HR: 16:45h
AN: C34A-04    [Abstracts]
TI: Interactions Between Snow Cover, Frozen Soils, and the Carbon Cycle
AU: * Schaefer, K
EM: kevin.schaefer@nsidc.org
AF: National Snow and Ice Data Center (NSIDC), 449 UCB, University of Colorado, Boulder, CO 80309-0449, United States
AU: Zhang, T
EM: tzhang@nsidc.org
AF: National Snow and Ice Data Center (NSIDC), 449 UCB, University of Colorado, Boulder, CO 80309-0449, United States
AU: Baker, I
EM: baker@atmos.colostate.edu
AF: Department of Atmospheric Sciences, Colorado State University, Fort Collins, CO 80523- 1371, United States
AU: Lu, L
EM: lixin@atmos.colostate.edu
AF: Department of Atmospheric Sciences, Colorado State University, Fort Collins, CO 80523- 1371, United States
AB: We evaluate the complex interactions between frozen soil, snow cover, and the carbon cycle to understand how the soil thermal regime and freeze-thaw processes determine seasonal and inter-annual variability in terrestrial biomass, photosynthesis, respiration, and net CO2 fluxes over continental North America. We use the Simple Biosphere Carnegie-Ames-Stanford Approach (SiBCASA) model driven by the NCEP North American Regional Reanalysis (NARR), the GIMMS NDVI dataset, and in situ snow depth. To improve simulated soil temperatures, we integrated the Sturm et al. [1995] global snow classification system into the snow parameterization from the Community Climate Model and added simple representations of depth hoar and wind slab development. We also added the effects of peat development in tundra and boreal ecosystems. These additions give more realistic soil and snowpack thermodynamic properties, resulting in significantly improved simulated soil temperatures, freeze and thaw depths, and permafrost. Here, we compare simulated and observed soil temperatures, biomass, and carbon fluxes at eddy covariance flux towers representing a broad range of biome types and snow conditions, from permafrost and boreal forests at high latitudes, to deep snow in the northeast US, to wind blown snow of the Great Plains.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0704 Seasonally frozen ground
DE: 0736 Snow (1827, 1863)
DE: 0766 Thermodynamics (1011, 3611, 8411)
SC: Cryosphere [C]
MN: 2007 Fall Meeting