PDO对夏季江淮地区雨量与太平洋海温年际相关的影响  

Effect of PDO on the interannual relationships between summer rainfall in the Yangze River and the Huaihe River valley and SST in the Pacific Ocean

作　　者：杨秋明[1] 

机构地区：[1]江苏省气象台,江苏南京210008

出　　处：《海洋科学》2007年第7期43-50,共8页Marine Sciences

摘　　要：研究了在太平洋年代际振荡(PDO)不同位相中夏季江淮地区降水与太平洋海温年际相关空间分布的差异,讨论了产生这种变化的可能的物理机制。结果表明,PDO冷暖位相中夏季江淮地区降水量与太平洋海温年际耦合振荡周期和强度均存在显著差异。PDO冷位相中,夏季江淮地区降水与前期冬季西南太平洋和同期夏季黑潮区海温在7～8a时间尺度上的耦合最显著;而在PDO暖位相中,与这些地区海温呈现极显著的准2a耦合振荡,并且与同期夏季赤道东太平洋地区海温的准2a耦合振荡也迅速加强。西太平洋地区海温的耦合振荡作用区域是时间稳定的,而东太平洋地区海温的耦合振荡作用区域存在时变性。因此,PDO对夏季江淮地区降水和太平洋海温年际耦合振荡的强度和周期的年代际变化有重要影响。The interdecadal variations of the distributions for the interannual teleconnections between the summer rainfall in the Yangtze River and the Huaihe River valley and the sea surface temperature （SST） in the Pacific are studied from cool phase （1951 -1976） and warm phase （1977-2000） of the Pacific Decadal Oscillation （PDO）, and possible mechanisms of these variations are also investigated. The main results are as follows： there is an evident interdecadal variation for the period and its intensity for the coupled interannual oscillation in different phases of PDO. During the PDO cool phase, the summer rainfall in the Yangtze River and the Huaihe River valley are well coupled with the SST in the northwestern Pacific summer and in the tropical southwestern Pacific for the preceding winter on the timescale of 7-8 a. During the PDO warm phase, however, there is a significant tropospheric biennial oscillation for the coupled interannual oscillations over these regions. In addition, it seems to have a stronger correlation with the SST of the tropical eastern Pacific summer. Stationary and nonstationsary coupled oscillation regions are located over the western and eastern Pacific ,respectively. Thus, the interdacadal variations for intensity and period of these coupled interannual oscillations are closely related to PDO.

关 键 词：江淮地区雨量 太平洋海温 太平洋年代际振荡 年际耦合振荡 年代际变化 

分 类 号：P461[天文地球—大气科学及气象学]