江淮梅雨期降水南北反位相分布与大气准双周振荡  

THE NORTH-SOUTH ANTI-PHASE DISTRIBUTION OF RAINFALL IN MEIYU PERIODS AND ITS RELATIONSHIP WITH QBWO IN ATMOSPHERE

作　　者：尹志聪[1,2] 王亚非[2] 袁东敏[3] 谢庄[1] 

机构地区：[1]北京市气象局,北京100089 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081 [3]中国气象局华风气象影视信息集团,北京100081

出　　处：《热带气象学报》2012年第4期517-526,共10页Journal of Tropical Meteorology

基　　金：国家自然基金委项目(40675034);科技部(2009DFB20540);JICA中日政府间合作项目;中国气象科学研究院灾害性天气重点实验室2009自主研究项目(2009LASWZF04);科技部973项目(2012CB417205)科技部共同资助

摘　　要：利用1954—2005年中国740站逐日降水资料和NCEP/NCAR再分析资料,分析江淮梅雨期降水的南北反位相分布(Anti-Phase Distribution:APD)和大气准双周振荡(Qusi-Biweekly Oscillation:QBWO)之间的关系,诊断结果表明:(1)1954—2005年江淮梅雨APD共有16年较为显著。从1990年代开始,梅雨APD显著增强,并且表现出显著的2年和4～6年振荡周期。在降水较多的区域,降水的准双周振荡往往也较强。(2)梅雨期降水APD和中国东部地区降水的南北变动同属一个位相,中国东部地区的南涝北旱或者南旱北涝在很大程度上可以由江淮地区降水的分布类型来说明。(3)"南旱北涝"年,准双周滤波的整层水汽通量能够传播到30°N以北,同时存在强烈的水汽通量辐合从中高纬度向南传播到江淮流域。而在"南涝北旱"年,准双周的水汽输送所能到达的纬度明显偏南,来自中高纬度向南传播的水汽通量辐合也不显著。(4)"南旱北涝"年降水正位相,西北太平洋副热带高压(简称西太副高)脊线位于22°N以北,850 hPa低频反气旋的位置相对于"南涝北旱"年偏北,调节西太副高进入南海位置也偏北。南海和江淮上空的准双周垂直速度异常位置整体偏北,第3位相的上升运动和第7位相的下沉运动都位于30°N以北,南海的垂直速度异常也主要位于南海北部,而在"南涝北旱"年,准双周垂直速度异常的分布偏南。Based on the 740 stations＇ daily rainfall datasets in China from 1954 to 2005 and the NCEP/NCAR reanalysis data, the relationship between the north-south anti-phase distribution （APD） of rainfall in Meiyu periods and the Qusi-Biweekly Oscillation （QBWO） in the atmosphere was analyzed. Diagnostic results are as follows： （1） There was significant north-south oscillation of Meiyu rainfall in the 16 years from 1954 to 2005. From the 1990s, the APD was enhanced significantly and showed 2- and 4-6-year period. In the region with more rainfall, the QBWO was always more active. （2） The APD of Meiyu and north-south movements of precipitation in eastem China belong to the same phase. （3） The 10-25-day filtered water vapor flux could spread to the area north of 30 °N in 1991. The divergence of the water vapor flux which propagated from middle- and higher- latitudes to the basins of Yangtze-Huaihe Rivers was significant in 1991, but the latitudes the water vapor flux could reach were further southward and there was no southward propagation of divergence in 1993. （4） The locations of Western Pacific Subtropical High（WPSH） and 10-25-day anti- cyclone, which modulated WPSH＇s advancement in and out of the South China Sea, were relatively northward in 1991. Furthermore, the vertical circulation showed north-south deviation between 1991 and 1993, just as other elements of the circulation do.

关 键 词：梅雨 反位相分布 准双周振荡 低频振荡 水汽通量 

分 类 号：P434.4[天文地球—大气科学及气象学]