PDO 和 ENSO 与我国华北地区夏季降水的关系分析

摘要

统计了不同太平洋年代际振荡背景下ENSO发生的频率、强度等特征，进而分析了PDO对ENSO的调制作用；计算了华北地区赤峰、北京等25个站作为华北地区代表站的夏季降水距平，分析得到两者与降水的关系，结果表明：（1）PDO的振荡周期为年代际尺度，为ENSO提供气候背景；（2）我国华北地区夏季降水存在年代际变化，与PDO指数大致呈负相关；（3）暖ENSO年我国华北地区夏季降水偏少，冷ENSO年则偏多。 ENSO对我国华北地区夏季降水的影响受到PDO的制约；该研究可以更好地对我国华北地区夏季降水进行短期预测，可预测2016年我国华北地区夏季降水将偏少。%This paper carried out a statistics of occurrence frequency , intensity and other characteristics of ENSO events un-der the background of different Pacific Decadal Oscillation (PDO), and further analyzed the regulatory effect of PDO on ENSO. The author calculated the anomalies of summer precipitation at 25 representative stations ( such as Chifeng and Beijing ) in North China, and further analyzed the relationships between PDO, ENSO and summer precipitation in North China.The results indicated that:(1) PDO had a decadal oscillation period, and it provided climatic background for ENSO;(2) The summer rain-fall in North China had a decadal variation, and it was generally negatively correlated with the PDO index;(3) The summer rain-fall in North China in warm ENSO year was less than that in normal year , while the summer rainfall in cold ENSO year was more than that in normal year.In conclusion, the impact of ENSO on the summer rainfall in North China was restricted by PDO .Based on the conclusions of this study, it is predicted that the summer rainfall in North China in 2016 will be at a lower level.