The effect of turbulence on drifting snow sublimation

TL;DR

This paper introduces a 3D model for drifting snow sublimation that accounts for turbulence and moisture diffusion, revealing that sublimation mainly occurs in the saltation layer due to high particle concentration.

Contribution

A novel 3D turbulent boundary layer model for snow sublimation that incorporates moisture diffusion and predicts sublimation dynamics more accurately.

Findings

Sublimation predominantly occurs in the saltation layer.

Turbulent diffusion significantly influences sublimation rates.

High particle concentration drives sublimation despite near-saturation humidity.

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.