华南大尺度空中水资源时空演变特征

Spatial and Temporal Variations of Large-scale Atmospheric Water Resources over Southern China

用1958-2004年NCEP/NCAR再分析资料和中国160站月降水量资料分析了华南年平均大尺度大气水汽汇的时空变化。结果表明:华南地区年平均水汽汇的主要变异区在华南中、东部地区以及华南西南地区。华南中、东部的年平均水汽汇与该地区的年平均降水一样,存在增加的气候变化趋势,而该地区的蒸发量则有减少的趋势。华南西南部的年平均水汽汇则以年际变化为主。华南中、东部以及西南部的水汽汇偏强(弱)时,东亚沿海上空水汽输送异常强(弱)导致这些地区的垂直积分的水汽通量辐合的增强(减弱)。

The spatial and temporal variations of annual mean large-scale atmospheric water resources （moisture sinks） over Southern China during a 47 - year period from 1958 to 2004 are studied using the NCEP/NCAR reanalysis data and the precipitation data at 160 stations in China. The results reveal that two main anomalous centers of moisture sinks are located in the central-eastern part and the south-western part of Southern China, respectively. There exists an increasing-trend variation in the annual mean moisture sink and the precipitation over the centraleastern part of Southern China and a decreasing-trend in the evaporation. The annual mean moisture sink over the south-western part of Southern China mainly experiences a interannual-scale variation. These anomalous variations of moisture sinks over the sub-regions in Southern China are closely linked to the anomalous variations in the divergence field of the vertical integrated moisture flux over East Asia.