The large-scale mass balance effects of blowing snow and surface sublimation

Stephen J. Déry and M. K. Yau


This study examines the effects of surface sublimation and blowing snow to the surface mass balance on a global and basin scale using the European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA15) data at a resolution of 2.5o that span the years 1979-1993. The combined processes of surface and blowing snow sublimation are estimated to remove 30 mm a-1 snow water equivalent (swe), disposing about 17 to 20% of the annual precipitation over Antarctica. In the Northern Hemisphere, these processes are generally less important in continental areas than over the frozen Arctic Ocean and polar seas where surface and blowing snow sublimation deplete upwards of 100 mm a-1 swe. Areas with frequent blowing snow episodes such as the coastal regions of Antarctica and the Arctic Ocean are also prone to a mass transport > 100 Mg m-1 a-1. Although important locally, values of the divergence of mass through wind redistribution are generally two orders of magnitude less than surface and blowing snow sublimation when averaged over large areas. For the entire Mackenzie River Basin of Canada, surface sublimation remains the dominant sink of mass as it removes 29 mm a-1 swe or about 7% of the watershed's annual precipitation.