Snow Assimilation with the NSIPP
Catchment-based Land Surface Model using the Extended Kalman filter
Land surface model: the
NASA NSIPP catchment-based Land Surface Model (Koster et al. 2000) that has a three-layer snow model component.
Snow model:
three-layer snow model (Fig. 1) that incorporates detailed physics including evaporation/sublimation/condensation, radiation,
precipitation as rain or snow, mechanical compression, melt water flow
through, etc (Lynch-Stieglitz, 1994;
Stieglitz et al., 2001).
Snow state variables: snow water equivalent (W), depth (D) and heat
content (H). To ensure a smooth transition
from bare-soil to snow-cover conditions, a minimum snow water equivalent of
13 mm is assumed. When fresh snow falls on bare soil, the fractional coverage
grows until the entire catchment is covered with snow. At this point, the
model begins to grow the snow pack.
Forcing: bias-corrected ECMWF
forcing data for the past 20 years over North America (Berg et al., 2001).