Land surface process schemes are key components of GCMs and hydrological models, and are very sensitive to snow cover. Many of these schemes however, are deficient in their representation of snow processes. New algorithms for estimating snow interception in forest canopies, blowing snow transport and sublimation, snowcover depletion and snowmelt have been developed and verified by field measurements. Recommendations for advances in snow modelling in land surface schemes are made with respect to:

(a) density of new and aged snow in open and forest environments
(b) interception of snow by evergreen canopies
(c) redistribution of snow water equivalent by blowing snow
(d) sublimation losses from intercepted and blowing snow
(e) depletion in snow-covered area during snowmelt
(f) albedo decay during snowmelt
(g) partitioning of energy between sensible and latent heat during snowmelt
(h) infiltration of meltwater into frozen soils.

It is felt that inclusion of these algorithms in land surface schemes will provide more physically realistic representations of snow processes in atmospheric and hydrological models and that such representations are necessary in evaluations of climate and landcover change.

#Division of Hydrology, University of Saskatchewan, Saskatoon