Enhanced correlation between ENSO and western North Pacific monsoon during boreal summer around the 1990s

The correlation between summertime Niño3.4 index and western North Pacific (WNP) summer monsoon index has strikingly enhanced since the early 1990s, with nonsignificant correlation before the early 1990s but significant correlation afterward. This observed interdecadal change around the 1990s may be...

Full description

Bibliographic Details
Published in:Atmospheric and Oceanic Science Letters
Main Authors: Minmin WU, Lei WANG
Format: Article in Journal/Newspaper
Language:English
Published: KeAi Communications Co., Ltd. 2019
Subjects:
Western North Pacific summer monsoon
ENSO
tropical Atlantic SST anomaly
interdecadal variability
inter-basin interaction
Environmental sciences
GE1-350
Oceanography
GC1-1581
Pacific
Indian
North Atlantic
Online Access:https://doi.org/10.1080/16742834.2019.1641397
https://doaj.org/article/2a4ff7f0fff544c187410c8d21e30215
Description
Summary:The correlation between summertime Niño3.4 index and western North Pacific (WNP) summer monsoon index has strikingly enhanced since the early 1990s, with nonsignificant correlation before the early 1990s but significant correlation afterward. This observed interdecadal change around the 1990s may be associated with more frequent occurrences of central Pacific (CP) El Niño and the interdecadal changes in ENSO-associated SST anomalies. During the post-1990s period (the pre-1990s period), highly noticeable tropical Atlantic (Indian) Ocean SST anomalies tend to co-occur with the summertime Niño3.4 SST anomalies. The concurrent tropical Atlantic (Indian) Ocean SST anomalies could constructively reinforce (destructively mitigate) the WNP monsoon circulation anomalies induced by the summertime Niño3.4 SST, thus boosting (muting) the correlation between summertime Niño3.4 SST and WNP monsoon. In addition, the faster decaying pace of preceding-winter El Niño after the 1990s, which may have been mainly induced by the influences from the spring tropical North Atlantic SST anomalies, could also have contributed to the enhanced correlation between the summertime Niño3.4 index and WNP monsoon. These results suggest that the enhanced influences from the tropical Atlantic SST may have triggered the intensified correlation between summertime ENSO and WNP monsoon since the early 1990s.

Similar Items