Simulation of above treeline snowdrift formation using a numerical snow-transport model

Abstract

A physically based, numerical snow-transport model (SnowTran-3D) is used to successfully simulate the above treeline snowdrift evolution around Montgomery Pass in the Northern Colorado Rocky Mountains. The model accounts for key snow-transport components including: saltation, suspension, deposition, erosion, and sublimation. The snow-transport model requires static inputs of vegetation type and topography, and temporally evolving spatial distributions of air temperature, humidity, precipitation, wind speed, and wind direction. A simple wind-flow model, driven by data from a ridge-top meteorological station, is used to simulate the flow field over the topographic drift catchment. The snow-transport model outputs include the spatial and temporal evolution of snow depth resulting from variations in precipitation, saltation and suspension transport, and sublimation. The model is forced using SNOTEL and meteorological data from the 1997–1998 winter, and the resulting model outputs are compared with observed snowdrift distributions.