HR: 0830h
AN: B51E-1009    [PDF]
TI: Effect of Snow Formulation on Springtime Carbon, Heat and Moisture Fluxes in Northern Forests, Using the Simple Biosphere Model (SiB)
AU: * Baker, I T
EM: baker@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523-1371 United States
AU: Denning, A S
EM: denning@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523-1371 United States
AU: Schaefer, K
EM: kevin@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523-1371 United States
AU: Bakwin, P
EM: peter.bakwin@noaa.gov
AF: Climate Monitoring Diagnostics Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305 United States
AU: Davis, K
EM: cheas@essc.psu.edu
AF: The Pennsylvania State University, Department of Meteorology, University Park, PA 16802-5013 United States
AB: The treatment of springtime fluxes of carbon, heat and moisture present a considerable problem to biophysical models at sites where canopy phenology shows a distinct annual cycle. At these sites spring is a time of change from dormant to active canopy, and many forest biomes shift from carbon source to sink during this period. Simulations made using the Simple Biosphere Model (SiB2.5) have produced unrealistically large carbon fluxes into the terrestrial biosphere over northern forest areas during the spring months. SiB2.5 commonly retains a thin layer of snow late into the spring, which acts to keep soil temperatures cold thus suppressing soil respiration. The result is net ecosystem exchange (NEE) values that are more representative of midsummer, and a premature conversion from carbon source to sink in model simulations. A reformulation of snow and soil processes in SiB version 3.0 remedies this problem; snowpack ablation is more reasonable in the springtime with the result that modeled fluxes are more self-consistent.
DE: 0315 Biosphere/atmosphere interactions
DE: 1818 Evapotranspiration
DE: 1863 Snow and ice (1827)
DE: 3322 Land/atmosphere interactions
SC: Biogeosciences [B]
MN: 2003 Fall Meeting