Regional Features of Microwave Radiation and Snow Cover Interaction on the Example of the North of the European Part of Russia

摘要

The present report discusses a structure dependent model of emissivity of snow cover. Microwave radiation of the snow cover laying on the surface of earth is primarily determined by two factors: the radiation of the snow layer and the radiation of the underlying surface. Both contributions are influenced by the air-snow and snow-soil boundaries and are subject to absorption and scattering by the snow thickness. The emergence of water in snow cover during melting results in dramatic changes in its physical and radiophysical characteristics. An adequate description of the interaction between electromagnetic radiation and wet snow medium requires an understanding of the spatial distribution of the water component. However, so far the problem is not investigated well enough. It has been known that water accumulates in snow pores and forms joints between ice grains. We have suggested two models of wet snow: model I - a medium containing spherical ice grains and water drops; model II - a medium containing spherical ice grains covered with water film and spherical water drops. DMSP SSM/I satellite data of brightness temperature for plain territories of the Northern Eurasia has been used for analysis (Global Hydrology Resource Center NASA). The main peculiarity of the created and developed data base is its animation ideology and construction of interface available for everybody. The comparative estimation of spatial and temporal variability of the modeling, satellite and ground data was carried out for key areas of the north of the European part of Russia. Similarity of statistical fields of satellite brightness temperatures of different belts, ground air temperature and snow depth was appreciated. In particular, the amplification of similarity of examined statistical fields of parameters from the south to the north has been revealed and codified.