黑河流域水汽输送及收支的时空结构分析

Temporal Variation and Spatial Structure of the Water Vapor Transport and Budget over the Heihe Drainage Area

利用NCEP/NCAR再分析气候资料和气象站地面观测资料,分析了黑河流域水汽输送及收支的时空结构变化.结果表明:在水汽输送的年变化中,6-9月为高输送时段,中层700~500 hPa为强输送层,大气水汽含量的年变化是主要影响因子;在水汽输送的年际变化中,1960年代中期和1970年代后期有两次较明显的转折,总体呈下降的长期变化趋势,水汽输送仍以中层输送为主,风速的年际变化是主要影响因子,大气水汽含量下降则提供了长期变化趋势背景.水汽输送的空间结构主要受气流分布的影响,多年平均6-9月的状况为:在低层为南北辐合状,中层为西风辐合状,高层为平直西风辐散状.水汽净收入以低层为主,占整层水汽净收入的85%以上.在黑河主流区2°×5°的范围内,大气水汽输入为2484×108m3,输出为2196×108m3,水汽净收入为288×108m3.

Based on the NCEP/ NCAR re-analysis climate data,with the resolution of 2.5°×2.5° and 1°×1°,the temporal variation and spatial structure of atmospheric water vapor transport and budget over the Heihe drainage area are analyzed.It is found that,in the monthly variation of the water vapor transportation,the main effect factor is water vapor content,the primary process is concentrated in June to September,and the strong transportation is in the layer of 700～500 hPa.In the annual variation of the water vapor tr...