湖北一次梅雨期暴雨过程的数值模拟及云微物理特征分析  

Numerical simulation and analysis on cloud microphysical characteristics during a Meiyu heavy rainfall event in Hubei province

作　　者：周志敏[1] 王斌[1] 郭英莲 杜牧云[1] 康兆萍 孙玉婷 ZHOU Zhimin;WANG Bin;GUO Yinglian;DU Muyun;KANG Zhaoping;SUN Yuting(China Meteorological Administration Basin Heavy Rainfall Key Laboratory/Hubei Key Laboratory for Heavy Rain Monitoring and Warning Research,Institute of Heavy Rain,CMA,Wuhan 430205)

机构地区：[1]中国气象局武汉暴雨研究所中国气象局流域强降水重点开放实验室/暴雨监测预警湖北省重点实验室,武汉430205

出　　处：《暴雨灾害》2023年第4期372-383,共12页Torrential Rain and Disasters

基　　金：国家自然科学基金项目(42230612,41905071,41620104009)。

摘　　要：受低涡和切变线的影响,2020年6月27—28日湖北地区发生一次梅雨期暴雨过程,造成严重灾害和重大经济损失。为了深入研究云微物理过程对梅雨期暴雨的影响,提高梅雨期暴雨的预报预警能力,针对本次暴雨过程,利用WRF模式进行了模拟并分析了该系统的云微物理特征,探讨了云微物理过程对本次暴雨过程的影响机制。结果表明:(1)数值试验较准确地模拟出暴雨的落区及中尺度对流系统演变过程,且区域平均降水随时间的演变与实况较为一致,但总体偏强。(2)降水强度急速上升阶段,冰相粒子融化量大于雨滴搜集云滴,雷达回波迅速增强。降水强度变化相对平缓阶段,雨滴搜集云滴量逐步增多,超过冰相粒子融化。各类水成物均快速发展,回波不断增强,冰晶增长速度超过雪和霰。在区域平均降水到达峰值前,水成物(除了雪粒子外)含量、上升气流及雷达回波均已达极值。上升气流中心与冰相粒子、云滴含量大值区分布较为一致,有利于淞附过程。(3)冰相粒子搜集云滴总量一直小于雨滴对云滴的搜集,云雨自动转化量在降水强度减弱时增长更明显。冰相粒子在降水发展初期主要通过贝吉龙过程产生,随着冰相粒子的发展,淞附过程占优,直到系统衰亡。Affected by a trough and shear line,a Meiyu heavy rainfall event occurred in Hubei Province from June 27th to 28th in 2020,resulting in severe disasters and significant economic losses..To investigate the impact of microphysical processes on Meiyu front heavy rainfall and improve the forecasting and warning capabilities,the heavy rainfall case was simulated utilizing the regional model WRF 3.4.1,and the effect of cloud microphysical characteristics on the heavy rainfall was discussed.Results are as follows:(1)The heavy rainfall area and evolution of area-averaged precipitation were simulated well with a little overestimation.At the same time,the mesoscale systems were reproduced well through model results.(2)When rainfall strengthened rapidly,melting of ice phase hydrometeors(Melt)contributed more to the growth of rain drop than accretion of cloud droplet by rain drop(CLcr)and the composite radar echo developed rapidly.When the rainfall strengthened a little more smoothly,the amount of CLcr was larger than that of Melt.All the hydrometeors grew significantly and the composite radar echo intensified dramatically.Ice crystals grew more rapidly than snow and graupel.Before the peak rainfall,the content of hydrometeors(except snow),updraft and composite radar echo had reached extreme values.The center of updraft is more consistent with the area of large values of ice-phase particles and cloud droplets content,which is favorable to the riming process.Ice,graupel and the amount of water vapor condensation reached their maximum content and the composite radar echo began to decay before the strongest precipitation occurred.(3)Less ice phase hydrometeors collected cloud droplet was produced than CLcr.Auto conversion of cloud droplet to rain increased significantly when the rainfall process decayed.The main pathway of ice phased hydrometeors was Bergeron process in the initial stage of the precipitation.With the growth of ice phase hydrometeors,riming process between cloud droplet and ice phase hydrometeors was dominant un

关 键 词：梅雨锋暴雨 数值模拟 云微物理 源汇项 

分 类 号：P458.121.1[天文地球—大气科学及气象学]