基于双频星载降水雷达GPM数据的华南地区降水垂直结构特征分析

华南汛期作为我国雨季爆发的第一阶段一直是预报与研究的热点问题，对其降水-云宏微观垂直特性的认识还不够深入。双频星载雷达资料对强、弱降水三维探测进行优化，并补充对洋面降水的探测。借助这两方面优势，对华南对流性、层云性两类主要降水类型的垂直特征进行统计，分析降水反射率因子与降水粒子垂直分布、亮带特征与垂直分层降水贡献，对比华南陆地在回波顶高方面与南海洋面的异同，最后针对华南前后汛期的降水垂直分布特征进行分析。(1)对流性降水反射率因子快速增长区域主要发生在低层，层云性降水反射率因子快速增长区域位于亮带层附近。(2)当发生强降水时，对流性降水的粒子浓度并不是总高于层云性降水，但前者粒子半径大于后者；强层云性降水往往来自于大小均一的粒子聚集，并没有形成更大直径的液滴。(3)华南陆地回波顶高季节变化较南海洋面强烈，浅薄对流降水发生频率受季风影响从春至秋存在先增后减特征，深对流发生频率在夏季增幅显著。南海地区回波顶高虽无明显季节变化但在3 km和5.5 km存在明显的双峰特征。(4)前汛期对流性降水的高浓度、大尺度的粒子更利于向更高高度发展，而层云性降水粒子浓度及半径的垂直分布在华南前后汛期无明显差异。前后汛期回波顶高异同主要出现在广西中部，广东中部和沿海地区。 

ANALYSIS OF THE VERTICAL STRUCTURE OF PRECIPITATION IN SOUTH CHINA BASED ON DUAL-FREQUENCY SPACEBORNE PRECIPITATION RADAR GPM PRODUCT

Using the dual-frequency precipitation radar GPM 2ADPR satellite data from March 2014 to March 2018, this study analyzed the vertical structure of convective and stratiform precipitation over south China. The results are as follows. (1) The rapid growth of convective precipitation reflectivity mainly occurs in the lower layer, and the rapid growth of the stratiform precipitation is located near the bright zone. (2) The hydrometeor profile shows that the particle concentration of convective precipitation is not always higher than that of the stratiform precipitation, and the former actually has a larger particle size than the latter. Strong stratiform precipitation often comes from the aggregation of uniform hydrogenic particles, suggesting no larger droplets or raindrops are formed. (3) The seasonal variation of the top height of land storms in south China is stronger than that of the sea surface of the South China Sea. The frequency of shallow convective precipitation is affected by the monsoon from spring to autumn. The frequency of deep convection increases significantly in summer. Although there is no obvious seasonal variation in the echo top height in the South China Sea, there are obvious bimodal characteristics at 3 km and 5.5 km. (4) The high concentration and large-scale particles of convective precipitation in the annually first rainy season are more likely to develop at higher levels, while the vertical distribution of the concentration and radius of the stratiform precipitation has no significant difference in the two rainy seasons in south China. The differences of echo top height in the two rainy seasons are mainly found in central Guangxi, central Guangdong and coastal areas.