hydrological model (Ctl-GCM) to produce summer and winter simulations. The same GCM was used with a conventional hydrological model (Ctl-GCM) to produce comparable 'control' summer and winter variations. It was found that SiB-GCM produced a more realistic partitioning of energy at the land surface than Ctl-GCM. Generally, SiB-GCM produced more sensible heat flux and less latent heat flux over vegetated land than did Ctl-GCM and this resulted in the development of a much deeper daytime planetary boundary and reduced precipitation rates over the continents in SiB-GCM. In the summer simulation, the 200 mb jet stream and the wind speed at 850 mb were slightly weakened in the SiB-GCM relative to the Ctl-GCM results and equivalent analyses from observations.

Improving the Amazonian Hydrologic Cycle in a Coupled Land-Atmosphere, Single Column Model

NASA Astrophysics Data System (ADS)

Harper, A. B.; Denning, S.; Baker, I.; Prihodko, L.; Branson, M.

2006-12-01

We have coupled a land-surface model, the Simple Biosphere Model (SiB3), to a single column of the Colorado State University General Circulation Model (CSU-GCM) in the Amazon River Basin. This is a preliminary step in the broader goal of improved simulation of Basin-wide hydrology. A previous version of the coupled model (SiB2) showed drought and catastrophic dieback of the Amazon rain forest. SiB3 includes updated soil hydrology and root physiology. Our test area for the coupled single column model is near Santarem, Brazil, where measurements from the km 83 flux tower in the Tapajos National Forest can be used to evaluate model output. The model was run for 2001 using NCEP2 Reanalysis as driver data. Preliminary results show that the updated biosphere model coupled to the GCM produces improved simulations of the seasonal cycle of surface water balance and precipitation. Comparisons of the diurnal and seasonal cycles of surface fluxes are also being made.

Applications of the U.S. Geological Survey's global land cover product

USGS Publications Warehouse

Reed, B.

1997-01-01

The U.S. Geological Survey (USGS), in partnership with several international agencies and universities, has produced a global land cover characteristics database. The land cover data were created using multitemporal analysis of advanced very high resolution radiometer satellite images in conjunction with other existing geographic data. A translation table permits the conversion of the land cover classes into several conventional land cover schemes that are used by ecosystem modelers, climate modelers, land management agencies, and other user groups. The alternative classification schemes include Global Ecosystems, the Biosphere Atmosphere Transfer Scheme, the Simple Biosphere, the USGS Anderson Level 2, and the International Geosphere Biosphere Programme. The distribution system for these data is through the World Wide Web (the web site address is: http://edcwww.cr.usgs.gov/landdaac/glcc/glcc.html) or by magnetic media upon special request The availability of the data over the World Wide Web, in conjunction with the flexible database structure, allows easy data access to a wide range of users. The web site contains a user registration form that allows analysis of the diverse applications of large-area land cover data. Currently, applications are divided among mapping (20 percent), conservation (30 percent), and modeling (35 percent).

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. A. Wasiolek

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Jinmei; Arritt, R.W.

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

Hands-On! Living in the Biosphere: Production, Pattern, Population, and Diversity. Developing Active Learning Module on the Human Dimensions of Global Change.

ERIC Educational Resources Information Center

Brown, Dwight

Biogeography examines questions of organism inventory and pattern, organisms' interactions with the environment, and the processes that create and change inventory, pattern, and interactions. This learning module uses time series maps and simple simulation models to illustrate how human actions alter biological productivity patterns at local and…

Modeling of interactions between biosphere and atmosphere on the global scale

NASA Technical Reports Server (NTRS)

Baer, Ferdinand; Mintz, Y.

1990-01-01

Simulations of weather and climate with general circulation models show that the circulation and rainfall are sensitive to the transfers of radiation, sensible heat, water vapor, and momentum across the atmosphere land surface interface. Because, in nature, these transfers depend in large measure on the morphological and physiological characteristics of the surface vegetation, an interactive biosphere is needed for GCM's. The simple model of the biosphere (SiB) that the authors have constructed is based on the recognized difference between ground cover vegetation (grasses and other herbaceous plants) and canopy vegetation (trees and shrubs), where the latter act like elevated blocks of porous material which efficiently extract momentum from the air that flows through them; by a large number of multiple reflections enhance the absorption of the incident solar radiation; when the canopy is wet, act like well ventilated psychrometers which extract sensible heat from the air and produce a negative Bowen ratio; and, in all of these ways, behave differently from ground cover vegetation. The complete set of governing equations of SiB, whereby the various allowable combinations of trees, ground covers, and bare ground, in interaction with the atmosphere, determine all of the vegetation dependent transfers at the land surface, have been presented and described.

Qualitative properties of the minimal model of carbon circulation in the biosphere

NASA Astrophysics Data System (ADS)

Pestunov, Aleksandr; Fedotov, Anatoliy; Medvedev, Sergey

2014-05-01

Substantial changes in the biosphere during recent decades have caused legitimate concern in the international community. The fact that feedbacks between the atmospheric CO2 concentration, global temperature, permafrost, ocean CO2 concentration and air humidity increases the risk of catastrophic phenomena on the planetary scale. The precautionary principle allows us to consider greenhouse effect using the mathematical models of the biosphere-climate system. Minimal models do not allow us to make a quantitative description of the "biosphere-climate" system dynamics, which is determined by the aggregate effect of the set of known climatic and biosphere processes. However, the study of such models makes it possible to understand the qualitative mechanisms of biosphere processes and to evaluate their possible consequences. The global minimal model of long-term dynamics of carbon in biosphere is considered basing on assumption that anthropogenous carbon emissions in atmosphere are absent [1]. Qualitative analysis of the model shows that there exists a set of model parameters (taken from the current estimation ranges), such that the system becomes unstable. It is also shown that external influences on the carbon circulation can lead either to degradation of the biosphere or to global temperature change [2]. This work is aimed at revealing the conditions under which the biosphere model can become unstable, which can result in catastrophic changes in the Earth's biogeocenoses. The minimal model of the biosphere-climate system describes an improbable, but, nevertheless, a possible worst-case scenario of the biosphere evolution takes into consideration only the most dangerous biosphere mechanisms and ignores some climate feedbacks (such as transpiration). This work demonstrates the possibility of implementing the trigger mode in the biosphere, which can lead to dramatic changes in the state of the biosphere even without additional burning of fossil fuels. This mode implementation is possible under parameter values of the biosphere, lying within the ranges of their existing estimates. Hence a potential hazard of any drastic change of the biosphere conditions that may speed up possible shift of the biosphere to a new stable state. References 1. Bartsev S.I., Degermendzhi A.G., Fedotov A.M., Medvedev S.B., Pestunov A.I., Pestunov I.A. The Biosphere Trigger Mechanism in the Minimal Model for the Global Carbon Cycle of the Earth // Doklady Earth Sciences, 2012, Vol. 443, Part 2, pp. 489-492. © Pleiades Publishing, Ltd., 2012. 2. Fedotov A.M., Medvedev S.B., Pestunov A.I., Pestunov I.A., Bartsev S.I., Degermendzhi A.G. Qualitative analysis of the minimal model of carbon dynamics in the biosphere // Computational Technologies. 2012. Vol. 17. N 3. pp. 91-108 (in Russian).

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

NASA Astrophysics Data System (ADS)

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

2013-09-01

Previous studies suggest that a large part of the variability in the atmospheric ratio of 13CO2/12CO2originates 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 investigate the contribution of interannual variability (IAV) in biospheric exchange to the observed atmospheric 13C variations. We use the Simple Biosphere - Carnegie-Ames-Stanford Approach biogeochemical model, including a detailed isotopic fractionation scheme, separate 12C and 13C biogeochemical pools, and satellite-observed fire disturbances. This model of 12CO2 and 13CO2 thus also produces return fluxes of 13CO2from its differently aged pools, contributing to the so-called disequilibrium flux. Our simulated terrestrial 13C budget closely resembles previously published model results for plant discrimination and disequilibrium fluxes and similarly suggests that variations in C3 discrimination and year-to-year variations in C3and C4 productivity are the main drivers of their IAV. But the year-to-year variability in the isotopic disequilibrium flux is much lower (1σ=±1.5 PgC ‰ yr-1) than required (±12.5 PgC ‰ yr-1) to match atmospheric observations, under the common assumption of low variability in net ocean CO2 fluxes. This contrasts with earlier published results. It is currently unclear how to increase IAV in these drivers suggesting that SiBCASA still misses processes that enhance variability in plant discrimination and relative C3/C4productivity. Alternatively, 13C budget terms other than terrestrial disequilibrium fluxes, including possibly the atmospheric growth rate, must have significantly different IAV in order to close the atmospheric 13C budget on a year-to-year basis.

Spatial interactions in a modified Daisyworld model: Heat diffusivity and greenhouse effects

NASA Astrophysics Data System (ADS)

Alberti, T.; Primavera, L.; Vecchio, A.; Lepreti, F.; Carbone, V.

2015-11-01

In this work we investigate a modified version of the Daisyworld model, originally introduced by Lovelock and Watson to describe in a simple way the interactions between an Earth-like planet, its biosphere, and the incoming solar radiation. Here a spatial dependency on latitude is included, and both a variable heat diffusivity along latitudes and a simple greenhouse effect description are introduced in the model. We show that the spatial interactions between the variables of the system can locally stabilize the coexistence of the two vegetation types. The feedback on albedo is able to generate equilibrium solutions which can efficiently self-regulate the planet climate, even for values of the solar luminosity relatively far from the current Earth conditions.

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

NASA Astrophysics Data System (ADS)

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

2018-06-01

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

Analysing Trends in Light-Use Efficiency and Their Influence on Seasonal CO2 Amplitude Using a Simple Land Ecosystem Model

NASA Astrophysics Data System (ADS)

Thomas, R.; Prentice, I. C. C.; Graven, H. D.

2016-12-01

A simple model for gross primary production (GPP), the P-model, is used to analyse the recent increase in the amplitude of the seasonal cycle of CO2 (ASC) at high northern latitudes. Current terrestrial biosphere models and Earth System Models generally underestimate the observed increase in ASC since 1960. The increased ASC is primarily driven by an increase in net primary productivity (NPP), rather than respiration, so models are likely underestimating increases in NPP. In a recent study of process-based terrestrial biosphere models from the Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP), we showed that the concept of light-use efficiency can be used to separate modelled NPP changes into structural and physiological components (Thomas et al, 2016). The structural component (leaf area) can be tested against observations of greening, while the physiological component (light-use efficiency) is an emergent model property. The analysis suggests that current models are capturing the increases in vegetation greenness, but underestimating the increases in light-use efficiency and NPP. We test this hypothesis using the P-model, which explicitly uses greenness data and includes the effects of rising CO2 and climate change. In the P-model, GPP is calculated using only a few equations, which are based on a strong empirical and theoretical framework, and vegetation is not separated into plant functional types. The model is driven by observed greenness, CO2, temperature and vapour pressure, and modelled photosynthetically active radiation at a monthly time-step. Photosynthetic assimilation is based on two key assumptions: the co-limitation hypothesis (electron transport- and Rubisco-limited photosynthetic rates are equal), and the least-cost hypothesis (optimal ci:ca ratio), and is limited by modelled soil moisture. We present simulated changes in GPP over the satellite period (1982-2011) in the P-model, and assess the associated changes in light-use efficiency and ASC. Our results have implications for the attribution of drivers of ecosystem change and the formulation of prognostic and diagnostic biosphere models. Thomas, R. T. et al. 2016, CO2 and greening observations indicate increasing light-use efficiency in Northern terrestrial ecosystems, Geophys Res Lett, in review.

Simple global carbon model: The atmosphere-terrestrial biosphere-ocean interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwon, O.Y.; Schnoor, J.L.

A simple global carbon model has been developed for scenario analysis, and research needs prioritization. CO{sub 2} fertilization and temperature effects are included in the terrestrial biosphere compartment, and the ocean compartment includes inorganic chemistry which, with ocean water circulation, enables the calculation of time-variable oceanic carbon uptake. Model-derived Q{sub 10} values (the increasing rate for every 10{degrees}C increase of temperature) are 1.37 for land biota photosynthesis, 1.89 for land biota respiration, and 1.95 for soil respiration, and feedback temperature is set at 0.01{degrees}C/ppm of CO{sub 2}. These could be the important parameters controlling the carbon cycle in potential globalmore » warming scenarios. Scenario analysis, together with sensitivity analysis of temperature feedback, suggests that if CO{sub 2} emissions from fossil fuel combustion continue at the present increasing rate of {approximately}1.5% per year, a CO{sub 2} doubling (to 560 ppm) will appear in year 2060. Global warming would be responsible for 40 Gt as carbon (Gt C) accumulation in the land biota, 88 Gt C depletion from the soil carbon, a 7 Gt C accumulation in the oceans, and a 19 ppm increase in atmospheric CO{sub 2}. The ocean buffering capacity to take up the excess CO{sub 2} will decrease with the increasing atmospheric CO{sub 2} concentration. 51 refs., 8 figs., 3 tabs.« less

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

NASA Astrophysics Data System (ADS)

Hoogakker, B. A. A.; Smith, R. S.; Singarayer, J. S.; Marchant, R.; Prentice, I. C.; Allen, J. R. M.; Anderson, R. S.; Bhagwat, S. A.; Behling, H.; Borisova, O.; Bush, M.; Correa-Metrio, A.; de Vernal, A.; Finch, J. M.; Fréchette, B.; Lozano-Garcia, S.; Gosling, W. D.; Granoszewski, W.; Grimm, E. C.; Grüger, E.; Hanselman, J.; Harrison, S. P.; Hill, T. R.; Huntley, B.; Jiménez-Moreno, G.; Kershaw, P.; Ledru, M.-P.; Magri, D.; McKenzie, M.; Müller, U.; Nakagawa, T.; Novenko, E.; Penny, D.; Sadori, L.; Scott, L.; Stevenson, J.; Valdes, P. J.; Vandergoes, M.; Velichko, A.; Whitlock, C.; Tzedakis, C.

2015-03-01

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.

The Impact of Prior Biosphere Models in the Inversion of Global Terrestrial CO2 Fluxes by Assimilating OCO-2 Retrievals

NASA Technical Reports Server (NTRS)

Philip, Sajeev; Johnson, Matthew S.

2018-01-01

Atmospheric mixing ratios of carbon dioxide (CO2) are largely controlled by anthropogenic emissions and biospheric fluxes. The processes controlling terrestrial biosphere-atmosphere carbon exchange are currently not fully understood, resulting in terrestrial biospheric models having significant differences in the quantification of biospheric CO2 fluxes. Atmospheric transport models assimilating measured (in situ or space-borne) CO2 concentrations to estimate "top-down" fluxes, generally use these biospheric CO2 fluxes as a priori information. Most of the flux inversion estimates result in substantially different spatio-temporal posteriori estimates of regional and global biospheric CO2 fluxes. The Orbiting Carbon Observatory 2 (OCO-2) satellite mission dedicated to accurately measure column CO2 (XCO2) allows for an improved understanding of global biospheric CO2 fluxes. OCO-2 provides much-needed CO2 observations in data-limited regions facilitating better global and regional estimates of "top-down" CO2 fluxes through inversion model simulations. The specific objectives of our research are to: 1) conduct GEOS-Chem 4D-Var assimilation of OCO-2 observations, using several state-of-the-science biospheric CO2 flux models as a priori information, to better constrain terrestrial CO2 fluxes, and 2) quantify the impact of different biospheric model prior fluxes on OCO-2-assimilated a posteriori CO2 flux estimates. Here we present our assessment of the importance of these a priori fluxes by conducting Observing System Simulation Experiments (OSSE) using simulated OCO-2 observations with known "true" fluxes.

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

NASA Technical Reports Server (NTRS)

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.

A Simplified Biosphere Model for Global Climate Studies.

NASA Astrophysics Data System (ADS)

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

1991-03-01

The Simple Biosphere Model (SiB) as described in Sellers et al. is a bio-physically based model of land surface-atmosphere interaction. For some general circulation model (GCM) climate studies, further simplifications are desirable to have greater computation efficiency, and more important, to consolidate the parametric representation. Three major reductions in the complexity of SiB have been achieved in the present study.The diurnal variation of surface albedo is computed in SiB by means of a comprehensive yet complex calculation. Since the diurnal cycle is quite regular for each vegetation type, this calculation can be simplified considerably. The effect of root zone soil moisture on stomatal resistance is substantial, but the computation in SiB is complicated and expensive. We have developed approximations, which simulate the effects of reduced soil moisture more simply, keeping the essence of the biophysical concepts used in SiB.The surface stress and the fluxes of heat and moisture between the top of the vegetation canopy and an atmospheric reference level have been parameterized in an off-line version of SiB based upon the studies by Businger et al. and Paulson. We have developed a linear relationship between Richardson number and aero-dynamic resistance. Finally, the second vegetation layer of the original model does not appear explicitly after simplification. Compared to the model of Sellers et al., we have reduced the number of input parameters from 44 to 21. A comparison of results using the reduced parameter biosphere with those from the original formulation in a GCM and a zero-dimensional model shows the simplified version to reproduce the original results quite closely. After simplification, the computational requirement of SiB was reduced by about 55%.

On the improbability of intelligent extraterrestrials

NASA Astrophysics Data System (ADS)

Bond, A.

1982-05-01

Discussions relating to the prevalence of extraterrestrial life generally remain ambiguous due to the lack of a suitable model for the development of biology. In this paper a simple model is proposed based on neutral evolution theory which leads to quantitative values for the genome growth rate within a biosphere. It is hypothesised that the genome size is a measure of organism complexity and hence an indicator of the likelihood of intelligence. The calculations suggest that organisms with the complexity of human beings may be rare and only occur with a probability below once per galaxy.

Modeling the surface evapotranspiration over the southern Great Plains

NASA Technical Reports Server (NTRS)

Liljegren, J. C.; Doran, J. C.; Hubbe, J. M.; Shaw, W. J.; Zhong, S.; Collatz, G. J.; Cook, D. R.; Hart, R. L.

1996-01-01

We have developed a method to apply the Simple Biosphere Model of Sellers et al to calculate the surface fluxes of sensible heat and water vapor at high spatial resolution over the domain of the US DOE's Cloud and Radiation Testbed (CART) in Kansas and Oklahoma. The CART, which is within the GCIP area of interest for the Mississippi River Basin, is an extensively instrumented facility operated as part of the DOE's Atmospheric Radiation Measurement (ARM) program. Flux values calculated with our method will be used to provide lower boundary conditions for numerical models to study the atmosphere over the CART domain.

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

PubMed

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

2014-02-01

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

Lignocellulose deconstruction in the biosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bomble, Yannick J.; Lin, Chien-Yuan; Amore, Antonella

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

Lignocellulose deconstruction in the biosphere.

PubMed

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

2017-12-01

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

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

USDA-ARS?s Scientific Manuscript database

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

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

PubMed

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 the uncertainties concerning the biosphere on very long timescales, stylised biosphere models are shown to provide a useful point of reference in themselves and remain a valuable tool for nuclear waste disposal licencing procedures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparing Amazon Basin CO2 fluxes from an atmospheric inversion with TRENDY biosphere models

NASA Astrophysics Data System (ADS)

Diffenbaugh, N. S.; Alden, C. B.; Harper, A. B.; Ahlström, A.; Touma, D. E.; Miller, J. B.; Gatti, L. V.; Gloor, M.

2015-12-01

Net exchange of carbon dioxide (CO2) between the atmosphere and the terrestrial biosphere is sensitive to environmental conditions, including extreme heat and drought. Of particular importance for local and global carbon balance and climate are the expansive tracts of tropical rainforest located in the Amazon Basin. Because of the Basin's size and ecological heterogeneity, net biosphere CO2 exchange with the atmosphere remains largely un-constrained. In particular, the response of net CO2 exchange to changes in environmental conditions such as temperature and precipitation are not yet well known. However, proper representation of these relationships in biosphere models is a necessary constraint for accurately modeling future climate and climate-carbon cycle feedbacks. In an effort to compare biosphere response to climate across different biosphere models, the TRENDY model intercomparison project coordinated the simulation of CO2 fluxes between the biosphere and atmosphere, in response to historical climate forcing, by 9 different Dynamic Global Vegetation Models. We examine the TRENDY model results in the Amazon Basin, and compare this "bottom-up" method with fluxes derived from a "top-down" approach to estimating net CO2 fluxes, obtained through atmospheric inverse modeling using CO2 measurements sampled by aircraft above the basin. We compare the "bottom-up" and "top-down" fluxes in 5 sub-regions of the Amazon basin on a monthly basis for 2010-2012. Our results show important periods of agreement between some models in the TRENDY suite and atmospheric inverse model results, notably the simulation of increased biosphere CO2 loss during wet season heat in the Central Amazon. During the dry season, however, model ability to simulate observed response of net CO2 exchange to drought was varied, with few models able to reproduce the "top-down" inversion flux signals. Our results highlight the value of atmospheric trace gas observations for helping to narrow the possibilities of future carbon-climate interactions, especially in historically under-observed regions like the Amazon.

Towards a representation of priming on soil carbon decomposition in the global land biosphere model ORCHIDEE (version 1.9.5.2)

NASA Astrophysics Data System (ADS)

Guenet, Bertrand; Esteban Moyano, Fernando; Peylin, Philippe; Ciais, Philippe; Janssens, Ivan A.

2016-03-01

Priming of soil carbon decomposition encompasses different processes through which the decomposition of native (already present) soil organic matter is amplified through the addition of new organic matter, with new inputs typically being more labile than the native soil organic matter. Evidence for priming comes from laboratory and field experiments, but to date there is no estimate of its impact at global scale and under the current anthropogenic perturbation of the carbon cycle. Current soil carbon decomposition models do not include priming mechanisms, thereby introducing uncertainty when extrapolating short-term local observations to ecosystem and regional to global scale. In this study we present a simple conceptual model of decomposition priming, called PRIM, able to reproduce laboratory (incubation) and field (litter manipulation) priming experiments. Parameters for this model were first optimized against data from 20 soil incubation experiments using a Bayesian framework. The optimized parameter values were evaluated against another set of soil incubation data independent from the ones used for calibration and the PRIM model reproduced the soil incubations data better than the original, CENTURY-type soil decomposition model, whose decomposition equations are based only on first-order kinetics. We then compared the PRIM model and the standard first-order decay model incorporated into the global land biosphere model ORCHIDEE (Organising Carbon and Hydrology In Dynamic Ecosystems). A test of both models was performed at ecosystem scale using litter manipulation experiments from five sites. Although both versions were equally able to reproduce observed decay rates of litter, only ORCHIDEE-PRIM could simulate the observed priming (R2 = 0.54) in cases where litter was added or removed. This result suggests that a conceptually simple and numerically tractable representation of priming adapted to global models is able to capture the sign and magnitude of the priming of litter and soil organic matter.

Towards a representation of priming on soil carbon decomposition in the global land biosphere model ORCHIDEE (version 1.9.5.2)

NASA Astrophysics Data System (ADS)

Guenet, B.; Moyano, F. E.; Peylin, P.; Ciais, P.; Janssens, I. A.

2015-10-01

Priming of soil carbon decomposition encompasses different processes through which the decomposition of native (already present) soil organic matter is amplified through the addition of new organic matter, with new inputs typically being more labile than the native soil organic matter. Evidence for priming comes from laboratory and field experiments, but to date there is no estimate of its impact at global scale and under the current anthropogenic perturbation of the carbon cycle. Current soil carbon decomposition models do not include priming mechanisms, thereby introducing uncertainty when extrapolating short-term local observations to ecosystem and regional to global scale. In this study we present a simple conceptual model of decomposition priming, called PRIM, able to reproduce laboratory (incubation) and field (litter manipulation) priming experiments. Parameters for this model were first optimized against data from 20 soil incubation experiments using a Bayesian framework. The optimized parameter values were evaluated against another set of soil incubation data independent from the ones used for calibration and the PRIM model reproduced the soil incubations data better than the original, CENTURY-type soil decomposition model, whose decomposition equations are based only on first order kinetics. We then compared the PRIM model and the standard first order decay model incorporated into the global land biosphere model ORCHIDEE. A test of both models was performed at ecosystem scale using litter manipulation experiments from 5 sites. Although both versions were equally able to reproduce observed decay rates of litter, only ORCHIDEE-PRIM could simulate the observed priming (R2 = 0.54) in cases where litter was added or removed. This result suggests that a conceptually simple and numerically tractable representation of priming adapted to global models is able to capture the sign and magnitude of the priming of litter and soil organic matter.

On the influence of biomass burning on the seasonal CO2 signal as observed at monitoring stations

USGS Publications Warehouse

Wittenberg, U.; Heimann, Martin; Esse, G.; McGuire, A.D.; Sauf, W.

1998-01-01

We investigated the role of biomass burning in simulating the seasonal signal in both prognostic and diagnostic analyses. The prognostic anaysis involved the High-Resolution Biosphere Model, a prognostic terrestrial biosphere model, and the coupled vegetation fire module, which together produce a prognostic data set of biomass burning. The diagnostic analysis invovled the Simple Diagnostic Biosphere Model (SDBM) and the Hao and Liu [1994] diagnostic data set of bimass burning, which have been scaled to global 2 and 4 Pg C yr-1, respectively. The monthly carbon exchange fields between the atmosphere and the biosphere with a spatial resolution of 0.5?? ?? 0.5??, the seasonal atmosphere-ocean exchange fields, and the emissions from fossil fuels have been coupled to the three-dimensional atmospheric transport model TM2. We have chosen eight monitoring stations of the National Oceanic and Atmospheric Administration network to compare the predicted seasonal atmospheric CO2 signals with those deduced from atmosphere-biosphere carbon exchange fluxes without any contribution from biomass burning. The prognostic analysis and the diagnostic analysis with global burning emissions of 4 Pg C yr-1 agree with respect to the change in the amplitude of the seasonal CO2 concentration introduced through biomass burning. We find that the seasonal CO2 signal at stations in higher northern latitudes (north of 30??N) is marginally influenced by biomass burning. For stations in tropical regions an increase in the CO2 amplitude of more an 1 oppmv (up to 50% with respect to the observed trough to peak amplitude) has been calculated. Biomass burning at stations farther south accounts for an increase in the CO2 amplitude of up to 59% (0.6 ppmv). A change in the phase of the seasonal CO2 signal at tropical and southern stations has been shown to be strongly influenced by the onset of biomass burning in southern tropical Africa and America. Comparing simulated and observed seasonal CO2 signals, we find higher discrepancies at southern troical stations if biomass burning emissions are included. This is caused by the additional increase in the amplitude in the prognostic analysis and a phase shift in a diagnostic analysis. In contrast, at the northern tropical stations biomass burning tends to improve the estimates of the seasonal CO2 signal in the prognostic analysis because of strengthening of the amplitude. Since the SDCM predicts the seasonal CO2 signal resonably well for the northern hemisphere tropical stations, no general improvement of the fit occurs if biomass burning emissions are considered.

Terraforming planet Dune: Climate-vegetation interactions on a sandy planet

NASA Astrophysics Data System (ADS)

Cresto Aleina, F.; Baudena, M.; D'Andrea, F.; Provenzale, A.

2012-04-01

The climate and the biosphere of planet Earth interact in multiple, complicated ways and on many spatial and temporal scales. Some of these processes can be studied with the help of simple mathematical models, as done for the effects of vegetation on albedo in desert areas and for the mechanisms by which terrestrial vegetation affects water fluxes in arid environments. Conceptual models of this kind do not attempt at providing quantitative descriptions of the climate-biosphere interaction, but rather to explore avenues and mechanisms which can play a role in the real system, providing inspiration for further research. In this work, we develop a simple conceptual box model in the spirit illustrated above, to explore whether and how vegetation affects the planetary hydrologic cycle. We imagine a planet with no oceans and whose surface is entirely covered with sand, quite similar to planet Dune of the science-fiction series by Frank Herbert (1965). We suppose that water is entirely in the sand, below the surface. Without vegetation, only evaporation takes place, affecting the upper sand layer for a maximum depth of a few cm. The amount of water that is evaporated in the atmosphere is relatively small, and not sufficient to trigger a full hydrologic cycle. The question is what happens to this planet when vegetation is introduced: the root depth can reach a meter or more, and plant transpiration can then transfer a much larger amount of water to the atmosphere. One may wonder whether the presence of vegetation is sufficient to trigger a hydrologic cycle with enough precipitation to sustain the vegetation itself and, if the answer is positive, what is the minimum vegetation cover that is required to maintain the cycle active. In more precise terms, we want to know whether the introduction of vegetation and of the evapotranspiration feedback allows for the existence of multiple equilibria (or solutions) in the soil-vegetation-atmosphere system. Although the box model introduced here is best formulated in terms of a hypothetical sandy planet, the results can be used to study the hydrologic cycle on wide continental regions of the Earth. On the other hand, our findings show how the definition of a habitable climate may also depend on surface characteristics, and in particular on biosphere and climate interactions.

In search of future earths: assessing the possibility of finding Earth analogues in the later stages of their habitable lifetimes.

PubMed

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

2015-05-01

Earth will become uninhabitable within 2-3 Gyr as a result of the increasing luminosity of the Sun changing the boundaries of the habitable zone (HZ). Predictions about the future of habitable conditions on Earth include declining species diversity and habitat extent, ocean loss, and changes to geochemical cycles. Testing these predictions is difficult, but the discovery of a planet that is an analogue to future Earth could provide the means to test them. This planet would need to have an Earth-like biosphere history and to be approaching the inner edge of the HZ at present. Here, we assess the possibility of finding such a planet and discuss the benefits of analyzing older Earths. Finding an old-Earth analogue in nearby star systems would be ideal, because this would allow for atmospheric characterization. Hence, as an illustrative example, G stars within 10 pc of the Sun are assessed as potential old-Earth-analog hosts. Six of these represent good potential hosts. For each system, a hypothetical Earth analogue is placed at locations within the continuously habitable zone (CHZ) that would allow enough time for Earth-like biosphere development. Surface temperature evolution over the host star's main sequence lifetime (assessed by using a simple climate model) is used to determine whether the planet would be in the right stage of its late-habitable lifetime to exhibit detectable biosignatures. The best candidate, in terms of the chances of planet formation in the CHZ and of biosignature detection, is 61 Virginis. However, planet formation studies suggest that only a small fraction (0.36%) of G stars in the solar neighborhood could host an old-Earth analogue. If the development of Earth-like biospheres is rare, requiring a sequence of low-probability events to occur, biosphere evolution models suggest they are rarer still, with only thousands being present in the Galaxy as a whole.

Mineral Bionization - Surface Chemical Modeling of the Emergence of Life

NASA Astrophysics Data System (ADS)

Arrhenius, G.

