Quantitative Precipitation Estimation Using X-band Polarimetric Radar Measurements over Southern China

X-band polarimetric radar has shown great performance in monitoring severe storms through high spatial and temporal resolution observations, especially at the lower level of atmosphere (<1km above ground level). Due to the rapid urbanization and climate changes, Guangdong, one of the most prosperous provinces in China, has experienced more and more severe weather events such as tornado and typhoon, which have caused tremendous loss of life and property. In order to monitor severe weather events in southern China especially in Guangdong, a high-resolution X-band dual-polarization radar network is being deployed in Foshan urban area. Quantitative Precipitation Estimation (QPE) is one of the major research thrusts in the development of this urban radar network.

In this study, we first investigate various polarimetric radar rainfall algorithms to yield high spatial (250m) and temporal (≤2 min) resolution QPE products over Foshan urban area. In addition, the S-band polarimetric radars over Guangdong province will be combined to produce high-quality rainfall products covering the whole province. The QPE algorithms utilizing different combinations of polarimetric radar measurements will be tested, including reflectivity, differential reflectivity, specific differential phase, and attenuation. The derivation of specific rainfall algorithms at S- and X-band will be detailed in this study. The performance of each algorithm will be evaluated against the gauge observations over this area.