Prairie and arctic areal snow cover mass balance using a blowing snow model

Abstract

Algorithms to calculate the threshold wind speed and the effect of exposed vegetation on saltation and to describe vertical profiles of humidity in blowing snow, permit the calculation of point blowing snow transport and sublimation fluxes using standard meteorological and landcover data or simple interfaces with climate models. Blowing snow transport and sublimation fluxes can be upscaled to calculate open environment snow accumulation by accounting for their variability over open snow fields, increase in transport and sublimation with fetch, and the effect of exposed vegetation on partitioning the shear stress available to drive transport. Blowing snow fluxes scaled in this manner were used to calculate snow mass balance and to simulate seasonal snow accumulation at a southern Saskatchewan prairie and an arctic site. Field measurements at these sites indicated that from 48% to 58% of snowfall was removed by blowing snow before melt began. Simulations suggest that the ratios of snow removed and sublimated by blowing snow to that transported were 2∶1 and 1∶1 at the prairie and arctic sites respectively. The resulting methodology was capable of estimating winter season mass balances for these snowpacks that compared well with snowfall and snow accumulation measurements.