Sub-surface Dlelting in a seasonal snow cover

ABSTRACT. The a bility of solar radiation to penetra te into a snow cover combined with the low therma l conductivity of snow can lead to a sub-surface temperature m aximum. This elevated sub-surface temperature a llows a layer of wet snow to form below the surface even on days when th e air temperature remains subfr eezing. A high-resolution frequency-modulated continuous wave (FMCvV) rada r has been used to d etect the onset of sub-surface m elting in a seasonal snow cover. The ex perimental observation of sub-surface melting is shown to be in good agreem ent with the predictions of a on e-dimensional mass- and energy-balance model. The effects of varying snow cha racteristi cs a nd solar ex tinction parameters on the sub-surface melt characteristics are investigated using model simulations