This study uses the China Meteorological Administration Mesoscale (CMA-MESO) model, employing three cloud microphysics schemes: the Weather Research and Forecasting (WRF) Single-Moment 6-Class Microphysics (WSM6), Thompson and LiuMa schemes to simulate and analyze the main features and differences in the rainfall, cloud macrophysical quantities and cloud microphysical quantities among the different schemes during the extreme rainstorm in Zhengzhou, Henan Province of China on July 20, 2021. The results show that the simulations based on all three cloud microphysics schemes successfully reproduce the 24-hour accumulated rainfall of the extreme rainstorm. Among them, the maximum 24-hour accumulated rainfall simulated by the WSM6 scheme is the closest to the observations. However, challenges remain in accurately simulating the temporal evolution of the precipitation intensity and the intensity of the maximum hourly rainfall. The maximum hourly precipitation simulated by the LiuMa scheme is the closest to the observations in terms of the spatial distribution, intensity and radar echoes. Cold and warm cloud precipitation processes jointly dominate the entire precipitation event, but the warm cloud precipitation process dominates the precipitation during the period with the maximum hourly precipitation intensity. The vertical distributions of liquid-phase hydrometeors simulated by the three schemes are relatively consistent, while the simulations of ice-phase hydrometeors are sensitive to the specific scheme used. During the period with the observed maximum precipitation intensity, the vertical distribution patterns of raindrop size and terminal velocity, as modeled by the three schemes, exhibit a harmonious alignment.
Chenyun et al. (2026) studied this question.