华南季风降水对应的环流指数  

A Circulation Index Reflecting the Monsoon Precipitation of South China

作　　者：姚才[1] 钱维宏[2] 林振敏[1] 刘合香[3] 

机构地区：[1]广西气象减灾研究所,南宁530022 [2]北京大学物理学院,北京100871 [3]广西师范学院,南宁530001

出　　处：《应用气象学报》2011年第3期302-311,共10页Journal of Applied Meteorological Science

基　　金：广西科学研究与技术开发计划项目(桂科攻0719005-3-2);中国气象局气象新技术推广项目(CMATG2008M49);广西科学研究与技术开发项目(桂科攻0993002-4);广西教育厅科研项目(200911MS151)

摘　　要：利用NCEP再分析资料及台站和格点降水量资料分析了华南季风降水与周边大气环流的关系,并由此建立了反映6月华南降水强度的季风指数,这一季风指数利用菲律宾及其以东与华南850 hPa涡度差定义。华南季风指数具有很好的区域代表性,华南季风指数与亚洲格点日降水量的主要正相关区集中在华南。华南季风指数可以很好地描述华南降水的年际变化和极端年份,季风指数强(弱)的年份也是华南降水偏多(少)的年份,极端的华南季风指数年份对应极端的华南降水年份。华南季风指数高与低年份对应的华南降水量差值通过了0.01的显著性检验。在年代际尺度上,季风指数强(弱)的年代与华南降水偏多(少)的年代有很好的对应关系。华南季风指数包含了西南季风、副热带高压以及中高纬度西风槽等各影响系统的信息,可在业务上使用。The South China monsoon precipitation and the monsoon over South China attract much attention.Using the NCEP reanalysis data and precipitation data of stations and grid,the relationship between the South China monsoon precipitation and atmospheric circulation are analyzed,and then a monsoon index of South China which can reflect the intensity of South China monsoon precipitation in June is established. The monsoon index of South China is defined based on the difference of 850 hPa vorticity between the subtropical Northwest Pacific near the Philippine Islands and the South China area.Then the relationship between this index and the South China monsoon precipitation are explored.The results indicate the monsoon index of South China has very good regional representative,the positive correlation coefficient between the monsoon index of South China and grid daily precipitation of Asia is mainly located in South China. The monsoon index of South China could fairly describe the inter-annual variability and extreme year of the precipitation.When the monsoon index of South China is stronger（weaker）,the precipitation of South China is more（less）correspondingly,and extreme of the monsoon index of South China also means the extreme of precipitation.The difference of the precipitation over South China between high and low monsoon index of South China is significant at 0.01 level.On inter-decadal scales,the decade in which the monsoon index of South China is stronger（weaker）is also the decade in which the precipitation of South China is more（less）. The relationship between the monsoon index of South China and the atmospheric circulation are also studied.The results indicate that the monsoon index of South China also includes the information of the important influencing systems such as southwest monsoon,the Pacific Subtropical High,the westerly trough over the middle-high latitudes,and so on.In the southeastern part of South China,there is abnormal anticyclonic circulation in lower and middle atmosphere,its cent

关 键 词：华南季风降水 季风指数 夏季 涡度 

分 类 号：P434[天文地球—大气科学及气象学]