西藏高原汛期旱涝年水汽输送差异特征  

Characteristics of Water Vapor Transport Differences between Flood and Drought Years in Rainy Season over Tibetan Plateau

作　　者：林志强 乔钰[2] 唐叔乙 

机构地区：[1]西藏自治区气象服务中心,拉萨850000 [2]南京信息工程大学大气科学学院,210044 [3]西藏自治区气象台,拉萨850000

出　　处：《气象科技》2014年第1期110-117,共8页Meteorological Science and Technology

基　　金：国家自然科学基金(41165011);公益事业行业专项(GYHY201106005);干旱气象科学研究基金(IAM201310)资助

摘　　要：利用西藏高原39个气象站自1961年或建站开始至2010年汛期(5—9月)的逐月降水资料,根据Z指数和区域旱涝指数分析了近50年西藏高原汛期旱涝的变化特征。在此基础上,选取了典型旱、涝年,采用NCEP/NCAR再分析月平均资料,通过合成分析方法分析了旱、涝年的水汽输送特征的差异。结果表明:近50年以来,西藏高原以旱为主,涝灾较少,干湿状况具有明显年代际变化;西藏高原汛期旱涝与水汽输送异常联系紧密,典型旱(涝)年北印度洋、西北太平洋和亚洲中纬度地区的整层水汽通量经向、纬向及整层水汽通量和水汽通量散度均存在显著差异,呈反位相分布。越赤道急流区的差异最为显著,索马里越赤道气流区的水汽输送差异主要表现在经向上,而菲律宾越赤道气流区的水汽输送差异主要表现在纬向上。Using the monthly precipitation data of 39 meteorological stations from 1961 to 2010 in rainy season over Tibetan Plateau and the NCAR/NCEP reanalysis data, the flood and drought distributions are discussed based on the Z index and regional flood/drought indexes. The composite analysis method is used to analyze water vapor transport differences between flood and drought years over the Tibetan Plateau. The results show that droughts occur much more frequently than floods over the Tibetan Plateau in recent 50 years. The dry and wet conditions have obvious inter-decadal variations. Floods and droughts over the Tibetan Plateau are closely linked to water vapor transport anomalies. There are significant differences between typical drought and flood years in the zonal, meridional, and the total water vapor fluxes and water vapor flux divergence over North Indian Ocean, the western North Pacific, and the mid-latitude regions of Asian. The difference appears most significantly at the cross-equatorial jet area; and the major difference in the zonal water vapor flux is found in the Somali jet area, and that in the meridional water vapor flux is found in in the Philippines jet area.

关 键 词：西藏高原 汛期降水 水汽输送 合成分析 区域旱涝指数 

分 类 号：P434.5[天文地球—大气科学及气象学]