Effect of Seasonality of Snow Accumulation and Melt on Snow Surface Energy Exchanges at a Continental Alpine Site

Abstract

Abstract Snow surface energy exchanges and snowmelt were measured during the 1994 and 1995 snowmelt seasons at an alpine site in the Colorado Front Range (3517 m MSL, 40°03′N, 105°35′W). Following a maximum accumulation of 0.49-m snow water equivalence (SWE), the 1994 snowmelt season began on 5 May and lasted 32 days until 6 June. In contrast, the 1995 maximum accumulation of 1.31-m SWE did not occur until 1 June, and the snowmelt season lasted 45 days until July 16. Thus, a nearly threefold larger snowpack ablated in only 41% more time in the later 1995 snowmelt season. In 1994, net radiation accounted for 75% of the energy available to melt snow, and sensible and latent heat fluxes accounted for the remaining 25%. During the 1995 snowmelt season the mean air temperature was warmer (+1.3°C) and the mean specific humidity was greater (+0.6 g kg−1) than during the 1994 snowmelt season. As a result, in 1995, sensible and latent heat fluxes accounted for 54% of the energy for snowmelt and net radiation accou...