冬季青藏高原湿中心区域水汽收支及其与中国降水的关系

Water Vapor Budget of High Water Vapor Content Region over Tibet Plateau in Winter and Its Relationship with Precipitation of China

利用ERA-Interim再分析资料（0.5°×0.5°）、探空观测资料及中国降水月值格点数据分析了冬季青藏高原（以下简称高原）大气水汽含量平均特征、高原湿中心区域的水汽收支特征及其与中国降水的关系。结果发现：冬季高原东南部地区存在湿中心,对应着水汽含量标准差大值中心;高原湿中心区域的水汽从西、南边界输入,东、北边界输出,净水汽收支多年平均为水汽＂盈余＂;该区域冬季净水汽收入、支出34 a总趋势是增加的,而净水汽收支是减少的,但三者均存在4~6 a左右的周期;冬季该区域净水汽收入对南疆、高原东部—四川盆地及云贵高原的降水有较好的指示性,净水汽支出对西南—华南的我国南方大部分地区降水有较好的指示性,净水汽收支则可表征高原东部及邻近地区、长江中游地区的降水;冬季该区域异常多（少）水汽支出年时,我国南方大部分地区的降水偏少（多）,水汽输送场不（有）利于水汽向我国南方的输送及辐合,即其水汽支出的强弱反映了水汽输送的强弱和我国降水的分布,体现出水汽收支通过环流对降水产生重要影响。

Mean characteristic of atmospheric water vapor content over Tibet Plateau in winter,water vapor budget characteristics of the high water vapor content region and its relationship with precipitation of China were analyzed by using ERA- Interim reanalysis data（ 0. 5° × 0. 5°）,sonde observation data and monthly mean China rainfall grid data,the results show that the high water vapor content center existed in southeastern area over the Tibet Plateau in winter,which corresponded to the high water vapor content standard deviation center. Water vapor inputed from the south and west boundary and outputed from the east and north boundary of high water vapor content region. Net water vapor budget was＂surplus＂in the high water vapor content region on average from 1979 to 2012. The trend of net water vapor input as well as net water vapor output was increasing and the trend of net water vapor budget was decreasing,but they all had about 4- 6 years cycle. Net water vapor input of the high water vapor content region in winter could instruct the precipitation of southern Xinjiang,from eastern Plateau to Sichuan basin and Yunnan- Guizhou Plateau,net water vapor output could instruct the precipitation from southwestern China to south China,while net water vapor budget could reflect the precipitation of eastern Plateau and its adjacent areas,middle reaches of the Yangtze river basin. The precipitation in most regions of southern China was less（ more） than normal during anomaly more（ less） water vapor output years in the high water vapor content region,and water vapor transmission wasn’t（ was） favorable to be transported to southern China and converged,this showed that the strength of the water vapor output in this region reflected the strength of water vapor transportation and distribution of precipitation in south China,and it also indicated the way how the water vapor budget effected the precipitation by means of circulating.