The Blowing Snow Model Intercomparison Project (BSMIP): An Update

Stephen J. Déry, Richard Bintanja, Graham Mann, Peter A. Taylor, Jingbing Xiao and M. K. Yau


In the high latitude regions of the world, including the Canadian Arctic, blowing snow occurs commonly. The redistribution of snow by wind and concurrent sublimation has attracted much interest in the past few years since the water budgets of these remote areas may be considerably influenced by these processes. Estimates of the contribution of blowing snow sublimation to the surface water budget have been of much debate with values ranging from a few millimetres snow water equivalent (swe) annually (King et al., 1996) to 10 or more mm swe annually (Marsh et al., 1994).

Since observations of blowing snow are difficult to conduct, a number of numerical models have been developed to estimate the sublimation and transport rates of blowing snow as well as the interactive effects between these processes and the atmospheric boundary layer (ABL). We will present here some of the initial results of the Blowing Snow Model Intercomparison Project (BSMIP). The three models subject of the BSMIP are PIEKTUK-T developed by the group at York University in Canada (Déry et al., 1998), WINDBLAST developed by the group at Leeds University in the United Kingdom (Mann, 1998) and SNOWSTORM developed by the group at Utrecht University in The Netherlands (Bintanja, 1998). Additional results from a bulk version of the PIEKTUK model, modified by Déry and Yau (1999) at McGill University, Canada, will also be reported. These four models, operating in a time-dependent, horizontally homogeneous mode, all show that sublimation is a self-limiting process, with the sublimation rate reaching a peak shortly after initiation of transport. This is due to the inclusion of the interactive thermodynamic feedbacks of the sublimation process in the models. Similarities and differences in model predictions will be discussed and explanations considered.