2001-12-01

The earliest stages in entering an RNA-world require natural mechanisms that are capable of selective concentration of simple aldehydes from dilute solution in the environment (4), furthermore phosphorylation of the sequestered aldehydes (2) and their catalytic condensation to form, selectively, tetrose- (threose) or pentose- (ribose) phosphate (3); the latter representing the R in RNA. A variety of common positively charged sheet structure minerals (mixed valence double layer metal hydroxide minerals such as hydrotalcite and green rust) have proven to be remarkably capable of performing these crucial tasks under simplified natural conditions (1). These prebiotic model reactions have demonstrated plausible closure of the gap, previously thought to preclude the natural formation of nucleoside phosphates, the backbone components of the information carrying genetic material. Pioneering research by other workers (5) has demonstrated the feasibility of necessary further steps in the chain toward functional RNA; mineral (montmorillonite) catalyzed oligomerization of nucleotides, the formation of complementary RNA strands (6) and the enzymatic activity of RNA (ribozymes). These contributions have placed the initially conjectural concept of an initial RNA-world on an experimental footing. Remaining problems include the initial transfer of information to spontaneously forming RNA, sufficient to convey biofunctionallity (7). Also in this central problem mineral surface interactions may be speculated to play a natural role; a question that is open to experimental verification. References. 1. Pitsch, S.; Eschenmoser, A.; Gedulin, B.; Hui, S. and Arrhenius, G. Origins Life Evol. Biosphere, 1994, 24 (5), 389. 2. Kolb, V.; Zhang, S.; Xu, Y.; Arrhenius, G. Origins Life Evol. Biosphere, 1997, 27, 485. 3. Krishnamurthy, R.; Pitsch, S.; Arrhenius, G. Origins Life Evol. Biosphere, Origins Life Evol. Biosphere 1999, 29, 139 4. Pitsch, S.; Krishnamurthy, R.; Arrhenius, G. Helv. Chim. Acta. 2000, 83, 2398. 5. Ferris, J. P.; Ertem, G. J. J. Am. Chem. Soc. 1993, 115, 1270. 6. Orgel ,L.E. J. Theoretical Biol. 1986, 123, 127-149 7. Arrhenius, G; Life out of Chaos. In Palyi et al. eds. Fundamentals of Life, Elsevier, Paris, 2001

Predator-prey Encounter Rates in Turbulent Environments: Consequences of Inertia Effects and Finite Sizes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pecseli, H. L.; Trulsen, J.

2009-10-08

Experimental as well as theoretical studies have demonstrated that turbulence can play an important role for the biosphere in marine environments, in particular also by affecting prey-predator encounter rates. Reference models for the encounter rates rely on simplifying assumptions of predators and prey being described as point particles moving passively with the local flow velocity. Based on simple arguments that can be tested experimentally we propose corrections for the standard expression for the encounter rates, where now finite sizes and Stokes drag effects are included.

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

NASA Technical Reports Server (NTRS)

Robock, Alan; Vinnikov, Konstantin YA.; Schlosser, C. Adam; Speranskaya, Nina A.; Xue, Yongkang

1995-01-01

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 fluxes, which would have large effects on GCM simulations.

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

PubMed

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

2013-01-01

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

Planetary Bootstrap: A Prelude to Biosphere Phenomenology

NASA Astrophysics Data System (ADS)

Kazansky, Alexander B.

2004-08-01

This paper deals with systemic status as well as with some phenomenological and evolutionary aspects of biosphere. Biosphere is represented as multilevel autopoietic system in which different organizational levels are nested into each other. The conceptual model of punctuated epigenesis, biosphere evolutionary process is suggested, in which endogenous planetary organizational crises play role of evolutionary mechanism, creating novelty. The hypothesis is proposed, that the biosphere reaction on the humankind destructive activity reminds the distributed immune response of biological organism, described by F.Varela in his "cognitive immunology". The biosphere evolution is interpreted as the hermeneutical spiral of "Process Being" self-uncovering thus illustrating the historical process of transformation of biosphere as the type of Being in the periods of crises. Some arguments are adduced in favor of biosphere phenomenology development and application of the methods of second-order cybernetics to actual problems of planetary scale.

Spanish methodological approach for biosphere assessment of radioactive waste disposal.

PubMed

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.

A biosphere modeling methodology for dose assessments of the potential Yucca Mountain deep geological high level radioactive waste repository.

PubMed

Watkins, B M; Smith, G M; Little, R H; Kessler, J

1999-04-01

Recent developments in performance standards for proposed high level radioactive waste disposal at Yucca Mountain suggest that health risk or dose rate limits will likely be part of future standards. Approaches to the development of biosphere modeling and dose assessments for Yucca Mountain have been relatively lacking in previous performance assessments due to the absence of such a requirement. This paper describes a practical methodology used to develop a biosphere model appropriate for calculating doses from use of well water by hypothetical individuals due to discharges of contaminated groundwater into a deep well. The biosphere model methodology, developed in parallel with the BIOMOVS II international study, allows a transparent recording of the decisions at each step, from the specification of the biosphere assessment context through to model development and analysis of results. A list of features, events, and processes relevant to Yucca Mountain was recorded and an interaction matrix developed to help identify relationships between them. Special consideration was given to critical/potential exposure group issues and approaches. The conceptual model of the biosphere system was then developed, based on the interaction matrix, to show how radionuclides migrate and accumulate in the biosphere media and result in potential exposure pathways. A mathematical dose assessment model was specified using the flexible AMBER software application, which allows users to construct their own compartment models. The starting point for the biosphere calculations was a unit flux of each radionuclide from the groundwater in the geosphere into the drinking water in the well. For each of the 26 radionuclides considered, the most significant exposure pathways for hypothetical individuals were identified. For 14 of the radionuclides, the primary exposure pathways were identified as consumption of various crops and animal products following assumed agricultural use of the contaminated water derived from the deep well. Inhalation of dust (11 radionuclides) and external irradiation (1 radionuclide) were also identified as significant exposure modes. Contribution to the total flux to dose conversion factor from the drinking water pathway for each radionuclide was also assessed and for most radionuclides was found to be less than 10% of the total flux to dose conversion factor summed across all pathways. Some of the uncertainties related to the results were considered. The biosphere modeling results have been applied within an EPRI Total Systems Performance Assessment of Yucca Mountain. Conclusions and recommendations for future performance assessments are provided.

Governing Portable Conservation and Development Landscapes: Reconsidering Evidence in the Context of the Mbaracayú Biosphere Reserve

ERIC Educational Resources Information Center

Elgert, Laureen

2014-01-01

Conservation-with-development landscapes, such as UNESCO's Man and Biosphere Reserves, differentiate between areas of "nature" and "society". In Paraguay's Mbaracayú Biosphere Reserve, as elsewhere, this model has been used to support governance that focuses on conservation in the "core area" and sustainable…

Reduced Diversity of Life around Proxima Centauri and TRAPPIST-1

NASA Astrophysics Data System (ADS)

Lingam, Manasvi; Loeb, Abraham

2017-09-01

The recent discovery of potentially habitable exoplanets around Proxima Centauri and TRAPPIST-1 has attracted much attention due to their potential for hosting life. We delineate a simple model that accurately describes the evolution of biological diversity on Earth. Combining this model with constraints on atmospheric erosion and the maximal evolutionary timescale arising from the star’s lifetime, we arrive at two striking conclusions: (I) Earth-analogs orbiting low-mass M-dwarfs are unlikely to be inhabited, and (II) K-dwarfs and some G-type stars are potentially capable of hosting more complex biospheres than the Earth. Hence, future searches for biosignatures may have higher chances of success when targeting planets around K-dwarf stars.

ISSOL Meeting, Barcelona, Spain, 1993

NASA Technical Reports Server (NTRS)

Ferris, James P. (Editor)

1995-01-01

Topics in a conference on the origins of life and the evolution of the biosphere include the origin of chirality, prebiotic chemistry of small biomolecules, primitive polymer formation, RNA regulation and control. Early origins of life and the ecology of hydrothermal systems such as ocean floor vents and their simple organisms are examined. The process of mineral catalysis in Montmorillonite as a model for early metabolism is used. The origin of the genetic code and the development of branching in molecular structures of amino acids is described. Studies are reported of the effects of meteorite impact on early Earth life.

Grain Yield Observations Constrain Cropland CO2 Fluxes Over Europe

NASA Astrophysics Data System (ADS)

Combe, M.; de Wit, A. J. W.; Vilà-Guerau de Arellano, J.; van der Molen, M. K.; Magliulo, V.; Peters, W.

2017-12-01

Carbon exchange over croplands plays an important role in the European carbon cycle over daily to seasonal time scales. A better description of this exchange in terrestrial biosphere models—most of which currently treat crops as unmanaged grasslands—is needed to improve atmospheric CO2 simulations. In the framework we present here, we model gross European cropland CO2 fluxes with a crop growth model constrained by grain yield observations. Our approach follows a two-step procedure. In the first step, we calculate day-to-day crop carbon fluxes and pools with the WOrld FOod STudies (WOFOST) model. A scaling factor of crop growth is optimized regionally by minimizing the final grain carbon pool difference to crop yield observations from the Statistical Office of the European Union. In a second step, we re-run our WOFOST model for the full European 25 × 25 km gridded domain using the optimized scaling factors. We combine our optimized crop CO2 fluxes with a simple soil respiration model to obtain the net cropland CO2 exchange. We assess our model's ability to represent cropland CO2 exchange using 40 years of observations at seven European FluxNet sites and compare it with carbon fluxes produced by a typical terrestrial biosphere model. We conclude that our new model framework provides a more realistic and strongly observation-driven estimate of carbon exchange over European croplands. Its products will be made available to the scientific community through the ICOS Carbon Portal and serve as a new cropland component in the CarbonTracker Europe inverse model.

A comparative radiological assessment of five European biosphere systems in the context of potential contamination of well water from the hypothetical disposal of radioactive waste.

PubMed

Olyslaegers, G; Zeevaert, T; Pinedo, P; Simon, I; Pröhl, G; Kowe, R; Chen, Q; Mobbs, S; Bergström, U; Hallberg, B; Katona, T; Eged, K; Kanyar, B

2005-12-01

In the framework of the BioMoSA project for the development of biosphere assessment models for radioactive waste disposal the Reference Biosphere Methodology developed in the IAEA programme BIOMASS was applied to five locations, situated in different European countries. Specific biosphere models were applied to assess the hypothetical contamination of a range of agricultural and environmental pathways and the dose to individuals, following contamination of well water. The results of these site-specific models developed by the different BioMoSA partners, and the individual normalised dose to the exposure groups were compared against each other. Ingestion of drinking water, fruit and vegetables were found to be among the most important pathways for almost all radionuclides. Stochastic calculations revealed that consumption habits, transfer factors, irrigation rates and distribution coefficients (Kd(s)) were the most important parameters that influence the end results. Variations in the confidence intervals were found to be higher for sorbing elements (e.g. (36)Cl, (237)Np, (99)Tc, (238)U, (129)I) than for mobile elements (e.g. (226)Ra, (79)Se, (135)Cs, (231)Pa, (239)Pu). The influence of daughter products, for which the distribution into the biosphere was calculated individually, was also shown to be important. This paper gives a brief overview of the deterministic and stochastic modelling results and the parameter sensitivity. A screening methodology was introduced to identify the most important pathways, simplify a generic biosphere tool and refine the existing models.

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

PubMed

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

2018-05-22

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

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

PubMed

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

2013-12-01

This study documents an optimization of a prognostic biosphere model (VISIT; Vegetation Integrative Similator for Trace gases) to observations of atmospheric CO2 concentration and above ground woody biomass by using a Bayesian inversion method combined with an atmospheric tracer transport model (NIES-TM; National Institute for Environmental Studies / Frontier Research Center for Global Change (NIES/FRCGC) off-line global atmospheric tracer transport model). The assimilated observations include 74 station records of surface atmospheric CO2 concentration and aggregated grid data sets of above ground woody biomass (AGB) and net primary productivity (NPP) over the globe. Both the biosphere model and the atmospheric transport model are used at a horizontal resolution of 2.5 deg x 2.5 deg grid with temporal resolutions of a day and an hour, respectively. The atmospheric transport model simulates atmospheric CO2 concentration with nine vertical levels using daily net ecosystem CO2 exchange rate (NEE) from the biosphere model, oceanic CO2 flux, and fossil fuel emission inventory. The models are driven by meteorological data from JRA-25 (Japanese 25-year ReAnalysis) and JCDAS (JMA Climate Data Assimilation System). Statistically optimum physiological parameters in the biosphere model are found by iterative minimization of the corresponding Bayesian cost function. We select thirteen physiological parameter with high sensitivity to NEE, NPP, and AGB for the minimization. Given the optimized physiological parameters, the model shows error reductions in seasonal variation of the CO2 concentrations especially in the northern hemisphere due to abundant observation stations, while errors remain at a few stations that are located in coastal coastal area and stations in the southern hemisphere. The model also produces moderate estimates of the mean magnitudes and probability distributions in AGB and NPP for each biome. However, the model fails in the simulation of the terrestrial vegetation compositions in some grids. These misfits are assumed to derive from simplified representation in the biosphere model without the impact of land use change and dire disturbance and the seasonal variability in the physiological parameters.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, T.

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,more » 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.« less

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

NASA Technical Reports Server (NTRS)

Zhang, Taiping

1994-01-01

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.

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

PubMed

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.

Evaluation of simulated biospheric carbon dioxide fluxes and atmospheric concentrations using global in situ observations

NASA Astrophysics Data System (ADS)

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

2016-12-01

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

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

NASA Technical Reports Server (NTRS)

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

2016-01-01

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

On the design of an interactive biosphere for the GLAS general circulation model

NASA Technical Reports Server (NTRS)

Mintz, Y.; Sellers, P. J.; Willmott, C. J.

1983-01-01

Improving the realism and accuracy of the GLAS general circulation model (by adding an interactive biosphere that will simulate the transfers of latent and sensible heat from land surface to atmosphere as functions of the atmospheric conditions and the morphology and physiology of the vegetation) is proposed.

Regionally strong feedbacks between the atmosphere and terrestrial biosphere

NASA Astrophysics Data System (ADS)

Green, Julia K.; Konings, Alexandra G.; Alemohammad, Seyed Hamed; Berry, Joseph; Entekhabi, Dara; Kolassa, Jana; Lee, Jung-Eun; Gentine, Pierre

2017-06-01

The terrestrial biosphere and atmosphere interact through a series of feedback loops. Variability in terrestrial vegetation growth and phenology can modulate fluxes of water and energy to the atmosphere, and thus affect the climatic conditions that in turn regulate vegetation dynamics. Here we analyse satellite observations of solar-induced fluorescence, precipitation, and radiation using a multivariate statistical technique. We find that biosphere-atmosphere feedbacks are globally widespread and regionally strong: they explain up to 30% of precipitation and surface radiation variance in regions where feedbacks occur. Substantial biosphere-precipitation feedbacks are often found in regions that are transitional between energy and water limitation, such as semi-arid or monsoonal regions. Substantial biosphere-radiation feedbacks are often present in several moderately wet regions and in the Mediterranean, where precipitation and radiation increase vegetation growth. Enhancement of latent and sensible heat transfer from vegetation accompanies this growth, which increases boundary layer height and convection, affecting cloudiness, and consequently incident surface radiation. Enhanced evapotranspiration can increase moist convection, leading to increased precipitation. Earth system models underestimate these precipitation and radiation feedbacks mainly because they underestimate the biosphere response to radiation and water availability. We conclude that biosphere-atmosphere feedbacks cluster in specific climatic regions that help determine the net CO2 balance of the biosphere.

Regionally Strong Feedbacks Between the Atmosphere and Terrestrial Biosphere

NASA Technical Reports Server (NTRS)

Green, Julia K.; Konings, Alexandra G.; Alemohammad, Seyed Hamed; Lee, Jung-Eun; Berry, Joseph; Entekhabi, Dara; Kolassa, Jana; Gentine, Pierre

2017-01-01

The terrestrial biosphere and atmosphere interact through a series of feedback loops. Variability in terrestrial vegetation growth and phenology can modulate fluxes of water and energy to the atmosphere, and thus affect the climatic conditions that in turn regulate vegetation dynamics. Here we analyze satellite observations of solar-induced fluorescence, precipitation, and radiation using a multivariate statistical technique. We find that biosphere-atmosphere feedbacks are globally widespread and regionally strong: they explain up to 30 of precipitation and surface radiation variance. Substantial biosphere-precipitation feedbacks are often found in regions that are transitional between energy and water limitation, such as semi-arid or monsoonal regions. Substantial biosphere-radiation feedbacks are often present in several moderately wet regions and in the Mediterranean, where precipitation and radiation increase vegetation growth. Enhancement of latent and sensible heat transfer from vegetation accompanies this growth, which increases boundary layer height and convection, affecting cloudiness, and consequently incident surface radiation. Enhanced evapotranspiration can increase moist convection, leading to increased precipitation. Earth system models underestimate these precipitation and radiation feedbacks mainly because they underestimate the biosphere response to radiation and water availability. We conclude that biosphere-atmosphere feedbacks cluster in specific climatic regions that help determine the net CO2 balance of the biosphere.

The Biosphere: A Decadal Vision

NASA Technical Reports Server (NTRS)

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

2003-01-01

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

Anthropogenic Transformation of the Biomes, 1700 to 2000

NASA Astrophysics Data System (ADS)

Ellis, E. C.; Lightman, D.; Klein Goldewijk, K.; Ramankutty, N.

2008-12-01

Current global patterns of terrestrial ecosystem form and process are now predominantly anthropogenic as a result of land use and other direct human interactions with ecosystems. This study investigates anthropogenic transformation of the terrestrial biosphere over the course of the industrial revolution by mapping and characterizing global transitions between wild and anthropogenic biomes between 1700 and 2000. A global map of potential natural vegetation was used to represent wild biomes. Anthropogenic biomes were mapped for 1700, 1800, 1900 and 2000 using rule-based classification of current and historical global data for human population density, urban area and percent land cover by cultivated crops (rainfed, irrigated, and rice) and pastures. By assuming that wild, climate-driven, biome patterns have been relatively constant since 1700, transitions between wild and anthropogenic biomes were characterized between 1700 and 2000 at century intervals. Historical analysis of wild to anthropogenic biome transitions reveal the global transition from a primarily wild to a primarily anthropogenic terrestrial biosphere. Moreover, by mapping and examining global transitions between wild and anthropogenic biome classes, we provide a simple framework for assessing and modeling both past and future global biotic and ecological patterns in the light of the extent, intensity and duration of their modification by humans.

C-LAMP Subproject Description:Climate Forcing by the Terrestrial Biosphere During the Second Half of the 20th Century

DOE Office of Scientific and Technical Information (OSTI.GOV)

Covey, Curt; Hoffman, Forrest

2008-10-02

This project will quantify selected components of climate forcing due to changes in the terrestrial biosphere over the period 1948-2004, as simulated by the climate / carboncycle models participating in C-LAMP (the Carbon-Land Model Intercomparison Project; see http://www.climatemodeling.org/c-lamp). Unlike other C-LAMP projects that attempt to close the carbon budget, this project will focus on the contributions of individual biomes in terms of the resulting climate forcing. Bala et al. (2007) used a similar (though more comprehensive) model-based technique to assess and compare different components of biospheric climate forcing, but their focus was on potential future deforestation rather than the historicalmore » period.« less

From Scientists to the Public: Communicating Results of Ecological Research.

ERIC Educational Resources Information Center

Damlamian, Jeanne; And Others

1985-01-01

Considers the need to educate people about environmental concerns beyond the emotional level of simple awareness. Describes the UNESCO Man and the Biosphere poster education effort called Ecology in Action, an exhibit which consists of 36 color posters printed in English, Spanish, and French and distributed to over 122 countries. (JDH)

Carbon 13 exchanges between the atmosphere and biosphere

NASA Astrophysics Data System (ADS)

Fung, I.; Field, C. B.; Berry, J. A.; Thompson, M. V.; Randerson, J. T.; MalmströM, C. M.; Vitousek, P. M.; Collatz, G. James; Sellers, P. J.; Randall, D. A.; Denning, A. S.; Badeck, F.; John, J.

1997-12-01

We present a detailed investigation of the gross 12C and 13C exchanges between the atmosphere and biosphere and their influence on the δ13C variations in the atmosphere. The photosynthetic discrimination Δ against 13C is derived from a biophysical model coupled to a general circulation model [Sellers et al., 1996a], where stomatal conductance and carbon assimilation are determined simultaneously with the ambient climate. The δ13C of the respired carbon is calculated by a biogeochemical model [Potter et al., 1993; Randerson et al., 1996] as the sum of the contributions from compartments with varying ages. The global flux-weighted mean photosynthetic discrimination is 12-16‰, which is lower than previous estimates. Factors that lower the discrimination are reduced stomatal conductance and C4 photosynthesis. The decreasing atmospheric δ13C causes an isotopic disequilibrium between the outgoing and incoming fluxes; the disequilibrium is ˜0.33‰ for 1988. The disequilibrium is higher than previous estimates because it accounts for the lifetime of trees and for the ages rather than turnover times of the biospheric pools. The atmospheric δ13C signature resulting from the biospheric fluxes is investigated using a three-dimensional atmospheric tracer model. The isotopic disequilibrium alone produces a hemispheric difference of ˜0.02‰ in atmospheric δ13C, comparable to the signal from a hypothetical carbon sink of 0.5 Gt C yr-1 into the midlatitude northern hemisphere biosphere. However, the rectifier effect, due to the seasonal covariation of CO2 fluxes and height of the atmospheric boundary layer, yields a background δ13C gradient of the opposite sign. These effects nearly cancel thus favoring a stronger net biospheric uptake than without the background CO2 gradient. Our analysis of the globally averaged carbon budget for the decade of the 1980s indicates that the biospheric uptake of fossil fuel CO2 is likely to be greater than the oceanic uptake; the relative proportions of the sinks cannot be uniquely determined using 12C and 13C alone. The land-ocean sink partitioning requires, in addition, information about the land use source, isotopic disequilibrium associated with gross oceanic exchanges, as well as the fractions of C3 and C4 vegetation involved in the biospheric uptake.

Recovery after mass extinction: evolutionary assembly in large-scale biosphere dynamics.

PubMed Central

Solé, Ricard V; Montoya, José M; Erwin, Douglas H

2002-01-01

Biotic recoveries following mass extinctions are characterized by a process in which whole ecologies are reconstructed from low-diversity systems, often characterized by opportunistic groups. The recovery process provides an unexpected window to ecosystem dynamics. In many aspects, recovery is very similar to ecological succession, but important differences are also apparently linked to the innovative patterns of niche construction observed in the fossil record. In this paper, we analyse the similarities and differences between ecological succession and evolutionary recovery to provide a preliminary ecological theory of recoveries. A simple evolutionary model with three trophic levels is presented, and its properties (closely resembling those observed in the fossil record) are compared with characteristic patterns of ecological response to disturbances in continuous models of three-level ecosystems. PMID:12079530

Constraining Centennial-Scale Ecosystem-Climate Interactions with a Pre-colonial Forest Reconstruction across the Upper Midwest and Northeastern United States

NASA Astrophysics Data System (ADS)

Matthes, J. H.; Dietze, M.; Fox, A. M.; Goring, S. J.; McLachlan, J. S.; Moore, D. J.; Poulter, B.; Quaife, T. L.; Schaefer, K. M.; Steinkamp, J.; Williams, J. W.

2014-12-01

Interactions between ecological systems and the atmosphere are the result of dynamic processes with system memories that persist from seconds to centuries. Adequately capturing long-term biosphere-atmosphere exchange within earth system models (ESMs) requires an accurate representation of changes in plant functional types (PFTs) through time and space, particularly at timescales associated with ecological succession. However, most model parameterization and development has occurred using datasets than span less than a decade. We tested the ability of ESMs to capture the ecological dynamics observed in paleoecological and historical data spanning the last millennium. Focusing on an area from the Upper Midwest to New England, we examined differences in the magnitude and spatial pattern of PFT distributions and ecotones between historic datasets and the CMIP5 inter-comparison project's large-scale ESMs. We then conducted a 1000-year model inter-comparison using six state-of-the-art biosphere models at sites that bridged regional temperature and precipitation gradients. The distribution of ecosystem characteristics in modeled climate space reveals widely disparate relationships between modeled climate and vegetation that led to large differences in long-term biosphere-atmosphere fluxes for this region. Model simulations revealed that both the interaction between climate and vegetation and the representation of ecosystem dynamics within models were important controls on biosphere-atmosphere exchange.

A global biogeocenotical biosphere simulation

NASA Technical Reports Server (NTRS)

Moiseyev, N. N.

1980-01-01

This model of the D. Forrester type, constructed in differential equations, predicts the food and mineral supply for the factors biosphere population, depending on two socio-economic factors, until about the year 2500. If contemporary rates of natural resources utilization are maintained and there is no management of the environment, food resources will begin to limit human population growth after 2200, and mineral resources will after 2300. A decrease in the biosphere pollution, increase in effective agricultural production, and discovery of new energy sources may forestall or completely avert the onset of a crisis situation. Conservation measures, according to the model, are to a considerable extent realizable only if carried out simultaneously in both areas.

Assessment of Anthropogenic and Climatic Impacts on the Global Carbon Cycle Using a 3-D Model Constrained by Isotopic Carbon Measurements and Remote Sensing of Vegetation

NASA Technical Reports Server (NTRS)

Keeling, Charles D.; Piper, S. C.

1998-01-01

Our original proposal called for improved modeling of the terrestrial biospheric carbon cycle, specifically using biome-specific process models to account for both the energy and water budgets of plant growth, to facilitate investigations into recent changes in global atmospheric CO2 abundance and regional distribution. The carbon fluxes predicted by these models were to be incorporated into a global model of CO2 transport to establish large-scale regional fluxes of CO2 to and from the terrestrial biosphere subject to constraints imposed by direct measurements of atmospheric CO2 and its 13C/12C isotopic ratio. Our work was coordinated with a NASA project (NASA NAGW-3151) at the University of Montana under the direction of Steven Running, and was partially funded by the Electric Power Research Institute. The primary objective of this project was to develop and test the Biome-BGC model, a global biological process model with a daily time step which simulates the water, energy and carbon budgets of plant growth. The primary product, the unique global gridded daily land temperature, and the precipitation data set which was used to drive the process model is described. The Biome-BGC model was tested by comparison with a simpler biological model driven by satellite-derived (NDVI) Normalized Difference Vegetation Index and (PAR) Photosynthetically Active Radiation data and by comparison with atmospheric CO2 observations. The simple NDVI model is also described. To facilitate the comparison with atmospheric CO2 observations, a three-dimensional atmospheric transport model was used to produce predictions of atmospheric CO2 variations given CO2 fluxes owing to (NPP) Net Primary Productivity and heterotrophic respiration that were produced by the Biome-BGC model and by the NDVI model. The transport model that we used in this project, and errors associated with transport simulations, were characterized by a comparison of 12 transport models.

Land Surface Modeling of an Enclosed Ecosystem: Vegetation Response to Short-Term Perturbations Inside Biosphere 2 Tropical Rainforest Biome

NASA Astrophysics Data System (ADS)

Rosolem, R.; Zeng, X.; Shuttleworth, W. J.; Saleska, S. R.; Huxman, T. E.

2009-12-01

Biosphere 2 (B2) is a large-scale Earth science facility near Tucson (Arizona) that encompasses about 3.15 acres of land and houses five natural biomes. Sealed off to the outside world, B2 allows scientists to exert precise climate and mass balance control at large scales. The tropical rainforest (TRF) mesocosm area is about 1900 sq. meters and contains plant species from different tropical regions. B2 provides a unique controlled laboratory for carrying out experiments to investigate rainforest biome behavior in response to imposed environmental stresses at plot-scales (e.g., temperature, rainfall, humidity, and CO2 levels), providing the missing link between the laboratory scale and the real world. However, lack of repetitions (the facility contains only a single mesocosm for each biome) poses limitations to the analysis of the results. A well-established land surface parameterization scheme (LSP) may overcome this lack of repetitions by providing a reliable assessment of the biome under a variety of conditions. Modeling approaches can also facilitate and improve future experimental designs in B2. Here we challenge a LSP, the Simple Biosphere 3 (SiB3) model, to simulate the main aspects of the biosphere-atmosphere exchanges inside B2-TRF biome. Model simulations include B2-TRF under normal (i.e., operational) conditions, and during short-term perturbations, such as drought conditions and different treatments of CO2 concentration. A hypothetical simulation which combines both drought and high CO2 levels is performed with SiB3 and analyzed on the basis of future predictions of tropical rainforest under climate change. The main objectives of this study is to determine whether or not SiB3 is capable of representing B2-TRF at a wide range of conditions, and if we can use the combination of past field experiments and modeling to improve our understanding on how tropical rainforests may respond to these changes. Results show that our modified version of SiB3 is capable of reproducing the characteristics of B2-TRF remarkably well. Net photosynthesis is reduced quite substantially during drought periods, followed by a recovery period when the biome is re-watered. Increase in CO2 levels tends to enhance net photosynthesis, but soil respiration remains fairly unchanged, similarly to what past B2-TRF studies suggested. When CO2 levels are increased in combination with drought periods (hypothetical experiment), the vegetation response in SiB3 is quite different depending on the available Photosynthetically Active Radiation (PAR). At relatively lower PAR levels, vegetation response to drought conditions is minimal. However, at relatively high PAR, drought effects offset any response to CO2 fertilization. We recognize that the combination of modeling and field experiments is beneficial in both ways, so that advancing of research inside B2 may be expanded to improve in situ experiments as well as future parameterizations in land surface models.

A review of recent research on improvement of physical parameterizations in the GLA GCM

NASA Technical Reports Server (NTRS)

Sud, Y. C.; Walker, G. K.

1990-01-01

A systematic assessment of the effect of a series of improvements in physical parameterizations of the Goddard Laboratory for Atmospheres (GLA) general circulation model (GCM) are summarized. The implementation of the Simple Biosphere Model (SiB) in the GCM is followed by a comparison of SiB GCM simulations with that of the earlier slab soil hydrology GCM (SSH-GCM) simulations. In the Sahelian context, the biogeophysical component of desertification was analyzed for SiB-GCM simulations. Cumulus parameterization is found to be the primary determinant of the organization of the simulated tropical rainfall of the GLA GCM using Arakawa-Schubert cumulus parameterization. A comparison of model simulations with station data revealed excessive shortwave radiation accompanied by excessive drying and heating to the land. The perpetual July simulations with and without interactive soil moisture shows that 30 to 40 day oscillations may be a natural mode of the simulated earth atmosphere system.

A statistical approach for isolating fossil fuel emissions in atmospheric inverse problems

DOE PAGES

Yadav, Vineet; Michalak, Anna M.; Ray, Jaideep; ...

