Model estimates of local advection of sensible heat over a patchy snow cover

Abstract

In agricultural, grassland, tundra and mountainous areas, patchy snow cover may occur for periods of many months. Although much is known about surface energy exchanges during periods of continuous snow cover, there are major gaps in our understanding of fluxes during periods when the land surface has both snow and snow-free patches. A boundary layer model is used to document that the efficiency of sensible heat advection from snow-free to snow patches decreases with increasing snow free area, and for the same snow-free area, increases as individual snow patch size decreases. The average sensible heat flux to the snow patches increases significantly with increasing snow-free area and decreasing snow patch size. These variations in sensible heat flux have important hydrological implications and should be accounted for in simulations of energy fluxes over snow covered terrain.