Energy Balance over Seasonal Snow Cover in Alpine Climate

Energy balance measurements over a seasonal snow cover have been performed during spring 1992 and 1993 near Davos in the eastern Swiss Alps. The measurements show a clear dominance of the net radiation as an energy source during the snowmelt period. The turbulent fluxes are less important in average, but may be larger in magnitude than net radiation on selected days (e.g. foehn periods). For all the energy fluxes, parameterizations based on automatic weather station data only, were verified against these measurements and against observed ablation. These parameterizations were used to determine the spatial distribution of the energy balance in the Davos area. For the parameterization of longwave radiation from terrain, for the albedo and for the turbulent fluxes new approaches are developped. The proposed model allows to determine the energy balance over the snow
cover in complex topography in different expositions and altitudes, if some simple meteorological measurements are available in the area of interest. The model is now tested in combination with a snow-model at Weissfluhjoch.

Contact: Atsumu Ohmura