2016-10-27

We study independent verification and quantification of fossil fuel (FF) emissions that constitutes a considerable scientific challenge. By coupling atmospheric observations of CO 2 with models of atmospheric transport, inverse models offer the possibility of overcoming this challenge. However, disaggregating the biospheric and FF flux components of terrestrial fluxes from CO 2 concentration measurements has proven to be difficult, due to observational and modeling limitations. In this study, we propose a statistical inverse modeling scheme for disaggregating winter time fluxes on the basis of their unique error covariances and covariates, where these covariances and covariates are representative of the underlyingmore » processes affecting FF and biospheric fluxes. The application of the method is demonstrated with one synthetic and two real data prototypical inversions by using in situ CO 2 measurements over North America. Also, inversions are performed only for the month of January, as predominance of biospheric CO 2 signal relative to FF CO 2 signal and observational limitations preclude disaggregation of the fluxes in other months. The quality of disaggregation is assessed primarily through examination of a posteriori covariance between disaggregated FF and biospheric fluxes at regional scales. Findings indicate that the proposed method is able to robustly disaggregate fluxes regionally at monthly temporal resolution with a posteriori cross covariance lower than 0.15 µmol m -2 s -1 between FF and biospheric fluxes. Error covariance models and covariates based on temporally varying FF inventory data provide a more robust disaggregation over static proxies (e.g., nightlight intensity and population density). However, the synthetic data case study shows that disaggregation is possible even in absence of detailed temporally varying FF inventory data.« less

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

NASA Astrophysics Data System (ADS)

Miller, Scot M.; Michalak, Anna M.; Yadav, Vineet; Tadić, Jovan M.

2018-05-01

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

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

PubMed

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

2014-09-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thornton, Peter E.; Calvin, Katherine; Jones, Andrew D.

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

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

NASA Astrophysics Data System (ADS)

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 planetary/lunar settlements. The improved health resulting from the calorie-restricted but nutrient dense Biosphere 2 diet was the first such scientifically controlled experiment with humans. The success of Biosphere 2 in creating a diversity of terrestrial and marine environments, from rainforest to coral reef, allowed detailed studies with comprehensive measurements such that the dynamics of these complex biomic systems are now better understood. The coral reef ecosystem, the largest artificial reef ever built, catalyzed methods of study now being applied to planetary coral reef systems. Restoration ecology advanced through the creation and study of the dynamics of adaptation and self-organization of the biomes in Biosphere 2. The international interest that Biosphere 2 generated has given new impetus to the public recognition of the sciences of biospheres (biospherics), biomes and closed ecological life systems. The facility, although no longer a materially-closed ecological system, is being used as an educational facility by Columbia University as an introduction to the study of the biosphere and complex system ecology and for carbon dioxide impacts utilizing the complex ecosystems created in Biosphere '.The many lessons learned from Biosphere 2 are being used by its key team of creators in their design and operation of a laboratory-sized closed ecological system, the Laboratory Biosphere, in operation as of March 2002, and for the design of a Mars on Earth ™ prototype life support system for manned missions to Mars and Mars surface habitats. Biosphere 2 is an important foundation for future advances in biospherics and closed ecological system research.

Forest response to elevated CO2 is conserved across a broad range of productivity

Treesearch

R. Norby; E. DeLucia; B. Gielen; C. Calfapietra; C. Giardina; J. King; J. Ledford; H. McCarthy; D. Moore; R. Ceulemans; P. De Angelis; A. C. Finzi; D. F. Karnosky; M. E. Kubiske; M. Lukac; K. S. Pregitzer; G. E. Scarascia-Mugnozza; W. Schlesinger and R. Oren.

2005-01-01

Climate change predictions derived from coupled carbon-climate models are highly dependent on assumptions about feedbacks between the biosphere and atmosphere. One critical feedback occurs if C uptake by the biosphere increases in response to the fossil-fuel driven increase in atmospheric [CO2] ("CO2 fertilization...

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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.

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

PubMed

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.

The Race for Space: Tracking Land-Cover Transformation in a Socio-ecological Landscape, South Africa

NASA Astrophysics Data System (ADS)

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

2013-09-01

Biosphere Reserves attempt to align existing biodiversity conservation with sustainable resource use, specifically for improving socio-economic circumstances of resident communities. Typically, the Biosphere Reserve model is applied to an established landscape mosaic of existing land uses; these are often socio-ecological systems where strict environmental protection and community livelihoods are in conflict, and environmental degradation frequently accompanies "use". This raises challenges for successful implementation of the model, as the reality of the existing land-use mosaic undermines the theoretical aspirations of the Biosphere concept. This study focuses on the Kruger to Canyons Biosphere Reserve (K2C), South Africa; a socio-ecological landscape where formal conservation is juxtaposed against extensive impoverished rural communities. We focus on land-cover changes of the existing land-use mosaic (1993-2006), specifically selected land-cover classes identified as important for biodiversity conservation and local-level resource utilization. We discuss the implications of transformation for conservation, sustainable resource-use, and K2C's functioning as a "Biosphere Reserve". Spatially, changes radiated outward from the settlement expanse, with little regard for the theoretical land-use zonation of the Biosphere Reserve. Settlement growth tracked transport routes, transforming cohesive areas of communal-use rangelands. Given the interdependencies between the settlement population and local environmental resources, the Impacted Vegetation class expanded accordingly, fragmenting the Intact Vegetation class, and merging rangelands. This has serious implications for sustainability of communal harvesting areas, and further transformation of intact habitat. The distribution and magnitude of Intact Vegetation losses raise concerns around connectivity and edge effects, with long-term consequences for ecological integrity of remnant habitat, and K2C's existing network of protected areas.

Monitoring of environmental UV radiation by biological dosimeters

NASA Astrophysics Data System (ADS)

Rontó, Gy.; Bérces, A.; Gróf, P.; Fekete, A.; Kerékgyártó, T.; Gáspár, S.; Stick, C.

As a consequence of the stratospheric ozone layer depletion biological systems can be damaged due to increased UV-B radiation. The aim of biological dosimetry is to establish a quantitative basis for the risk assessment of the biosphere. DNA is the most important target molecule of biological systems having special sensitivity against short wavelength components of the environmental radiation. Biological dosimeters are usually simple organisms, or components of them, modeling the cellular DNA. Phage T7 and polycrystalline uracil biological dosimeters have been developed and used in our laboratory for monitoring the environmental radiation in different radiation conditions (from the polar to equatorial regions). Comparisons with Robertson-Berger (RB) meter data, as well as with model calculation data weighted by the corresponding spectral sensitivities of the dosimeters are presented. Suggestion is given how to determine the trend of the increase in the biological risk due to ozone depletion.

Land-Atmosphere Interactions: Successes, Problems and Prospects

NASA Technical Reports Server (NTRS)

Sud, Y. C.; Mocko, D. M.

1999-01-01

After two decades of active research, a much better understanding of the broader role of biospheric processes on the local climate has emerged. A surface-albedo increase, particularly in desert border regions of the subtropics (as well as the deforested tropical regions), leads to a net surface energy deficit, which in turn leads to a relative sinking and reduced rainfall. On the other hand, studies of the influence of altered ratios of evapotranspiration and sensible fluxes, in situations where the net solar income is unchanged, show that evapotranspiration is a more desirable flux for increased precipitation and vitality of the biosphere. Besides providing water vapor and convective available potential energy (CAPE) to the lower troposphere, evapotranspiration helps in building larger CAPE before "turning on" the moist-convection. Larger CAPE in the lower troposphere enables convection to reach into the deeper atmosphere thereby heating the upper troposphere; indeed, moist-convection is also accompanied by the evaporation of falling precipitation that cools and moistens the lower atmosphere. While convective, as opposed to stratiform, precipitation reduces the fractional cloud cover; it also allows more solar radiation to reach the surface thereby invigorating surface fluxes. These, together with moist convection and associated downdrafts help to maintain the characteristic upper temperature limit(s) of the moist-land as well as oceanic regions. Regardless of the above understanding, several important problems continue to hinder the accurate simulation of a realistic land atmosphere interaction in a numerical model (both GCM and/or Meso-scale models). Among the unsolved problems are parameterization of sub-grid scale land processes that include small-scale variability of soil moisture, snow-cover and snow-physics, the biodiversity of the biosphere, orography, local drainage characteristics under natural conditions, and surface flow over the natural terrain. A well-known non-linear response of surface fluxes to these variations makes the problem of parameterizing land-atmosphere interaction processes hard-to-address and simulate, particularly in a GCM. In our presentation, we will discuss how orographic, snow-cover, and water table interactions can be included into a Simple Biosphere Model such as SiB/SSiB. Figure I shows how, in the Russian region, spring snowmelt affects the soil moisture profile. Corresponding figure 2 shows how interaction with the water table decreases the natural evapotranspiration in the Sahel region simulation. While these simulations need better validation with data, the simulations reveal that surface processes are sensitive to these parameterizations. With these developments, we continue to advance our understanding of the interaction of land with the atmosphere aloft, but the intrinsic variability of the newer parameters, e. g., hydraulic properties of the soil, diminish the positive influences of these advances on the improved climate simulation with GCMs.

Strategy for modeling putative multilevel ecosystems on Europa.

PubMed

Irwin, Louis N; Schulze-Makuch, Dirk

2003-01-01

A general strategy for modeling ecosystems on other worlds is described. Two alternative biospheres beneath the ice surface of Europa are modeled, based on analogous ecosystems on Earth in potentially comparable habitats, with reallocation of biomass quantities consistent with different sources of energy and chemical constituents. The first ecosystem models a benthic biosphere supported by chemoautotrophic producers. The second models two concentrations of biota at the top and bottom of the subsurface water column supported by energy harvested from transmembrane ionic gradients. Calculations indicate the plausibility of both ecosystems, including small macroorganisms at the highest trophic levels, with ionotrophy supporting a larger biomass than chemoautotrophy.

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

NASA Astrophysics Data System (ADS)

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 health resulting from the calorie-restricted but nutrient dense Biosphere 2 diet was the first such scientifically-controlled experiment with humans. The success of Biosphere in creating a diversity of terrestrial and marine environments, from rainforest to coral reef, allowed detailed studies with comprehensive measurements such that the dynamics of these complex biomic systems can be better understood. The coral reef ecosystem, the largest artificial reef ever built, catalyzed methods of study now being applied to planetary coral reef systems. Restoration ecology can learn much from the creation and dynamics of adaptation of the biomes in Biosphere 2. The international interest that Biosphere 2 generated has given new impetus to the public recognition of the sciences of biospheres, biospherics, biomes and closed ecological life systems. The facility is still being used as an educational facility by Columbia University as an introduction to the study of the biosphere and complex system ecology. The many lessons learned from Biosphere 2, from its successes, surprises and challenges, is being used by its key team of creators as the foundations for their design of a laboratory-sized closed ecological system and Mars on Earth prototype life support system for Mars exploration and can be an important foundation for future advances in biospherics and closed ecological system research.

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

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

PubMed Central

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

Gene expression in the deep biosphere.

PubMed

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.

Community Assembly Processes of the Microbial Rare Biosphere.

PubMed

Jia, Xiu; Dini-Andreote, Francisco; Falcão Salles, Joana

2018-03-14

Our planet teems with microorganisms that often present a skewed abundance distribution in a local community, with relatively few dominant species coexisting alongside a high number of rare species. Recent studies have demonstrated that these rare taxa serve as limitless reservoirs of genetic diversity, and perform disproportionate types of functions despite their low abundances. However, relatively little is known about the mechanisms controlling rarity and the processes promoting the development of the rare biosphere. Here, we propose the use of multivariate cut-offs to estimate rare species and phylogenetic null models applied to predefined rare taxa to disentangle the relative influences of ecoevolutionary processes mediating the assembly of the rare biosphere. Importantly, the identification of the factors controlling rare species assemblages is critical for understanding the types of rarity, how the rare biosphere is established, and how rare microorganisms fluctuate over spatiotemporal scales, thus enabling prospective predictions of ecosystem responses. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Regional CO2 Observing System Simulation Experiment Using ASCENDS Observations and WRF-STILT Footprints

NASA Technical Reports Server (NTRS)

Wang, James S.; Kawa, S. Randolph; Eluszkiewicz, Janusz; Collatz, G. J.; Mountain, Marikate; Henderson, John; Nehrkorn, Thomas; Aschbrenner, Ryan; Zaccheo, T. Scott

2012-01-01

Knowledge of the spatiotemporal variations in emissions and uptake of CO2 is hampered by sparse measurements. The recent advent of satellite measurements of CO2 concentrations is increasing the density of measurements, and the future mission ASCENDS (Active Sensing of CO2 Emissions over Nights, Days and Seasons) will provide even greater coverage and precision. Lagrangian atmospheric transport models run backward in time can quantify surface influences ("footprints") of diverse measurement platforms and are particularly well suited for inverse estimation of regional surface CO2 fluxes at high resolution based on satellite observations. We utilize the STILT Lagrangian particle dispersion model, driven by WRF meteorological fields at 40-km resolution, in a Bayesian synthesis inversion approach to quantify the ability of ASCENDS column CO2 observations to constrain fluxes at high resolution. This study focuses on land-based biospheric fluxes, whose uncertainties are especially large, in a domain encompassing North America. We present results based on realistic input fields for 2007. Pseudo-observation random errors are estimated from backscatter and optical depth measured by the CALIPSO satellite. We estimate a priori flux uncertainties based on output from the CASA-GFED (v.3) biosphere model and make simple assumptions about spatial and temporal error correlations. WRF-STILT footprints are convolved with candidate vertical weighting functions for ASCENDS. We find that at a horizontal flux resolution of 1 degree x 1 degree, ASCENDS observations are potentially able to reduce average weekly flux uncertainties by 0-8% in July, and 0-0.5% in January (assuming an error of 0.5 ppm at the Railroad Valley reference site). Aggregated to coarser resolutions, e.g. 5 degrees x 5 degrees, the uncertainty reductions are larger and more similar to those estimated in previous satellite data observing system simulation experiments.

Aeolian Processes and the Biosphere

NASA Astrophysics Data System (ADS)

Ravi, Sujith; D'Odorico, Paolo; Breshears, David D.; Field, Jason P.; Goudie, Andrew S.; Huxman, Travis E.; Li, Junran; Okin, Gregory S.; Swap, Robert J.; Thomas, Andrew D.; Van Pelt, Scott; Whicker, Jeffrey J.; Zobeck, Ted M.

2011-08-01

Aeolian processes affect the biosphere in a wide variety of contexts, including landform evolution, biogeochemical cycles, regional climate, human health, and desertification. Collectively, research on aeolian processes and the biosphere is developing rapidly in many diverse and specialized areas, but integration of these recent advances is needed to better address management issues and to set future research priorities. Here we review recent literature on aeolian processes and their interactions with the biosphere, focusing on (1) geography of dust emissions, (2) impacts, interactions, and feedbacks, (3) drivers of dust emissions, and (4) methodological approaches. Geographically, dust emissions are highly spatially variable but also provide connectivity at global scales between sources and effects, with “hot spots” being of particular concern. Recent research reveals that aeolian processes have impacts, interactions, and feedbacks at a variety of scales, including large-scale dust transport and global biogeochemical cycles, climate mediated interactions between atmospheric dust and ecosystems, impacts on human health, impacts on agriculture, and interactions between aeolian processes and dryland vegetation. Aeolian dust emissions are driven largely by, in addition to climate, a combination of soil properties, soil moisture, vegetation and roughness, biological and physical crusts, and disturbances. Aeolian research methods span laboratory and field techniques, modeling, and remote sensing. Together these integrated perspectives on aeolian processes and the biosphere provide insights into management options and aid in identifying research priorities, both of which are increasingly important given that global climate models predict an increase in aridity in many dryland systems of the world.

Probabilistic biosphere modeling for the long-term safety assessment of geological disposal facilities for radioactive waste using first- and second-order Monte Carlo simulation.

PubMed

Ciecior, Willy; Röhlig, Klaus-Jürgen; Kirchner, Gerald

2018-10-01

In the present paper, deterministic as well as first- and second-order probabilistic biosphere modeling approaches are compared. Furthermore, the sensitivity of the influence of the probability distribution function shape (empirical distribution functions and fitted lognormal probability functions) representing the aleatory uncertainty (also called variability) of a radioecological model parameter as well as the role of interacting parameters are studied. Differences in the shape of the output distributions for the biosphere dose conversion factor from first-order Monte Carlo uncertainty analysis using empirical and fitted lognormal distribution functions for input parameters suggest that a lognormal approximation is possibly not always an adequate representation of the aleatory uncertainty of a radioecological parameter. Concerning the comparison of the impact of aleatory and epistemic parameter uncertainty on the biosphere dose conversion factor, the latter here is described using uncertain moments (mean, variance) while the distribution itself represents the aleatory uncertainty of the parameter. From the results obtained, the solution space of second-order Monte Carlo simulation is much larger than that from first-order Monte Carlo simulation. Therefore, the influence of epistemic uncertainty of a radioecological parameter on the output result is much larger than that one caused by its aleatory uncertainty. Parameter interactions are only of significant influence in the upper percentiles of the distribution of results as well as only in the region of the upper percentiles of the model parameters. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

PubMed

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. No claim to original US Government works. New Phytologist © 2014 New Phytologist Trust.

The UNESCO biosphere reserve concept as a tool for urban sustainability: the CUBES Cape Town case study.

PubMed

Stanvliet, R; Jackson, J; Davis, G; De Swardt, C; Mokhoele, J; Thom, Q; Lane, B D

2004-06-01

The Cape Town Case Study (CTCS) was a multi-institutional collaborative project initiated by CUBES, a knowledge networking initiative of UNESCO's Ecological Sciences Division and the Earth Institute at Columbia University. Cape Town was selected as a CUBES site on the basis of its high biological and cultural significance, together with its demonstrated leadership in promoting urban sustainability. The CTCS was conducted by the Cape Town Urban Biosphere Group, a cross-disciplinary group of specialists drawn from national, provincial, municipal, and civil society institutions, mandated to examine the potential value of the UNESCO Biosphere Reserve concept as a tool for environmental management, social inclusion, and poverty alleviation in Cape Town. This article provides a contextualization of the CTCS and its collaborative process. It also reviews the biosphere reserve concept relative to urban sustainability objectives and proposes a more functional application of that concept in an urban context. A detailed analysis of key initiatives at the interface of conservation and poverty alleviation is provided in table format. Drawing on an examination of successful sustainability initiatives in Cape Town, specific recommendations are made for future application of the biosphere reserve concept in an urban context, as well as a model by which urban areas might affiliate with the UNESCO World Network of Biosphere Reserves, and criteria for such affiliation.

Large-scale climatic and geophysical controls on the leaf economics spectrum.

PubMed

Asner, Gregory P; Knapp, David E; Anderson, Christopher B; Martin, Roberta E; Vaughn, Nicholas

2016-07-12

Leaf economics spectrum (LES) theory suggests a universal trade-off between resource acquisition and storage strategies in plants, expressed in relationships between foliar nitrogen (N) and phosphorus (P), leaf mass per area (LMA), and photosynthesis. However, how environmental conditions mediate LES trait interrelationships, particularly at large biospheric scales, remains unknown because of a lack of spatially explicit data, which ultimately limits our understanding of ecosystem processes, such as primary productivity and biogeochemical cycles. We used airborne imaging spectroscopy and geospatial modeling to generate, to our knowledge, the first biospheric maps of LES traits, here centered on 76 million ha of Andean and Amazonian forest, to assess climatic and geophysical determinants of LES traits and their interrelationships. Elevation and substrate were codominant drivers of leaf trait distributions. Multiple additional climatic and geophysical factors were secondary determinants of plant traits. Anticorrelations between N and LMA followed general LES theory, but topo-edaphic conditions strongly mediated and, at times, eliminated this classic relationship. We found no evidence for simple P-LMA or N-P trade-offs in forest canopies; rather, we mapped a continuum of N-P-LMA interactions that are sensitive to elevation and temperature. Our results reveal nested climatic and geophysical filtering of LES traits and their interrelationships, with important implications for predictions of forest productivity and acclimation to rapid climate change.

Using observations to evaluate biosphere-atmosphere interactions in models

NASA Astrophysics Data System (ADS)

Green, Julia; Konings, Alexandra G.; Alemohammad, Seyed H.; Gentine, Pierre

2017-04-01

Biosphere-atmosphere interactions influence the hydrologic cycle by altering climate and weather patterns (Charney, 1975; Koster et al., 2006; Seneviratne et al., 2006), contributing up to 30% of precipitation and radiation variability in certain regions (Green et al., 2017). They have been shown to contribute to the persistence of drought in Europe (Seneviratne et al., 2006), as well as to increase rainfall in the Amazon (Spracklen et al., 2012). Thus, a true representation of these feedbacks in Earth System Models (ESMs) is crucial for accurate forecasting and planning. However, it has been difficult to validate the performance of ESMs since often-times surface and atmospheric flux data are scarce and/or difficult to observe. In this study, we use the results of a new global observational study (using remotely sensed solar-induced fluorescence to represent the biosphere flux) (Green et al., 2017) to determine how well a suite of 13 ESMs capture biosphere-atmosphere feedbacks. We perform a Conditional Multivariate Granger Causality analysis in the frequency domain with radiation, precipitation and temperature as atmospheric inputs and GPP as the biospheric input. Performing the analysis in the frequency domain allows for separation of feedbacks at different time-scales (subseasonal, seasonal or interannual). Our findings can be used to determine whether there is agreement between models, as well as, to pinpoint regions or time-scales of model bias or inaccuracy, which will provide insight on potential improvement. We demonstrate that in addition to the well-known problem of convective parameterization over land in models, the main issue in representing feedbacks between the land and the atmosphere is due to the misrepresentation of water stress. These results provide a direct quantitative assessment of feedbacks in models and how to improve them. References: Charney, J.G. Dynamics of deserts and drought in the Sahel. Quarterly Journal of the Royal Meteorological Society 101, 193-202 (1975). Green, J.K., Konings, A.G., Alemohammad, S.H., Berry, J., Entekhabi, D., Kolassa, J., Lee, J.E., Gentine, P. Hotspots of terrestrial biosphere-atmosphere feedbacks. In review. (2017). Koster, R. D. et al. GLACE: The Global Land - Atmosphere Coupling Experiment. Part I: Overview. J. Hydrometeorol. 7, 611-625 (2006). Seneviratne, S.I., Lüthi, D., Litschi M., Schär, C. Land-atmosphere coupling and climate change in Europe. Nature 443, 205-209 (2006). Spracklen, D.V, Arnold, S.R., Taylor, C.M. Observations of increased tropical rainfall preceded by air passage over forests. Nature 489, 282-285 (2012).

An extensive phase space for the potential martian biosphere.

PubMed

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

2011-12-01

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

The interaction of the flux errors and transport errors in modeled atmospheric carbon dioxide concentrations

NASA Astrophysics Data System (ADS)

Feng, S.; Lauvaux, T.; Butler, M. P.; Keller, K.; Davis, K. J.; Jacobson, A. R.; Schuh, A. E.; Basu, S.; Liu, J.; Baker, D.; Crowell, S.; Zhou, Y.; Williams, C. A.

2017-12-01

Regional estimates of biogenic carbon fluxes over North America from top-down atmospheric inversions and terrestrial biogeochemical (or bottom-up) models remain inconsistent at annual and sub-annual time scales. While top-down estimates are impacted by limited atmospheric data, uncertain prior flux estimates and errors in the atmospheric transport models, bottom-up fluxes are affected by uncertain driver data, uncertain model parameters and missing mechanisms across ecosystems. This study quantifies both flux errors and transport errors, and their interaction in the CO2 atmospheric simulation. These errors are assessed by an ensemble approach. The WRF-Chem model is set up with 17 biospheric fluxes from the Multiscale Synthesis and Terrestrial Model Intercomparison Project, CarbonTracker-Near Real Time, and the Simple Biosphere model. The spread of the flux ensemble members represents the flux uncertainty in the modeled CO2 concentrations. For the transport errors, WRF-Chem is run using three physical model configurations with three stochastic perturbations to sample the errors from both the physical parameterizations of the model and the initial conditions. Additionally, the uncertainties from boundary conditions are assessed using four CO2 global inversion models which have assimilated tower and satellite CO2 observations. The error structures are assessed in time and space. The flux ensemble members overall overestimate CO2 concentrations. They also show larger temporal variability than the observations. These results suggest that the flux ensemble is overdispersive. In contrast, the transport ensemble is underdispersive. The averaged spatial distribution of modeled CO2 shows strong positive biogenic signal in the southern US and strong negative signals along the eastern coast of Canada. We hypothesize that the former is caused by the 3-hourly downscaling algorithm from which the nighttime respiration dominates the daytime modeled CO2 signals and that the latter is mainly caused by the large-scale transport associated with the jet stream that carries the negative biogenic CO2 signals to the northeastern coast. We apply comprehensive statistics to eliminate outliers. We generate a set of flux perturbations based on pre-calibrated flux ensemble members and apply them to the simulations.

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

NASA Astrophysics Data System (ADS)

Davies-Barnard, Taraka; Ridgwell, Andy; Singarayer, Joy; Valdes, Paul

2017-10-01

The terrestrial biosphere is thought to be a key component in the climatic variability seen in the palaeo-record. It has a direct impact on surface temperature through changes in surface albedo and evapotranspiration (so-called biogeophysical effects) and, in addition, has an important indirect effect through changes in vegetation and soil carbon storage (biogeochemical effects) and hence modulates the concentrations of greenhouse gases in the atmosphere. The biogeochemical and biogeophysical effects generally have opposite signs, meaning that the terrestrial biosphere could potentially have played only a very minor role in the dynamics of the glacial-interglacial cycles of the late Quaternary. Here we use a fully coupled dynamic atmosphere-ocean-vegetation general circulation model (GCM) to generate a set of 62 equilibrium simulations spanning the last 120 kyr. The analysis of these simulations elucidates the relative importance of the biogeophysical versus biogeochemical terrestrial biosphere interactions with climate. We find that the biogeophysical effects of vegetation account for up to an additional -0.91 °C global mean cooling, with regional cooling as large as -5 °C, but with considerable variability across the glacial-interglacial cycle. By comparison, while opposite in sign, our model estimates of the biogeochemical impacts are substantially smaller in magnitude. Offline simulations show a maximum of +0.33 °C warming due to an increase of 25 ppm above our (pre-industrial) baseline atmospheric CO2 mixing ratio. In contrast to shorter (century) timescale projections of future terrestrial biosphere response where direct and indirect responses may at times cancel out, we find that the biogeophysical effects consistently and strongly dominate the biogeochemical effect over the inter-glacial cycle. On average across the period, the terrestrial biosphere has a -0.26 °C effect on temperature, with -0.58 °C at the Last Glacial Maximum. Depending on assumptions made about the destination of terrestrial carbon under ice sheets and where sea level has changed, the average terrestrial biosphere contribution over the last 120 kyr could be as much as -50 °C and -0.83 °C at the Last Glacial Maximum.

Development of a biosphere hydrological model considering vegetation dynamics and its evaluation at basin scale under climate change

NASA Astrophysics Data System (ADS)

Li, Qiaoling; Ishidaira, Hiroshi

2012-01-01

SummaryThe biosphere and hydrosphere are intrinsically coupled. The scientific question is if there is a substantial change in one component such as vegetation cover, how will the other components such as transpiration and runoff generation respond, especially under climate change conditions? Stand-alone hydrological models have a detailed description of hydrological processes but do not sufficiently parameterize vegetation as a dynamic component. Dynamic global vegetation models (DGVMs) are able to simulate transient structural changes in major vegetation types but do not simulate runoff generation reliably. Therefore, both hydrological models and DGVMs have their limitations as well as advantages for addressing this question. In this study a biosphere hydrological model (LPJH) is developed by coupling a prominent DGVM (Lund-Postdam-Jena model referred to as LPJ) with a stand-alone hydrological model (HYMOD), with the objective of analyzing the role of vegetation in the hydrological processes at basin scale and evaluating the impact of vegetation change on the hydrological processes under climate change. The application and validation of the LPJH model to four basins representing a variety of climate and vegetation conditions shows that the performance of LPJH is much better than that of the original LPJ and is similar to that of stand-alone hydrological models for monthly and daily runoff simulation at the basin scale. It is argued that the LPJH model gives more reasonable hydrological simulation since it considers both the spatial variability of soil moisture and vegetation dynamics, which make the runoff generation mechanism more reliable. As an example, it is shown that changing atmospheric CO 2 content alone would result in runoff increases in humid basins and decreases in arid basins. Theses changes are mainly attributable to changes in transpiration driven by vegetation dynamics, which are not simulated in stand-alone hydrological models. Therefore LPJH potentially provides a powerful tool for simulating vegetation response to climate changes in the biosphere hydrological cycle.

The Aggregate Representation of Terrestrial Land Covers Within Global Climate Models (GCM)

NASA Technical Reports Server (NTRS)

Shuttleworth, W. James; Sorooshian, Soroosh

1996-01-01

This project had four initial objectives: (1) to create a realistic coupled surface-atmosphere model to investigate the aggregate description of heterogeneous surfaces; (2) to develop a simple heuristic model of surface-atmosphere interactions; (3) using the above models, to test aggregation rules for a variety of realistic cover and meteorological conditions; and (4) to reconcile biosphere-atmosphere transfer scheme (BATS) land covers with those that can be recognized from space; Our progress in meeting these objectives can be summarized as follows. Objective 1: The first objective was achieved in the first year of the project by coupling the Biosphere-Atmosphere Transfer Scheme (BATS) with a proven two-dimensional model of the atmospheric boundary layer. The resulting model, BATS-ABL, is described in detail in a Masters thesis and reported in a paper in the Journal of Hydrology Objective 2: The potential value of the heuristic model was re-evaluated early in the project and a decision was made to focus subsequent research around modeling studies with the BATS-ABL model. The value of using such coupled surface-atmosphere models in this research area was further confirmed by the success of the Tucson Aggregation Workshop. Objective 3: There was excellent progress in using the BATS-ABL model to test aggregation rules for a variety of realistic covers. The foci of attention have been the site of the First International Satellite Land Surface Climatology Project Field Experiment (FIFE) in Kansas and one of the study sites of the Anglo-Brazilian Amazonian Climate Observational Study (ABRACOS) near the city of Manaus, Amazonas, Brazil. These two sites were selected because of the ready availability of relevant field data to validate and initiate the BATS-ABL model. The results of these tests are given in a Masters thesis, and reported in two papers. Objective 4: Progress far exceeded original expectations not only in reconciling BATS land covers with those that can be recognized from space, but also in then applying remotely-sensed land cover data to map aggregate values of BATS parameters for heterogeneous covers and interpreting these parameters in terms of surface-atmosphere exchanges.

Towards more accurate isoscapes encouraging results from wine, water and marijuana data/model and model/model comparisons.

NASA Astrophysics Data System (ADS)

West, J. B.; Ehleringer, J. R.; Cerling, T.

