【摘要】 利用自动气象观测站降水数据、ERA5再分析数据和葵花8号卫星数据，对2020年10月18日三亚市出现的大暴雨过程的对流云物理特征进行了分析。结果发现，强烈的南海辐合带和南下的大陆高压相互作用，及低空偏东风急流相伴，为此次大暴雨的发生提供了有利的动力和水汽条件，海上中尺度对流云团在偏东气流引导下移入三亚市，造成三亚市陆续出现强降水。对流云团的红外窗区通道和水汽通道亮温差能较好地反映雨强的大小，降水强度超过20.0 mm·h^-1时，出现亮温差小于0℃的亮温逆转现象。云顶高度、云光学厚度与雨强的相关性优于云顶温度的，而云粒子有效半径与雨强的相关性较差。20.0 mm·h^-1以上的短时强降水对应的云顶温度为-67.9℃、云顶高度为15.1 km、云光学厚度为114。在有利的大尺度环流背景下，对中尺度对流云团亮温、云特征参数进行深入分析得到的重要特征可为强对流天气的短时临近预报预警业务提供参考依据。更多还原

【Abstract】 Based on hourly precipitation data, ERA5 reanalysis data and Himawari-8 satellite data, the physical characteristics of convective clouds in the heavy rainstorm that occurred on October 18, 2020 in Sanya are analyzed. The results show that the interaction between the strong Intertropical Convergence Zone in the South China Sea and the southward continental high pressure, and low-level easterly jet stream, provided favorable dynamic and moisture conditions for the occurrence of the heavy rainstorm. The mesoscale convective clouds moved westward under the guidance of the easterly jet, resulting in two periods of heavy rainfall in Sanya. The brightness temperature difference between infrared window channel and water vapor channel of the convective clouds could effectively reflect rainfall intensity. When the precipitation intensity exceeded 20.0 mm·h^-1, there was a bright temperature reversal phenomenon with a brightness temperature difference less than 0 ℃. The correlation of the cloud top height and cloud optical thickness with rainfall intensity was superior to the correlation between cloud top temperature and rainfall intensity, while the correlation between cloud particle effective radius and rainfall intensity was poor. When the cloud top temperature was-67.9 ℃, the cloud top height was 15.1 km and the cloud optical thickness was 114, the rainfall intensity exceeded 20.0 mm·h^-1. The important features obtained by in-depth analysis of the brightness temperature and cloud characteristic parameters of mesoscale convective cloud clusters in a favorable large-scale circulation background could provide a reference basis for short-time nowcasting and early warning of severe convection weather.更多还原