Capturing Precipitation Characteristics Across Multiple Temporal Scales: Evaluation of Satellite Precipitation Products During an Extreme Precipitation Event in Guangdong, China

Under accelerating global climate change, the increasing frequency and intensity of extreme precipitation events (EPEs) pose severe threats to socioeconomic and ecological security, highlighting the critical importance of satellite precipitation products (SPPs) for EPE monitoring. However, comprehensive multi-scale, multi-characteristic evaluations of different SPP types during EPEs remain limited. This study systematically evaluated five SPPs from three categories—satellite-derived products (IMERG-Early, IMERG-Late, IMERG-Final), reanalysis products (ERA5-Land), and merged products (MSWEP-NRT)—during an EPE in Guangdong Province, China (August 16–21, 2024), across three temporal scales (3-hour, 12-hour, 24-hour) and four precipitation characteristics (amount, frequency, intensity, duration). All SPPs exhibit significant scale dependence and systematic biases in reproducing EPEs. The IMERG near-real-time products (Early/Late) provide the best overall multi-scale performance, demonstrating superior spatial fidelity and preservation of dynamic features like intensity gradients and duration. In contrast, ERA5-Land and MSWEP-NRT suffer from excessive smoothing, while the bias-corrected IMERG-Final overly suppresses heavy rainfall intensity. A key limitation across all products is a severe underestimation of precipitation peaks. This study provides critical guidance for SPP selection in EPE monitoring and identifies that future algorithmic improvements must focus on enhancing the identification and quantitative retrieval of convective precipitation to improve reliability.