Consideration of the stratigraphy of snow cover in modeling its emissivity in the microwave

Abstract

Measurements of snow cover emissivity parameters conducted nowadays, show that microwave brightness temperature strongly depends on physical parameters of the snow. The character of such dependence is determined by the stratigraphy of snow cover. Quantitative retrieval of snow cover physical parameters from remotely sensed data calls for an electrodynamic model of snow cover involving stratigraphy in the description of its emissivity. One of the reasons of the disagreement of experimental and theoretical data is the practised averaging of natural stratigraphy of snow cover. The use of snow characteristics averaged over the whole thickness can lead to wrong interpretation of data of remote sensing. In this sense, electrodynamic models of dry snow cover suggested by D. Boyarskii et al. (1993), and considering its structural and stratigraphic properties are more accurate. The main purpose of the present work is to develop a structure dependent model of emissivity of the snow cover. Snow cover is considered a medium consisting of ice and air, in the case of dry snow, and of ice, air and water, in the case of wet snow. Ice and water inclusions are assumed spherical with lognormal size distribution.