2006-12-01

Understanding how the biosphere responds to change it at the heart of biogeochemistry, ecology, and other Earth sciences. The dramatic increase in human population and technological capacity over the past 200 years or so has resulted in numerous, simultaneous changes to biosphere structure and function. This, then, has lead to increased urgency in the scientific community to try to understand how systems have already responded to these changes, and how they might do so in the future. Since all biospheric processes exhibit some patchiness or patterns over space, as well as time, we believe that understanding the dynamic interactions between natural systems and human technological manipulations can be improved if these systems are studied in an explicitly spatial context. We present here results of some of our efforts to model the spatial variation in the stable isotope ratios (δ2H and δ18O) of plants over large spatial extents, and how these spatial model predictions compare to spatially explicit data. Stable isotopes trace and record ecological processes and as such, if modeled correctly over Earth's surface allow us insights into changes in biosphere states and processes across spatial scales. The data-model comparisons show good agreement, in spite of the remaining uncertainties (e.g., plant source water isotopic composition). For example, inter-annual changes in climate are recorded in wine stable isotope ratios. Also, a much simpler model of leaf water enrichment driven with spatially continuous global rasters of precipitation and climate normals largely agrees with complex GCM modeling that includes leaf water δ18O. Our results suggest that modeling plant stable isotope ratios across large spatial extents may be done with reasonable accuracy, including over time. These spatial maps, or isoscapes, can now be utilized to help understand spatially distributed data, as well as to help guide future studies designed to understand ecological change across landscapes.

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

PubMed

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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).

Atmospheric CO2 inversions on the mesoscale using data-driven prior uncertainties: quantification of the European terrestrial CO2 fluxes

NASA Astrophysics Data System (ADS)

Kountouris, Panagiotis; Gerbig, Christoph; Rödenbeck, Christian; Karstens, Ute; Koch, Thomas F.; Heimann, Martin

2018-03-01

Optimized biogenic carbon fluxes for Europe were estimated from high-resolution regional-scale inversions, utilizing atmospheric CO2 measurements at 16 stations for the year 2007. Additional sensitivity tests with different data-driven error structures were performed. As the atmospheric network is rather sparse and consequently contains large spatial gaps, we use a priori biospheric fluxes to further constrain the inversions. The biospheric fluxes were simulated by the Vegetation Photosynthesis and Respiration Model (VPRM) at a resolution of 0.1° and optimized against eddy covariance data. Overall we estimate an a priori uncertainty of 0.54 GtC yr-1 related to the poor spatial representation between the biospheric model and the ecosystem sites. The sink estimated from the atmospheric inversions for the area of Europe (as represented in the model domain) ranges between 0.23 and 0.38 GtC yr-1 (0.39 and 0.71 GtC yr-1 up-scaled to geographical Europe). This is within the range of posterior flux uncertainty estimates of previous studies using ground-based observations.

Constraints on natural global atmospheric CO2 fluxes from 1860 to 2010 using a simplified explicit forward model

PubMed Central

Hellevang, Helge; Aagaard, Per

2015-01-01

Land-use changes until the beginning of the 20th century made the terrestrial biosphere a net source of atmospheric carbon. Later, burning of fossil fuel surpassed land use changes as the major anthropogenic source of carbon. The terrestrial biosphere is at present suggested to be a carbon sink, but the distribution of excess anthropogenic carbon to the ocean and biosphere sinks is highly uncertain. Our modeling suggest that land-use changes can be tracked quite well by the carbon isotopes until mid-20th century, whereas burning of fossil fuel dominates the present-day observed changes in the isotope signature. The modeling indicates that the global carbon isotope fractionation has not changed significantly during the last 150 years. Furthermore, increased uptake of carbon by the ocean and increasing temperatures does not yet appear to have resulted in increasing the global gross ocean-to-atmosphere carbon fluxes. This may however change in the future when the excess carbon will emerge in the ocean upwelling zones, possibly reducing the net-uptake of carbon compared to the present-day ocean. PMID:26611741

[Is there a connection between biodiversity and the greenhouse effect].

PubMed

Rozanov, S I

1998-01-01

It was discussed the role of biodiversity in ecosystems capacity to control CO2 in atmosphere as the main reason not only of "greenhouse effect" but "greenhouse catastrophe". The necessity to perfect the preventive measures has been defined by time factor. This time may be so little for completing the evolution theory and models of biosphere management. The temps of contemporaneous species extinction exceed two orders as minimum ones how it has been known from planet history. It doesn't permit to discharge that evolutional process will be successful to create organisms which have been capable to stabilize biosphere in conditions of its changing status. It's possible that such change may be provocated with the crisis in civilization-biosphere interrelations.

Egoistic, altruistic, and biospheric environmental concerns: a path analytic investigation of their determinants.

PubMed

Swami, Viren; Chamorro-Premuzic, Tomas; Snelgar, Rosemary; Furnham, Adrian

2010-04-01

Previous studies have shown that environmental concerns (ECs) can be reduced to a three-factor model - comprising altruistic, biospheric, and egoistic concerns - but there have been few studies examining individual difference predictors of ECs. In this study with 203 individuals from a British community sample, we show that biospheric concern was significantly associated with participants' age, political orientation, Machiavellianism, and the Big Five personality traits of Agreeableness, Emotional Stability, and Conscientiousness. Altruistic concern was significantly associated with sex, age, political orientation, and Machiavellianism, but not the Big Five traits, whereas egoistic concern was not significantly associated with any of these predictors except sex. These results are discussed in relation to previous work on ECs and pro-environmental behavior.

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

NASA Astrophysics Data System (ADS)

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

2010-07-01

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

Benthic δ13C stacks: Metrics for deglacial changes in deep ocean carbon storage and the terrestrial biosphere

NASA Astrophysics Data System (ADS)

Peterson, C.; Lisiecki, L. E.

2016-12-01

Across the deglaciation, atmospheric CO2 and global temperatures rise while the deep ocean ventilates carbon to the atmosphere and terrestrial biosphere. As the terrestrial biosphere expands, the mean global ocean δ13C signature increases in response. How well constrained is the global mean benthic δ13C from 20-6 ka? Are the atmosphere and terrestrial biosphere signals in benthic δ13C coupled across the deglaciation? Improved understanding of deglacial carbon cycle interactions can help close the gap between data-based and model-based estimates of global mean benthic δ13C and deep ocean carbon storage changes. Here we present a 118-record compilation of Cibicides wuellerstorfi δ13C time series that span 20-6 kyr. The δ13C records with a resolution better than 3 kyr and gaps between data smaller than 4 kyr are aligned to age models that are constrained by planktic 14C ages (Stern and Lisiecki, 2014). The δ13C records are stacked within nine regions. Then these regional stacks are combined using volume-weighted averages to create intermediate, deep and whole ocean δ13C stacks. The δ13C gradient between the intermediate and deep stacks covaries with atmospheric CO2 change. Meanwhile the deglacial global ocean mean δ13C rise tracks the expansion of the global terrestrial biosphere from 19-6 ka. From this volume-weighted global δ13C stack, the LGM-Holocene mean δ13C change is 0.35±0.10‰ similar to previous estimates (Curry et al., 1988; Duplessy et al., 1988; Peterson et al., 2015; Gebbie et al., 2015). The δ13C stacks and this 4D δ13C compilation are ideal for model-data comparisons and time-stepping 3D visualizations.

A first-order analysis of the potential role of CO2 fertilization to affect the global carbon budget: A comparison of four terrestrial biosphere models

USGS Publications Warehouse

Kicklighter, D.W.; Bruno, M.; Donges, S.; Esser, G.; Heimann, Martin; Helfrich, J.; Ift, F.; Joos, F.; Kaduk, J.; Kohlmaier, G.H.; McGuire, A.D.; Melillo, J.M.; Meyer, R.; Moore, B.; Nadler, A.; Prentice, I.C.; Sauf, W.; Schloss, A.L.; Sitch, S.; Wittenberg, U.; Wurth, G.

1999-01-01

We compared the simulated responses of net primary production, heterotrophic respiration, net ecosystem production and carbon storage in natural terrestrial ecosystems to historical (1765 to 1990) and projected (1990 to 2300) changes of atmospheric CO2 concentration of four terrestrial biosphere models: the Bern model, the Frankfurt Biosphere Model (FBM), the High-Resolution Biosphere Model (HRBM) and the Terrestrial Ecosystem Model (TEM). The results of the model intercomparison suggest that CO2 fertilization of natural terrestrial vegetation has the potential to account for a large fraction of the so-called 'missing carbon sink' of 2.0 Pg C in 1990. Estimates of this potential are reduced when the models incorporate the concept that CO2 fertilization can be limited by nutrient availability. Although the model estimates differ on the potential size (126 to 461 Pg C) of the future terrestrial sink caused by CO2 fertilization, the results of the four models suggest that natural terrestrial ecosystems will have a limited capacity to act as a sink of atmospheric CO2 in the future as a result of physiological constraints and nutrient constraints on NPP. All the spatially explicit models estimate a carbon sink in both tropical and northern temperate regions, but the strength of these sinks varies over time. Differences in the simulated response of terrestrial ecosystems to CO2 fertilization among the models in this intercomparison study reflect the fact that the models have highlighted different aspects of the effect of CO2 fertilization on carbon dynamics of natural terrestrial ecosystems including feedback mechanisms. As interactions with nitrogen fertilization, climate change and forest regrowth may play an important role in simulating the response of terrestrial ecosystems to CO2 fertilization, these factors should be included in future analyses. Improvements in spatially explicit data sets, whole-ecosystems experiments and the availability of net carbon exchange measurements across the globe will also help to improve future evaluations of the role of CO2 fertilization on terrestrial carbon storage.

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

NASA Astrophysics Data System (ADS)

Beech, Martin

2011-12-01

A brief review of the threat posed to Earth's biosphere via near-by supernova detonations is presented. The expected radiation dosage, cosmic ray flux and expanding blast wave collision effects are considered, and it is argued that a typical supernova must be closer than ˜10-pc before any appreciable and potentially harmful atmosphere/biosphere effects are likely to occur. In contrast, the critical distance for Gamma-ray bursts is of order 1-kpc. In spite of the high energy effects potentially involved, the geological record provides no clear-cut evidence for any historic supernova induced mass extinctions and/or strong climate change episodes. This, however, is mostly a reflection of their being numerous possible (terrestrial and astronomical) forcing mechanisms acting upon the biosphere and the difficulty of distinguishing between competing scenarios. Key to resolving this situation, it is suggested, is the development of supernova specific extinction and climate change linked ecological models. Moving to the future, we estimate that over the remaining lifetime of the biosphere (˜2 Gyr) the Earth might experience 1 GRB and 20 supernova detonations within their respective harmful threat ranges. There are currently at least 12 potential pre-supernova systems within 1-kpc of the Sun. Of these systems IK Pegasi is the closest Type Ia pre-supernova candidate and Betelgeuse is the closest potential Type II supernova candidate. We review in some detail the past, present and future behavior of these two systems. Developing a detailed evolutionary model we find that IK Pegasi will likely not detonate until some 1.9 billion years hence, and that it affords absolutely no threat to Earth's biosphere. Betelgeuse is the closest, reasonably well understood, pre-supernova candidate to the Sun at the present epoch, and may undergo detonation any time within the next several million years. The stand-off distance of Betelgeuse at the time of its detonation is estimated to fall between 150 and 300-pc—again, affording no possible threat to Earth's biosphere. Temporally, the next most likely, close, potential Type Ic supernova to the Sun is the Wolf-Rayet star within the γ 2 Velorum binary system located at least 260-pc away. It is suggested that evidence relating to large-scale astroengineering projects might fruitfully be looked for in those regions located within 10 to 30-pc of any pre-supernova candidate system.

Biospheric Monitoring and Ecological Forecasting using EOS/MODIS data, ecosystem modeling, planning and scheduling technologies

NASA Astrophysics Data System (ADS)

Nemani, R. R.; Votava, P.; Golden, K.; Hashimoto, H.; Jolly, M.; White, M.; Running, S.; Coughlan, J.

2003-12-01

The latest generation of NASA Earth Observing System satellites has brought a new dimension to continuous monitoring of the living part of the Earth System, the Biosphere. EOS data can now provide weekly global measures of vegetation productivity and ocean chlorophyll, and many related biophysical factors such as land cover changes or snowmelt rates. However, information with the highest economic value would be forecasting impending conditions of the biosphere that would allow advanced decision-making to mitigate dangers, or exploit positive trends. We have developed a software system called the Terrestrial Observation and Prediction System (TOPS) to facilitate rapid analysis of ecosystem states/functions by integrating EOS data with ecosystem models, surface weather observations and weather/climate forecasts. Land products from MODIS (Moderate Resolution Imaging Spectroradiometer) including land cover, albedo, snow, surface temperature, leaf area index are ingested into TOPS for parameterization of models and for verifying model outputs such as snow cover and vegetation phenology. TOPS is programmed to gather data from observing networks such as USDA soil moisture, AMERIFLUX, SNOWTEL to further enhance model predictions. Key technologies enabling TOPS implementation include the ability to understand and process heterogeneous-distributed data sets, automated planning and execution of ecosystem models, causation analysis for understanding model outputs. Current TOPS implementations at local (vineyard) to global scales (global net primary production) can be found at http://www.ntsg.umt.edu/tops.

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

PubMed Central

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

2013-01-01

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 ([14C]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 × 105 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. PMID:23530229

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

PubMed

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

2013-04-09

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.

Strong regional atmospheric 14C signature of respired CO 2 observed from a tall tower over the midwestern United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaFranchi, B. W.; McFarlane, K. J.; Miller, J. B.

Radiocarbon in CO 2 ( 14CO 2) measurements can aid in discriminating between fast (<1 year) and slower (>5–10 years) cycling of C between the atmosphere and the terrestrial biosphere due to the 14C disequilibrium between atmospheric and terrestrial C. However, 14CO 2 in the atmosphere is typically much more strongly impacted by fossil fuel emissions of CO 2, and, thus, observations often provide little additional constraints on respiratory flux estimates at regional scales. Here we describe a data set of 14CO 2 observations from a tall tower in northern Wisconsin (USA) where fossil fuel influence is far enough removedmore » that during the summer months, the biospheric component of the 14CO 2 budget dominates. We find that the terrestrial biosphere is responsible for a significant contribution to 14CO 2 that is 2–3 times higher than predicted by the Carnegie-Ames-Stanford approach terrestrial ecosystem model for observations made in 2010. This likely includes a substantial contribution from the North American boreal ecoregion, but transported biospheric emissions from outside the model domain cannot be ruled out. The 14CO 2 enhancement also appears somewhat decreased in observations made over subsequent years, suggesting that 2010 may be anomalous. Furthermore, with these caveats acknowledged, we discuss the implications of the observation/model comparison in terms of possible systematic biases in the model versus short-term anomalies in the observations. Going forward, this isotopic signal could be exploited as an important indicator to better constrain both the long-term carbon balance of terrestrial ecosystems and the short-term impact of disturbance-based loss of carbon to the atmosphere.« less

Strong regional atmospheric 14C signature of respired CO 2 observed from a tall tower over the midwestern United States

DOE PAGES

LaFranchi, B. W.; McFarlane, K. J.; Miller, J. B.; ...

2016-08-31

Radiocarbon in CO 2 ( 14CO 2) measurements can aid in discriminating between fast (<1 year) and slower (>5–10 years) cycling of C between the atmosphere and the terrestrial biosphere due to the 14C disequilibrium between atmospheric and terrestrial C. However, 14CO 2 in the atmosphere is typically much more strongly impacted by fossil fuel emissions of CO 2, and, thus, observations often provide little additional constraints on respiratory flux estimates at regional scales. Here we describe a data set of 14CO 2 observations from a tall tower in northern Wisconsin (USA) where fossil fuel influence is far enough removedmore » that during the summer months, the biospheric component of the 14CO 2 budget dominates. We find that the terrestrial biosphere is responsible for a significant contribution to 14CO 2 that is 2–3 times higher than predicted by the Carnegie-Ames-Stanford approach terrestrial ecosystem model for observations made in 2010. This likely includes a substantial contribution from the North American boreal ecoregion, but transported biospheric emissions from outside the model domain cannot be ruled out. The 14CO 2 enhancement also appears somewhat decreased in observations made over subsequent years, suggesting that 2010 may be anomalous. Furthermore, with these caveats acknowledged, we discuss the implications of the observation/model comparison in terms of possible systematic biases in the model versus short-term anomalies in the observations. Going forward, this isotopic signal could be exploited as an important indicator to better constrain both the long-term carbon balance of terrestrial ecosystems and the short-term impact of disturbance-based loss of carbon to the atmosphere.« less

Strong regional atmospheric 14C signature of respired CO2 observed from a tall tower over the midwestern United States

NASA Astrophysics Data System (ADS)

LaFranchi, B. W.; McFarlane, K. J.; Miller, J. B.; Lehman, S. J.; Phillips, C. L.; Andrews, A. E.; Tans, P. P.; Chen, H.; Liu, Z.; Turnbull, J. C.; Xu, X.; Guilderson, T. P.

2016-08-01

Radiocarbon in CO2 (14CO2) measurements can aid in discriminating between fast (<1 year) and slower (>5-10 years) cycling of C between the atmosphere and the terrestrial biosphere due to the 14C disequilibrium between atmospheric and terrestrial C. However, 14CO2 in the atmosphere is typically much more strongly impacted by fossil fuel emissions of CO2, and, thus, observations often provide little additional constraints on respiratory flux estimates at regional scales. Here we describe a data set of 14CO2 observations from a tall tower in northern Wisconsin (USA) where fossil fuel influence is far enough removed that during the summer months, the biospheric component of the 14CO2 budget dominates. We find that the terrestrial biosphere is responsible for a significant contribution to 14CO2 that is 2-3 times higher than predicted by the Carnegie-Ames-Stanford approach terrestrial ecosystem model for observations made in 2010. This likely includes a substantial contribution from the North American boreal ecoregion, but transported biospheric emissions from outside the model domain cannot be ruled out. The 14CO2 enhancement also appears somewhat decreased in observations made over subsequent years, suggesting that 2010 may be anomalous. With these caveats acknowledged, we discuss the implications of the observation/model comparison in terms of possible systematic biases in the model versus short-term anomalies in the observations. Going forward, this isotopic signal could be exploited as an important indicator to better constrain both the long-term carbon balance of terrestrial ecosystems and the short-term impact of disturbance-based loss of carbon to the atmosphere.

An international land-biosphere model benchmarking activity for the IPCC Fifth Assessment Report (AR5)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, Forrest M; Randerson, James T; Thornton, Peter E

2009-12-01

The need to capture important climate feedbacks in general circulation models (GCMs) has resulted in efforts to include atmospheric chemistry and land and ocean biogeochemistry into the next generation of production climate models, called Earth System Models (ESMs). While many terrestrial and ocean carbon models have been coupled to GCMs, recent work has shown that such models can yield a wide range of results (Friedlingstein et al., 2006). This work suggests that a more rigorous set of global offline and partially coupled experiments, along with detailed analyses of processes and comparisons with measurements, are needed. The Carbon-Land Model Intercomparison Projectmore » (C-LAMP) was designed to meet this need by providing a simulation protocol and model performance metrics based upon comparisons against best-available satellite- and ground-based measurements (Hoffman et al., 2007). Recently, a similar effort in Europe, called the International Land Model Benchmark (ILAMB) Project, was begun to assess the performance of European land surface models. These two projects will now serve as prototypes for a proposed international land-biosphere model benchmarking activity for those models participating in the IPCC Fifth Assessment Report (AR5). Initially used for model validation for terrestrial biogeochemistry models in the NCAR Community Land Model (CLM), C-LAMP incorporates a simulation protocol for both offline and partially coupled simulations using a prescribed historical trajectory of atmospheric CO2 concentrations. Models are confronted with data through comparisons against AmeriFlux site measurements, MODIS satellite observations, NOAA Globalview flask records, TRANSCOM inversions, and Free Air CO2 Enrichment (FACE) site measurements. Both sets of experiments have been performed using two different terrestrial biogeochemistry modules coupled to the CLM version 3 in the Community Climate System Model version 3 (CCSM3): the CASA model of Fung, et al., and the carbon-nitrogen (CN) model of Thornton. Comparisons of the CLM3 offline results against observational datasets have been performed and are described in Randerson et al. (2009). CLM version 4 has been evaluated using C-LAMP, showing improvement in many of the metrics. Efforts are now underway to initiate a Nitrogen-Land Model Intercomparison Project (N-LAMP) to better constrain the effects of the nitrogen cycle in biosphere models. Presented will be new results from C-LAMP for CLM4, initial N-LAMP developments, and the proposed land-biosphere model benchmarking activity.« less

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

PubMed

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.

Evaluation of Terrestrial Carbon Cycle with the Land Use Harmonization Dataset

NASA Astrophysics Data System (ADS)

Sasai, T.; Nemani, R. R.

2017-12-01

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

Biospheric energization and stability

NASA Astrophysics Data System (ADS)

Budding, E.; Ozel, M. E.; Gunduz, G.

2013-09-01

We utilize the physical properties of a hypothetical molecular schema giving rise to an autocatalytic biosphere. A key concept is the driving of terrestrial life as a parametric oscillation: i.e. that the biosphere behaves fundamentally as an oscillatory system into which solar energy is diurnally deposited. The schema, containing 'A, B and C' type components acting together in a 'bottom-up' driving mechanism, underlies all biospheric superstructure. Surviving modes of the oscillation are consistent with Darwinian organization, or hierarchical structures appearing to have top-down propagation through the growth of cellular replication. The model was detailed by Budding et al (2012), where experimental support from the work of Powner et al (2009) is presented, as well as suggestions on supportive fossil evidence. Although the growth in total energization is very slow in this model, it is important to notice its exponential character, suggestive of potential instability. The model is applicable to generally expectable processes on planets, including zonal segregation, complexity growth and Haeckel's biogenic principle within surviving life-forms. Fermi's exobiological paradox can be resolved in terms of the exponential growth and low L solutions of Drake's equation. Feasible values for the particular growth of selected species (the human one in herelevent terrestrial case) allow for L to be less than a few  100 y, recalling Rees' (2004) 'final century' discussion. This arises when the species' disposable energization attains a value comparable to that of the total available daily driving energy. At that point, accidental, or stochastic disturbances of this species' energy ("error") can significantly disrupt the daily driving mechanism.

Carbon isotope discrimination of arctic and boreal biomes inferred from remote atmospheric measurements and a biosphere-atmosphere model

NASA Astrophysics Data System (ADS)

Randerson, J. T.; Still, C. J.; Ballé, J. J.; Fung, I. Y.; Doney, S. C.; Tans, P. P.; Conway, T. J.; White, J. W. C.; Vaughn, B.; Suits, N.; Denning, A. S.

2002-07-01

Estimating discrimination against 13C during photosynthesis at landscape, regional, and biome scales is difficult because of large-scale variability in plant stress, vegetation composition, and photosynthetic pathway. Here we present estimates of 13C discrimination for northern biomes based on a biosphere-atmosphere model and on National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostics Laboratory and Institute of Arctic and Alpine Research remote flask measurements. With our inversion approach, we solved for three ecophysiological parameters of the northern biosphere (13C discrimination, a net primary production light use efficiency, and a temperature sensitivity of heterotrophic respiration (a Q10 factor)) that provided a best fit between modeled and observed δ13C and CO2. In our analysis we attempted to explicitly correct for fossil fuel emissions, remote C4 ecosystem fluxes, ocean exchange, and isotopic disequilibria of terrestrial heterotrophic respiration caused by the Suess effect. We obtained a photosynthetic discrimination for arctic and boreal biomes between 19.0 and 19.6‰. Our inversion analysis suggests that Q10 and light use efficiency values that minimize the cost function covary. The optimal light use efficiency was 0.47 gC MJ-1 photosynthetically active radiation, and the optimal Q10 value was 1.52. Fossil fuel and ocean exchange contributed proportionally more to month-to-month changes in the atmospheric growth rate of δ13C and CO2 during winter months, suggesting that remote atmospheric observations during the summer may yield more precise estimates of the isotopic composition of the biosphere.

Potentials for Soil Enzyme as Indicators of Ecological Management

NASA Technical Reports Server (NTRS)

Senwo, Z. N.; Manu, A.; Coleman, T. L.

1997-01-01

Activity measurements of selected soil enzymes (cellulase, glucosidase, amidohydrolase, phosphatase, arylsulfatase) involved in carbon, nitrogen, phosphorus, and sulfur cycling in the biosphere, hold potential as early and sensitive indicators of soil ecological stress and restoration, These measurements are advantageous because the procedures are simple, rapid, and reproducible over time. Enzyme activities are sensitive to short-term changes in soil and kind-use management. Enzyme activities have also been observed to be closely related to soil organic matter proposed as an index of soil quality.

Multi-site assimilation of a terrestrial biosphere model (BETHY) using satellite derived soil moisture data

NASA Astrophysics Data System (ADS)

Wu, Mousong; Sholze, Marko

2017-04-01

We investigated the importance of soil moisture data on assimilation of a terrestrial biosphere model (BETHY) for a long time period from 2010 to 2015. Totally, 101 parameters related to carbon turnover, soil respiration, as well as soil texture were selected for optimization within a carbon cycle data assimilation system (CCDAS). Soil moisture data from Soil Moisture and Ocean Salinity (SMOS) product was derived for 10 sites representing different plant function types (PFTs) as well as different climate zones. Uncertainty of SMOS soil moisture data was also estimated using triple collocation analysis (TCA) method by comparing with ASCAT dataset and BETHY forward simulation results. Assimilation of soil moisture to the system improved soil moisture as well as net primary productivity(NPP) and net ecosystem productivity (NEP) when compared with soil moisture derived from in-situ measurements and fluxnet datasets. Parameter uncertainties were largely reduced relatively to prior values. Using SMOS soil moisture data for assimilation of a terrestrial biosphere model proved to be an efficient approach in reducing uncertainty in ecosystem fluxes simulation. It could be further used in regional an global assimilation work to constrain carbon dioxide concentration simulation by combining with other sources of measurements.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thornton, Peter E.; Calvin, Katherine; Jones, Andrew D.

Fossil fuel combustion and land-use change are the two largest contributors to industrial-era increases in atmospheric CO 2 concentration. Projections of these are thus fundamental inputs for coupled Earth system models (ESMs) used to estimate the physical and biological consequences of future climate system forcing. While historical datasets are available to inform past and current climate analyses, assessments of future climate change have relied on projections of energy and land use from energy economic models, constrained by assumptions about future policy, land-use patterns, and socio-economic development trajectories. We show that the climatic impacts on land ecosystems drives significant feedbacks inmore » energy, agriculture, land-use, and carbon cycle projections for the 21st century. We also find that exposure of human appropriated land ecosystem productivity to biospheric change results in reductions of land area used for crops; increases in managed forest area and carbon stocks; decreases in global crop prices; and reduction in fossil fuel emissions for a low-mid range forcing scenario. Furthermore, the feedbacks between climate-induced biospheric change and human system forcings to the climate system demonstrated here are handled inconsistently, or excluded altogether, in the one-way asynchronous coupling of energy economic models to ESMs used to date.« less

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

NASA Astrophysics Data System (ADS)

Thornton, Peter E.; Calvin, Katherine; Jones, Andrew D.; di Vittorio, Alan V.; Bond-Lamberty, Ben; Chini, Louise; Shi, Xiaoying; Mao, Jiafu; Collins, William D.; Edmonds, Jae; Thomson, Allison; Truesdale, John; Craig, Anthony; Branstetter, Marcia L.; Hurtt, George

2017-07-01

Fossil fuel combustion and land-use change are the two largest contributors to industrial-era increases in atmospheric CO 2 concentration. Projections of these are thus fundamental inputs for coupled Earth system models (ESMs) used to estimate the physical and biological consequences of future climate system forcing. While historical data sets are available to inform past and current climate analyses, assessments of future climate change have relied on projections of energy and land use from energy-economic models, constrained by assumptions about future policy, land-use patterns and socio-economic development trajectories. Here we show that the climatic impacts on land ecosystems drive significant feedbacks in energy, agriculture, land use and carbon cycle projections for the twenty-first century. We find that exposure of human-appropriated land ecosystem productivity to biospheric change results in reductions of land area used for crops; increases in managed forest area and carbon stocks; decreases in global crop prices; and reduction in fossil fuel emissions for a low-mid-range forcing scenario. The feedbacks between climate-induced biospheric change and human system forcings to the climate system--demonstrated here--are handled inconsistently, or excluded altogether, in the one-way asynchronous coupling of energy-economic models to ESMs used to date.

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

DOE PAGES

Thornton, Peter E.; Calvin, Katherine; Jones, Andrew D.; ...

2017-06-12

Fossil fuel combustion and land-use change are the two largest contributors to industrial-era increases in atmospheric CO 2 concentration. Projections of these are thus fundamental inputs for coupled Earth system models (ESMs) used to estimate the physical and biological consequences of future climate system forcing. While historical datasets are available to inform past and current climate analyses, assessments of future climate change have relied on projections of energy and land use from energy economic models, constrained by assumptions about future policy, land-use patterns, and socio-economic development trajectories. We show that the climatic impacts on land ecosystems drives significant feedbacks inmore » energy, agriculture, land-use, and carbon cycle projections for the 21st century. We also find that exposure of human appropriated land ecosystem productivity to biospheric change results in reductions of land area used for crops; increases in managed forest area and carbon stocks; decreases in global crop prices; and reduction in fossil fuel emissions for a low-mid range forcing scenario. Furthermore, the feedbacks between climate-induced biospheric change and human system forcings to the climate system demonstrated here are handled inconsistently, or excluded altogether, in the one-way asynchronous coupling of energy economic models to ESMs used to date.« less

A New Canopy Integration Factor

NASA Astrophysics Data System (ADS)

Badgley, G.; Anderegg, L. D. L.; Baker, I. T.; Berry, J. A.

2017-12-01

Ecosystem modelers have long debated how to best represent within-canopy heterogeneity. Can one big leaf represent the full range of canopy physiological responses? Or you need two leaves - sun and shade - to get things right? Is it sufficient to treat the canopy as a diffuse medium? Or would it be better to explicitly represent separate canopy layers? These are open questions that have been subject of an enormous amount of research and scrutiny. Yet regardless of how the canopy is represented, each model must grapple with correctly parameterizing its canopy in a way that properly translates leaf-level processes to the canopy and ecosystem scale. We present a new approach for integrating whole-canopy biochemistry by combining remote sensing with ecological theory. Using the Simple Biosphere model (SiB), we redefined how SiB scales photosynthetic processes from leaf-to-canopy as a function of satellite-derived measurements of solar-induced chlorophyll fluorescence (SIF). Across multiple long-term study sites, our approach improves the accuracy of daily modeled photosynthesis by as much as 25 percent. We share additional insights on how SIF might be more directly integrated into photosynthesis models, as well as present ideas for harnessing SIF to more accurately parameterize canopy biochemical variables.

