Validation of 1-D Snow-Cover Simulations
by the CLASS Land Surface Scheme for GCMs
The Canadian Land Surface Scheme for GCMs (CLASS; Verseghy 1991) employs a simplified
one-layer treatment of the snowpack. It has been stated (Loth et al. 1993, Lynch-Stieglitz 1994) that
multilayer models are required to resolve the characteristic steep near-surface temperature and
vapor gradients in a snowpack in order to successfully model snowpack processes. This paper
compared CLASS snowpack simulations with those of a detailed multilayer model (CROCUS;
Brun et al. 1992) with meteorological and snow data from measurement sites in different snow
climate zones. The one-layer model was observed to exhibit a consistent cold bias in snow surface
temperature and underestimated the aging of snow during the snow season. In spite of these prob-
lems, the one-layer model was able to provide realistic simulations of interannual and seasonal
variation in important snowpack properties (albedo, snow cover, snow depth, SWE, and runoff).
Brun, E., P. David, M. Sudul, and G. Brunot (1992) A numerical model to simulate snow-cover
stratigraphy for operational avalanche forecasting. J. Glaciol., 38: 1322.
Loth, B., H.F. Graf, and J.F. Oberhuber (1993) Snow cover model for global climate simulations.
J. Geophys. Res., 98(D6): 10,45119,464.
Lynch-Stieglitz, M. (1994) The development and validation of a simple snow model for the GISS
GCM. J. Climate, 7: 18421855.
Verseghy, D. (1991) CLASS--A Canadian land surface scheme for GCMS. I: Soil model. Int. J.
Climatol., 11: 111133.
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