Turbulent fluxes during blowing snow: field tests of model sublimation predictions

Abstract

Sublimation fluxes during blowing snow have been estimated to return 10–50% of seasonal snowfall to the atmosphere in North American prairie and arctic environments. These fluxes are calculated as part of blowing snow two-phase particle transport models with provision for phase change based upon a particle-scale energy balance. Blowing snow models have normally been evaluated based upon their ability to reproduce diagnostic mass flux gradient measurements and regional-scale snow redistribution patterns and snow mass. Direct evidence is presented here that large latent heat fluxes (40–60 W m−2) that result in sublimation rates of 0·05–0·075 mm snow water equivalent hour−1, are associated with mid-winter, high-latitude blowing snow events. For events with wind speeds above the threshold level for snow transport, these fluxes are in the range of those predicted by the Prairie Blowing Snow Model. The fluxes are well in excess of those found during spring snowmelt and which can be predicted by standard bulk aerodynamic transfer equations, suggesting that blowing snow physics will have to be incorporated in land surface schemes and hydrological models in order to properly represent snow surface mass and energy exchange during blowing snow events. Copyright © 1999 John Wiley & Sons, Ltd.