A NEW ACTIVE/PASSIVE MICROWAVE RADIATIVE TRANSFER MODEL FOR SNOW (SMRT) TO FOSTER INTER-COMPARISONS OF MODEL COMPONENTS

The Snow Microwave Radiative Transfer (SMRT) model computes the thermal emission and backscatter model of snopwpack. Compared to similar existing models, it was developed to unify and inter-compare different descriptions of the snow microstructure found in different microwave models. For that, SMRT offer the capability of switching between different electromagnetic theories, representations of snow microstructure, and other modules involved in various calculation steps. The current version of SMRT includes the Dense Media Radiative Transfer theory (DMRT), the Improved Born Approximation (IBA) and independent Rayleigh scatterers to compute the intrinsic electromagnetic properties of snow layers. Under IBA, SMRT was used to compare sticky hard sphere and exponential microstructure representation and to identify that several former studies conducting simulations with in-situ measured snow properties are now comparable and moreover appear to be quantitatively nearly equivalent. The model is available as open source software.