Weakening relationship between East Asian winter monsoon and ENSO after mid-1970s
Weakening relationship between East Asian winter monsoon and ENSO after mid-1970s
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DOI：
10.1007/s11434-012-5285-x
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发表时间：
2012-06
影响因子：
--
通讯作者：
Huijun Wang;Shengping He
中科院分区：
文献类型：
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作者：
Huijun Wang;Shengping He
东亚冬季风以频繁的寒潮活动为特征，与西伯利亚高压、东亚大槽和高空西风急流有着密切的联系。ENSO循环与印度洋-西太平洋海表温度存在协变关系，可以调节东亚冬季风的海陆热力对比，因此ENSO循环对东亚冬季风具有调制作用。本文通过对EAWM、ENSO及其相关的海气变率的分析，证明了20世纪70年代以后EAWM与ENSO关系的减弱。20世纪70年代以后，显著的异相相互关系被发现减弱。进一步的研究表明，20世纪70年代后与ENSO相关的热带印度-西太平洋气候的协变减弱是导致相互关系减弱的部分原因。同时，EAWM年际变率的减小和与EAWM相关的气候变率的北退有利于ENSO与EAWM联系的减弱。
The East Asian winter monsoon (EAWM) is characterized by the frequent cold surges and associated closely with the Siberia High, East Asian Trough, and high-level westerly jet stream. The ENSO cycle can modulate the EAWM since it has co-variability with the sea surface temperature over the Indo-Western-Pacific which can tune the land-sea thermal contrast for the EAWM. This paper, by analyzing the EAWM, ENSO, and associated atmosphere-ocean variability, documents the weakening of the EAWM-ENSO relationship after the 1970s. The significant out-of-phase inter-relationship is found to be diminished after the 1970s. Further study in this work suggests that the weakened co-variability of the tropical Indo-Western-Pacific climate associated with ENSO after the 1970s is partly responsible for the weakened inter-relationship. Meanwhile, the reduced EAWM interannual variability and northward retreat of the EAWM-associated climate variability are favorable to the weakened ENSO-EAWM connection.