Energy balance measurements over a seasonal snow cover were performed near Davos, Switzerland at 2,540 m a.s.l. The energy fluxes were studied over dry and melting snow covers. The beginning of snowmelt clearly coincides with the beginning of positive daily sums of net radiation. During snowmelt, net radiation is the dominant energy source. Latent and sensible heat fluxes do not show a significant seasonal change and remain slight over most of the measuring period. This minor contribution of the turbulent heat fluxes can be attributed to generally low wind speeds in this inner alpine region and to frequent inversions over the melting snow cover.
In a changing climate the turbulent heat fluxes could become increasingly important in the energy balance. Therefore, evaluations of the turbulent heat fluxes from profile measurements and the eddy correlation method are compared with simple approximations commonly used in snowmelt models. The conditions under which these approximations can be used for routine discharge forecasts are identified.
- Received September 1993.
- Revision received December 8, 1993.
- Accepted January 4, 1994.
- © IWA Publishing 1994