Snow Size Distribution and Aggregation Modeling Based on the Bicontinuous Model

Previous experiments showed that the frequency dependence of snow volume scattering from 18 to 90GHz is power of 2.8, which is much weaker than the power of 4 of Rayleigh scattering. Recently monitoring snow using existing satellites (such as Sentinel-1, COSMO-SkyMed and QuickScat) have been widely studied. The radar signatures from C to Ku band are important for active remote sensing of snow. In this paper, we study the snow aggregation effects and its frequency dependence of volume scattering from C to Ku band (4-18GHz) with the bicontinuous model. The bicontinuous media model is applied to model the snow microstructure with aggregates. The integral equation of snow scattering volume is derived based on the Born approximation which then leads to the scattering coefficients. Scattering coefficients of snow are computed from C to Ku band giving a frequency dependence of ~2.6 power, weaker than that of Rayleigh scattering because of the aggregation effects. In addition, results are also in good agreement with the full wave numerical solutions from X to Ku band.