The effect of turbulence on drifting snow sublimation

Abstract

Sublimation of drifting snow, which is significant for the balances of mass and energy of the polar ice sheet, is a complex physical process with intercoupling between ice crystals, wind field, temperature, and moisture. Here a three-dimensional drifting snow sublimation model in a turbulent boundary layer is proposed. In contrast to most previous models, it takes into account turbulent diffusion of moisture from lower to higher elevations, allowing the air humidity near the surface to be undersaturated and thus sublimation to occur. From simulations with this model, we find that snow sublimation in the saltation layer near the surface dominates overall snow sublimation, despite an only marginal departure from humidity saturation ($<1\%$), because of a large particle concentration.