Comparison of Five Cloud Microphysical Schemes on the Rainstorm Weather Induced by Typhoon Ampil

The mesoscale model (WRF3.9.1) model was used to simulate the heavy rainfall process caused by Typhoon Ampil in Hebei and Tianjin from July 23 to 24, 2018. In this study, the typhoon track, structure and rainfall distribution simulated by different cloud microphysics schemes were compared, and the relationship between the difference of mixing ratio of hydrometeors in clouds and vertical motion was analyzed. The results showed that: ①All schemes can well simulate the structure and intensity of typhoon as it moves northward. Morrsion 2-moment scheme is the most accurate one to reproduce the period, region, and center of heavy rainfall. ②The water particles in cloud body in major precipitation area of the typhoon are distributed in 0−8 km, and the height of 0 ℃ is in 4−5 km, indicating lot of supercooled water is in the cloud body. ③In heavy rainfall period, the simulated vertical velocities of all schemes are in good agreement with hourly rainfall intensity, and the cloud top in the rain area reaches 10−15 km, with large amount of supercooled water and solid hydrometeors in the cloud and strong upward movement within cloud cluster. ④The cloud graupel mixing ratio of Thompson scheme and Morrsion 2-moment scheme is significantly higher than that of the other schemes, and cloud graupel particles and water particles exhibit overlap above 0 ℃, which are key factors of the Bergeron process in clouds and have direct impactc on the rainfall. ⑤The intensity of the vertical upward movement in the cloud simulated by each microphysical scheme has a good correlation with hourly rainfall intensity. These results can not only provide ideology for improving the cloud microphysics impacting typhoon process but also help to improve the cloud microphysical parameterization schemes in typhoon simulations.