利用2001年青藏高原及周边地区的地基GPS观测资料、M O DIS卫星遥感资料和N CEP格点再分析资料分析了青藏高原及周边地区大气水汽分布及其变化特征。研究结果表明,青藏高原东南部地区大气总水汽量的年变化在0.3～3.0cm之间,高原其它地区大气总水汽量的年变化在0.2～2.0cm之间;青藏高原东南部河谷的导流作用非常显著,是暖湿气流进入青藏高原内部地区的重要途径;地理纬度和海拔高度决定了青藏高原地区南湿北干的大气水汽分布特征,而大气环流变化则是造成青藏高原及周边地区大气水汽分布季节变化的主要原因。

Based on the ground GPS,MODIS remote sensing data and NCEP data grid reanalysis data on the Tibetan Plateau and its surroundings in 2001,precipitable water vapor distribution and its seasonal variation characteristics are studied over these areas.The result shows that precipitable water vapor column changes between 3 and 30mm in the southeastern part,and between 2 and 20mm in other parts of the Tibetan Plateau.So it is moist in the southeastern part and dry in the northwestern part.There are two high water vapor centers throughout the year,one is over the Grand Canyon of the Yarlung Zangbo River southeast of the Plateau,the other is over Sichuan Basin east of the Plateau.There are also two moisture centers over the surrounding areas.The Grand Canyon is an important access through which a great deal of water vapor reaches the interior of the Plateau.With seasons alternating,the transportation of water vapor from the Grand Canyon changes obviously.Reasonably,a moisture region in the southeastern part and a dry region in the northwestern part of the Plateau are determined by its geographical latitude and the altitude.However precipitable water vapor distribution and its seasonal variations over the Plateau and its adjacent areas are mainly determined by general circulation of atmosphere.Moreover,the transportation of water vapor to the interior of the Plateau by general circulation is different during different seasons,and the transportion intensity of water vapor to different parts of the Plateau is different as well.