PDO的时空分布特征及其与ENSO的关系

利用1900~2013年美国国家气候数据中心ERSSTv3b2°×2°数据,通过EOF分析、小波分析、曼-肯德尔法、累积距平法分析太平洋年代际振荡(The Pacific Decadal Oscillation,简称PDO)的时间、空间分布规律。结果表明,PDO指数存在准48年的周期变化,周期内“冷-暖”相位交替出现,1925年左右和1975年左右,由冷相位转变为暖相位;1941年左右和1995年左右,由暖相位转变为冷相位。北太平洋海温大致以40°N为轴南北对称分布,其大值区域分布从北美西海岸—墨西哥半岛向北一直延伸到阿拉斯加,小值区域出现在夏威夷群岛北侧和日本群岛东侧。PDO指数与Nino3.4指数的相关系数是0.43,是显著正相关关系。PDO指数异常年与Nino3.4指数异常年对应率平均值是51.42%。 

Analysis on the Spatial and Temporal Distribution of the PDO and Its Relationship with ENSO

Using the 2°×2° ERSSTv3 b data (1900 ~ 2013) that from the national climate data center, the spatial and temporal distribution of the Pacific Decadal Oscillation (PDO) was analyzed by using EOF analysis, wavelet analysis, MannKendall method and cumulative departure method. The results show that there is 48 years variation period about the PDO Index.During the 48 years period, a “cold-warm”phase appears alternately, with the “cold” (“warm”) knee points were found around 1925 and 1975 (around 1941 and 1995), respectively. The North Pacific SST is symmetrically distributed around 40°N in the south-north direction. The high value areas distribute from the west coast of North America-Mexico peninsula stretching north to Alaska. The small value areas appear in the north of the Hawaiian Islands and the east of the Japan islands. The correlation coefficient between the PDO Index and the Nino3. 4 Index is 0. 43, which revealed a significant positive correlation. In addition, the corresponding average rate between the PDO Index and the Nino3. 4 Index in abnormal years is 51. 42%.