Some conceptual and scaling evaluations of snowmelt events forced by warm soil

Abstract

Snowfall occasionally occurs over bare soil with high thermal storage in its upper layer. Quantification and generalization of the potential impact of the thermal storage on episodic snowmelt is evaluated using a scaling approach and assuming negligible net thermal flux at the snow cover top. Soil thermal flux contribution to snowmelt is found to be affected significantly by the level of soil wetness. It is shown that, for a soil temperature of 10°C prior to the snowfall, the contribution of wet soil thermal flux is significant within the first 12 h when compared with intense surface moist enthalpy flux or solar radiation. Implications of these results to modeling of snowmelt using coupled soil-atmosphere models are elaborated.