新疆水汽输送的气候特征及其变化

Climate Characteristics of Water Vapor Transportation and Its Variation over Xinjiang

利用1961—2000年NCEP/NCAR再分析逐日资料,分析了新疆地区对流层不同层次空中水汽输送特征。结果表明：地面～300 hPa每年平均有26114.8×10^8t水汽流入新疆,25647.7×10^8t水汽流出新疆,净水汽收入量为467.1×10^8t。由于三面环山的地形,新疆地区四季和年对流层中层水汽输送量最大,低层和高层接近。夏季水汽输送量最大,约占全年的38%,春、秋季相当,约占全年的23%～25%,冬季最少。近40年新疆年平均、春、夏和秋季空中水汽总流入量、总流出量为减少趋势,变化率很接近,且1976年后无明显变化趋势,使得净收支量无显著变化趋势。

Using the daily NCEP/NCAR reanalysis data from 1961 to 2000,the features of water vapor transportation of different layers over Xinjiang are analyzed.The results show that from surface to 300 hPa,26114.8×10^8t water vapor（WV） input Xinjiang and 25647.7×10^8t WV export from Xinjiang per year,as a result,annual net WV earning quantity is 467.1×10^8t.Due to the terrain of surrounding mountains in Xinjiang,water vapor transportation quantity（WVTQ） of middle layer is the most,and WVTQ of the lower and the high layers is adjacent.In summer,WVTQ is the most occupying about 38% of all year,23%～25% of all year in spring or autumn,and the least in winter.There are the almost similar decreasing trends of total WV inflow and outflow for annual average,spring,summer and autumn in the last 40 years,furthermore without distinct change trends since 1976,resulting that annual net WVTQ doesn＇t present the obvious change trends.