Climatological Snow Cover Feedbacks to the Land-Atmosphere System

The seasonal southward advance and northward retreat of northern hemisphere snow cover is one of the most dynamic and regular oscillations in Earth's surface energy and moisture balance. The presence of snow increases albedo, decreases surface skin temperature, and enhances moisture fluxes into the atmospheric boundary layer and soil surface. As a consequence, the boundary layer is on average, colder and moister over a snow covered surface. However, the extent to which this can feedback onto larger scale climate processes by modification of lower-atmosphere mid-latitude baroclinicity or teleconnections is not fully understood. Further, snow melt is a significant moisture source to ecosystems, and as a consequence regulates ensuing spring moisture and carbon fluxes between the land surface and atmosphere. Multi-year integration of snow cover dynamics, mid-latitude disturbance trajectories, potential vorticity inversion of snow-cover induced flow variation in a mesoscale model, and analysis of moisture and carbon flux relationships among a network of eddy covariance sites will be discussed to present a general conceptual framework on the role of climatological variations of snow cover on land and atmosphere processes.