HR: 0800h
AN: B51C-0221    [Abstracts]
TI: GEMS-EDCM Upscaling of Terrestrial Carbon Dynamics From Sites to Regions
AU: * Liu, S
EM: sliu@usgs.gov
AF: SAIC, U.S. Geological Survey Center for Earth Resources Observation and Science (EROS), 47914 252nd Street, Sioux Falls, SD 57198 United States
AB: Estimating the dynamic evolution of the magnitude, spatial patterns, mechanisms, and uncertainty of carbon sources and sinks at the regional scale is challenging owing to the spatial and temporal variances and covariance of driving variables and the uncertainties in both the model and the input data. We develop the General Ensemble Biogeochemical Modeling System (GEMS) for upscaling carbon stocks and fluxes from sites to regions with measures of uncertainty. GEMS relies on site-scale biogeochemical models (e.g., the Erosion-Deposition-Carbon Model (EDCM) and CENTURY) to simulate the carbon dynamics at the site scale. The spatial deployment of the site-scale model in GEMS is based on the spatial and temporal joint frequency distribution of major driving variables (e.g., land cover and land use change, climate, soils, disturbances, and management). At the site scale, GEMS uses stochastic ensemble simulations to incorporate input uncertainty and to quantify uncertainty transfer from input to output. Using data assimilation techniques, GEMS simulations can be constrained by field and satellite observations or census data including estimates of net primary productivity from the Moderate Resolution Imaging Spectroradiometer (MODIS), grain yield and cropping practices, and forest inventories. The modeling philosophy embedded in GEMS makes it ideal for incorporating and assimilating information with various uncertainties at a range of spatio-temporal resolutions. The GEMS-EDCM has been applied to quantify the spatial and temporal distributions of the terrestrial carbon sources and sinks in the conterminous United States and in Africa.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0466 Modeling
DE: 1632 Land cover change
DE: 3275 Uncertainty quantification (1873)
SC: Biogeosciences [B]
MN: Fall Meeting 2005