Observations of Hailstorms from Multi-frequency Airborne and Ground-based Polarimetric Radar During MC3E and IPHEX

Retrieval of precipitation in mixed-phase region in convection over land is a challenging problem in GPM DPR algorithm. Observations from Dual-wavelength (Ku/Ka band) airborne radar system (ER-2 HIWRAP) flew on NASA’s ER2 high altitude aircraft could be used to test assumptions in the algorithm. In this study, we examine the observations of a hailstorm during NASA’s Mid-Latitude Continental Convective Clouds Experiment in 2011 by the airborne radar and radiometer as well as a ground-based S-band polarimetric radar. The hail region at low level is easily identified by the S-band reflectivity greater than 65 dBZ and near zero ZDR. The tall ZDR column extended above freezing level is coincided with regions of maximum updraft, indicating wet hail growth process. An updraft greater than 50 m/s, derived from the Ku-band Doppler velocity, indicates the presence of hail at an altitude of around 12 km. The presence of mixed-phased hydrometeor (e.g., water-coated hail/graupel) produces a scattering signature that is similar to the bright band in stratiform rain. Such signature may be used to identify the mixed phased region in deep convective storms. We will also discuss additional observations of another hailstorm during IPHEX in 2014 from ER-2 airborne 4-frequencies (X, Ku, Ka, and W) and S-band ground-based polarimetric radar.