Modelling of particle distribution in the melting layer

The analysis of radiowave propagation through, and radar scattering from, the melting layer requires a model of the melting ice particles with appropriate statistics of shape, size, and orientation distributions. Previous studies have indicated that the melting layer can be modelled by a collection of wet snow spheroids in air, of which the effective permittivity and the volume fraction are the most important parameters. It is proposed that the distribution of spheroid shapes can be modelled by a flat probability density of depolarisation parameter lambda ₃ between a minimum and a maximum value. The location of the average lambda ₃ is crucial; the width is less important.