中文摘要：

利用NCEP/NCAR全球再分析资料以及环流特征量资料,计算分析了东亚夏季风、南亚夏季风和西北地区东部水汽输送的关系,研究了南亚夏季风强弱和热带太平洋海表温度的关系,并通过对热带太平洋对热带印度洋的＂充电＂作用的验证,探讨了西北东部夏季经向水汽输送变化机制.研究表明,夏季,对西北地区东部经向水汽输送起主要作用的是南亚季风,东亚季风影响不大;前一年秋季赤道中东太平洋SST显著偏暖（冷）,El Nin觸o（La Nin觸a）发生,通过沃克环流的影响,使得印度洋SST一致偏暖（偏冷）,从而引起大气＂Matsuno-Gill型＂响应,造成南亚高压偏强（偏弱）,致使高原南侧垂直环流出现异常,导致南亚季风偏弱（偏强）,并使得西北地区东部水汽通量减弱（增加）.

英文摘要：

Based on NCEP/NCAR global reanalysis data as well as characteristic values of atmosphere circulation, the relationships between the East Asian summer monsoon, the South Asian summer monsoon and the summer meridional water vapor transport were computed and analyzed in eastern part of Northwest China, the relationship between the South Asian summer monsoon strength and sea surface temperature in the tropical Pacific was researched, the change mechanism for summer meridional water vapor transport in the eastern part of Northwest China was discussed by the verification of the＂charging＂role of the tropical Pacific to the tropical Indian Ocean. The results show that the South Asian monsoon plays a major role on the meridional moisture transport and East Asian monsoon has little effect in summer; the equatorial eastern and central Pacific Ocean SST was uncommonly warm（cold） in the fall of the previous year, led to the occurrence of El Nio（La Nia）, and Indian Ocean SST was consistent warmer（colder） through atmospheric bridge（Walker circulation）, then it caused the atmosphere＂Matsuno- Gill pattern＂response, South Asia High stronger（weaker）, vertical circulation abnormal in the plateau south side,South Asian monsoon weaker（stronger） and water vapor flux decreased（increased） in the eastern part of Northwest.