Observational Characteristics of Dual-Polarization Radar for Heavy Rainfall Events in Capital Area

Abstract

In this study, the observational characteristics of dual-polarization radar for studying the heavy rainfall in the capital area were evaluated. To this end, three rainfall events that had caused significant flood damage due to the heavy rainfall from June to August 2020 were selected. The application of dual-polarization radar data revealed a significant change in precipitation during the analysis of observation characteristics of the affected capital area’s heavy rainfall. Moreover, the physical characteristics of reflectivity, differential reflectivity, specific differential phase, and copolar-correlation coefficient and their temporal dynamics in radar rainfall were compared to rain gauge rainfall. The radar reflectivity has been identified at the frequency of ≥ 40 dBZ due to the effects of heavy rainfall in the capital area, while the differential reflectivity has confirmed that the particle size was larger. The specific differential phase seemingly exhibited the most similar distribution to rain gauge rainfall, while exhibiting local characteristics of heavy rainfall in the capital area, according to the differential reflectivity result. The copolar-correlation coefficient confirmed the consistent observational performance of the dual-polarization radar for evaluation of heavy rainfall. Overall, the radar rainfall demonstrated good performance in simulating the peak time, and CSU-HIDRO estimated the rainfall with up to 32.4% more accuracy than JPOLE.