Toward “optimal” integration of terrestrial biosphere models

DOE PAGES

Schwalm, Christopher R.; Huntzinger, Deborah N.; Fisher, Joshua B.; ...

2015-06-10

Multimodel ensembles (MME) are commonplace in Earth system modeling. Here we perform MME integration using a 10-member ensemble of terrestrial biosphere models (TBMs) from the Multiscale synthesis and Terrestrial Model Intercomparison Project (MsTMIP). We contrast optimal (skill based for present-day carbon cycling) versus naive (one model-one vote) integration. MsTMIP optimal and naive mean land sink strength estimates (-1.16 versus -1.15 Pg C per annum respectively) are statistically indistinguishable. This holds also for grid cell values and extends to gross uptake, biomass, and net ecosystem productivity. TBM skill is similarly indistinguishable. The added complexity of skill-based integration does not materially changemore » MME values. This suggests that carbon metabolism has predictability limits and/or that all models and references are misspecified. Finally, resolving this issue requires addressing specific uncertainty types (initial conditions, structure, and references) and a change in model development paradigms currently dominant in the TBM community.« less

A regional high-resolution carbon flux inversion of North America for 2004

NASA Astrophysics Data System (ADS)

Schuh, A. E.; Denning, A. S.; Corbin, K. D.; Baker, I. T.; Uliasz, M.; Parazoo, N.; Andrews, A. E.; Worthy, D. E. J.

2010-05-01

Resolving the discrepancies between NEE estimates based upon (1) ground studies and (2) atmospheric inversion results, demands increasingly sophisticated techniques. In this paper we present a high-resolution inversion based upon a regional meteorology model (RAMS) and an underlying biosphere (SiB3) model, both running on an identical 40 km grid over most of North America. Current operational systems like CarbonTracker as well as many previous global inversions including the Transcom suite of inversions have utilized inversion regions formed by collapsing biome-similar grid cells into larger aggregated regions. An extreme example of this might be where corrections to NEE imposed on forested regions on the east coast of the United States might be the same as that imposed on forests on the west coast of the United States while, in reality, there likely exist subtle differences in the two areas, both natural and anthropogenic. Our current inversion framework utilizes a combination of previously employed inversion techniques while allowing carbon flux corrections to be biome independent. Temporally and spatially high-resolution results utilizing biome-independent corrections provide insight into carbon dynamics in North America. In particular, we analyze hourly CO2 mixing ratio data from a sparse network of eight towers in North America for 2004. A prior estimate of carbon fluxes due to Gross Primary Productivity (GPP) and Ecosystem Respiration (ER) is constructed from the SiB3 biosphere model on a 40 km grid. A combination of transport from the RAMS and the Parameterized Chemical Transport Model (PCTM) models is used to forge a connection between upwind biosphere fluxes and downwind observed CO2 mixing ratio data. A Kalman filter procedure is used to estimate weekly corrections to biosphere fluxes based upon observed CO2. RMSE-weighted annual NEE estimates, over an ensemble of potential inversion parameter sets, show a mean estimate 0.57 Pg/yr sink in North America. We perform the inversion with two independently derived boundary inflow conditions and calculate jackknife-based statistics to test the robustness of the model results. We then compare final results to estimates obtained from the CarbonTracker inversion system and at the Southern Great Plains flux site. Results are promising, showing the ability to correct carbon fluxes from the biosphere models over annual and seasonal time scales, as well as over the different GPP and ER components. Additionally, the correlation of an estimated sink of carbon in the South Central United States with regional anomalously high precipitation in an area of managed agricultural and forest lands provides interesting hypotheses for future work.

The Modern Era of Research in Biosphere Atmosphere Interactions

NASA Astrophysics Data System (ADS)

Fung, I. Y.; Sellers, P. J.; Randall, D. A.; Tucker, C. J.; Field, C. B.; Berry, J. A.; Ustin, S.

2015-12-01

Dr. Diane Wickland, the Program Scientist for NASA's EOS InterDisciplinary Science (IDS), encouraged and nurtured the growth of the field of global ecology and eco-climatology. This talk reviews the developments in, and integration of, theory, satellite and field observations that enabled the global modeling of biosphere-atmosphere interactions. Emphasis will be placed on the advances made during the EOS era in global datasets and global coupled carbon-climate models. The advances include functional classifications of the land surface using the NDVI, a global terrestrial carbon-energy-water model, and the greening of the CSU GCM. An equally important achievement of the EOS-IDS program is a new generation of multi-disciplinary scientists who are now leaders in the field.

NASA's Carbon Monitoring System Flux-Pilot Project: A Multi-Component Analysis System for Carbon-Cycle Research and Monitoring

NASA Technical Reports Server (NTRS)

Pawson, S.; Gunson, M.; Potter, C.; Jucks, K.

2012-01-01

The importance of greenhouse gas increases for climate motivates NASA s observing strategy for CO2 from space, including the forthcoming Orbiting Carbon Observatory (OCO-2) mission. Carbon cycle monitoring, including attribution of atmospheric concentrations to regional emissions and uptake, requires a robust modeling and analysis infrastructure to optimally extract information from the observations. NASA's Carbon-Monitoring System Flux-Pilot Project (FPP) is a prototype for such analysis, combining a set of unique tools to facilitate analysis of atmospheric CO2 along with fluxes between the atmosphere and the terrestrial biosphere or ocean. NASA's analysis system is unique, in that it combines information and expertise from the land, oceanic, and atmospheric branches of the carbon cycle and includes some estimates of uncertainty. Numerous existing space-based missions provide information of relevance to the carbon cycle. This study describes the components of the FPP framework, assessing the realism of computed fluxes, thus providing the basis for research and monitoring applications. Fluxes are computed using data-constrained terrestrial biosphere models and physical ocean models, driven by atmospheric observations and assimilating ocean-color information. Use of two estimates provides a measure of uncertainty in the fluxes. Along with inventories of other emissions, these data-derived fluxes are used in transport models to assess their consistency with atmospheric CO2 observations. Closure is achieved by using a four-dimensional data assimilation (inverse) approach that adjusts the terrestrial biosphere fluxes to make them consistent with the atmospheric CO2 observations. Results will be shown, illustrating the year-to-year variations in land biospheric and oceanic fluxes computed in the FPP. The signals of these surface-flux variations on atmospheric CO2 will be isolated using forward modeling tools, which also incorporate estimates of transport error. The results will be discussed in the context of interannual variability of observed atmospheric CO2 distributions.

Water: the bloodstream of the biosphere.

PubMed

Ripl, Wilhelm

2003-12-29

Water, the bloodstream of the biosphere, determines the sustainability of living systems. The essential role of water is expanded in a conceptual model of energy dissipation, based on the water balance of whole landscapes. In this model, the underlying role of water phase changes--and their energy-dissipative properties--in the function and the self-organized development of natural systems is explicitly recognized. The energy-dissipating processes regulate the ecological dynamics within the Earth's biosphere, in such a way that the development of natural systems is never allowed to proceed in an undirected or random way. A fundamental characteristic of self-organized development in natural systems is the increasing role of cyclic processes while loss processes are correspondingly reduced. This gives a coincidental increase in system efficiency, which is the basis of growing stability and sustainability. Growing sustainability can be seen as an increase of ecological efficiency, which is applicable at all levels up to whole landscapes. Criteria for necessary changes in society and for the design of the measures that are necessary to restore sustainable landscapes and waters are derived.

Water: the bloodstream of the biosphere.

PubMed Central

Ripl, Wilhelm

2003-01-01

Water, the bloodstream of the biosphere, determines the sustainability of living systems. The essential role of water is expanded in a conceptual model of energy dissipation, based on the water balance of whole landscapes. In this model, the underlying role of water phase changes--and their energy-dissipative properties--in the function and the self-organized development of natural systems is explicitly recognized. The energy-dissipating processes regulate the ecological dynamics within the Earth's biosphere, in such a way that the development of natural systems is never allowed to proceed in an undirected or random way. A fundamental characteristic of self-organized development in natural systems is the increasing role of cyclic processes while loss processes are correspondingly reduced. This gives a coincidental increase in system efficiency, which is the basis of growing stability and sustainability. Growing sustainability can be seen as an increase of ecological efficiency, which is applicable at all levels up to whole landscapes. Criteria for necessary changes in society and for the design of the measures that are necessary to restore sustainable landscapes and waters are derived. PMID:14728789

Constraining a land-surface model with multiple observations by application of the MPI-Carbon Cycle Data Assimilation System V1.0

NASA Astrophysics Data System (ADS)

Schürmann, Gregor J.; Kaminski, Thomas; Köstler, Christoph; Carvalhais, Nuno; Voßbeck, Michael; Kattge, Jens; Giering, Ralf; Rödenbeck, Christian; Heimann, Martin; Zaehle, Sönke

2016-09-01

We describe the Max Planck Institute Carbon Cycle Data Assimilation System (MPI-CCDAS) built around the tangent-linear version of the JSBACH land-surface scheme, which is part of the MPI-Earth System Model v1. The simulated phenology and net land carbon balance were constrained by globally distributed observations of the fraction of absorbed photosynthetically active radiation (FAPAR, using the TIP-FAPAR product) and atmospheric CO2 at a global set of monitoring stations for the years 2005 to 2009. When constrained by FAPAR observations alone, the system successfully, and computationally efficiently, improved simulated growing-season average FAPAR, as well as its seasonality in the northern extra-tropics. When constrained by atmospheric CO2 observations alone, global net and gross carbon fluxes were improved, despite a tendency of the system to underestimate tropical productivity. Assimilating both data streams jointly allowed the MPI-CCDAS to match both observations (TIP-FAPAR and atmospheric CO2) equally well as the single data stream assimilation cases, thereby increasing the overall appropriateness of the simulated biosphere dynamics and underlying parameter values. Our study thus demonstrates the value of multiple-data-stream assimilation for the simulation of terrestrial biosphere dynamics. It further highlights the potential role of remote sensing data, here the TIP-FAPAR product, in stabilising the strongly underdetermined atmospheric inversion problem posed by atmospheric transport and CO2 observations alone. Notwithstanding these advances, the constraint of the observations on regional gross and net CO2 flux patterns on the MPI-CCDAS is limited through the coarse-scale parametrisation of the biosphere model. We expect improvement through a refined initialisation strategy and inclusion of further biosphere observations as constraints.

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

PubMed

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

2017-01-01

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

Temporal variations of atmospheric CO2 and CO at Ahmedabad in western India

NASA Astrophysics Data System (ADS)

Chandra, Naveen; Lal, Shyam; Venkataramani, S.; Patra, Prabir K.; Sheel, Varun

2016-05-01

About 70 % of the anthropogenic carbon dioxide (CO2) is emitted from the megacities and urban areas of the world. In order to draw effective emission mitigation policies for combating future climate change as well as independently validating the emission inventories for constraining their large range of uncertainties, especially over major metropolitan areas of developing countries, there is an urgent need for greenhouse gas measurements over representative urban regions. India is a fast developing country, where fossil fuel emissions have increased dramatically in the last three decades and are predicted to continue to grow further by at least 6 % per year through to 2025. The CO2 measurements over urban regions in India are lacking. To overcome this limitation, simultaneous measurements of CO2 and carbon monoxide (CO) have been made at Ahmedabad, a major urban site in western India, using a state-of-the-art laser-based cavity ring down spectroscopy technique from November 2013 to May 2015. These measurements enable us to understand the diurnal and seasonal variations in atmospheric CO2 with respect to its sources (both anthropogenic and biospheric) and biospheric sinks. The observed annual average concentrations of CO2 and CO are 413.0 ± 13.7 and 0.50 ± 0.37 ppm respectively. Both CO2 and CO show strong seasonality with lower concentrations (400.3 ± 6.8 and 0.19 ± 0.13 ppm) during the south-west monsoon and higher concentrations (419.6 ± 22.8 and 0.72 ± 0.68 ppm) during the autumn (SON) season. Strong diurnal variations are also observed for both the species. The common factors for the diurnal cycles of CO2 and CO are vertical mixing and rush hour traffic, while the influence of biospheric fluxes is also seen in the CO2 diurnal cycle. Using CO and CO2 covariation, we differentiate the anthropogenic and biospheric components of CO2 and found significant contributions of biospheric respiration and anthropogenic emissions in the late night (00:00-05:00 h, IST) and evening rush hours (18:00-22:00 h) respectively. We compute total yearly emissions of CO to be 69.2 ± 0.07 Gg for the study region using the observed CO : CO2 correlation slope and bottom-up CO2 emission inventory. This calculated emission of CO is 52 % larger than the estimated emission of CO by the emissions database for global atmospheric research (EDGAR) inventory. The observations of CO2 have been compared with an atmospheric chemistry-transport model (ACTM), which incorporates various components of CO2 fluxes. ACTM is able to capture the basic variabilities, but both diurnal and seasonal amplitudes are largely underestimated compared to the observations. We attribute this underestimation by the model to uncertainties in terrestrial biosphere fluxes and coarse model resolution. The fossil fuel signal from the model shows fairly good correlation with observed CO2 variations, which supports the overall dominance of fossil fuel emissions over the biospheric fluxes in this urban region.

Nutrient inputs via rock weathering point to enhanced CO2 uptake capacity of the terrestrial biosphere

NASA Astrophysics Data System (ADS)

Dass, P.; Houlton, B. Z.; Wang, Y.; Pak, B. C.; Morford, S.

2016-12-01

Empirical evidence of widespread scarcity of nitrogen (N) and phosphorus (P) availability in natural land ecosystems constrains the carbon dioxide (CO2) uptake capacity of the global biosphere. Recent studies have pointed to the importance of rock weathering in supplying both N and P to terrestrial soils and vegetation; however, the potential for N and P to rapidly weather from different rocks and thereby alter the global carbon (C) cycle remains an open question, particularly at the global scale. Here, we combine empirical measurements and a new global simulation model to quantify the flux of N and P released from rocks to the terrestrial biosphere. Our model considers the role of tectonic uplift and physical and chemical weathering on rock nutrient cycling by using a probabilistic approach that is anchored in watershed-scale 10Be and Na data from the world's rivers. We use USGS DEM data for relief, monthly averaged MODIS evapotranspiration data and global precipitation datasets. Based on simulations using mean climate data for the past 10 years, we estimate annual values of 11 Tg of N and 6 Tg of P to weather from rocks to the terrestrial biosphere. The rate of N weathering rivals that of atmospheric N deposition in natural ecosystems, and the P weathering flux is approximately 6 times higher than prior estimates based on a modeling approach where the chemical weathering is dependant on lithology and runoff with further factors correcting for soil shielding and temperature. The increase in nutrient inputs we simulate reveals an important role for rock weathering to support new production in terrestrial ecosystems, and thereby allow for additional CO2 uptake in sectors of the biosphere where weathering rates are substantial. Given that current generation of models are yet to consider how short-term weathering of rocks can affect nutrient limited C storage, these results will help to advance the geochemical aspects of carbon-climate feedback this century. Moreover, we will present results for CO2 uptake capacity based on the future climate scenario involving the least mitigation storyline, i.e. RCP 8.5 as well as historic uptake from the beginning of the retreat if the glaciers, i.e. the Last Glacial Maximum.

What are the Outstanding Questions in Biosphere-Atmosphere Exchange?

NASA Astrophysics Data System (ADS)

Katul, G.; Finnigan, J.

2002-12-01

Our answer to this question has three parts. At the highest level human population is now so large (and will grow to 10-12 million by 2050 before stabilizing and reversing) and our capacity to influence the biosphere is so profound that we must now treat human, biophysical and geophysical processes as a single interacting system: the Anthroposphere. The Anthroposphere is a complex adaptive system (CAS) in the sense that action of humans individually or in groups (as large as nations) are a response to an environment that includes not just the geosphere and biosphere but the sum of human interactions as well. These actions, in turn, will change this system that provides critical ecosystem services that we are just now realizing are finite and threatened. At present we lack the tools and understanding even to frame key questions about the Anthroposphere although the emerging discipline of Complex System Science is hinting at ways this might be done. At the next level we address the problems posed by cross-scale interactions central to the state and function of the geosphere and biosphere, where processes at the cellular level, (e.g. photosynthesis and respiration), have consequences on the global level and vice-versa through a sequence of non-linear upscale and downscale interactions. Currently there are large gaps in our understanding of this scale cascade that inhibit our ability to parameterize, model and predict phenomena such as the rapid shifts in climate that recent studies of the paleo record have revealed. In short, we need to quantify the risk that our current actions may cause abrupt climate changes that may then feed upon the Anthrosphere. Unless we can reduce the uncertainty with which we describe quantitatively the non-human parts of the Anthroposphere, the injection of models of human interaction, initially tentative, may reduce our predictive ability to unusable levels. Finally we can detail a set of key processes that are themselves critical to geosphere-biosphere functioning but which are poorly understood as yet.

Interplay between solid Earth and biological evolution

NASA Astrophysics Data System (ADS)

Höning, Dennis; Spohn, Tilman

2017-04-01

Major shifts in Earth's evolution led to progressive adaptations of the biosphere. Particularly the emergence of continents permitted efficient use of solar energy. However, the widespread evolution of the biosphere fed back to the Earth system, often argued as a cause for the great oxidation event or as an important component in stabilizing Earth's climate. Furthermore, biologically enhanced weathering rates alter the flux of sediments in subduction zones, establishing a potential link to the deep interior. Stably bound water within subducting sediments not only enhances partial melting but further affects the mantle rheology. The mantle responds by enhancing its rates of convection, water outgassing, and subduction. How crucial is the emergence and evolution of life on Earth to these processes, and how would Earth have been evolved without the emergence of life? We here discuss concepts and present models addressing these questions and discuss the biosphere as a major component in evolving Earth system feedback cycles.

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Toward “optimal” integration of terrestrial biosphere models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwalm, Christopher R.; Huntingzger, Deborah; Fisher, Joshua B.

2015-06-10

Multi-model ensembles (MME) are commonplace in Earth system modeling. Here we perform MME integration using a 10-member ensemble of terrestrial biosphere models (TBMs) from the Multi-scale synthesis and Terrestrial Model Intercomparison Project (MsTMIP). We contrast optimal (skill-based for present-day carbon cycling) versus naïve (“one model – one vote”) integration. MsTMIP optimal and naïve mean land sink strength estimates (–1.16 vs. –1.15 Pg C per annum respectively) are statistically indistinguishable. This holds also for grid cell values and extends to gross uptake, biomass, and net ecosystem productivity. TBM skill is similarly indistinguishable. The added complexity of skill-based integration does not materiallymore » change MME values. This suggests that carbon metabolism has predictability limits and/or that all models and references are misspecified. Resolving this issue requires addressing specific uncertainty types (initial conditions, structure, references) and a change in model development paradigms currently dominant in the TBM community.« less

A roadmap for improving the representation of photosynthesis in Earth System Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, Alistair; Medlyn, Belinda E.; Dukes, Jeffrey S.

Accurate representation of photosynthesis in terrestrial biosphere models (TBMs) is essential for robust projections of global change. However, current representations vary markedly between TBMs, contributing uncertainty projections of global carbon fluxes.

A roadmap for improving the representation of photosynthesis in Earth System Models

DOE PAGES

Rogers, Alistair; Medlyn, Belinda E.; Dukes, Jeffrey S.; ...

2016-11-28

Accurate representation of photosynthesis in terrestrial biosphere models (TBMs) is essential for robust projections of global change. However, current representations vary markedly between TBMs, contributing uncertainty projections of global carbon fluxes.

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

NASA Technical Reports Server (NTRS)

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

2000-01-01

The survival of our early biosphere depended upon efficient coordination anion- diverse microbial populations. Microbial mats exhibit a 3.46-billion-year fossil record, thus they are the oldest known ecosystems. Photosynthetic microbial mats were key because, today, sunlight powers more than 99 percent of global primary productivity. Thus photosynthetic ecosystems have affected the atmosphere profoundly and have created the most pervasive, easily-detected fossils. Photosynthetic biospheres elsewhere will be most detectible via telescopes or spacecraft. As a part of the Astrobiology Institute, our Ames Microbial Ecosystems group examines the roles played by ecological processes in the early evolution of our biosphere, as recorded in geologic fossils and in the macromolecules of living cells: (1) We are defining the microbial mat microenvironment, which was an important milieu for early evolution. (2) We are comparing mats in contrasting environments to discern strategies of adaptation and diversification, traits that were key for long-term survival. (3) We have selected sites that mimic key environmental attributes of early Earth and thereby focus upon evolutionary adaptations to long-term changes in the global environment. (4) Our studies of gas exchange contribute to better estimates of biogenic gases in Earth's early atmosphere. This group therefore directly addresses the question: How have the Earth and its biosphere influenced each other over time Our studies strengthen the systematics for interpreting the microbial fossil record and thereby enhance astrobiological studies of martian samples. Our models of biogenic gas emissions will enhance models of atmospheres that might be detected on inhabited extrasolar planets. This work therefore also addresses the question: How can other biospheres be recogniZed" Our choice of field sites helps us explore Earth's evolving early environment. For example, modern mats that occupy thermal springs and certain freshwater environments experience conditions such as low O2 and sulfate and high inorganic carbon and sulfide levels that resemble those of ancient marine environments. Later in history, both biologically-induced carbonate precipitation and the trapping and binding of suspended grains of carbonate became a dominant mechanism for carbonate deposition. Modern marine carbonate platforms and alkaline offer good examples of microbiologically-induced calcification. Both marine platforms and solar salterns illustrate microbially-driven trapping and binding. We are also exploring the effects of water composition upon the exchange of biogenic gases with the atmosphere.

ESTIMATING GASEOUS EXCHANGES BETWEEN THE ATMOSPHERE AND PLANTS USING A COUPLED BIOCHEMICAL DRY DEPOSITION MODEL

EPA Science Inventory

To study gaseous exchanges between the soil, biosphere and atmosphere, a biochemical model was coupled with the latest version of Meyers Multi-Layer Deposition Model. The biochemical model describes photosynthesis and respiration and their coupling with stomatal resistance for...

Climate Sensitivity Controls Uncertainty in Future Terrestrial Carbon Sink

NASA Astrophysics Data System (ADS)

Schurgers, Guy; Ahlström, Anders; Arneth, Almut; Pugh, Thomas A. M.; Smith, Benjamin

2018-05-01

For the 21st century, carbon cycle models typically project an increase of terrestrial carbon with increasing atmospheric CO2 and a decrease with the accompanying climate change. However, these estimates are poorly constrained, primarily because they typically rely on a limited number of emission and climate scenarios. Here we explore a wide range of combinations of CO2 rise and climate change and assess their likelihood with the climate change responses obtained from climate models. Our results demonstrate that the terrestrial carbon uptake depends critically on the climate sensitivity of individual climate models, representing a large uncertainty of model estimates. In our simulations, the terrestrial biosphere is unlikely to become a strong source of carbon with any likely combination of CO2 and climate change in the absence of land use change, but the fraction of the emissions taken up by the terrestrial biosphere will decrease drastically with higher emissions.

Integrating ecosystems measurements from multiple eddy-covariance sites to a simple model of ecosystem process - Are there possibilities for a uniform model calibration?

NASA Astrophysics Data System (ADS)

Minunno, Francesco; Peltoniemi, Mikko; Launiainen, Samuli; Mäkelä, Annikki

2014-05-01

Biogeochemical models quantify the material and energy flux exchanges between biosphere, atmosphere and soil, however there is still considerable uncertainty underpinning model structure and parametrization. The increasing availability of data from of multiple sources provides useful information for model calibration and validation at different space and time scales. We calibrated a simplified ecosystem process model PRELES to data from multiple sites. In this work we had the following objective: to compare a multi-site calibration and site-specific calibrations, in order to test if PRELES is a model of general applicability, and to test how well one parameterization can predict ecosystem fluxes. Model calibration and evaluation were carried out by the means of the Bayesian method; Bayesian calibration (BC) and Bayesian model comparison (BMC) were used to quantify the uncertainty in model parameters and model structure. Evapotranspiration (ET) and gross primary production (GPP) measurements collected in 9 sites of Finland and Sweden were used in the study; half dataset was used for model calibrations and half for the comparative analyses. 10 BCs were performed; the model was independently calibrated for each of the nine sites (site-specific calibrations) and a multi-site calibration was achieved using the data from all the sites in one BC. Then 9 BMCs were carried out, one for each site, using output from the multi-site and the site-specific versions of PRELES. Similar estimates were obtained for the parameters at which model outputs are most sensitive. Not surprisingly, the joint posterior distribution achieved through the multi-site calibration was characterized by lower uncertainty, because more data were involved in the calibration process. No significant differences were encountered in the prediction of the multi-site and site-specific versions of PRELES, and after BMC, we concluded that the model can be reliably used at regional scale to simulate carbon and water fluxes of Boreal forests. Despite being a simple model, PRELES provided good estimates of GPP and ET; only for one site PRELES multi-site version underestimated water fluxes. Our study implies convergence of GPP and water processes in boreal zone to the extent that their plausible prediction is possible with a simple model using global parameterization.

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

ERIC Educational Resources Information Center

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…

Detection and Attribution of Simulated Climatic Extreme Events and Impacts: High Sensitivity to Bias Correction

NASA Astrophysics Data System (ADS)

Sippel, S.; Otto, F. E. L.; Forkel, M.; Allen, M. R.; Guillod, B. P.; Heimann, M.; Reichstein, M.; Seneviratne, S. I.; Kirsten, T.; Mahecha, M. D.

2015-12-01

Understanding, quantifying and attributing the impacts of climatic extreme events and variability is crucial for societal adaptation in a changing climate. However, climate model simulations generated for this purpose typically exhibit pronounced biases in their output that hinders any straightforward assessment of impacts. To overcome this issue, various bias correction strategies are routinely used to alleviate climate model deficiencies most of which have been criticized for physical inconsistency and the non-preservation of the multivariate correlation structure. We assess how biases and their correction affect the quantification and attribution of simulated extremes and variability in i) climatological variables and ii) impacts on ecosystem functioning as simulated by a terrestrial biosphere model. Our study demonstrates that assessments of simulated climatic extreme events and impacts in the terrestrial biosphere are highly sensitive to bias correction schemes with major implications for the detection and attribution of these events. We introduce a novel ensemble-based resampling scheme based on a large regional climate model ensemble generated by the distributed weather@home setup[1], which fully preserves the physical consistency and multivariate correlation structure of the model output. We use extreme value statistics to show that this procedure considerably improves the representation of climatic extremes and variability. Subsequently, biosphere-atmosphere carbon fluxes are simulated using a terrestrial ecosystem model (LPJ-GSI) to further demonstrate the sensitivity of ecosystem impacts to the methodology of bias correcting climate model output. We find that uncertainties arising from bias correction schemes are comparable in magnitude to model structural and parameter uncertainties. The present study consists of a first attempt to alleviate climate model biases in a physically consistent way and demonstrates that this yields improved simulations of climate extremes and associated impacts. [1] http://www.climateprediction.net/weatherathome/

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

PubMed

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. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

VIS and NIR land surface albedo sensitivity of the Ent Terrestrial Biosphere Model to forcing leaf area index

NASA Astrophysics Data System (ADS)

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

2016-12-01

Land surface albedo is a major controlling factor in vegetation-atmosphere transfers, modifying the components of the energy budget, the ecosystem productivity and patterns of regional and global climate. General Circulation Models (GCMs) are coupled to Dynamic Global Vegetation Models (DGVMs) to solve vegetation albedo by using simple schemes prescribing albedo based on vegetation classification, and approximations of canopy radiation transport for multiple plant functional types (PFTs). In this work, we aim at evaluating the sensitivity of the NASA Ent Terrestrial Biosphere Model (TBM), a demographic DGVM coupled to the NASA Goddard Institute for Space Studies (GISS) GCM, in estimating VIS and NIR surface albedo by using variable forcing leaf area index (LAI). The Ent TBM utilizes a new Global Vegetation Structure Dataset (GVSD) to account for geographically varying vegetation tree heights and densities, as boundary conditions to the gap-probability based Analytical Clumped Two-Stream (ACTS) canopy radiative transfer scheme (Ni-Meister et al., 2010). Land surface and vegetation characteristics for the Ent GVSD are obtained from a number of earth observation platforms and algorithms, including 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), and 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 LAI products are used as input to ACTS/Ent TBM: MODIS MOD15A2H product (Yang et al., 2006), Beijing Normal University LAI (Yuan et al., 2011), and Global Data Sets of Vegetation (LAI3g) (Zhu et al. 2013). The sensitivity of the Ent TBM VIS and NIR albedo to the three LAI products is assessed, compared against the previous GISS GCM vegetation classification and prescribed Lambertian albedoes (Matthews, 1984), and against MODIS snow-free black-sky and white-sky albedo estimates. In addition, we test the sensitivity of the Ent/ACTS albedo to different sets of leaf spectral albedos derived from the literature.

Biosphere reserves: Attributes for success.

PubMed

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

2017-03-01

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

FORest canopy atmosphere transfer (FORCAsT) 1.0: a 1-D model of biosphere-atmosphere chemical exchange

NASA Astrophysics Data System (ADS)

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

2015-07-01

Biosphere-atmosphere interactions play a critical role in governing atmospheric composition, mediating the concentration 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) one-dimensional 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 (SOA) 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 summer 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.

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

NASA Astrophysics Data System (ADS)

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.

Greenhouse gas network design using backward Lagrangian particle dispersion modelling - Part 1: Methodology and Australian test case

NASA Astrophysics Data System (ADS)

Ziehn, T.; Nickless, A.; Rayner, P. J.; Law, R. M.; Roff, G.; Fraser, P.

2014-09-01

This paper describes the generation of optimal atmospheric measurement networks for determining carbon dioxide fluxes over Australia using inverse methods. A Lagrangian particle dispersion model is used in reverse mode together with a Bayesian inverse modelling framework to calculate the relationship between weekly surface fluxes, comprising contributions from the biosphere and fossil fuel combustion, and hourly concentration observations for the Australian continent. Meteorological driving fields are provided by the regional version of the Australian Community Climate and Earth System Simulator (ACCESS) at 12 km resolution at an hourly timescale. Prior uncertainties are derived on a weekly timescale for biosphere fluxes and fossil fuel emissions from high-resolution model runs using the Community Atmosphere Biosphere Land Exchange (CABLE) model and the Fossil Fuel Data Assimilation System (FFDAS) respectively. The influence from outside the modelled domain is investigated, but proves to be negligible for the network design. Existing ground-based measurement stations in Australia are assessed in terms of their ability to constrain local flux estimates from the land. We find that the six stations that are currently operational are already able to reduce the uncertainties on surface flux estimates by about 30%. A candidate list of 59 stations is generated based on logistic constraints and an incremental optimisation scheme is used to extend the network of existing stations. In order to achieve an uncertainty reduction of about 50%, we need to double the number of measurement stations in Australia. Assuming equal data uncertainties for all sites, new stations would be mainly located in the northern and eastern part of the continent.

