Identification of multi-temporal snow melting patterns with microwave radars

The amplitude of the backscattered signal collected by space-born radars, e.g., Sentinel-1, when illuminating snow-covered areas, is strongly dependent upon the conditions of the snow. In particular, there is a potential evidence of a relationship between the melting phases of the snowpack and the amplitude of the backscattered signal. However, the exact quantitative description of this phenomenon it is not fully determined. This paper proposes a first-order preliminary model, based on plane-wave incidence on stratified media, to describe the effect of several physical parameters of the snowpack (depth, liquid water content, density, snow water equivalent) on the amplitude of the backscattered signal. The model is tested against experimental data for a site in the Italian Alps (Malga Fadner), where data from Sentinel-1, as well as in-situ data about the composition of the snowpack, are available for entire winter season 2017/18, showing good general agreement.