Comparison of Reflectivity Consistency between Spaceborne Precipitation Radar and Ground-based Weather Radar in China and the United States

The Global Precipitation Measurement (GPM) dual-frequency precipitation radar (DPR) products (Version 07A) are employed for a rigorous comparative analysis with ground-based operational weather radar (GR) networks. The reflectivity observed by GPM KuPR is compared quantitatively against GR networks from CINRAD of China and NEXRAD of the United States, and the volume matching method is used for spatial matching. Additionally, a novel frequency correction method for all phases as well as precipitation types is used to correct the GPM KuPR radar frequency to the GR frequency. A total of 20 GRs (including 10 from CINRAD and 10 from NEXRAD) are included in this comparative analysis. The results indicate that, compared with CINRAD matched data, NEXRAD exhibits larger biases in reflectivity when compared with the frequency-corrected KuPR. The root-mean-square difference for CINRAD is calculated at 2.38 dB, whereas for NEXRAD it is 3.23 dB. The mean bias of CINRAD matched data is −0.16 dB, while the mean bias of NEXRAD is −2.10 dB. The mean standard deviation of bias for CINRAD is 2.15 dB, while for NEXRAD it is 2.29 dB. This study effectively assesses weather radar data in both the United States and China, which is crucial for improving the overall consistency of global precipitation estimates.