Radar observations of polarization characteristics and lightning-induced realignment of atmospheric ice crystals

The reflectivity and polarization characteristics of ice crystals as measured with a 1.8-cm radar are reported. Included are measurements on stratiform ice crystal clouds, showing cancelation ratios of 16 to 20 dB and reflectivities of 7 to 28 dBZ. The degree of preferred orientation was approximately 40 to 50%. Some vertical soundings in snow appear to show changes in the snow crystal form with height. Observations of the rapid changes in polarization characteristics in the upper levels of thunderstorms show some cases for which the depolarizing particles are not the same as those which are responsible for the radar backscatter.