Experimental validation activities of HUT snow emission model

Modeling of snow emission properties on microwave frequencies is necessary in order to understand the complex relations between the snowpack microwave emission and its characteristics, such as density, snow grain size, moisture content and snowpack vertical structure. With a reliable model, snowpack characteristics could be derived from passive microwave observations using model inversion, potentially improving retrieval accuracy of snow parameters when compared to traditional empirical inversion algorithms. In this study, we present a summary of recent activities aiming at experimental validation of the semi-empirical HUT snow emission model. The activities consist of comparisons of modeled brightness temperatures against tower-based and airborne reference radiometer data. Model inputs are derived form intensive field measurements of snowpack characteristics. Forward modeling of snow emission on the satellite scale, and a comparison with satellite observations is presented. Furthermore, a recent update of the model, enabling simulation of multiple snow layers and special cases such as snow covered lake ice, is experimented.