On the relationship between stickiness in DMRT theory and physical parameters of snowpack. Theoretical formulation and experimental validation with SNOWPACK snow model and X-band SAR data

This study aims at relating the stickiness parameter (?) of the Dense Media Radiative Transfer theory integrated with Sticky Hard Sphere (SHS) model (DMRT-QMS), to the physical parameters of the layered snowpack. A relationship has been derived to express ?, which modulates the attractive contact force between ice spheres, as a function of ice volume fraction (?) and coordination number (nc). Since ? is not a measurable parameter, this is a step forward with respect to what is commonly made in literature, where ? is assumed as an arbitrary parameter, generally ranging between 0.1 and 0.3, to fit simulated backscattering data with those measured. As a first validation, DMRT-QMS was integrated with SNOWPACK model to simulate backscattering at X band (9.6 GHz) driven by nivo-meteorological data acquired on a test area located in Monti Alti di Ornella, Italy. The simulations were compared with Synthetic Aperture Radar COSMO-SkyMed (CSK) satellite observations. The results show a significant agreement (R2=0.68), although for a limited dataset of eight points in a unique winter season.