Exploration of a Subsurface Biosphere in a Volcanic Massive Sulfide: Results of the Mars Analog Rio Tinto Drilling Experiment

NASA Astrophysics Data System (ADS)

Stoker, C. R.; Stevens, T.; Amils, R.; Fernandez, D.

2005-12-01

Biological systems on Earth require three key ingredients-- liquid water, an energy source, and a carbon source, that are found in very few extraterrestrial environments. Previous examples of independent subsurface ecosystems have been found only in basalt aquifers. Such lithotrophic microbial ecosystems (LME) have been proposed as models for steps in the early evolution of Earth's biosphere and for potential biospheres on other planets where the surface is uninhabitable, such as Mars and Europa.. The Mars Analog Rio Tinto Experiment (MARTE) has searched in a volcanic massive sulfide deposit in Rio Tinto Spain for a subsurface biosphere capable of living without sunlight or oxygen and found a subsurface ecosystem driven by the weathering of the massive sulfide deposit (VMS) in which the rock matrix provides sufficient resources to support microbial metabolism, including the vigorous production of H2 by water-rock interactions. Microbial production of methane and sulfate occurred in the sulfide orebody and microbial production of methane and hydrogen sulfide continued in an anoxic plume downgradient from the sulfide ore. Organic carbon concentrations in the parent rock were too low to support microbes. The Rio Tinto system thus represents a new type of subsurface ecosystem with strong relevance for exobiological studies. Commercial drilling was used to reach the aquifer system at 100 m depth and conventional laboratory techniques were used to identify and characterize the biosphere. Then, the life search strategy that led to successful identification of this biosphere was applied to the development of a robotic drilling, core handling, inspection, subsampling, and life detection system built on a prototype planetary lander that was deployed in Rio Tinto Spain in September 2005 to test the capability of a robotic drilling system to search for subsurface life. A remote science team directed the simulation and analyzed the data from the MARTE robotic drill. The results of this experiment have important implications for the strategy for searching for life on Mars.

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

NASA Astrophysics Data System (ADS)

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.

Anthropogenic transformation of the terrestrial biosphere.

PubMed

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.

[Search for life in deep biospheres].

PubMed

Naganuma, Takeshi

2003-12-01

The life in deep biospheres bridges conventional biology and future exobiology. This review focuses the microbiological studies from the selected deep biospheres, i.e., deep-sea hydrothermal vents, sub-hydrothermal vents, terrestrial subsurface and a sub-glacier lake. The dark biospheres facilitate the emergence of organisms and communities dependent on chemolithoautotrophy, which are overwhelmed by photoautotrophy (photosynthesis) in the surface biospheres. The life at deep-sea hydrothermal vents owes much to chemolithoautotrophy based on the oxidation of sulfide emitted from the vents. It is likely that similarly active bodies such as the Jovian satellite Europa may have hydrothermal vents and associated biological communities. Anoxic or anaerobic condition is characteristic of deep subsurface biospheres. Subsurface microorganisms exploit available oxidants, or terminal electron acceptors (TEA), for anaerobic respiration. Sulfate, nitrate, iron (III) and CO2 are the representative TEAs in the deep subsurface. Below the 3000-4000 m-thick glacier on Antarctica, there have been >70 lakes with liquid water located. One of such sub-glacial lakes, Lake Vostok, is about to be drill-penetrated for microbiological studies. These deep biosphere "platforms" provide new knowledge about the diversity and potential of the Earth's life. The expertise obtained from the deep biosphere expeditions will facilitate the capability of exobiologial exploration.

The role of plant phenology in stomatal ozone flux modeling.

PubMed

Anav, Alessandro; Liu, Qiang; De Marco, Alessandra; Proietti, Chiara; Savi, Flavia; Paoletti, Elena; Piao, Shilong

2018-01-01

Plant phenology plays a pivotal role in the climate system as it regulates the gas exchange between the biosphere and the atmosphere. The uptake of ozone by forest is estimated through several meteorological variables and a specific function describing the beginning and the termination of plant growing season; actually, in many risk assessment studies, this function is based on a simple latitude and topography model. In this study, using two satellite datasets, we apply and compare six methods to estimate the start and the end dates of the growing season across a large region covering all Europe for the year 2011. Results show a large variability between the green-up and dormancy dates estimated using the six different methods, with differences greater than one month. However, interestingly, all the methods display a common spatial pattern in the uptake of ozone by forests with a marked change in the magnitude, up to 1.9 TgO 3 /year, and corresponding to a difference of 25% in the amount of ozone that enters the leaves. Our results indicate that improved estimates of ozone fluxes require a better representation of plant phenology in the models used for O 3 risk assessment. © 2017 John Wiley & Sons Ltd.

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

NASA Astrophysics Data System (ADS)

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

2017-11-01

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

Effects of primitive photosynthesis on Earth's early climate system

NASA Astrophysics Data System (ADS)

Ozaki, Kazumi; Tajika, Eiichi; Hong, Peng K.; Nakagawa, Yusuke; Reinhard, Christopher T.

2018-01-01

The evolution of different forms of photosynthetic life has profoundly altered the activity level of the biosphere, radically reshaping the composition of Earth's oceans and atmosphere over time. However, the mechanistic impacts of a primitive photosynthetic biosphere on Earth's early atmospheric chemistry and climate are poorly understood. Here, we use a global redox balance model to explore the biogeochemical and climatological effects of different forms of primitive photosynthesis. We find that a hybrid ecosystem of H2-based and Fe2+-based anoxygenic photoautotrophs—organisms that perform photosynthesis without producing oxygen—gives rise to a strong nonlinear amplification of Earth's methane (CH4) cycle, and would thus have represented a critical component of Earth's early climate system before the advent of oxygenic photosynthesis. Using a Monte Carlo approach, we find that a hybrid photosynthetic biosphere widens the range of geochemical conditions that allow for warm climate states well beyond either of these metabolic processes acting in isolation. Our results imply that the Earth's early climate was governed by a novel and poorly explored set of regulatory feedbacks linking the anoxic biosphere and the coupled H, C and Fe cycles. We suggest that similar processes should be considered when assessing the potential for sustained habitability on Earth-like planets with reducing atmospheres.

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

PubMed Central

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 <20 to several thousand years) and depth (171 to 448 m) revealed phylogenetically distinct microbial community subsets that either passed or were retained by a 0.22 μm filter. Such cells of <0.22 μm would have been overlooked in previous studies relying on membrane capture. 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

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

PubMed

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 <20 to several thousand years) and depth (171 to 448 m) revealed phylogenetically distinct microbial community subsets that either passed or were retained by a 0.22 μm filter. Such cells of <0.22 μm would have been overlooked in previous studies relying on membrane capture. 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.

Constraining gross primary production and ecosystem respiration estimates for North America using atmospheric observations of carbonyl sulfide (OCS) and CO2

NASA Astrophysics Data System (ADS)

He, W.; Ju, W.; Chen, H.; Peters, W.; van der Velde, I.; Baker, I. T.; Andrews, A. E.; Zhang, Y.; Launois, T.; Campbell, J. E.; Suntharalingam, P.; Montzka, S. A.

2016-12-01

Carbonyl sulfide (OCS) is a promising novel atmospheric tracer for studying carbon cycle processes. OCS shares a similar pathway as CO2 during photosynthesis but not released through a respiration-like process, thus could be used to partition Gross Primary Production (GPP) from Net Ecosystem-atmosphere CO2 Exchange (NEE). This study uses joint atmospheric observations of OCS and CO2 to constrain GPP and ecosystem respiration (Re). Flask data from tower and aircraft sites over North America are collected. We employ our recently developed CarbonTracker (CT)-Lagrange carbon assimilation system, which is based on the CT framework and the Weather Research and Forecasting - Stochastic Time-Inverted Lagrangian Transport (WRF-STILT) model, and the Simple Biosphere model with simulated OCS (SiB3-OCS) that provides prior GPP, Re and plant uptake fluxes of OCS. Derived plant OCS fluxes from both process model and GPP-scaled model are tested in our inversion. To investigate the ability of OCS to constrain GPP and understand the uncertainty propagated from OCS modeling errors to constrained fluxes in a dual-tracer system including OCS and CO2, two inversion schemes are implemented and compared: (1) a two-step scheme, which firstly optimizes GPP using OCS observations, and then simultaneously optimizes GPP and Re using CO2 observations with OCS-constrained GPP in the first step as prior; (2) a joint scheme, which simultaneously optimizes GPP and Re using OCS and CO2 observations. We will evaluate the result using an estimated GPP from space-borne solar-induced fluorescence observations and a data-driven GPP upscaled from FLUXNET data with a statistical model (Jung et al., 2011). Preliminary result for the year 2010 shows the joint inversion makes simulated mole fractions more consistent with observations for both OCS and CO2. However, the uncertainty of OCS simulation is larger than that of CO2. The two-step and joint schemes perform similarly in improving the consistence with observations for OCS, implicating that OCS could provide independent constraint in joint inversion. Optimization makes less total GPP and Re but more NEE, when testing with prior CO2 fluxes from two biosphere models. This study gives an in-depth insight into the role of joint atmospheric OCS and CO2 observations in constraining CO2 fluxes.

Southern Appalachian Man and the Biosphere - SAMAB.ORG

Science.gov Websites

Southern Appalachian Man and the Biosphere Home Who We Are SAMAB Initiatives Archives Welcome to SAMAB This slideshow requires JavaScript. The Southern Appalachian Man and the Biosphere (SAMAB

Growing wheat in Biosphere 2 under elevated CO2: observations and modeling

NASA Technical Reports Server (NTRS)

Tubiello, F. N.; Mahato, T.; Morton, T.; Druitt, J. W.; Volk, T.; Marino, B. D.

1999-01-01

Spring wheat (Triticum aestivum L., cv. Yecora Rojo) was grown in the intensive agricultural biome (IAB) of Biosphere 2 during the l995-l996 winter/spring season. Environmental conditions were characterized by a day/night temperature regime of 27/17 degrees C, relative humidity (RH) levels around 45%, mean atmospheric CO2 concentration of 450 ppmv, and natural light conditions with mean intensities about half of outside levels. Weekly samples of above-ground plant matter were collected throughout the growing season and phenological events recorded. A computer model, CERES-Wheat, previously tested under both field and controlled conditions, was used to simulate the observed crop growth and to help in data analysis. We found that CERES-Wheat simulated the data collected at Biosphere 2 to within 10% of observed, thus suggesting that wheat growth inside the IAB was comparable to that documented in other environments. The model predicts phenological stages and final dry matter (DM) production within l0% of the observed data. Measured DM production rates, normalized for light absorbed by the crop. suggested photosynthetic efficiencies intermediate between those observed under optimal field conditions and those recorded in NASA-Controlled Ecological Life-Support Systems (CELSS). We suggest that such a difference can be explained primarily in terms of low light levels inside the IAB, with additional effects due to elevated CO2 concentrations and diffuse light fractions.

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

PubMed

Weisse, Thomas

2014-01-01

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

Simulating estimation of California fossil fuel and biosphere carbon dioxide exchanges combining in situ tower and satellite column observations

DOE PAGES

Fischer, Marc L.; Parazoo, Nicholas; Brophy, Kieran; ...

2017-03-09

Here, we report simulation experiments estimating the uncertainties in California regional fossil fuel and biosphere CO 2 exchanges that might be obtained by using an atmospheric inverse modeling system driven by the combination of ground-based observations of radiocarbon and total CO 2, together with column-mean CO 2 observations from NASA's Orbiting Carbon Observatory (OCO-2). The work includes an initial examination of statistical uncertainties in prior models for CO 2 exchange, in radiocarbon-based fossil fuel CO 2 measurements, in OCO-2 measurements, and in a regional atmospheric transport modeling system. Using these nominal assumptions for measurement and model uncertainties, we find thatmore » flask measurements of radiocarbon and total CO 2 at 10 towers can be used to distinguish between different fossil fuel emission data products for major urban regions of California. We then show that the combination of flask and OCO-2 observations yields posterior uncertainties in monthly-mean fossil fuel emissions of ~5–10%, levels likely useful for policy relevant evaluation of bottom-up fossil fuel emission estimates. Similarly, we find that inversions yield uncertainties in monthly biosphere CO 2 exchange of ~6%–12%, depending on season, providing useful information on net carbon uptake in California's forests and agricultural lands. Finally, initial sensitivity analysis suggests that obtaining the above results requires control of systematic biases below approximately 0.5 ppm, placing requirements on accuracy of the atmospheric measurements, background subtraction, and atmospheric transport modeling.« less

Simulating estimation of California fossil fuel and biosphere carbon dioxide exchanges combining in situ tower and satellite column observations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, Marc L.; Parazoo, Nicholas; Brophy, Kieran

Here, we report simulation experiments estimating the uncertainties in California regional fossil fuel and biosphere CO 2 exchanges that might be obtained by using an atmospheric inverse modeling system driven by the combination of ground-based observations of radiocarbon and total CO 2, together with column-mean CO 2 observations from NASA's Orbiting Carbon Observatory (OCO-2). The work includes an initial examination of statistical uncertainties in prior models for CO 2 exchange, in radiocarbon-based fossil fuel CO 2 measurements, in OCO-2 measurements, and in a regional atmospheric transport modeling system. Using these nominal assumptions for measurement and model uncertainties, we find thatmore » flask measurements of radiocarbon and total CO 2 at 10 towers can be used to distinguish between different fossil fuel emission data products for major urban regions of California. We then show that the combination of flask and OCO-2 observations yields posterior uncertainties in monthly-mean fossil fuel emissions of ~5–10%, levels likely useful for policy relevant evaluation of bottom-up fossil fuel emission estimates. Similarly, we find that inversions yield uncertainties in monthly biosphere CO 2 exchange of ~6%–12%, depending on season, providing useful information on net carbon uptake in California's forests and agricultural lands. Finally, initial sensitivity analysis suggests that obtaining the above results requires control of systematic biases below approximately 0.5 ppm, placing requirements on accuracy of the atmospheric measurements, background subtraction, and atmospheric transport modeling.« less

Historical overview of the Biosphere 2 project

NASA Technical Reports Server (NTRS)

Allen, John P.

1990-01-01

An extensive historical overview is given of the Biosphere 2 project. The overview begins in late 1969, as the moon landings commenced, when work began on ecological projects which laid the conceptual foundation for the current Biosphere 2 project. Continuing through to taking a complete functional suite of microbes together with their associated aquatic elements and an air volume and putting them inside a closed lab flask in which to measure the oxygen and CO2 levels, study energy flows and visually observe the changes therein. The laws of biospherics formulated by the author which can be tested in the Biosphere 2 project are listed.

Interpretation of Biosphere Reserves.

ERIC Educational Resources Information Center

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)

The Effects of Decomposition on the Oxidative Ratio and Carbon Oxidation State of Organic Matter

NASA Astrophysics Data System (ADS)

Gallagher, M. E.; Masiello, C. A.; Clark, N.; Randerson, J. T.; Robertson, G. P.

2006-12-01

Ecosystem oxidative ratio (OR) and the related parameter carbon oxidation state (Cox) are critical in the apportionment of anthropogenic CO2 between the terrestrial biosphere and ocean reservoirs. OR is the ratio of O2 to CO2 in gas exchange fluxes between the biosphere and the atmosphere (Fba and Fab). Accurate measurements of OR have been challenging (Seibt et al. 2004); instead we approach the problem by measuring Cox and calculating OR from biomass reservoirs. Cox can range from -4 to +4 (CH4 to CO2) and is driven by photosynthesis, respiration, and decomposition. The net OR of the biosphere varies with ecosystem type, and this can affect the apportionment of anthropogenic CO2 between the terrestrial biosphere and ocean reservoirs (Randerson et al. 2006). This makes it essential to constrain ecosystem Cox and OR values. Although small variations in global ecosystem OR have the potential to cause shifts in atmospheric O2 concentrations, no whole ecosystem measurements of Cox yet exist. To constrain ORba and ORab, and improve our understanding of how decomposition affects Cox, we performed a litter bag experiment at the Kellogg Biological Station-Long Term Ecological Research (KBS-LTER) in Michigan at the end of the 2005 agricultural season. We placed 15 corn biomass litter bags in an agricultural field and collected 3 bags at 2, 4, 7, 26, and 29 weeks. These samples were analyzed for %C, %H, %N, and %O via elemental analysis, and these data were used to calculate Cox. Aboveground Cox was measured similarly. We anticipated that the Cox of the corn litter would become more reduced with decomposition, as the percentage of carbohydrates would decrease with time, while that of protein, lignin, and lipids would increase (Baldock et al. 2004). We report differences between the Cox of biomass fixation and biomass degradation from our experiments. Using simple assumptions about ecosystem nitrogen cycling, we convert Cox to OR and report the existence or absence of a temporal offset between ORab and ORba within an agricultural ecosystem.

Biomedical program at Space Biospheres Ventures

NASA Technical Reports Server (NTRS)

Walford, Roy

1990-01-01

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

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

NASA Astrophysics Data System (ADS)

Vorobyov, Sergey

2018-01-01

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

SimilarityExplorer: A visual inter-comparison tool for multifaceted climate data

Treesearch

J. Poco; A. Dasgupta; Y. Wei; W. Hargrove; C. Schwalm; R. Cook; E. Bertini; C. Silva

2014-01-01

Inter-comparison and similarity analysis to gauge consensus among multiple simulation models is a critical visualization problem for understanding climate change patterns. Climate models, specifically, Terrestrial Biosphere Models (TBM) represent time and space variable ecosystem processes, for example, simulations of photosynthesis and respiration, using algorithms...

Exploration and protection of Europa's biosphere: implications of permeable ice.

PubMed

Greenberg, Richard

2011-03-01

Europa has become a high-priority objective for exploration because it may harbor life. Strategic planning for its exploration has been predicated on an extreme model in which the expected oceanic biosphere lies under a thick ice crust, buried too deep to be reached in the foreseeable future, which would beg the question of whether other active satellites might be more realistic objectives. However, Europa's ice may in fact be permeable, with very different implications for the possibilities for life and for mission planning. A biosphere may extend up to near the surface, making life far more readily accessible to exploration while at the same time making it vulnerable to contamination. The chances of finding life on Europa are substantially improved while the need for planetary protection becomes essential. The new National Research Council planetary protection study will need to go beyond its current mandate if meaningful standards are to be put in place. © Mary Ann Liebert, Inc.

The Biosphere.

ERIC Educational Resources Information Center

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)

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

NASA Astrophysics Data System (ADS)

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.

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

NASA Astrophysics Data System (ADS)

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henderson-Sellers, A.

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

Complexity and the Arrow of Time

NASA Astrophysics Data System (ADS)

Lineweaver, Charles H.; Davies, Paul C. W.; Ruse, Michael

2013-08-01

1. What is complexity? Is it increasing? Charles H. Lineweaver, Paul C. W. Davies and Michael Ruse; 2. Directionality principles from cancer to cosmology Paul C. W. Davies; 3. A simple treatment of complexity: cosmological entropic boundary conditions on increasing complexity Charles H. Lineweaver; 4. Using complexity science to search for unity in the natural sciences Eric J. Chaisson; 5. On the spontaneous generation of complexity in the universe Seth Lloyd; 6. Emergent spatiotemporal complexity in field theory Marcelo Gleiser; 7. Life: the final frontier for complexity? Simon Conway Morris; 8. Evolution beyond Newton, Darwin, and entailing law: the origin of complexity in the evolving biosphere Stuart A. Kauffman; 9. Emergent order in processes: the interplay of complexity, robustness, correlation, and hierarchy in the biosphere D. Eric Smith; 10. The inferential evolution of biological complexity: forgetting nature by learning to nurture David C. Krakauer; 11. Information width: a way for the second law to increase complexity David Wolpert; 12. Wrestling with biological complexity: from Darwin to Dawkins Michael Ruse; 13. The role of generative entrenchment and robustness in the evolution of complexity William C. Wimsatt; 14. On the plurality of complexity-producing mechanisms Philip Clayton; Index.

NEW DIRECTIONS: VOCS AND BIOSPHERE-ATMOSPHERE FEEDBACKS

EPA Science Inventory

Shallcross and Monks [New Directions: a Role For Isoprene in Biosphere-Climate-Chemistry Feedbacks, Atmospheric Environment, Vol. 34 (2000) pp. 1659-1660] recently summarized the importance of biogenic isoprene in a biosphere-atmosphere system under constant change. In this art...

Hot spots of multivariate extreme anomalies in Earth observations

NASA Astrophysics Data System (ADS)

Flach, M.; Sippel, S.; Bodesheim, P.; Brenning, A.; Denzler, J.; Gans, F.; Guanche, Y.; Reichstein, M.; Rodner, E.; Mahecha, M. D.

2016-12-01

Anomalies in Earth observations might indicate data quality issues, extremes or the change of underlying processes within a highly multivariate system. Thus, considering the multivariate constellation of variables for extreme detection yields crucial additional information over conventional univariate approaches. We highlight areas in which multivariate extreme anomalies are more likely to occur, i.e. hot spots of extremes in global atmospheric Earth observations that impact the Biosphere. In addition, we present the year of the most unusual multivariate extreme between 2001 and 2013 and show that these coincide with well known high impact extremes. Technically speaking, we account for multivariate extremes by using three sophisticated algorithms adapted from computer science applications. Namely an ensemble of the k-nearest neighbours mean distance, a kernel density estimation and an approach based on recurrences is used. However, the impact of atmosphere extremes on the Biosphere might largely depend on what is considered to be normal, i.e. the shape of the mean seasonal cycle and its inter-annual variability. We identify regions with similar mean seasonality by means of dimensionality reduction in order to estimate in each region both the `normal' variance and robust thresholds for detecting the extremes. In addition, we account for challenges like heteroscedasticity in Northern latitudes. Apart from hot spot areas, those anomalies in the atmosphere time series are of particular interest, which can only be detected by a multivariate approach but not by a simple univariate approach. Such an anomalous constellation of atmosphere variables is of interest if it impacts the Biosphere. The multivariate constellation of such an anomalous part of a time series is shown in one case study indicating that multivariate anomaly detection can provide novel insights into Earth observations.

Development of wildfires in Australia over the last century

NASA Astrophysics Data System (ADS)

Nieradzik, Lars Peter; Haverd, Vanessa; Briggs, Peter; Canadell, Josep G.; Smith, Ben

2017-04-01

Wildfires and their emissions are key biospheric processes in the modeling of the carbon cycle that still are insufficiently understood. In Australia, fire emissions constitute a large flux of carbon from the biosphere to the atmosphere of approximately 1.3 times larger than the annual fossil fuel emissions. In addition, fire plays a big role in determining the composition of vegetation which in turn affects land-atmosphere fluxes. Annualy, up to 4% of the vegetated land-surface area is burned which amounts to up to 3% of global NPP and results in the reslease of about 2 Pg carbon into the atmosphere. There are indications that burned area has decreased globally over recent decades but so far there is not a clear trend in the development in fire-intensity and fuel availability. Net emissions from wildfires are not generally included in global and regional carbon budgets, because it is assumed that gross fire emissions are in balance with post-fire carbon uptake by recovering vegetation. This is a valid assumption as long as climate and fire regimes are in equilibrium, but not when the climate and other drivers are changing. We present a study on the behaviour of wildfires on the Australian continent over the last century (1911 - 2012) introducing the novel fire model BLAZE (BLAZe induced biosphere-atmosphere flux Estimator) that has been designed to address the feedbacks between climate, fuel loads, and fires. BLAZE is used within the Australian land-surface model CABLE (Community Atmophere-Biosphere-Land Exchange model). The study shows two significant outcomes: A regional shift in fire patterns shift during this century due to fire suppression and greening effects as well as an increase of potential fire-line intensity (the risk that a fire becomes more intense), especially in regions where most of Australia's population resides. This strongly emphasises the need to further investigate fire dynamics under future climate scenarios. The fire model BLAZE has been developed at the CSIRO Oceans and Atmosphere, Canberra, Australia and will be part of the upcoming release of the dynamic global vegetation model LPJ-GUESS version 4.1 within the MERGE project at Lund University, Sweden. It will also be included in the EC-Earth ESM within the EU Horizon 2020 project CRESCENDO.

Biosphere 2: The True Story.

ERIC Educational Resources Information Center

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)

Improved Carbon Flux Observations over Urban Areas Using Carbonyl Sulfide (COS) to Differentiate Contributions from Biosphere

NASA Astrophysics Data System (ADS)

Whelan, M.; LaFranchi, B. W.; Bambha, R.; Michelsen, H. A.; Fischer, M. L.; Graven, H. D.; Baker, I. T.; Guilderson, T.; Campbell, J. E.

2016-12-01

Direct measurement and attribution of carbon exchange over urban areas is challenging because of the heterogeneity of the landscape and errors introduced by flux source partitioning. One important contribution to uncertainty is the influence of the urban biosphere on the regional carbon budget. Atmospheric observations of carbonyl sulfide (COS) are an emerging tool for estimating gross primary productivity: COS is consumed in plant leaves by parallel pathways to CO2 uptake, without the additional complexity of an analogous respiration term. This study makes use of COS measurements to better understand fluctuations in total CO2 concentrations over an urban region due to the balance of photosynthesis and respiration. In situ ground-based observations of trace gas concentrations were made from a tower in Livermore, CA, USA, and interpreted with WRF-STILT back trajectories and gridded data sets (e.g. VULCAN, a new anthropogenic COS inventory), supplemented with biosphere models (SiB, CASA-GFED3). CO2, 14CO2, and CO observations were used to first parse the contribution of fossil fuel emissions to total CO2. Changes in the remainder CO2 was differentiated as the sum of biosphere components with associated uncertainties. This approach could be used to better validate carbon emissions reduction measures and ecosytem-based carbon capture projects on the regional scale.

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

NASA Astrophysics Data System (ADS)

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

2013-07-01

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

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) andmore » 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 its efforts to reach out to the local and regional community. As you have read, some have had great success, while others consider their successes almost negligible. All document tremendous effort from many people to improve the communication among landowners, land managers, scientists, and any others interested in the health and well-being of the natural and human environment of the biosphere reserve.« less

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

PubMed

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.

The First International Biosphere Reserve Congress.

ERIC Educational Resources Information Center

Laird, John

1984-01-01

Presents objectives (and related activities) of a plan designed for international collaboration in conserving key natural areas (biosphere reserves) of the globe. The plan (focusing on such areas as management, conservation, research, monitoring, and environmental education/training) was formulated during the First International Biosphere Reserve…

Global carbon export from the terrestrial biosphere controlled by erosion.

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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-chemical species schemes. Their level of complexity depends on their purpose, the spatial scale at which they are applied, the current level of parameterisation, and the availability of the input data they require. State-of-the-art solutions for determining the emission/sink Γ potentials through the soil/canopy system include coupled, interactive chemical transport models (CTM) and soil/ecosystem modelling at the regional scale. However, it remains a matter for debate to what extent realistic options for future regional and global models should be based on process-based mechanistic versus empirical and regression-type models. Further discussion is needed on the extent and timescale by which new approaches can be used, such as integration with ecosystem models and satellite observations.

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

NASA Astrophysics Data System (ADS)

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. Their level of complexity depends on their purpose, the spatial scale at which they are applied, the current level of parameterization, and the availability of the input data they require. State-of-the-art solutions for determining the emission/sink Γ potentials through the soil/canopy system include coupled, interactive chemical transport models (CTM) and soil/ecosystem modelling at the regional scale. However, it remains a matter for debate to what extent realistic options for future regional and global models should be based on process-based mechanistic versus empirical and regression-type models. Further discussion is needed on the extent and timescale by which new approaches can be used, such as integration with ecosystem models and satellite observations.

Development and evaluation of an ammonia bidirectional flux parameterization for air quality models

EPA Science Inventory

Ammonia is an important contributor to particulate matter in the atmosphere and can significantly impact terrestrial and aquatic ecosystems. Surface exchange between the atmosphere and biosphere is a key part of the ammonia cycle. New modeling techniques are being developed for u...

Modeling Global Atmospheric CO2 Fluxes and Transport Using NASA MERRA Reanalysis Data

NASA Astrophysics Data System (ADS)

Liu, Y.; Kawa, S. R.; Collatz, G. J.

2010-12-01

We present our first results of CO2 surface biosphere fluxes and global atmospheric CO2 transport using NASA’s new MERRA reanalysis data. MERRA is the Modern Era Retrospective-Analysis For Research And Applications based on the Goddard Global Modeling and Assimilation Office GEOS-5 data assimilation system. After some application testing and analysis, we have generated biospheric CO2 fluxes at 3-hourly temporal resolution from an updated version of the CASA carbon cycle model using the 1x1.25-degree reanalysis data. The experiment covers a period of 9 years from 2000 -2008. The affects of US midwest crop (largely corn and soy) carbon uptake and removal by harvest are explicitly included in this version of CASA. Across the agricultural regions of the Midwest US, USDA crop yield data are used to scale vegetation fluxes producing a strong sink in the growing season and a comparatively weaker source from respiration after harvest. Comparisons of the new fluxes to previous ones generated using GEOS-4 data are provided. The Parameterized Chemistry/Transport Model (PCTM) is then used with the analyzed meteorology in offline CO2 transport. In the simulation of CO2 transport, we have a higher vertical resolution from MERRA (the lowest 56 of 72 levels are used in our simulation). A preliminary analysis of the CO2 simulation results is carried out, including diurnal, seasonal and latitudinal variability. We make comparisons of our simulation to continuous CO2 analyzer sites, especially those in agricultural regions. The results show that the model captures reasonably well the observed synoptic variability due to transport changes and biospheric fluxes.

Identification of sensitive parameters of a tropical forest in Southern Mexico to improve the understanding of C-band radar images

NASA Astrophysics Data System (ADS)

Monsivais-Huertero, A.; Jimenez-Escalona, J. C.; Ramos, J.; Zempoaltecatl-Ramirez, E.

2013-05-01

Forest areas cover the 32% of the Mexican territory. Due to their geographical location, Mexico presents heterogeneous climatic and topographic conditions. The country is divided into two different regions: an arid /semiarid zone (North) and a tropical/temperate zone (South). Due to the effects of climate change, Mexico has been affected in two ways. In the North, there has been a desertification of regions as result of the absence of rainfall and a low rate of soil moisture. On the other hand, in the South, there has been an increase in the intensity of rainfall causing serious flooding. Another effect is the excessive deforestation in Southern Mexico. The FAO has determined that Mexico could present one of the highest losses of forest areas mainly in temperate and subtropical ecosystems. The Biosphere Reserve of Calakmul is the protected area with the largest surface of tropical forest in Mexico. The Biosphere Reserve of Calakmul is located in the state of Campeche that the flora and fauna are being affected. The type of vegetation located in the reserve of Calakmul Biosphere is rainforest with high spatial density and highly heterogeneous due to multiple plant species and the impact of human activities in the area. The satellite remote sensing techniques becomes a very useful tool to monitor the area because a large area can be covered. To understand the radar images, the identification of sensitive parameters governing the radar signal is necessary. With the launch of the satellites Radarsat-2, ASAR-Envisat and ALOSPalSAR, significant progress has been done in the interpretation of satellite radar images. Directly applying physical models becomes a problem due to the large number of input parameters in the models, together with the difficulty in measuring these parameters in the field. The models developed so far have been applied and validated for homogeneous forests with low or average spatial density of trees. This is why it is recommended in a comprehensive validation of the models for heterogeneous forests with a high density of trees, such as Calakmul. This paper presents a methodology for identifying sensitive parameters governing the scenes backscatter vegetables reserve Calakmul Biosphere from a physical model.

