海口市不同云天条件下水汽含量特征及降水效率分析

Characters and Change of Water Vapor under Different Cloud Conditions in Haikou

分析不同云天条件时的水汽含量及其变化,可以对人工增雨作业时机及效果评估提供有价值的信息。应用2005年11月海口市地基GPS遥感大气水汽含量资料、逐时降水资料分析了大气水汽含量在不同云天条件下的特征与实际降水的对应关系以及不同降水云系的降水效率。结果表明:GPS反演的水汽含量与探空计算得到的水汽数据具有较好的一致性,同时水汽含量值与地面降水吻合较好。在海南岛冬季三类热带降水云中,积雨云水汽含量最大,降水期间变化幅度也最大,浓积云次之,最低是蔽光层积云。海南岛冬季降水云的自然降水效率不高,空中水汽约97.6%不能转化降落到地面,有一定的人工增雨潜力。

Using the data of water vapor detected by ground-based GPS and hourly precipitation in Haikou, Hainan in November 2005, the characters of water vapor under different cloud conditions and its relation with precipitation were analyzed, and the precipitation efficiency under different cloud conditions was also estimated. Results show that there is little difference between water vapor content detected by groundbased GPS and that calculated from radiosonde data, and that the water vapor content fits well with the precipitation. Of the three tropical precipitation clouds in winter in Hainan the water vapor content is the highest in cumulonimbus and varies most greatly during precipitation, the second highest in cumulus congestus and the lowest in stratocumulus opacus. The precipitation clouds in winter in Hainan do not precipitate efficiently （less than 2.4%）, and about 97.6% of water vapor can not precipitate and hence has some potential for cloud seeding.