Simultaneous multiparameter radar and 2D-video disdrometer observations of snow

Polarimetric radars are very useful for remote sensing of storm microphysics. Multiparameter radar signatures have been used for quantitative and qualitative interpretation of convective storms. However, the interpretation of these signatures for aggregating snow particles is complicated because of many unknowns, such as bulk densities, and shapes of snow particles. During the winter of 1996-1997, extensive data were collected in Colorado winter storms using the CSU-CKILL radar in conjunction with a 2D-video disdrometer located on ground. This paper presents a comparison of multiparameter radar and in-situ microphysical observations in winter precipitation during two storm events of different characteristics. The comparison includes, investigation of radar signatures of these storms to study their microphysical evolution, generation of in-situ particle size distribution using the 2D-video disdrometer at different integration times, as well as estimation of particle densities and shapes. A model for radar backscatter, considering particle types, shapes, sizes, orientations, and densities is used, providing a framework for microphysical interpretation and for comparing radar signatures and disdrometer observations