Detecting a Terrestrial Biosphere Sink for Carbon Dioxide: Interannual Ecosystem Modeling for the Mid-1980s

NASA Technical Reports Server (NTRS)

Potter, Christopher S.; Klooster, Steven A.; Brooks, Vanessa; Gore, Warren J. (Technical Monitor)

1998-01-01

There is considerable uncertainty as to whether interannual variability in climate and terrestrial ecosystem production is sufficient to explain observed variation in atmospheric carbon content over the past 20-30 years. In this paper, we investigated the response of net CO2 exchange in terrestrial ecosystems to interannual climate variability (1983 to 1988) using global satellite observations as drivers for the NASA-CASA (Carnegie-Ames-Stanford Approach) simulation model. This computer model of net ecosystem production (NEP) is calibrated for interannual simulations driven by monthly satellite vegetation index data (NDVI) from the NOAA Advanced Very High Resolution Radiometer (AVHRR) at 1 degree spatial resolution. Major results from NASA-CASA simulations suggest that from 1985 to 1988, the northern middle-latitude zone (between 30 and 60 degrees N) was the principal region driving progressive annual increases in global net primary production (NPP; i.e., the terrestrial biosphere sink for carbon). The average annual increase in NPP over this predominantly northern forest zone was on the order of +0.4 Pg (10 (exp 15) g) C per year. This increase resulted mainly from notable expansion of the growing season for plant carbon fixation toward the zonal latitude extremes, a pattern uniquely demonstrated in our regional visualization results. A net biosphere source flux of CO2 in 1983-1984, coinciding with an El Nino event, was followed by a major recovery of global NEP in 1985 which lasted through 1987 as a net carbon sink of between 0.4 and 2.6 Avg C per year. Analysis of model controls on NPP and soil heterotrophic CO2 fluxes (Rh) suggests that regional warming in northern forests can enhance ecosystem production significantly. In seasonally dry tropical zones, periodic drought and temperature drying effects may carry over with at least a two-year lag time to adversely impact ecosystem production. These yearly patterns in our model-predicted NEP are consistent in magnitude with the estimated exchange of CO2 by the terrestrial biosphere with the atmosphere, as determined by previous isotopic (delta (sup 13 C) convolution analysis. Ecosystem simulation results can help further target locations where net carbon sink fluxes have occurred in the past or may be verified in subsequent field studies.

HESS Opinions Catchments as meta-organisms - a new blueprint for hydrological modelling

NASA Astrophysics Data System (ADS)

Savenije, Hubert H. G.; Hrachowitz, Markus

2017-02-01

Catchment-scale hydrological models frequently miss essential characteristics of what determines the functioning of catchments. The most important active agent in catchments is the ecosystem. It manipulates and partitions moisture in a way that supports the essential functions of survival and productivity: infiltration of water, retention of moisture, mobilization and retention of nutrients, and drainage. Ecosystems do this in the most efficient way, establishing a continuous, ever-evolving feedback loop with the landscape and climatic drivers. In brief, hydrological systems are alive and have a strong capacity to adjust themselves to prevailing and changing environmental conditions. Although most models take Newtonian theory at heart, as best they can, what they generally miss is Darwinian theory on how an ecosystem evolves and adjusts its environment to maintain crucial hydrological functions. In addition, catchments, such as many other natural systems, do not only evolve over time, but develop features of spatial organization, including surface or sub-surface drainage patterns, as a by-product of this evolution. Models that fail to account for patterns and the associated feedbacks miss a critical element of how systems at the interface of atmosphere, biosphere and pedosphere function. In contrast to what is widely believed, relatively simple, semi-distributed conceptual models have the potential to accommodate organizational features and their temporal evolution in an efficient way, a reason for that being that because their parameters (and their evolution over time) are effective at the modelling scale, and thus integrate natural heterogeneity within the system, they may be directly inferred from observations at the same scale, reducing the need for calibration and related problems. In particular, the emergence of new and more detailed observation systems from space will lead towards a more robust understanding of spatial organization and its evolution. This will further permit the development of relatively simple time-dynamic functional relationships that can meaningfully represent spatial patterns and their evolution over time, even in poorly gauged environments.

The Study of Socio-Biospheric Problems.

ERIC Educational Resources Information Center

Scott, Andrew M.

Concepts, tools, and a methodology are needed which will permit the analysis of emergent socio-biospheric problems and facilitate their effective management. Many contemporary problems may be characterized as socio-biospheric; for example, pollution of the seas, acid rain, the growth of cities, and an atmosphere loaded with carcinogens. However,…

[The ways in which variations in space and atmospheric factors act upon the biosphere and humans].

PubMed

Chernogor, L F

2010-01-01

The system analysis is validated to be an efficient means for studying the channels through which variations in space and tropospheric weather affect the biosphere (humans). The basics of the system analysis paradigm are presented. The causes of variations in space and tropospheric weather are determined, and the interrelations between them are demonstrated. The ways in which these variations affect the biosphere (humans) are discussed. Aperiodic and quasi-periodic disturbances in the physical fields that influence the biosphere (humans) are intercompared.

Detecting Biosphere anomalies hotspots

NASA Astrophysics Data System (ADS)

Guanche-Garcia, Yanira; Mahecha, Miguel; Flach, Milan; Denzler, Joachim

2017-04-01

The current amount of satellite remote sensing measurements available allow for applying data-driven methods to investigate environmental processes. The detection of anomalies or abnormal events is crucial to monitor the Earth system and to analyze their impacts on ecosystems and society. By means of a combination of statistical methods, this study proposes an intuitive and efficient methodology to detect those areas that present hotspots of anomalies, i.e. higher levels of abnormal or extreme events or more severe phases during our historical records. Biosphere variables from a preliminary version of the Earth System Data Cube developed within the CAB-LAB project (http://earthsystemdatacube.net/) have been used in this study. This database comprises several atmosphere and biosphere variables expanding 11 years (2001-2011) with 8-day of temporal resolution and 0.25° of global spatial resolution. In this study, we have used 10 variables that measure the biosphere. The methodology applied to detect abnormal events follows the intuitive idea that anomalies are assumed to be time steps that are not well represented by a previously estimated statistical model [1].We combine the use of Autoregressive Moving Average (ARMA) models with a distance metric like Mahalanobis distance to detect abnormal events in multiple biosphere variables. In a first step we pre-treat the variables by removing the seasonality and normalizing them locally (μ=0,σ=1). Additionally we have regionalized the area of study into subregions of similar climate conditions, by using the Köppen climate classification. For each climate region and variable we have selected the best ARMA parameters by means of a Bayesian Criteria. Then we have obtained the residuals by comparing the fitted models with the original data. To detect the extreme residuals from the 10 variables, we have computed the Mahalanobis distance to the data's mean (Hotelling's T^2), which considers the covariance matrix of the joint distribution. The proposed methodology has been applied to different areas around the globe. The results show that the method is able to detect historic events and also provides a useful tool to define sensitive regions. This method and results have been developed within the framework of the project BACI (http://baci-h2020.eu/), which aims to integrate Earth Observation data to monitor the earth system and assessing the impacts of terrestrial changes. [1] V. Chandola, A., Banerjee and v., Kumar. Anomaly detection: a survey. ACM computing surveys (CSUR), vol. 41, n. 3, 2009. [2] P. Mahalanobis. On the generalised distance in statistics. Proceedings National Institute of Science, vol. 2, pp 49-55, 1936.

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

EPA Science Inventory

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...

Development and Evaluation of an Ammonia Bi-Directional Flux Model for Air Quality Models

EPA Science Inventory

Ammonia is an important contributor to particulate matter in the atmosphere and can significantly impact terrestrial and aquatic ecosystems. Surface exchange between the atmosphere and biosphere is a key part of the ammonia cycle. Agriculture, in particular. is a large source of...

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

NASA Astrophysics Data System (ADS)

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

2015-09-01

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

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

NASA Astrophysics Data System (ADS)

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 humidity in the air handlers and from the glass space frame to produce high quality freshwater, wastewater treatment with constructed wetlands and desalination through reverse osmosis and flash evaporation were key to recycling water with appropriate quality throughout the Biosphere 2 facility. Wastewater from all human uses and the domestic animals in Biosphere 2 was treated and recycled through a series of constructed wetlands, which had hydraulic loading of 0.9-1.1 m 3 day -1 (240-290 gal d -1). Plant production in the wetland treatment system produced 1210 kg dry weight of emergent and floating aquatic plant wetland which was used as fodder for the domestic animals while remaining nutrients/water was reused as part of the agricultural irrigation supply. There were pools of water with recycling times of days to weeks and others with far longer cycling times within Biosphere 2. By contrast, the Laboratory Biosphere with a total water reservoir of less than 500 L has far quicker cycling rapidity: for example, atmospheric residence time for water vapor was 5-20 min in the Laboratory Biosphere vs. 1-4 h in Biosphere 2, as compared with 9 days in the Earth's biosphere. Just as in Biosphere 2, humidity in the Laboratory Biosphere amounts to a very small reservoir of water. The amount of water passing through the air in the course of a 12-h operational day is two orders of magnitude greater than the amount stored in the air. Thus, evaporation and condensation collection are vital parts of the recycle system just as in Biosphere 2. The water cycle and sustainable water recycling in closed ecological systems presents problems requiring further research - such as how to control buildup of salinity in materially closed ecosystems and effective ways to retain nutrients in optimal quantity and useable form for plant growth. These issues are common to all closed ecological systems of whatever size, including planet Earth's biosphere and are relevant to a global environment facing increasing water shortages while maintaining water quality for human and ecosystem health. Modular biospheres offer a test bed where technical methods of resolving these problems can be tested for feasibility.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fung, Inez

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-Dmore » 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.« less

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

Treesearch

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

2016-01-01

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

Maximum entropy production in environmental and ecological systems.

PubMed

Kleidon, Axel; Malhi, Yadvinder; Cox, Peter M

2010-05-12

The coupled biosphere-atmosphere system entails a vast range of processes at different scales, from ecosystem exchange fluxes of energy, water and carbon to the processes that drive global biogeochemical cycles, atmospheric composition and, ultimately, the planetary energy balance. These processes are generally complex with numerous interactions and feedbacks, and they are irreversible in their nature, thereby producing entropy. The proposed principle of maximum entropy production (MEP), based on statistical mechanics and information theory, states that thermodynamic processes far from thermodynamic equilibrium will adapt to steady states at which they dissipate energy and produce entropy at the maximum possible rate. This issue focuses on the latest development of applications of MEP to the biosphere-atmosphere system including aspects of the atmospheric circulation, the role of clouds, hydrology, vegetation effects, ecosystem exchange of energy and mass, biogeochemical interactions and the Gaia hypothesis. The examples shown in this special issue demonstrate the potential of MEP to contribute to improved understanding and modelling of the biosphere and the wider Earth system, and also explore limitations and constraints to the application of the MEP principle.

Selection, management and utilization of biosphere reserves.

Treesearch

Jerry F. Franklin; Stanley L. Krugman

1979-01-01

This publication is directed to the analysis of the selection, management, and utilization of Biosphere Reserves as viewed by scientists from the United States and the Union of Soviet Socialist Republics. Soviet papers focus on types of research and monitoring programs that should be developed on Biosphere Reserves, with emphasis on their use in pollutant monitoring....

Space Observations for Global Change

NASA Technical Reports Server (NTRS)

Rasool, S. I.

1991-01-01

There is now compelling evidence that man's activities are changing both the composition of the atmospheric and the global landscape quite drastically. The consequences of these changes on the global climate of the 21st century is currently a hotly debated subject. Global models of a coupled Earth-ocean-atmosphere system are still very primitive and progress in this area appears largely data limited, specially over the global biosphere. A concerted effort on monitoring biospheric functions on scales from pixels to global and days to decades needs to be coordinated on an international scale in order to address the questions related to global change. An international program of space observations and ground research was described.

High Performance Geostatistical Modeling of Biospheric Resources

NASA Astrophysics Data System (ADS)

Pedelty, J. A.; Morisette, J. T.; Smith, J. A.; Schnase, J. L.; Crosier, C. S.; Stohlgren, T. J.

2004-12-01

We are using parallel geostatistical codes to study spatial relationships among biospheric resources in several study areas. For example, spatial statistical models based on large- and small-scale variability have been used to predict species richness of both native and exotic plants (hot spots of diversity) and patterns of exotic plant invasion. However, broader use of geostastics in natural resource modeling, especially at regional and national scales, has been limited due to the large computing requirements of these applications. To address this problem, we implemented parallel versions of the kriging spatial interpolation algorithm. The first uses the Message Passing Interface (MPI) in a master/slave paradigm on an open source Linux Beowulf cluster, while the second is implemented with the new proprietary Xgrid distributed processing system on an Xserve G5 cluster from Apple Computer, Inc. These techniques are proving effective and provide the basis for a national decision support capability for invasive species management that is being jointly developed by NASA and the US Geological Survey.

Value orientation and payment for ecosystem services: Perceived detrimental consequences lead to willingness-to-pay for ecosystem services.

PubMed

Obeng, Elizabeth Asantewaa; Aguilar, Francisco Xavier

2018-01-15

This research analyzed whether the three distinct value orientations posited under the Value-Belief-Norm (VBN) model determine willingness-to-pay (WTP) for a payment for ecosystem services (PES) program. A survey instrument gathered U.S. residents' knowledge and attitudes toward ecosystem services and PES, and elicited WTP for the restoration of a hypothetical degraded forest watershed for improved ecosystem services. Data from over 1000 respondents nationwide were analyzed using exploratory factor analysis (EFA) and ordered logistic regression. Urban respondents were more familiar with the concepts of ecosystem service and PES than rural respondents but familiarity did not yield statistically different WTP estimates. Based on results from the EFA, we posit that latent value orientations might be distinguished as 'detrimental', 'biospheric' and 'beneficial (egoistic)' - as compared to 'altruistic', 'biospheric' and 'egoistic' as suggested in the VBN's general awareness of consequences scale. Awareness of biospheric and detrimental consequences along with ascriptions to personal norms had positive and significant effects on stated WTP. Beneficial (egoistic) value orientation was negatively associated with WTP and carried a negative average WTP per household per year (US$ -30.48) for the proposed PES restoration program as compared with biospheric (US$ 15.53) and detrimental (US$ 3.96) orientations. Besides personal norms, awareness of detrimental consequences to human wellbeing from environmental degradation seems the stronger driver of WTP for the restoration and protection of forest watershed ecosystem services under a PES program. Copyright © 2017 Elsevier Ltd. All rights reserved.

Snowball Earth: Response of the biosphere?

NASA Astrophysics Data System (ADS)

Runnegar, B.

2001-05-01

Snowball Earth is a script for global catastrophe that rivals giant impact theories in the likely severity of its environmental effects. This is particularly true for the "hard" version of the hypothesis, which requires the atmosphere to be effectively isolated from the ocean so that its carbon dioxide concentration can build up to the level ( ~100 PAL) ultimately required to melt the ice. However, coupled GCM-EMB models (Hyde et al. Nature 405, 425-430; Crowley & Hyde, GRL 28, 283-286) allow equatorial open water solutions under plausible Neoproterozoic conditions. These "softer" scenarios are more appealing if one considers the possible effects of snowball Earth episodes on the global biosphere. The meager Neoproterozoic fossil record makes it difficult to observe the biospheric response directly, but we know from evolutionary trees constructed from aligned protein and DNA sequences from living organisms, calibrated by the fossil record, that many lines of descent passed through the Cryogenian glacial periods. They include various kinds of prokaryotic and eukaryotic algae, a range of protists, and probably, a number of different kinds of animals and fungi. In addition, most of the microbial groups shown on comprehensive 16S rRNA trees have molecular clock ages that predate the snowball episodes. As the global environmental perturbations associated with the "hard" snowball hypothesis (freezing temperatures; huge and rapid changes in temperature; sudden carbon dioxide overload) are thought to have been biologically limiting during the Phanerozoic, the inferred response of the biosphere to Neoprotereozic glaciations may, indeed, provide a way of testing alternative snowball Earth scenarios.

Life systems for a lunar base

NASA Technical Reports Server (NTRS)

Nelson, Mark; Hawes, Philip B.; Augustine, Margret

1992-01-01

The Biosphere 2 project is pioneering work on life systems that can serve as a prototype for long-term habitation on the Moon. This project will also facilitate the understanding of the smaller systems that will be needed for initial lunar base life-support functions. In its recommendation for a policy for the next 50 years in space, the National Commission on Space urged, 'To explore and settle the inner Solar System, we must develop biospheres of smaller size, and learn how to build and maintain them' (National Commission on Space, 1986). The Biosphere 2 project, along with its Biospheric Research and Development Center, is a materially closed and informationally and energetically open system capable of supporting a human crew of eight, undertaking work to meet this need. This paper gives an overview of the Space Biospheres Ventures' endeavor and its lunar applications.

Preliminary Feasibility Study of a Hybrid Solar and Modular Pumped Storage Hydro System at Biosphere 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lansey, Kevin; Hortsman, Chris

2016-10-01

In this study, the preliminary feasibility of a hybrid solar and modular pumped storage system designed for high energy independence at Biosphere 2 is assessed. The system consists of an array of solar PV panels that generate electricity during the day to power both Biosphere 2 and a pump that sends water through a pipe to a tank at a high elevation. When solar power is not available, the water is released back down the pipe towards a tank at a lower elevation, where it passes through a hydraulic water turbine to generate hydroelectricity to power Biosphere 2. The hybridmore » system is sized to generate and store enough energy to enable Biosphere 2 to operate without a grid interconnection on an average day.« less

Biosphere as a complex life-support system (LSS) for human civilization

NASA Astrophysics Data System (ADS)

Pechurkin, Nickolay

As a continuously growing link of the Biosphere, we should keep in mind that biotic cycles induced by flows of a solar energy are the source of Biosphere and ecosystems functioning. Our pressure on the Biosphere which is connected with biotic cycle’s alterations and damages is menacingly growing. There are innumerable examples of atmosphere, water and soil pollution. We have contaminated even Earth-Space orbits with different uncontrolled debris. Ecological Footprint (EF) is a proper quantitative measure of anthropogenic impact on the Biosphere and ecosystems functioning. The comparative dynamics of the United Nations’ Human Development Index (HDI) and Ecological Footprint (EF) is discussed in the paper. The main call of sustainable development of mankind: all humans can have opportunity to fulfill their lives without degrading the Biosphere. To support sustainability, we should make an effort to develop each nation and the mankind as a whole with a high HDI and with a low ecological footprint. It means: to have high level of HDI at low level of EF. But current tendency of economical and social development shows: the higher HDI, the bigger EF. EF of mankind is rising threateningly. Now actual pressure of the human civilization of our planet (2014) upon 60 % exceeds its potential possibilities (biological capacity, measured as the area of "global" green hectares). It means that now we require more than 1.5 planets of the Earth’s type for sustainable development. It leads to ecological incident in the scale of Biosphere. Our Biosphere is the large, multilevel, hierarchically organized system, and our civilization is only a part of it. This part is not central; it can disappear for ever, if we do not cope to be included in the Biosphere as a great complex system. An example of Krasnoyarsk region as a representative region with high level of industry and technological energy production is considered in the paper. This work was supported by the Russian Foundation for Basic Research, project number 13-06-00060.

Demonstrations To Save the World.

ERIC Educational Resources Information Center

Brown, Tom; Dias, Michael

2003-01-01

Presents two environmental modeling activities, biosphere bubbles and a crystal ball of population growth, along with a related online exercise and explains proven teaching methods that make demonstrations less teacher-centered and more engaging for groups of collaborating students. (KHR)

Global Catastrophes in Earth History: An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality

NASA Technical Reports Server (NTRS)

1988-01-01

Topics addressed include: Cretaceous-Tertiary mass extinctions; geologial indicators for meteorite collisions; carbon dioxide catastrophes; volcanism; climatic changes; geochemistry; mineralogy; fossil records; biospheric traumas; stratigraphy; mathematical models; and ocean dynamics.

Man and the Biosphere: Ground Truthing Coral Reefs for the St. John Island Biosphere Reserve.

ERIC Educational Resources Information Center

Brody, Michael J.; And Others

Research on the coral species composition of St. John's reefs in the Virgin Islands was conducted through the School for Field Studies (SFS) Coral Reef Ecology course (winter 1984). A cooperative study program based on the United Nations Educational, Scientific, and Cultural Organization's (Unesco) program, Man and the Biosphere, was undertaken by…

Developing Starlight connections with UNESCO sites through the Biosphere Smart

NASA Astrophysics Data System (ADS)

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 committed to the preservation of the values associated with the night sky. A new step ahead in our common task of protecting the starry skies at UNESCO sites.

Initial experimental results from the Laboratory Biosphere closed ecological system facility

NASA Astrophysics Data System (ADS)

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 scaled up for natural ecosystems and the global environment.

Application of AVHRR vegetation index to study atmosphere-biosphere exchange of CO2: Results from a 3-D tracer transport model

NASA Technical Reports Server (NTRS)

Fung, Inez Y.; Tucker, C. J.; Prentice, Katharine C.

1985-01-01

The 'normalized difference vegetation indices' (NVI) derived from AVHRR radiances are combined with field data of soil respiration and a global map of net primary productivity to prescribe, for the globe, the seasonal exchange of CO2 between the atmosphere and the terrestrial biosphere. The monthly fluxes of CO2 thus obtained are used as inputs to a 3-D tracer transport model which uses winds generated by a 3-D atmospheric general circulation model to advect CO2 as an inert constituent. Analysis of the 3-D model results shows reasonable agreement between the simulated and observed annual cycles of atmospheric CO2 at the locations of the remote monitoring stations. The application is shown of atmospheric CO2 distributions to calibrate the NVI in terms of carbon fluxes. The approach suggests that the NVI may be used to provide quantitative information about long term and global scale variations of photosynthetic activity and of atmospheric CO2 concentrations provided that variations in the atmospheric circulation and in atmospheric composition are known.

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

NASA Astrophysics Data System (ADS)

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 proven using 14C-radiolabelled substrates for methanogenesis, bacterial cell counts and intact phospholipids. Altogether, these results point to an overlap of abiotic thermal degradation reactions going on in the same part of the sedimentary column as where a deep biosphere exists. The organic matter preserved in Nankai Trough sediments is of the type that generates putative feedstocks for microbial activity, namely oxygenated compounds and hydrocarbons. Furthermore, the rates of thermal degradation calculated from the kinetic model closely resemble rates of respiration and electron donor consumption independently measured in other deep biosphere environments. We deduce that abiotically driven degradation reactions have provided substrates for microbial activity in deep sediments at this convergent continental margin.

Using the kingfisher (Alcedo atthis) as a bioindicator of PCBs and PBDEs in the dinghushan biosphere reserve, China.

PubMed

Mo, Ling; Wu, Jiang-Ping; Luo, Xiao-Jun; Li, Ke-Lin; Peng, Ying; Feng, An-Hong; Zhang, Qiang; Zou, Fa-Sheng; Mai, Bi-Xian

2013-07-01

The Dinghushan Biosphere Reserve is a nature reserve and a site for the study of tropical and subtropical forest ecosystems. Rapid industrialization and intensive electronic waste-recycling activities around the biosphere reserve have resulted in elevated levels of industrial organic contaminants in the local environment that may cause adverse effects on wildlife that inhabits this area. In the present study, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and 2 alternative brominated flame retardants (BFRs)-decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE)-were investigated in the biosphere reserve and a reference site by using the kingfisher (Alcedo atthis) as a bioindicator. Residue concentrations in kingfishers from the Dinghushan Biosphere Reserve ranged from 490 ng/g to 3000 ng/g, 51 ng/g to 420 ng/g, 0.44 ng/g to 90 ng/g, and 0.04 ng/g to 0.87 ng/g lipid weight for ∑PCBs, ∑PBDEs, DBDPE, and BTBPE, respectively. With the exception of the BTBPE, these levels were 2 to 5 times higher than those detected in kingfishers from the reference site. The contaminant patterns from the biosphere reserve were also different, with larger PCB contributions in comparison with the reference site. The estimated predator-prey biomagnification factors (BMFs) showed that most of the PCB and PBDE congeners and BTBPE were biomagnified in kingfishers from the biosphere reserve. The calculated toxic equivalent quantity (TEQ) concentrations of major coplanar PCB congeners in kingfishers from the biosphere reserve ranged from 18 pg/g to 66 pg/g wet weight, with some of these TEQ concentrations reaching or exceeding the levels known to impair bird reproduction and survival. Copyright © 2013 SETAC.

How well do terrestrial biosphere models simulate coarse-scale runoff in the contiguous United States?

Treesearch

C.R. Schwalm; D.N. Huntzinger; R.B. Cook; Y. Wei; I.T. Baker; R.P. Neilson; B. Poulter; Peter Caldwell; G. Sun; H.Q. Tian; N. Zeng

2015-01-01

Significant changes in the water cycle are expected under current global environmental change. Robust assessment of present-day water cycle dynamics at continental to global scales is confounded by shortcomings in the observed record. Modeled assessments also yield conflicting results which are linked to differences in model structure and simulation protocol. Here we...

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

The biosphere: Problems and solutions; Proceedings of the Miami International Symposium on the Biosphere, Miami Beach, FL, April 23, 24, 1984

NASA Astrophysics Data System (ADS)

Veziroglu, T. N.

The objective of the Miami International Symposium on the Biosphere was to provide a forum for the presentation of the latest research findings on the environmental effects of human activities. The topics discussed are related to biosphere reserves, environmental aspects of hydrocarbon fuels, radioactivity and nuclear waste, land management, acid rains, water quality, water resources, coastal resources management, the pollution of rivers, industrial waste, economic development and the environment, health hazards and solutions, endangered species, environmentally compatible systems, space pollution, and global considerations. Attention is given to questions regarding global security and sustainable development, environethics as a global strategy for environmental quality, a gestalt approach to the environment, potential indicators for monitoring biosphere reserves, a review of regional impacts associated with the development of U.S. synthetic fuel resources, water resources in the Soviet Union, and pollution-free pesticides.

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

NASA Astrophysics Data System (ADS)

Migliavacca, M.; Sonnentag, O.; Keenan, T. F.; Cescatti, A.; O'Keefe, J.; Richardson, A. D.

2012-06-01

Phenology, the timing of recurring life cycle events, controls numerous land surface feedbacks to the climate system through the regulation of exchanges of carbon, water and energy between the biosphere and atmosphere. Terrestrial biosphere models, however, are known to have systematic errors in the simulation of spring phenology, which potentially could propagate to uncertainty in modeled responses to future climate change. Here, we used the Harvard Forest phenology record to investigate and characterize sources of uncertainty in predicting phenology, and the subsequent impacts on model forecasts of carbon and water cycling. Using a model-data fusion approach, we combined information from 20 yr of phenological observations of 11 North American woody species, with 12 leaf bud-burst models that varied in complexity. Akaike's Information Criterion indicated support for spring warming models with photoperiod limitations and, to a lesser extent, models that included chilling requirements. We assessed three different sources of uncertainty in phenological forecasts: parameter uncertainty, model uncertainty, and driver uncertainty. The latter was characterized running the models to 2099 using 2 different IPCC climate scenarios (A1fi vs. B1, i.e. high CO2 emissions vs. low CO2 emissions scenario). Parameter uncertainty was the smallest (average 95% Confidence Interval - CI: 2.4 days century-1 for scenario B1 and 4.5 days century-1 for A1fi), whereas driver uncertainty was the largest (up to 8.4 days century-1 in the simulated trends). The uncertainty related to model structure is also large and the predicted bud-burst trends as well as the shape of the smoothed projections varied among models (±7.7 days century-1 for A1fi, ±3.6 days century-1 for B1). The forecast sensitivity of bud-burst to temperature (i.e. days bud-burst advanced per 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.

Biosphere 2 test module experimentation program

NASA Technical Reports Server (NTRS)

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

1990-01-01

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

Rarity in aquatic microbes: placing protists on the map.

PubMed

Logares, Ramiro; Mangot, Jean-François; Massana, Ramon

2015-12-01

Most microbial richness at any given time tends to be represented by low-abundance (rare) taxa, which are collectively referred to as the "rare biosphere". Here we review works on the rare biosphere using high-throughput sequencing (HTS), with a particular focus on unicellular eukaryotes or protists. Evidence thus far indicates that the rare biosphere encompasses dormant as well as metabolically active microbes that could potentially play key roles in ecosystem functioning. Rare microbes appear to have biogeography, and sometimes the observed patterns can be similar to what is observed among abundant taxa, suggesting similar community-structuring mechanisms. There is limited evidence indicating that the rare biosphere contains taxa that are phylogenetically distantly related to abundant counterparts; therefore, the rare biosphere may act as a reservoir of deep-branching phylogenetic diversity. The potential role of the rare biosphere as a bank of redundant functions that can help to maintain continuous ecosystem function following oscillations in taxonomic abundances is hypothesized as its main ecological role. Future studies focusing on rare microbes are crucial for advancing our knowledge of microbial ecology and evolution and unveiling their links with ecosystem function. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Opportunities and challenges in studies of deep life (Invited)

NASA Astrophysics Data System (ADS)

Edwards, K. J.

2010-12-01

Over the past two decades, there has been an increasing awareness within the geological, microbiological, and oceanographic communities of the potentially vast microbial biosphere that is harbored beneath the surface of the Earth. With this awareness has come a mounting effort to study this potential biome - to better quantify biomass abundance, activity, and biogeochemical activity. In the Earth system, the largest deep subsurface biome is also the least accessible - the deep ocean subsurface biosphere. The oceanic deep biosphere also has greatest potential for influencing global scale biogeochemical processes -the carbon and energy cycles for example, and other elemental cycles. To address these topics and mount interdisciplinary efforts to study the deep subsurface marine biosphere, we have recently formed a center in support integrative, collaborative investigations. The national science foundation Center for Dark Biosphere Investigations (C-DEBI), has been initiated for the explicit purpose of resolving the extent, function, dynamics and implications of the subseafloor biosphere. This talk will discuss C-DEBI science, with focus on some of the opportunities and challenges in the study of deep life in the ocean, and the role that C-DEBI will play in meeting them

The Jena Diversity Model: Towards a Richer Representation of the Terrestrial Biosphere for Earth System Modelling

NASA Astrophysics Data System (ADS)

Pavlick, R.; Reu, B.; Bohn, K.; Dyke, J.; Kleidon, A.

