四川2020年8月16日暴雨天气过程分析
Analysis of Rainstorm Weather Process in Sichuan Province on August 16, 2020

利用气象站常规观测资料、FY-2G卫星云顶黑体亮度温度(TBB)资料、欧洲气象中心(ECMWF)第五代大气再分析数据资料(ERA5)，基于天气学和天气学诊断分析方法，从天气系统以及动力、热力和水汽条件角度，对发生在2020年8月16日四川地区的一次特大暴雨天气过程进行分析，结果表明：1) 此次暴雨天气过程是受到西南低涡、西太平洋副热带高压、西南低空急流和中尺度对流系统共同影响所引起。2) 动力条件表明：低层气旋性涡度辐合、高层反气旋性涡度辐散，垂直上升运动强烈。3) 热力条件表明：假相当位温随高度增加而降低，大气层结处于不稳定状态，其等值线密集区反映出锋面所在；温度平流反映出地面处于高能高湿状态，上空积蓄大量不稳定能量。4) 水汽条件表明：水汽补充来源于孟加拉湾和我国南海海面，以西南低空急流为载体，向降雨落区输送。5) 云顶黑体亮温(TBB)负大值区与降水的强度和落区有很好的对应关系。
Utilizing conventional observation data from weather stations, the FY-2G satellite black body temperature (TBB) data, the European Centre for Medium-Range Weather Forecasts (ECMWF) fifth-generation atmospheric reanalysis (ERA5), based on synoptic and synoptic diagnostic analysis methods, from the perspective of the weather system and the dynamic, the thermal, the moisture conditions were analyzed for a heavy rainstorm that occurred in Sichuan on August 16, 2020. The results showed that: 1) The rainstorm was affected by the southwest vortex, the Western Pacific subtropical high, the southwest low-level jet and the mesoscale convective system. 2) The dynamic conditions show that the low-level cyclonic vorticity converges, the high-level anticyclonic vorticity diverges, and the vertical upward movement is strong. 3) The thermal conditions show that: The pseudo-equivalent potential temperature decreases with the increase in altitude, the atmosphere stratification is in an unstable state, and the dense contour area reflects that there is a frontal area in this surface; the temperature advection reflects that the land is in a state of high energy and high humidity, a large amount of unstable energy is accumulated in the high-level. 4) The moisture conditions indicate that the moisture replenishment comes from the Bay of Bengal and the surface of South China Sea, and is transported to the rainfall area with the southwest low-level jet as the carrier. 5) The negative large value areas of black body temperature (TBB) have a great corresponding relationship with the intensity and zones of precipitation.