【摘要】 在利用三江源地区及邻近区域探空资料对NCEP/NCAR I再分析资料进行适用性分析的基础上,采用1971—2010年再分析资料的逐日风场和比湿数据,分析三江源地区水汽输送的变化。结果表明:1971—2010年,经向流入三江源地区的水汽显著减少,使区域总水汽收支也呈显著减少趋势。水汽通量在1970年代和1980年代的变化相对较小,在1990年代和2000年代的变化幅度则较大。三江源地区总水汽收支在春季、夏季和秋季均呈明显减少趋势,冬季则无明显变化。三江源地区水汽输入明显减少,特别是6月和9月显著减少,对该地区降水形成不利。更多还原

【Abstract】 Based on the applicability analysis of the NCEP/NCAR reanalysis I data by the radiosonde data in the Three Rivers’ Headstream region and the adjacent regions,trends of water vapor transports in the Three Rivers’ Headstream region were analyzed by applying the daily wind and specific humidity of the reanalysis data during 1971-2010.The results show that the meridional water vapor input in the Three Rivers’ Headstream region decreased significantly,causing the net water vapor budget decreasing.The decadal variations of water vapor fluxes in the 1970s and 1980s were relatively weaker than those in the 1990s and 2000s.During 1971-2010,the water vapor budget showed an obvious decreasing trend in spring,summer and autumn,while no significant trend in winter. Overall,the water vapor transport into the region decreased significantly,especially in June and September during 1971-2010,which had adverse impacts on precipitation formation.更多还原