Absorption of Solar Radiation by Snow-and-Ice Cover of Lakes

Based on the analysis of data of many-year actinometric observations, a considerable temporal (interannual, seasonal, synoptic, and diurnal) and spatial variability of the albedo of the snow-and-ice cover of a shallow lake is shown. The ranges of variations in the albedo of snow and ice for a wide spectrum of the state of surface and weather conditions are presented. The variability of the thickness and structure of snow-and-ice cover is analyzed for different periods in winter. The results of field experiments aimed to determine the degree of absorption of solar radiation by snow and ice are presented. The effective coefficients of absorption of solar radiation by snow and ice are determined. The comparison of the observed and calculated values of the under-ice radiation has shown that the determined coefficients adequately describe the absorption of solar radiation by snow-and-ice cover.