Abstract
Short-term heat balance studies were carried out for three surfaces—moraine, ice and snow—in a partly glacierized watershed in Arctic Alaska, for an 11-day period in summer 1971. It was found that the radiation balances for the moraine and the ice surface were very similar, as the reduced shortwave radiation balance resulting from the higher albedo of the ice (33%) compared to the moraine surface (19%) was compensated for by the less negative longwave radiation balance resulting from the lower surface temperature of the ice surface compared to the moraine. However, the less negative longwave radiation balance for the snow surface was not able to compensate for the loss of shortwave radiation resulting from the high albedo (59%) of the snow surface. For the moraine, the radiation balance (146 ly day−1) was the only energy source. It was used to warm the air (49%), for evaporation (43%), and to heat the ground (8%). For the ice surface the energy sources were the radiation (149 ly day−1) and the sensible heat flux (116 ly day−1). Most of this energy was utilized to melt ice (89%), while only small fluxes were found for evaporation (4%) and warming the ice (7%). For the snow surface, the portion of the radiation balance (88 ly day−1) and sensible heat flux (52 ly day−1) are similar; however, the fluxes are smaller. Again, most of the energy is used for ablation (59%), but evaporation (40%) is also of substantial importance. The heat flux into the snow by conductivity is very small for a snow surface (1%).
