Introduction to Blowing and Drifting Snow Processes and Their Representation in Numerical Models

In this seminar I will introduce the basic processes of turbulent snow transport and how these processes are represented in models. These processes are of interest in polar and high mountain regions due to the impact of sublimation rates on mass and momentum fluxes and the subsequent effects on the surface mass balance and associated hydrological processes. Turbulent snow transport is often considered in two regimes: drifting and blowing snow. Drifting snow occurs within the lowest 0.1 meters of the ABL, while blowing snow typically occurs when snow is lofted higher into the boundary layer flow and transported via suspension. The blowing snow cases have major implications for sublimation, but past studies have identified significant underestimation of sublimation in cases of drifting snow in large scale models. The techniques used to model turbulent transport of snow have largely been adopted from the study of blowing sand in deserts. Most of these studies have focused on using a Lagrangian point particle approach for representing snow particles which allows for a more detailed representation of important physical processes but is very computationally expensive. This expense limits the applicability of these models to small-scale settings. We are interested in representing the processes associated with turbulent snow transport in a Eulerian framework which will allow for larger simulations of morphologically important features like glaciers, ice shelves, or entire ice sheets and lead to tools for the numerical study of the surface mass balance in alpine and polar regions.