华北夏季大气水汽输送特征及其与夏季旱涝的关系  

Climatological characteristics of atmospheric water vapor transport and its relation with rainfall over north China in summer

作　　者：谢坤[1] 任雪娟[1] 

机构地区：[1]南京大学灾害性天气气候研究所,南京210093

出　　处：《气象科学》2008年第5期508-514,共7页Journal of the Meteorological Sciences

基　　金：国家自然科学基金(40775044);国家重点基础研究发展规划项目(2006CB400506)

摘　　要：本文利用ECMWF再分析资料ERA40和中国160站的降水资料,分析了我国华北地区1958年—2002年夏季的大气水汽含量和水汽输送的基本气候特征,研究了华北夏季旱涝年的大气水汽含量和水汽输送异常情况,最后利用线性回归的方法探讨了该地区大气水汽含量和水汽输送的变化趋势。结果表明:华北地区夏季降水的大气水汽来源主要有3支:来自孟加拉湾的水汽、来自我国南海和西太平洋的水汽以及中高纬西风带的水汽输送。华北地区对流层低层以经向水汽输送通量为主,到了中高层则以纬向输送通量为主;与华北地区夏季旱涝密切相关的异常水汽输送主要是南海和西太平洋以及西风带水汽输送异常,华北地区南边界水汽输入异常和东边界水汽输出异常是造成华北夏季旱涝年水汽收支异常的主要原因;近半个世纪以来,伴随着华北干旱化的加剧,华北地区南边界输入的大气水汽呈现显著的减少趋势。The atmospheric water vapor transport （AWVT） in summer and precipitable water （PW） over north China have been investigated for the period 1958-2002, with ECMWF reanalysis data and precipitation data at 160 stations in China. The differences of AWVT and PW associated with rainfall anomaly are studied, while the linear trends of AWVT and PW from 1958 to 2002 are both analysed in the end of this paper. There are three main atmospheric water vapor sources in north China： the Bay of Bengal, south China sea and west Pacific, and midlatitude westerlines. The AWVT is characterized by meridional transport in low troposphere, and by zonal transport in upper troposphere. AWVT anomaly from south China sea, west Pacific and westerlines plays a crucial role in the sources which may result in flood or drought in north China. Especially AWVT cross south and east boundary of the target region is the dominant factor in budget anomaly. It is noticed that water vapor cross south boundary has been declining sharply since 1958 and aridity of north China is aggravated at the same time.

关 键 词：大气水汽输送 华北夏季旱涝 线性趋势 

分 类 号：P434.5[天文地球—大气科学及气象学]