Characteristics of the atmospheric surface layer and heat budget over the Arctic ice in summer

Observational data of August 19-24, 1999 during the first Chinese arctic research exploration were analyzed and the vertical distribution of meteorological variables in the surface layer and the heat budget problem over ice in the Arctic region in summer were discussed. The results show that the humidity of surface layer is very high relative to the ice surface, and is often close to its saturated value. The ice temperature has a significant diurnal variation. The ice temperature gradient near the surface is relatively large at night, and is very small during daytime. For the top 40cm of ice, the ice temperature sometimes reaches a maximum value at 20cm depth. The heat budget analysis shows that the heat loss during night caused by the radiation cooling effect is compensated by heat transferred from the inner ice layer to the ice surface. In daytime, the inner ice heat comes mainly from penetrating shortwave radiation, and heat exchange between the ice surface and inner ice is very weak. The ice/snow thaw heat in daytime can not be neglected.