青藏高原夏季降水的水汽分布特征

WATER FEATURE OF SUMMER PRECIPITATION ON TIBETAN PLATEAU

本文利用青藏高原上夏季降水资料以及 NCEP再分析资料 ,分析了高原上夏季降水与邻近地区水汽输送的相互关系。结果发现 ,高原夏季降水与春季的水汽分布关系比降水与同期的关系更为密切 ,最明显的相关区位于南海 -云贵高原 -孟加拉湾一带以及帕米尔高原地区。青藏高原降水典型旱、涝年的水汽分布具有相反的特征。追踪最主要的水汽中心发现 ,水汽是从阿拉伯海一带逐渐向东移 ,然后再从高原的东南部进入高原。

This paper investigated the relationship between the summer precipitation at 36 stations of Tibetan plateau and water vapor distribution of neighboring area of NCEP reanalysis data from 1961 to 1997.Evidence shows that the relationship of summer precipitation to water distribution of spring was much closer than that of summer.The most remarkable positive relation areas were located in the South China Sea,Yungui Plateau and North of Vietnam,Bay of Bengal and Pamir.Opposite feature of water distribution exists in typical drought and flood years.The major water center moved from round the Arabic Sea and entered into the plateau from its southeast part,this phenomenon perhaps was related with Somali cross-equatorial flow.