青海高原近43年夏季水汽分布及演变特征

Distribution and Changing Character of Water Vapor over Qinghai Plateau in Summer in Recent 43 Years

通过对青海高原近43年夏季空中水汽分布及演变的研究，结果表明；（1）夏季来自盂加拉湾的暖湿水汽在东亚夏季风的驱动下向东北方向输送，与沿中纬度的西风环流输送的水汽在青海高原会合，但受高原大地形阻挡，到达该区的水汽含量较源区大大减小；（2）青海高原水汽通量场自西界向东界增加，水汽通量高值区基本分布在青海东部的边坡地带；（3）近43年青海高原净水汽通量收支有正有负，但整体上却呈增加趋势；（4）早年青海高原水汽通量比平均状况偏少10～40kg·m^-1·s^-1；涝年偏多10～20kg·m^-1·s^-1；无论旱涝年，青海高原空中净水汽通量均呈正值，但早年比平均状况偏少21．88％，涝年偏多53．99％。

Based on the research about distribution and changing character of water vapor over Qinghai Plateau during the recent 43 years, the obtained results are as follow. （1） In summer, the warm and moist water vapors from Bay of Bengal is transported by the East Asian summer monsoon into the Qinghai Plat eau, and the west wind water vapor is transported to this region at the same time too, but because of ter rain of Qinghai Plateau blocking off, the total content of water vapor in this region is greatly decreased. （2） The content of water vapor flux is increasing from west to east boundaries, the high value belt of water vapor flux lies to the east part of Qinghai Plateau. （3） The net vapor flux has an increasing tendency in recent 43 years. （4） In the dry year, the decreasing of water vapor is about 10-40 kg · m ^-1 · s^-1, and the increasing of water vapor is about 10-20 kg · m^- 1 · s^-1 in wet year. The net water vapor flux is positive always, but its content is low about 21.88% than average state in dry year, and is high about 53.99% in wet year.