对比分析海南热带积雨云带的降水特征

Comparative Analysis of Precipitation Characteristics of Tropical Cumulonimbus Belt in Hainan

摘要: 海南2021年4月26日出现了与2020年4月22日类似云带持续的强降水天气过程，这是冷空气偏东(西)下锋消天气过程的重要天气类型之一，探讨其降水机理对人们的生产生活具有重要意义。本文利用常规地面、高空、卫星、多普勒雷达资料，特别使用NCEP/NCAR的FNL再分析资料，对这类天气的降水云带的结构及其特征进行研究，最后与2020年4月22日作对比分析。结果表明：1) 有一条雷达回波带呈西南–东北向，从西边往东边移过海南岛，移动过程中地面有强降水发生；2) 海南岛的对流风为西风，风速在4~8 m/s之间，其温度在−83℃~−81℃之间，高度在16,640~17,889 m之间；3) 海南岛的对流凝结高度在4844~5158 m之间，柱体可降水为49.5~63.2 kg/m²之间；4) 与2020年4月22日相比：相对湿度中低层的变化不大，上层有水汽补充；位势高度低层有所增高，中高层几乎相近；各层温度也几乎相近；对流风温度和位势高度、对流冰点位势高度也几乎相近。

Abstract: On April 26, 2021, in Hainan the weather process of continuous heavy precipitation occurred simi-lar to that on April 22, 2020, which is one of the important weather types: the front disappearance of cold air eastward (westward). It is of great significance to study the precipitation mechanism for people's production and life. The structure and characteristics of precipitation cloud are analyzed using the ground observation, high-altitude data, satellite, Doppler radar data, especially the NCEP/NCAR FNL data. Finally, it is compared with April 22, 2020. The results show that: 1) There is a radar echo belt in the southwest northeast direction, moving across Hainan Island from the west to the east, accompanied by heavy rainfall; 2) The convective wind on Hainan Island is west wind, with wind speed ranging from 4 o 8 m/s, temperature ranging from −83˚C to −81˚C, and height ranging from 16,640 to 17,889 m; 3) The convective condensation height of Hainan Island is be-tween 4844~5158 m; the precipitable water vapor of the column range from 49.5 and 63.2 kg/m²; 4) Compared with April 22, 2020: The relative humidity in the middle and lower layers is relatively stable, and the upper layer is supplemented by water vapor; The geopotential height is higher in the lower layer, and almost the same in the middle and upper layers; The temperature of each layer is almost the same; The temperature and geopotential height of the convective wind and the geo-potential height of the convective freezing point are almost similar.