作　　者： (敬文琪）; (崔园园）; (刘瑞霞）; (王业桂）; (方涵先）; (赵小艳）; (马杰）;

机构地区： 国防科技大学气象海洋学院,南京211101

出　　处： 《高原气象》 2017年第4期900-911,共12页

摘　　要： 基于2008年夏季JICA高原探空资料、1979-2015年ERA-Interim和MERRA再分析资料和中国160站点降水资料,首先评估了两种再分析资料在青藏高原(下称高原)的适用性;其次,提出将高原高低层水汽通量散度差定义为高原水汽抽吸指数;然后,采用合成分析法定义了与长江中下游(MLRYR)夏季降水关系密切的水汽路径有5条:孟加拉湾路径、云贵路径、南海路径、低纬路径和汇合路径,并对其强度进行了定量计算。研究表明:ERA-Interim相对MERRA再分析资料在高原适用性更优。在年际变化上,5条水汽路径与MLRYR夏季降水呈同相位变化。5条路径之间关联密切,构成了两条影响M LRYR降水的反气旋式水汽输送相关链:"南海-孟加拉湾-高原南缘-云贵-M LRYR"和"南海-华南-M LRYR"。南海水汽路径是中国东部地区降水重要的水汽通道;汇合路径是调控M LRYR夏季降水的重要水汽输入通道,而云贵东向路径与整个长江流域的降水呈显著正相关。影响MLRYR夏季降水的高原水汽抽吸作用主要发生在高原南缘。高原水汽抽吸作用可以将低层的水汽抽吸至高层,通过增加长江流域西入的纬向水汽输送间接影响到长江流域的降水。 Based on JICA Tibetan sounding data in 2008,ERA-Interim and MERRA reanalysis data during 19792015 and monthly average precipitation of 160 stations in China,firstly this study evaluates the applicability of two reanalysis data on Qinghai-Tibetan Plateau（ QTP） and defines the high-level and low-level difference of water vapor flux divergence on QTP as QTP water vapor pumping index; By synthetic analysis,it is found that there are mainly five water vapor paths influencing summer precipitation in middle and lower reach of Yangtze River（ MLRYR） ： The Bay of Bengal path,Yunnan-Guizhou Plateau path,South China Sea path,lowlatitude path and confluent water vapor path,whose magnitude is calculated by index. The result shows that ERA-Interim reanalysis data shows better applicability than MERRA reanalysis data on QTP. On the inter-annual variability,all the water vapor paths perform the same phase change with MLRYR summer rainfall. Five paths are closely related,making up two anticyclonic water vapor transport correlation-chains： One is ＂South China Sea-the Bay of Bengal-southern edge of QTP-Yunnan-Gui Zhou Plateau-MLRYR ＂,the other is ＂South China Sea-YunnanGuizhou Plateau-MLRYR＂. South China Sea path is important water vapor channel of the rainfall in east China;Confluent path is the vital water vapor channel controlling the summer rainfall in MLRYR,but Yunnan-Guizhou Plateau path shows significant correlation with the summer rainfall in whole reach of Yangtze River. QTP water vapor pumping,which effects summer rainfall in MLRYR,mainly occurs over southern edge of QTP. QTP water vapor pumping can pump up water vapor in lower level to the top of QTP,and plays an indirect role in influencing the summer rainfall in Yangtze River by increasing zonal water vapor transport towards the Yangtze River Basin.

关 键 词： 青藏高原 水汽抽吸 水汽路径 长江中下游 夏季降水