On the impact of blowing snow sublimation in the Mackenzie River Basin water budget.

Stephen J. Déry and Peter A. Taylor

Abstract

Blowing snow is commonly known as a hazardous meteorological process in Canada. Blowing snow may also be a significant hydrological process in the water cycle due to the redistribution of snow and the sublimation of airborne snow while in transport. The process of snow sublimation by the wind may also act as a significant source of moisture and a sink of sensible heat in the MAGS (Mackenzie GEWEX Study) area and should be included in northern atmospheric boundary-layer models.

We will discuss one such model which is a spectral adaptation of the Prairie Blowing Snow Model (PBSM) that determines the thermodynamic effects of blowing snow sublimation to the near-surface air. Results show that air temperature decreases can reach 1oC. Saturation of air, however, accompanies this temperature change and occurs quite rapidly near the surface thus significantly reducing sublimation rates at long fetches. This would indicate that the overall impact of blowing snow sublimation in the Mackenzie River Basin water budget may be less than previously anticipated. Horizontal transport and redistribution of snow by wind remain, however, significant processes.