Development of Snow Movement over Open Terrain for Hydrology (SMOOTH) model

Abstract:

The blowing snow and drifted snow cause significant traffic hazards as well as major errors in snowmelt modeling in snowy and windy prairies. Therefore, it is important to quantify the snow redistribution by wind and gravity after touching down to the ground surface. The snow movement equations were formulated in terms of snow transport, wind snow diffusion, and snow gravitational movement effects, for horizontal two-dimensional watershed scale applications in this study. It was shown that the snow surface diffusion coefficient by wind can be evaluated from an autocorrelation function of the measurable wind velocity field using G.I. Taylor’s theorem. In this presentation, the numerical algorithm for the generalized snow movement equation will be discussed in detail, as it requires a mechanism to limit the over-erosion of the immobilized snow and the ground after mobile snow disappearance. This numerical algorithm was named SMOOTH model that can explicitly describe the dynamic snow transportation from peaks and ridges to dips, valleys, and places behind objects. Two dominating components of wind-snow process, advection and diffusion, will be discussed using the SMOOTH model outputs for several sites in Wyoming.