2010-12-01

The terrestrial biosphere is a complex, self-organizing system which is continually both adapting to and altering its global environment. It also exhibits a vast diversity of vegetation forms and functioning. However, the terrestrial biosphere components within current state-of-the-art Earth System Models abstract this diversity in to a handful of relatively static plant functional types. These coarse and static representations of functional diversity might contribute to overly pessimistic projections regarding terrestrial ecosystem responses to scenarios of global change (e.g. Amazonian and boreal forest diebacks). In the Jena Diversity (JeDi) model, we introduce a new approach to vegetation modelling with a richer representation of functional diversity, based not on plant functional types, but on unavoidable plant ecophysiological trade-offs, which we hypothesize should be more stable in time. The JeDi model tests a large number of plant growth strategies. Each growth strategy is simulated using a set of randomly generated parameter values, which characterize its functioning in terms of carbon allocation, ecophysiology, and phenology, which are then linked to the growing conditions at the land surface. The model is constructed in such a way that these parameters inherently lead to ecophysiological trade-offs, which determine whether a growth strategy is able to survive and reproduce under the prevalent climatic conditions. Kleidon and Mooney (2000) demonstrated that this approach is capable of reproducing the geographic distribution of species richness. More recently, we have shown the JeDi model can explain other biogeographical phenomena including the present-day global pattern of biomes (Reu et al., accepted), ecosystem evenness (Kleidon et al. 2009), and possible mechanisms for biome shifts and biodiversity changes under scenarios of global warming (Reu et al., submitted). We have also evaluated the simulated biogeochemical fluxes from JeDi against a variety of site, field, and satellite observations (Pavlick et al., submitted) following a protocol established by the Carbon-Land Model Intercomparison Project (Randerson et al. 2009). We found that the global patterns of biogeochemical fluxes and land surface properties are reasonably well simulated using this bottom-up trade-off approach and compare favorably with other state of the art terrestrial biosphere models. Here, we present some results from JeDi simulations, wherein we varied the modelled functional diversity to quantify its impact on terrestrial biogeochemical fluxes under both present-day conditions and projected scenarios of global change. We also present results from a set of simulations wherein we vary the ability of the modelled ecosystems to adapt through changes in functional composition, leading to different projection responses of the carbon cycle to global warming. This plant functional tradeoff approach sets the foundation for many applications, including exploring the emergence and climatic impacts of major vegetation transitions throughout the last 400 million years as well as quantifying the significance of preserving functional diversity to hedge against uncertain climates in the future.

Response of the rare biosphere to environmental stressors in a highly diverse ecosystem (Zodletone spring, OK, USA).

PubMed

Coveley, Suzanne; Elshahed, Mostafa S; Youssef, Noha H

2015-01-01

Within highly diverse ecosystems, the majority of bacterial taxa are present in low abundance as members of the rare biosphere. The rationale for the occurrence and maintenance of the rare biosphere, and the putative ecological role(s) and dynamics of its members within a specific ecosystem is currently debated. We hypothesized that in highly diverse ecosystems, a fraction of the rare biosphere acts as a backup system that readily responds to environmental disturbances. We tested this hypothesis by subjecting sediments from Zodletone spring, a sulfide- and sulfur-rich spring in Southwestern OK, to incremental levels of salinity (1, 2, 3, 4, and 10% NaCl), or temperature (28°, 30°, 32°, and 70 °C), and traced the trajectories of rare members of the community in response to these manipulations using 16S rRNA gene analysis. Our results indicate that multiple rare bacterial taxa are promoted from rare to abundant members of the community following such manipulations and that, in general, the magnitude of such recruitment is directly proportional to the severity of the applied manipulation. Rare members that are phylogenetically distinct from abundant taxa in the original sample (unique rare biosphere) played a more important role in the microbial community response to environmental disturbances, compared to rare members that are phylogenetically similar to abundant taxa in the original sample (non-unique rare biosphere). The results emphasize the dynamic nature of the rare biosphere, and highlight its complexity and non-monolithic nature.

Evaluation of the Committed Carbon Emissions and Global Warming due to the Permafrost Carbon Feedback

NASA Astrophysics Data System (ADS)

Elshorbany, Y. F.; Schaefer, K. M.; Jafarov, E. E.; Yumashev, D.; Hope, C.

2017-12-01

We quantify the increase in carbon emissions and temperature due to Permafrost Carbon feedback (PCF), defined as the amplification of anthropogenic warming due to carbon emissions from thawing permafrost (i.e., of near-surface layers to 3 m depth). We simulate the Committed PCF emissions, the cumulative total emissions from thawing permafrost by 2300 for a given global temperature increase by 2100, and investigate the resulting global warming using the Simple Biosphere/Carnegie-Ames-Stanford Approach SiBCASA model. We estimate the committed PCF emissions and warming for the Fifth Assessment Report, Representative Concentration Pathway scenarios 4.5 and 8.5 using two ensembles of five projections. For the 2 °C warming target of the global climate change treaty, committed PCF emissions increase to 24 Gt C by 2100 and 76 Gt C by 2300 and the committed PCF warming is 0.23 °C by 2300. Our calculations show that as the global temperature increase by 2100 approaches 5.8 °C, the entire stock of frozen carbon thaws out, resulting in maximum committed PCF emissions of 560 Gt C by 2300.

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

ERIC Educational Resources Information Center

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…

Biodiversity of Terrestrial Vegetation during Past Warm Periods

NASA Astrophysics Data System (ADS)

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

2016-12-01

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

False Negatives for Remote Life Detection on Ocean-Bearing Planets: Lessons from the Early Earth

NASA Astrophysics Data System (ADS)

Reinhard, Christopher T.; Olson, Stephanie L.; Schwieterman, Edward W.; Lyons, Timothy W.

2017-04-01

Ocean-atmosphere chemistry on Earth has undergone dramatic evolutionary changes throughout its long history, with potentially significant ramifications for the emergence and long-term stability of atmospheric biosignatures. Though a great deal of work has centered on refining our understanding of false positives for remote life detection, much less attention has been paid to the possibility of false negatives, that is, cryptic biospheres that are widespread and active on a planet's surface but are ultimately undetectable or difficult to detect in the composition of a planet's atmosphere. Here, we summarize recent developments from geochemical proxy records and Earth system models that provide insight into the long-term evolution of the most readily detectable potential biosignature gases on Earth - oxygen (O2), ozone (O3), and methane (CH4). We suggest that the canonical O2-CH4 disequilibrium biosignature would perhaps have been challenging to detect remotely during Earth's ˜4.5-billion-year history and that in general atmospheric O2/O3 levels have been a poor proxy for the presence of Earth's biosphere for all but the last ˜500 million years. We further suggest that detecting atmospheric CH4 would have been problematic for most of the last ˜2.5 billion years of Earth's history. More broadly, we stress that internal oceanic recycling of biosignature gases will often render surface biospheres on ocean-bearing silicate worlds cryptic, with the implication that the planets most conducive to the development and maintenance of a pervasive biosphere will often be challenging to characterize via conventional atmospheric biosignatures.

The Ecosystem Concept and Linking Models of Physical-Chemical Processes to Ecological Responses: Introduction and Annotated Bibliography

DTIC Science & Technology

2007-07-01

Schneider, D. C. 1994. Quantitative ecology. Spatial and temporal scaling. Academic Press. Shugart, H. H. 1990. Ecological models and the ecotone . In: The...ecology and management of aquatic-terrestrial ecotones . Man and the biosphere series, Vol. 4. ed. R. J. Naiman and H. Decamps, 23-36. Paris, France

MODELING THE DYNAMICS OF THE INTEGRATED EARTH SYSTEM AND THE VALUE OF GLOBAL ECOSYSTEM SERVICES USING THE GUMBO MODEL. (R827169)

EPA Science Inventory

A global unified metamodel of the biosphere (GUMBO) was developed to simulate the integrated earth system and assess the dynamics and values of ecosystem services. It is a `metamodel' in that it represents a synthesis and a simplification of several existing dynamic gl...

Global variability in leaf respiration in relation to climate, plant functional types and leaf traits

Treesearch

Owen K. Atkin; Keith J. Bloomfield; Peter B. Reich; Mark G. Tjoelker; Gregory P. Asner; Damien Bonal; Gerhard Bonisch; Matt G. Bradford; Lucas A. Cernusak; Eric G. Cosio; Danielle Creek; Kristine Y. Crous; Tomas F. Domingues; Jeffrey S. Dukes; John J. G. Egerton; John R. Evans; Graham D. Farquhar; Nikolaos M. Fyllas; Paul P. G. Gauthier; Emanuel Gloor; Teresa E. Gimeno; Kevin L. Griffin; Rossella Guerrieri; Mary A. Heskel; Chris Huntingford; Franc_oise Yoko Ishida; Jens Kattge; Hans Lambers; Michael J. Liddell; Jon Lloyd; Christopher H. Lusk; Roberta E. Martin; Ayal P. Maksimov; Trofim C. Maximov; Yadvinder Malhi; Belinda E. Medlyn; Patrick Meir; Lina M. Mercado; Nicholas Mirotchnick; Desmond Ng; Ulo Niinemets; Odhran S. O’Sullivan; Oliver L. Phillips; Lourens Poorter; Pieter Poot; I. Colin Prentice; Norma Salinas; Lucy M. Rowland; Michael G. Ryan; Stephen Sitch; Martijn Slot; Nicholas G. Smith; Matthew H. Turnbull; Mark C. VanderWel; Fernando Valladares; Erik J. Veneklaas; Lasantha K. Weerasinghe; Christian Wirth; Ian J. Wright; Kirk R. Wythers; Jen Xiang; Shuang Xiang; Joana Zaragoza-Castells

2015-01-01

A challenge for the development of terrestrial biosphere models (TBMs) and associated land surface components of Earth system models (ESMs) is improving representation of carbon (C) exchange between terrestrial plants and the atmosphere, and incorporating biological variation arising from diversity in plant functional types (PFTs) and climate (Sitch et al.,...

QND &NDASH; DESIGNING A PARTICIPATORY SCENARIO MODELING TOOL TO INTEGRATE TECHNOLOGY, ECOLOGY, AND SOCIOLOGY IN GUATEMALA&RSQUO;S MAYA BIOSPHERE RESERVE AND BEYOND

EPA Science Inventory

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...

Simulation of carbon isotope discrimination of the terrestrial biosphere

NASA Astrophysics Data System (ADS)

Suits, N. S.; Denning, A. S.; Berry, J. A.; Still, C. J.; Kaduk, J.; Miller, J. B.; Baker, I. T.

2005-03-01

We introduce a multistage model of carbon isotope discrimination during C3 photosynthesis and global maps of C3/C4 plant ratios to an ecophysiological model of the terrestrial biosphere (SiB2) in order to predict the carbon isotope ratios of terrestrial plant carbon globally at a 1° resolution. The model is driven by observed meteorology from the European Centre for Medium-Range Weather Forecasts (ECMWF), constrained by satellite-derived Normalized Difference Vegetation Index (NDVI) and run for the years 1983-1993. Modeled mean annual C3 discrimination during this period is 19.2‰; total mean annual discrimination by the terrestrial biosphere (C3 and C4 plants) is 15.9‰. We test simulation results in three ways. First, we compare the modeled response of C3 discrimination to changes in physiological stress, including daily variations in vapor pressure deficit (vpd) and monthly variations in precipitation, to observed changes in discrimination inferred from Keeling plot intercepts. Second, we compare mean δ13C ratios from selected biomes (Broadleaf, Temperate Broadleaf, Temperate Conifer, and Boreal) to the observed values from Keeling plots at these biomes. Third, we compare simulated zonal δ13C ratios in the Northern Hemisphere (20°N to 60°N) to values predicted from high-frequency variations in measured atmospheric CO2 and δ13C from terrestrially dominated sites within the NOAA-Globalview flask network. The modeled response to changes in vapor pressure deficit compares favorably to observations. Simulated discrimination in tropical forests of the Amazon basin is less sensitive to changes in monthly precipitation than is suggested by some observations. Mean model δ13C ratios for Broadleaf, Temperate Broadleaf, Temperate Conifer, and Boreal biomes compare well with the few measurements available; however, there is more variability in observations than in the simulation, and modeled δ13C values for tropical forests are heavy relative to observations. Simulated zonal δ13C ratios in the Northern Hemisphere capture patterns of zonal δ13C inferred from atmospheric measurements better than previous investigations. Finally, there is still a need for additional constraints to verify that carbon isotope models behave as expected.

FluidCam 1&2 - UAV-based Fluid Lensing Instruments for High-Resolution 3D Subaqueous Imaging and Automated Remote Biosphere Assessment of Reef Ecosystems

NASA Astrophysics Data System (ADS)

Chirayath, V.; Instrella, R.

2016-02-01

We present NASA ESTO FluidCam 1 & 2, Visible and NIR Fluid-Lensing-enabled imaging payloads for Unmanned Aerial Vehicles (UAVs). Developed as part of a focused 2014 earth science technology grant, FluidCam 1&2 are Fluid-Lensing-based computational optical imagers designed for automated 3D mapping and remote sensing of underwater coastal targets from airborne platforms. Fluid Lensing has been used to map underwater reefs in 3D in American Samoa and Hamelin Pool, Australia from UAV platforms at sub-cm scale, which has proven a valuable tool in modern marine research for marine biosphere assessment and conservation. We share FluidCam 1&2 instrument validation and testing results as well as preliminary processed data from field campaigns. Petabyte-scale aerial survey efforts using Fluid Lensing to image at-risk reefs demonstrate broad applicability to large-scale automated species identification, morphology studies and reef ecosystem characterization for shallow marine environments and terrestrial biospheres, of crucial importance to improving bathymetry data for physical oceanographic models and understanding climate change's impact on coastal zones, global oxygen production, carbon sequestration.

FluidCam 1&2 - UAV-Based Fluid Lensing Instruments for High-Resolution 3D Subaqueous Imaging and Automated Remote Biosphere Assessment of Reef Ecosystems

NASA Astrophysics Data System (ADS)

Chirayath, V.

2015-12-01

We present NASA ESTO FluidCam 1 & 2, Visible and NIR Fluid-Lensing-enabled imaging payloads for Unmanned Aerial Vehicles (UAVs). Developed as part of a focused 2014 earth science technology grant, FluidCam 1&2 are Fluid-Lensing-based computational optical imagers designed for automated 3D mapping and remote sensing of underwater coastal targets from airborne platforms. Fluid Lensing has been used to map underwater reefs in 3D in American Samoa and Hamelin Pool, Australia from UAV platforms at sub-cm scale, which has proven a valuable tool in modern marine research for marine biosphere assessment and conservation. We share FluidCam 1&2 instrument validation and testing results as well as preliminary processed data from field campaigns. Petabyte-scale aerial survey efforts using Fluid Lensing to image at-risk reefs demonstrate broad applicability to large-scale automated species identification, morphology studies and reef ecosystem characterization for shallow marine environments and terrestrial biospheres, of crucial importance to improving bathymetry data for physical oceanographic models and understanding climate change's impact on coastal zones, global oxygen production, carbon sequestration.

Gaps in knowledge and data driving uncertainty in models of photosynthesis.

PubMed

Dietze, Michael C

2014-02-01

Regional and global models of the terrestrial biosphere depend critically on models of photosynthesis when predicting impacts of global change. This paper focuses on identifying the primary data needs of these models, what scales drive uncertainty, and how to improve measurements. Overall, there is a need for an open, cross-discipline database on leaf-level photosynthesis in general, and response curves in particular. The parameters in photosynthetic models are not constant through time, space, or canopy position but there is a need for a better understanding of whether relationships with drivers, such as leaf nitrogen, are themselves scale dependent. Across time scales, as ecosystem models become more sophisticated in their representations of succession they needs to be able to approximate sunfleck responses to capture understory growth and survival. At both high and low latitudes, photosynthetic data are inadequate in general and there is a particular need to better understand thermal acclimation. Simple models of acclimation suggest that shifts in optimal temperature are important. However, there is little advantage to synoptic-scale responses and circadian rhythms may be more beneficial than acclimation over shorter timescales. At high latitudes, there is a need for a better understanding of low-temperature photosynthetic limits, while at low latitudes the need is for a better understanding of phosphorus limitations on photosynthesis. In terms of sampling, measuring multivariate photosynthetic response surfaces are potentially more efficient and more accurate than traditional univariate response curves. Finally, there is a need for greater community involvement in model validation and model-data synthesis.

An Estimate of the Total DNA in the Biosphere

PubMed Central

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

2015-01-01

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. PMID:26066900

An Estimate of the Total DNA in the Biosphere.

PubMed

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.

Do we know what difference a delay makes?

NASA Astrophysics Data System (ADS)

Risbey, James S.; Handel, Mark David; Stone, Peter H.

In our original comment [Risbey et al.., 1991] we argued that the work of Schlesinger and Jiang [1991a] is too limited to determine whether or not (as they put it) “the penalty is small for a 10-year delay in initiating the transition to a regime in which greenhouse-gas emissions are reduced.” In their reply, Schlesinger and Jiang [1991b] (hereafter S&J) presented their reasons for concluding definitively that the penalty is small. However S&J's discussion of the evidence and literature on climate change and greenhouse warming contains significant omissions and mis-statements.In dismissing our concern that their model was too simple to evaluate the possibility of abrupt climate change, S&J rely on results from coupled ocean-atmosphere general circulation models (GCMs), in particular the work of Cubasch et al.. [1991]. Here S&J make two claims, one of which is incorrect and the other questionable. First, they claim that “the coupled atmosphere-ocean model of Cubasch et al. [1991] does allow the nonlinearities that Risbey et al.. [1991] criticize our simple model for not including.” In fact we explicitly mentioned changes in polar ice caps [Oerlemans and van der Veen, 1984] and release of methane from clathrates [MacDonald, 1990; Bell, 1982], neither of which are included in the model of Cubasch et al.. [1991]. Indeed, none of the published simulations of global warming using coupled ocean-atmosphere GCMs include these effects. Nor do these models yet include in their enhanced greenhouse simulations many of the possible feedbacks involving the carbon cycle and biosphere [Lashof, 1989; Bacastow and Maier-Reimer, 1990; Sellers, 1987] that could significantly alter greenhouse gas concentrations and surface properties. The published simulations with these models do allow for some changes in deep ocean circulation and cloud behavior, but there is controversy over whether they correctly represent these processes [Marotzke, 1991; Mitchell, 1989; Cess, 1990]. In addition the coupled models must be arbitrarily tuned (requiring substantial artificial fluxes of heat and moisture) to get the current climate right [Manabe et al.., 1991; Cubasch et al.., 1991]. Their greenhouse change simulations are at least partly constrained by these flux adjustments.

Rewiring food systems to enhance human health and biosphere stewardship

NASA Astrophysics Data System (ADS)

Gordon, Line J.; Bignet, Victoria; Crona, Beatrice; Henriksson, Patrik J. G.; Van Holt, Tracy; Jonell, Malin; Lindahl, Therese; Troell, Max; Barthel, Stephan; Deutsch, Lisa; Folke, Carl; Jamila Haider, L.; Rockström, Johan; Queiroz, Cibele

2017-10-01

Food lies at the heart of both health and sustainability challenges. We use a social-ecological framework to illustrate how major changes to the volume, nutrition and safety of food systems between 1961 and today impact health and sustainability. These changes have almost halved undernutrition while doubling the proportion who are overweight. They have also resulted in reduced resilience of the biosphere, pushing four out of six analysed planetary boundaries across the safe operating space of the biosphere. Our analysis further illustrates that consumers and producers have become more distant from one another, with substantial power consolidated within a small group of key actors. Solutions include a shift from a volume-focused production system to focus on quality, nutrition, resource use efficiency, and reduced antimicrobial use. To achieve this, we need to rewire food systems in ways that enhance transparency between producers and consumers, mobilize key actors to become biosphere stewards, and re-connect people to the biosphere.

Simulating Energy, Water and Carbon Fluxes at the Shortgrass Steppe Long Term Ecological Research (LTER) Site

NASA Astrophysics Data System (ADS)

Beltran-Przekurat, A. B.; Pielke, R. A.; Morgan, J. A.; Burke, I. C.

2005-12-01

Coupled atmospheric-biospheric models are a particularly valuable tool for studying the potential effects of land-use and land-cover changes on the near-surface atmosphere since the atmosphere and biosphere are allowed to dynamically interact through the surface and canopy energy balance. GEMRAMS is a coupled atmospheric-biospheric model comprised of an atmospheric model, RAMS, and an ecophysiological process-based model, GEMTM. In the first part of this study, the soil-vegetation-atmosphere-transfer (SVAT) scheme, LEAF2, from RAMS, coupled with GEMTM, are used to simulate energy, water and carbon fluxes over different cropping systems (winter wheat and irrigated corn) and over a mixed C3/C4 shortgrass prairie located at the USDA-ARS Central Plains Experimental Range near Nunn, Colorado, the LTER Shortgrass Steppe site. The new SVAT scheme, GEMLEAF, is forced with air temperature and humidity, wind speed and photosynthetic active radiation (PAR). Calculated canopy temperature and relative humidity, soil moisture and temperature and PAR are used to compute sunlit/shaded leaf photosynthesis (for C3 and C4 plant types) and respiration. Photosynthate is allocated to leaves, shoots, roots and reproductive organs with variable partition coefficients, which are functions of soil water conditions. As water stress increases, the fraction of photosynthate allocated to root growth increases. Leaf area index (LAI) is estimated from daily leaf biomass growth, using the vegetation-prescribed specific leaf area. Canopy conductance, computed and based on photosynthesis and relative humidity, is used to calculate latent heat flux. Simulated energy and CO2 fluxes are compared to observations collected using Bowen ratio flux towers during two growing seasons. Seasonality of the fluxes reflecting different plant phenologies agrees well with the observed patterns. In the second part of this study, simulations for two clear days are performed with GEMRAMS over a model domain centered at the SGS site. Simulated spatial differences in the energy fluxes can be associated with the highly heterogeneous landscape in this area.

Using Landsat, MODIS, and a Biophysical Model to Evaluate LST in Urban Centers

NASA Technical Reports Server (NTRS)

Al-Hamdan, Mohammad Z.; Quattrochi, Dale A.; Bounoua, Lahouari; Lachir, Asia; Zhang, Ping

2016-01-01

In this paper, we assessed and compared land surface temperature (LST) in urban centers using data from Landsat, MODIS, and the Simple Biosphere model (SiB2). We also evaluated the sensitivity of the models LST to different land cover types, fractions (percentages), and emissivities compared to reference points derived from Landsat thermal data. This was demonstrated in three climatologically- and morphologically-different cities of Atlanta, GA, New York, NY, and Washington, DC. Our results showed that in these cities SiB2 was sensitive to both the emissivity and the land cover type and fraction, but much more sensitive to the latter. The practical implications of these results are rather significant since they imply that the SiB2 model can be used to run different scenarios for evaluating urban heat island (UHI) mitigation strategies. This study also showed that using detailed emissivities per land cover type and fractions from Landsat-derived data caused a convergence of the model results towards the Landsat-derived LST for most of the studied cases. This study also showed that SiB2 LSTs are closer in magnitude to Landsat-derived LSTs than MODIS-derived LSTs. It is important, however, to emphasize that both Landsat and MODIS LSTs are not direct observations and, as such, do not represent a ground truth. More studies will be needed to compare these results to in situ LST data and provide further validation.

Response of the rare biosphere to environmental stressors in a highly diverse ecosystem (Zodletone spring, OK, USA)

PubMed Central

Coveley, Suzanne; Elshahed, Mostafa S.

2015-01-01

Within highly diverse ecosystems, the majority of bacterial taxa are present in low abundance as members of the rare biosphere. The rationale for the occurrence and maintenance of the rare biosphere, and the putative ecological role(s) and dynamics of its members within a specific ecosystem is currently debated. We hypothesized that in highly diverse ecosystems, a fraction of the rare biosphere acts as a backup system that readily responds to environmental disturbances. We tested this hypothesis by subjecting sediments from Zodletone spring, a sulfide- and sulfur-rich spring in Southwestern OK, to incremental levels of salinity (1, 2, 3, 4, and 10% NaCl), or temperature (28°, 30°, 32°, and 70 °C), and traced the trajectories of rare members of the community in response to these manipulations using 16S rRNA gene analysis. Our results indicate that multiple rare bacterial taxa are promoted from rare to abundant members of the community following such manipulations and that, in general, the magnitude of such recruitment is directly proportional to the severity of the applied manipulation. Rare members that are phylogenetically distinct from abundant taxa in the original sample (unique rare biosphere) played a more important role in the microbial community response to environmental disturbances, compared to rare members that are phylogenetically similar to abundant taxa in the original sample (non-unique rare biosphere). The results emphasize the dynamic nature of the rare biosphere, and highlight its complexity and non-monolithic nature. PMID:26312178

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

PubMed

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 sensitivity analyses.

Piezophilic Bacteria Isolated from Sediment of the Shimokita Coalbed, Japan

NASA Astrophysics Data System (ADS)

Fang, J.; Kato, C.; Hori, T.; Morono, Y.; Inagaki, F.

2013-12-01

The Earth is a cold planet as well as pressured planet, hosting both the surface biosphere and the deep biosphere. Pressure ranges over four-orders of magnitude in the surface biosphere and probably more in the deep biosphere. Pressure is an important thermodynamic property of the deep biosphere that affects microbial physiology and biochemistry. Bacteria that require high-pressure conditions for optimal growth are called piezophilic bacteria. Subseafloor marine sediments are one of the most extensive microbial habitats on Earth. Marine sediments cover more than two-thirds of the Earth's surface, and represent a major part of the deep biosphere. Owing to its vast size and intimate connection with the surface biosphere, particularly the oceans, the deep biosphere has enormous potential for influencing global-scale biogeochemical processes, including energy, climate, carbon and nutrient cycles. Therefore, studying piezophilic bacteria of the deep biosphere has important implications in increasing our understanding of global biogeochemical cycles, the interactions between the biosphere and the geosphere, and the evolution of life. Sediment samples were obtained during IODP Expedition 337, from 1498 meters below sea floor (mbsf) (Sample 6R-3), 1951~1999 mbsf (19R-1~25R-3; coalbed mix), and 2406 mbsf (29R-7). The samples were mixed with MB2216 growth medium and cultivated under anaerobic conditions at 35 MPa (megapascal) pressure. Growth temperatures were adjusted to in situ environmental conditions, 35°C for 6R-3, 45°C for 19R-1~25R-3, and 55°C for 29R-7. The cultivation was performed three times, for 30 days each time. Microbial cells were obtained and the total DNA was extracted. At the same time, isolation of microbes was also performed under anaerobic conditions. Microbial communities in the coalbed sediment were analyzed by cloning, sequencing, and terminal restriction fragment length polymorphism (t-RFLP) of 16S ribosomal RNA genes. From the partial 16S rRNA gene sequences, we have identified abundant Alkalibacterium sp. in 6R-3 and 29R-7 at the first HP cultivation. We also identified Haloactibacillus sp. in 6R-3 and Anoxybacillus related sp. in 19R-1~25R-3 at the third HP cultivation. These microorganisms are likely piezophiles and play an important role in degradation of sedimentary organic matter and production of microbial metabolites sustaining the deep microbial ecosystem in the Shimokita Coalbed. The complete 16S sequencing and isolation of piezophiles are now ongoing.

Evaluation of CH4 and N2O Budget of Natural Ecosystems and Croplands in Asia with a Process-based Model

NASA Astrophysics Data System (ADS)

Ito, A.

2017-12-01

Terrestrial ecosystems are important sink of carbon dioxide (CO2) but significant sources of other greenhouse gases such as methane (CH4) and nitrous oxide (N2O). To resolve the role of terrestrial biosphere in the climate system, we need to quantify total greenhouse gas budget with an adequate accuracy. In addition to top-down evaluation on the basis of atmospheric measurements, model-based approach is required for integration and up-scaling of filed data and for prediction under changing environment and different management practices. Since the early 2000s, we have developed a process-based model of terrestrial biogeochemical cycles focusing on atmosphere-ecosystem exchange of trace gases: Vegetation Integrated SImulator for Trace gases (VISIT). The model includes simple and comprehensive schemes of carbon and nitrogen cycles in terrestrial ecosystems, allowing us to capture dynamic nature of greenhouse gas budget. Beginning from natural ecosystems such as temperate and tropical forests, the models is now applicable to croplands by including agricultural practices such as planting, harvest, and fertilizer input. Global simulation results have been published from several papers, but model validation and benchmarking using up-to-date observations are remained for works. The model is now applied to several practical issues such as evaluation of N2O emission from bio-fuel croplands, which are expected to accomplish the mitigation target of the Paris Agreement. We also show several topics about basic model development such as revised CH4 emission affected by dynamic water-table and refined N2O emission from nitrification.

Terrestrial biosphere changes over the last 120 kyr

NASA Astrophysics Data System (ADS)

Hoogakker, B. A. A.; Smith, R. S.; Singarayer, J. S.; Marchant, R.; Prentice, I. C.; Allen, J. R. M.; Anderson, R. S.; Bhagwat, S. A.; Behling, H.; Borisova, O.; Bush, M.; Correa-Metrio, A.; de Vernal, A.; Finch, J. M.; Fréchette, B.; Lozano-Garcia, S.; Gosling, W. D.; Granoszewski, W.; Grimm, E. C.; Grüger, E.; Hanselman, J.; Harrison, S. P.; Hill, T. R.; Huntley, B.; Jiménez-Moreno, G.; Kershaw, P.; Ledru, M.-P.; Magri, D.; McKenzie, M.; Müller, U.; Nakagawa, T.; Novenko, E.; Penny, D.; Sadori, L.; Scott, L.; Stevenson, J.; Valdes, P. J.; Vandergoes, M.; Velichko, A.; Whitlock, C.; Tzedakis, C.

2016-01-01

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 and the BIOME4 vegetation model to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial-interglacial cycle. Simulated biome distributions using BIOME4 driven by HadCM3 and FAMOUS at the global scale over time generally agree well with those inferred from pollen data. Global average areas of grassland and dry shrubland, desert, and tundra biomes show large-scale increases during the Last Glacial Maximum, between ca. 64 and 74 ka BP and cool substages of Marine Isotope Stage 5, at the expense of the tropical forest, warm-temperate forest, and temperate forest biomes. These changes are reflected in BIOME4 simulations of global net primary productivity, showing good agreement between the two models. Such changes are likely to affect terrestrial carbon storage, which in turn influences the stable carbon isotopic composition of seawater as terrestrial carbon is depleted in 13C.