Showing papers on "Ice-albedo feedback published in 1979"

Water level fluctuations and ice cover of Lake Myvatn

Abstract: The various factors that cause water level fluctations in Lake Mrvatn, and their relative importance are discussed. In the shallow north basin the maximum wind induced amplitude amounts to 0.9 m, but in the deeper south basin the amplitude is less or 0.5 m. Ice blockages in the outlet have raised the water level for 0.3 m. During winter the channel of the River Krdka sometimes becomes blocked by ice on the flat land. The water then switches its course to Lake Grwnavatn, through River Grwnilamkur into Lake Myvan, and its water level rises about 5 cm. Man-made effects on the lake level are also defined. The instability of the size of the current-lead just above the outlet is important with regard to choking by ice at the outlet channels, which is of vital importance for the operation of the Laxa' power plants. Average duration of the ice cover is 189 d, from October to May. The changes in ice cover during winter in the south basin are very important and characteristic in relation to spring-leads. Volcanic activity since 1975 has caused a land rise especially on the NE side of the

Effect of surface meltwater accumulation on the dissipation of lake ice

Abstract: The rate of ice melt with and without water accumulation on the ice surface has been computed based on the interfacial heat exchange processes, the thermal diffusion of heat through the accumulated water, and the internal absorption of solar radiation. Although the accumulated water does increase the net absorbed solar radiation due to reduced albedo, the resulting air-water interface temperature is found to be considerably greater than 0°C, thereby decreasing the net long-wave, sensible, and evaporative heat inputs. The findings indicate that the overall effect of accumulated water on ice melt may not be quite as large as expected from albedo differences alone.