Characteristic Analysis of X-band Dual Polarization Radar in a Hail Process

According to X-band dual-polarized radar data from Beijing area, the authors analyzed the radar echo characteristics of a strong convective hail cloud which used the algorithm for identifying hail and polarization characteristics. The results show that the convective cloud has a distinct V- shaped gap, and the vertex of the gap is facing the radar station. The strong echo structure at the vertex of the gap is compact. The echo top is 13 km, and the maximum reflectivity factor is 57.5 dBZ. Around the V-shaped gap, the differential reflectance factors which are far from the radar station show negative value, indicating that this area is a hail area; the differential reflectance factors which are near the radar station show positive value, indicating that this area has a heavy raindrop. The reflectivity factors at 19:18, 19:48, 20:09, and 20:30 were selected, and the vertical profile was made along the lower inflow direction and the core of strongest reflectance factor. The vertical profile exhibits typical echo characteristics such as WER, BWER and echo overhang. The differential reflectivity factors and correlation coefficients have obvious stratification characteristics, which reflect the precipitation particles within clouds rising continually under the influence of low-level inflow airflow and the upper ice particles moving to the right side of the WER with the upper horizontal airflow and then dropping gradually. This process verifies the evolution of hail rising and falling.