Filters: Tags: Carbon cycle (X)
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The NRP had its beginnings in the late 1950's. Since that time, the program has grown to encompass a broad spectrum of scientific investigations. The sciences of hydrology, mathematics, chemistry, physics, ecology, biology, geology, and engineering are used to gain a fundamental understanding of the processes that affect the availability, movement, and quality of the Nation's water resources. Results of NRP's long-term research investigations often lead to the development of new concepts, techniques, and approaches that are applicable not only to the solution of current water problems, but also to future issues that may affect the Nation's water resources. Basic tools of hydrology that have been developed by the...
Categories: Project;
Types: ScienceBase Project;
Tags: Acid Mine Drainage,
Aquatic Habitat,
Arid Land Hydrology,
Carbon Cycle,
Contaminant Reactions and Transport,
For his MS thesis, Brendan Rogers used the vegetation model MC1 to simulate vegetation dynamics, associated carbon and nitrogen cycle, water budget and wild fire impacts across the western 2/3 of the states of Oregon and Washington using climate input data from the the PRISM group (Chris Daly, OSU) at a 30arc second (800m) spatial grain. The model was run from 1895 to 2100 assuming that nitrogen demand from the plants was always met so that the nitrogen concentrations in various plant parts never dropped below their minimum reported values. A CO2 enhancement effect increased productivity and water use efficiency as the atmospheric CO2 concentration increased. Future climate change scenarios were generated through...
For carbon sequestration the issues of monitoring, risk assessment, and verification of carbon content and storage efficacy are perhaps the most uncertain. Yet these issues are also the most critical challenges facing the broader context of carbon sequestration as a means for addressing climate change. In response to these challenges, Carbon Sequestration and Its Role in the Global Carbon Cycle presents current perspectives and research that combine five major areas:• The global carbon cycle and verification and assessment of global carbon sources and sinks • Potential capacity and temporal/spatial scales of terrestrial, oceanic, and geologic carbon storage • Assessing risks and benefits associated with terrestrial,...
Data provided here describe geochemical correction of carbon-14 in dissolved inorganic carbon (DIC) for groundwater age dating. Datasets include major ion chemistry of groundwater samples, model parameter inputs, and final corrected carbon-14 in DIC. Geochemical correction was completed in two phases: determination of reactive phase mole transfers through an inverse geochemical model (PHREEQC; Parkhurst and Appleo, 1992) and tracking of isotopic mass transfer among phases (NetpathXL; Parkhusrtand Charlton, 2008). Parkhurst, D.L., and Appelo, C.A.J., 2013, Description of input and examples for PHREEQC version 3—A computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical...
Climate change is causing measurable changes in rainfall patterns, and will likely cause increases in extreme rainfall events, with uncertain implications for key processes in ecosystem function and carbon cycling. We examined how variation in rainfall total quantity (Q), the interval between rainfall events (I), and individual event size (SE) affected soil water content (SWC) and three aspects of ecosystem function: leaf photosynthetic carbon gain (inline image), aboveground net primary productivity (ANPP), and soil respiration (inline image). We utilized rainout shelter-covered mesocosms (2.6 m3) containing assemblages of tallgrass prairie grasses and forbs. These were hand watered with 16 I�Q treatment combinations,...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Global Change Biology,
carbon cycle,
climate change,
mesocosm,
photosynthesis,
Soil gas methane and combustible gas concentrations collected from oil and gas well pad locations in Utah. Soil gas samples were measured on site and/or collected for later analysis as described in supporting documentation. Multiple sample locations around well head and depths within the soil profile are available for select sites. Supporting documents provide information of sample collection protocol and data quality assurance.
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Big Flat,
Big Indian North,
Big Indian South,
Big Valley,
Bluebell,
For his MS thesis, Brendan Rogers used the vegetation model MC1 to simulate vegetation dynamics, associated carbon and nitrogen cycle, water budget and wild fire impacts across the western 2/3 of the states of Oregon and Washington using climate input data from the the PRISM group (Chris Daly, OSU) at a 30arc second (800m) spatial grain. The model was run from 1895 to 2100 assuming that nitrogen demand from the plants was always met so that the nitrogen concentrations in various plant parts never dropped below their minimum reported values. A CO2 enhancement effect increased productivity and water use efficiency as the atmospheric CO2 concentration increased. Future climate change scenarios were generated through...
