Snowmelt Estimated from Energy Budget Studies

Abstract

The snowmelt at a point is estimated through a simplified energy budget. From the energy equation a degree-day method is derived. The rate of snowmelt is found as a constant multiplied by the temperature excess over an equilibrium temperature which depends on solar radiation. The snowmelt events in Kiruna (3 years) and Luleå (4 years) are analysed utilizing energy balance computations and the degree-day method. First observed and calculated day when the ground was free of snow is for all seven years in good agreement. The rate of snowmelt calculated by the proposed degree-day method is almost identical to the rate found from energy balance computations. Snowmelt rates estimated by a simple degree-day method using a constant equilibrium temperature are too fast in the beginning and too slow at the end of the melting season.