Snow cover model for global climate simulations

Abstract

Because of the high sensitivity of the climate system to anomalies of the snow cover, appropriate models of the latter are required. In this paper a one‐dimensional multilayer model of a snow cover is presented combining relatively accurate model physics with minimal computer time. The model is based on the balance of mass and energy, including the important internal processes such as the diffusion of temperature and water vapor, melting and freezing, the extinction of short wave radiation, and the retention of liquid water. In order to keep the possibility of using the model on a global scale, no local parameterizations are employed. An efficient numerical scheme makes the model suitable for long‐term climate studies. Integrations for Potsdam (52°N, 13°E) with standard synoptic measurements over a period of six winters demonstrate good correspondence between the model results and the observed values. The most serious problem remaining is the choice of a satisfactory criterion to distinguish between snowfall and rain which strongly affects the simulation of snow depth and water equivalent.