This release contains data from field and laboratory tests conducted by the USGS Groundwater Dating Laboratory between 2014 and 2017 during the development of a new dissolved and gas phase carbon dioxide sensor. The release also contains results of calibration, intercomparison, temperature, humidity, and stability experiments, as well as monitoring studies of CO2 in soil surface gas in the Amargosa Desert during the Toxic Substances Hydrology Amargosa Desert Research Site (ADRS) project, and measurements of dissolved CO2 (pCO2) in Upper Klamath Lake, in laboratory plant mesocosm studies at USGS headquarters in Reston, Virginia, as well as in creeks and streams in Northern Virginia.
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Amargosa Desert, NV,
Climatology,
Environmental Health,
Fairfax County,
Geochemistry,
For his MS thesis, Brendan Rogers used the vegetation model MC1 to simulate vegetation dynamics, associated carbon and nitrogen cycle, water budget and wild fire impacts across the western 2/3 of the states of Oregon and Washington using climate input data from the the PRISM group (Chris Daly, OSU) at a 30arc second (800m) spatial grain. The model was run from 1895 to 2100 assuming that nitrogen demand from the plants was always met so that the nitrogen concentrations in various plant parts never dropped below their minimum reported values. A CO2 enhancement effect increased productivity and water use efficiency as the atmospheric CO2 concentration increased. Future climate change scenarios were generated through...
Our research focuses on assessing the components of the Net Ecoystem Carbon Balance using the eddy covariance approach to measure atmospheric fluxes of heat, energy, carbon dioxide and methane and testing equipment and techniques to measure the tidal exchange of dissolved organic (DOC) and inorganic carbon (DIC). The atmospheric flux tower is located south of Solano Land Trust's Rush Ranch, a working ranch encompassing 2,070 acres of marsh and rolling grasslands that provides both recreational and educational experiences for the public (http://www.solanolandtrust.org/RushRanch.aspx). Lateral fluxes are being collected at the San Francisco Bay National Estuarine Research Reserve First Mallard water quality station...
Categories: Project;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Annual variability,
Aquatic Carbon,
Atmospheric fluxes,
Biogeochemistry,
CH4 emissions,
A discrete sample introduction module (DSIM) was developed and interfaced to a cavity ring-down spectrometer to enable measurements of methane and CO2 concentrations and 13C values with a commercially available cavity ring-down spectrometer (CRDS). The DSIM-CRDS system permits the analysis of limited volume (5 - 100-ml) samples ranging six orders-of-magnitude from 100% analyte to the lower limit of instrument detection (2 ppm). We demonstrate system performance for methane by comparing concentrations and 13C results obtained by the DSIM and traditional methods for a variety of sample types, including low concentration (nanomolar) seawater and high concentration (> 90%) natural gas. The expansive concentration range...
Categories: Data;
Tags: Geochemistry,
Temperate Northern Atlantic,
Temperate Northern Pacific,
U.S. Geological Survey,
USGS,
For his MS thesis, Brendan Rogers used the vegetation model MC1 to simulate vegetation dynamics, associated carbon and nitrogen cycle, water budget and wild fire impacts across the western 2/3 of the states of Oregon and Washington using climate input data from the the PRISM group (Chris Daly, OSU) at a 30arc second (800m) spatial grain. The model was run from 1895 to 2100 assuming that nitrogen demand from the plants was always met so that the nitrogen concentrations in various plant parts never dropped below their minimum reported values. A CO2 enhancement effect increased productivity and water use efficiency as the atmospheric CO2 concentration increased. Future climate change scenarios were generated through...
Cyanobacterial soil crusts are a community of microorganisms living in the soil surface of different habitats worldwide. Through photosynthesis, cyanobacteria produce extracellular polysaccharides (EPS) increasing the soil carbon (C) pool as carbohydrates. The layer of polysaccharides also acts as a mechanical structure surrounding the filamentous cyanobacteria that together with the soil particles form stable aggregates in the topsoil thus decreasing C loss by erosion. Thus despite their apparent importance to the dryland system we have only a limited understanding of their role and possible applications in dryland soil environments. This review draws on these disparate sources of information in order to provide...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Journal of Arid Environments,
carbohydrates,
carbon cycle,
eps,
nutrient sequestration,
Analyses of carbon isotope ratios (?13C) in soil organic matter (SOM) and soil respired CO2 provide insights into dynamics of the carbon cycle. ?13C analyses do not provide direct measures of soil CO2 efflux rates but are useful as a constraint in carbon cycle models. In many cases, ?13C analyses allow the identification of components of soil CO2 efflux as well as the relative contribution of soil to overall ecosystem CO2 fluxes. ?13C values provide a unique tool for quantifying historical shifts between C3 and C4 ecosystems over decadal to millennial time scales, which are relevant to climate change and land-use change issues. We identify the need to distinguish between ?13C analyses of SOM and those of soil CO2...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Ecological Applications,
Ecological Society of America,
below ground processes and global change,
c3 and c4 ecosystems,
carbon cycle,
NOTE: This data release has been deprecated. In support of the USGS LandCarbon project, field observations of stream and lake carbon gas fluxes and other water-quality data were collected from surface waters in the conterminous US. The sampling was designed to cover a variety of geographic, climatic, and environmental settings to better understand the ranges and distributions of carbon gas fluxes from surface waters. Field observations of carbon gas concentration and flux were paired with laboratory measurements of stream chemical characteristics. Locations were derived from field GPS values or from listed coordinates of USGS streamgages located at the sampling site. Discharge data was either measured in the field...
