Study on the impact of cloud micro-physics schemes on the forecast of warm regions heavy rainfall

WRFv3.7 model was applied to simulate the warm-sector precipitation process in the coast area of Fujian on May 7,2018.Five selected microphysics schemes all effectively indicated the location and amount of precipitation.The Thompson (THOM) and WDM6 schemes with better simulation results were selected to further analyze the characteristics and micro-physics mechanisms of cloud system.The results showed that the forecast of precipitation in the WDM6 scheme was better than that of the THOM scheme.These two schemes exhibited good consistency in simulating cloud macroscopic characteristics,liquid water content,and cloud sources and sinks.However,some differences existed in simulating ice water content:in the THOM scheme,ice-phase hydrometeor mainly consisted of snow (81.4%),graupel (4.8%),and a small amount of ice.In the WDM6 scheme,snow (29.7%) and graupel (33.3%) account for half of the total aqueous contents.In the THOM scheme,surface precipitation mainly originated from liquid processes within clouds,with rain collecting cloud water (58.7%) as the primary source,followed by snow melting (25.3%).In the WDM6 scheme,the main source of rain was the melting of graupel (67%),followed by the growth of rain collecting cloud water (18.4%).