应用矢量经验正交函数方法、利用1958年1月至2001年12月850hPa月平均风场(5°~40°N,100°~160°E)范围网格点资料对东亚季风区异常季风场进行分析。结果表明,异常季风典型流场第一模态(VEOF-1)属于ENSO相关模态,其时间模态与ENSO之间具有高的正相关关系,但以季风异常滞后ENSO进程7~8个月为最显著。这表明,东亚热带和副热带季风风场变异规律与ENSO活动有紧密联系。提出了一个VEOF-1与ENSO之间相互作用的概念模型。
Anomalous monsoon wind fields over east Asian monsoon region are analyzed with the vector empirical orthogonal function (VEOF) method. Monthly mean grid winds at 850 hPa, covering the period from January 1958 to December 2001 and the area of 100°-160°E , 5°-40°N, constitute the dataset for this study. The results indicate that the first VEOF mode of the anomalous monsoon flow patterns is characterized by latitudinal flow patterns and closely associated with anomalies of the subtropical high and that of precipitation in the mainland China. The first VEOF is an ENSO related mode, and the temporal VEOF mode is correlated with ENSO with a positive correlation coefficient of 0.65, but has a 7-8 month lag with respect to the SSTA of NINO3). This reveals the wind variabilities over the tropical and extra tropical east Asian monsoon regions, which are closely associated with ENSO events. A possible concept model was proposed on the interaction mechanism between the first VEOF mode and ENSO.