Categories: Data;
Types: Citation;
Tags: Carbon cycle,
Conterminous U.S.,
Inland waters,
USGS Science Data Catalog (SDC),
Water Resources
Fluxes of CO2 during the snow-covered season contribute to annual carbon budgets, but our understanding of the mechanisms controlling the seasonal pattern and magnitude of carbon emissions in seasonally snow-covered areas is still developing. In a subalpine meadow on Niwot Ridge, Colorado, soil CO2 fluxes were quantified with the gradient method through the snowpack in winter 2006 and 2007 and with chamber measurements during summer 2007. The CO2 fluxes of 0.71 ?mol m?2 s?1 in 2006 and 0.86 ?mol m?2 s?1 in 2007 are among the highest reported for snow-covered ecosystems in the literature. These fluxes resulted in 156 and 189 g C m?2 emitted over the winter, ~30% of the annual soil CO2 efflux at this site. In general,...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Biogeochemistry,
CO2 flux,
Carbon cycle,
Climate change,
Snowpack,
Forests sequester the majority of the terrestrial biosphere’s carbon and are key components of the global carbon cycle, potentially contributing substantial feedbacks to ongoing climatic changes. It is therefore remarkable that no consensus yet exists about the fundamental nature of tree mass growth (and thus carbon sequestration rate). Specifically, does tree mass growth rate increase, decrease, or stay the same with increasing tree size? The answer could have profound implications for our ability to forecast the role of forests in the global carbon cycle and to devise appropriate adaptation and mitigation strategies for forests in the face of rapid climatic changes. We will conduct the first global-scale characterization...
We have developed a dynamic land model (LM3V) able to simulate ecosystem dynamics and exchanges of water, energy, and CO2 between land and atmosphere. LM3V is specifically designed to address the consequences of land use and land management changes including cropland and pasture dynamics, shifting cultivation, logging, fire, and resulting patterns of secondary regrowth. Here we analyze the behavior of LM3V, forced with the output from the Geophysical Fluid Dynamics Laboratory (GFDL) atmospheric model AM2, observed precipitation data, and four historic scenarios of land use change for 1700–2000. Our analysis suggests a net terrestrial carbon source due to land use activities from 1.1 to 1.3 GtC/a during the 1990s,...
Categories: Publication;
Types: Citation;
Tags: CO2,
Carbon cycle,
dynamic land model,
land use,
veget
For his MS thesis, Brendan Rogers used the vegetation model MC1 to simulate vegetation dynamics, associated carbon and nitrogen cycle, water budget and wild fire impacts across the western 2/3 of the states of Oregon and Washington using climate input data from the the PRISM group (Chris Daly, OSU) at a 30arc second (800m) spatial grain. The model was run from 1895 to 2100 assuming that nitrogen demand from the plants was always met so that the nitrogen concentrations in various plant parts never dropped below their minimum reported values. A CO2 enhancement effect increased productivity and water use efficiency as the atmospheric CO2 concentration increased. Future climate change scenarios were generated through...
For his MS thesis, Brendan Rogers used the vegetation model MC1 to simulate vegetation dynamics, associated carbon and nitrogen cycle, water budget and wild fire impacts across the western 2/3 of the states of Oregon and Washington using climate input data from the the PRISM group (Chris Daly, OSU) at a 30arc second (800m) spatial grain. The model was run from 1895 to 2100 assuming that nitrogen demand from the plants was always met so that the nitrogen concentrations in various plant parts never dropped below their minimum reported values. A CO2 enhancement effect increased productivity and water use efficiency as the atmospheric CO2 concentration increased. Future climate change scenarios were generated through...
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