暴雨和中尺度气象学问题

目前人们对超级单体云团降水回波结构的认知仍有限。本文采用GPM (Global Precipitation Measurement) 卫星搭载的测雨雷达DPR (Dual-frequency Precipitation Radar)和微波成像仪GMI (GPM Microwave Imager)的探测结果，结合FY-4A静止卫星多通道扫描成像辐射计(AGRI)的热红外10.8 μm通道观测结果、探空站的温湿风观测结果及欧洲天气预报中心再分析数据，利用雷达回波剖面和回波反射率因子概率密度随高度分布的方法，分析了2018年5月重庆地区超级单体云团的降水结构特征。结果表明：该超级单体云团由西北向东南运动的冷空气与暖湿空气交汇而引发；超级单体云团内存在对流降水和层状降水等次尺度系统；强降水区位于云贵高原与四川盆地交界处至盆地的西南部；超级单体暴雨云中冰相粒子多；对流降水的回波顶高度超过12 km，且最大回波强度多数位于地面上空4-5 km；对流降水比层状降水拥有更高的降水粒子浓度，而粒子大小却小于后者；对流降水的粒子尺度随着高度下降而明显增大，反映了其明显碰并增长过程。

The relationship between large-scale convective rainfall and cold cloud over the Western Hemisphere during 1982-1984

The knowledge of the echo structure of precipitation generated by supercell cloud is still limited. In this study by using measurements of the GPM (Global Precipitation Measurement) DPR (Dual-frequency Precipitation Radar) and GMI (GPM Microwave Imager), combined with observations by the thermal infrared channel of FY-4 (Fengyun-4), a stationary satellite, and temperature/humidity/wind observations by atmospheric sounding, as well as reanalysis data issued by the European Weather Forecast Centre, the vertical cross-section and two-dimensional probability density distribution of radar echoes for a supercell cloud occurred near Chongqing in May 2018 were analyzed. The results show that the supercell cloud system is caused by the convergence of a cold airmass moving from northwest to southeast and a warm-humid airmass. There are subscale systems of convective precipitation and layered precipitation in supercell cloud, which induced strong precipitation located at the junction of Yunnan-Guizhou Plateau and Sichuan Basin to the southwest of the basin. There are many ice phase particles in the supercell cloud. The echo top height of convective precipitation is more than 12 km, and the maximum echo intensity is mostly located 4~5 km above the ground. Convective precipitation has higher precipitation particle concentration than stratiform precipitation, and its particle size is smaller than the latter. The particle size of convective precipitation increases obviously with the decrease of the height, which reflects the obvious collision and growth process of these particles.