THEORETICAL AND EXPERIMENTAL STUDIES OF SNOW COVERS MICROWAVE EMISSIVITY

Microwave radiometers, operating at 3.95, 19.5, 37.5 and 150 GHz and p laced in a tower, were used for snow measurements during the winters o f 1985-1989. The effects of snow structure, wetness, and grain size we re examined in detail. The emissivity of snowpack has been calculated by a quasi-static method and by applying the equation of radiative tra nsfer. The latter takes into account the physical-mechanical propertie s of the real snowpack obtained by direct glaciological methods. The e xperimental data are compared against theoretical results. The quasist atic model is shown to be adequate for f < 20 GHz whereas the radiativ e transfer model agrees for f < 150 GHz, especially when the size dist ribution of ice particles in snow is included.