Interdecadal Changes in the Links Between Late‐Winter NAO and North Atlantic Tripole SST and Possible Mechanism

• Published in: Geophysical Research Letters
• Main Authors: Xiaolei Song, Zhicong Yin, Huijun Wang
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2024
• Subjects: NAO; subseasonal; interdecadal variation; air‐sea interaction; north atlantic tripole SST; Geophysics. Cosmic physics; QC801-809; North Atlantic; North Atlantic oscillation
• Online Access: https://doi.org/10.1029/2024GL110138; https://doaj.org/article/968d9aca0c544ed3ad775c5317c4e8bb

Abstract The North Atlantic Oscillation (NAO) and North Atlantic tripole sea surface temperature (SST_tri) are important modes in the atmosphere and ocean over the North Atlantic, respectively. The link between the two is well‐known. However, this link weakened during 1980–2001, which is particularly pronounced in late winter and was not detected in early winter. This phenomenon has not been well revealed. The role of NAO in the above correlation changes was discussed. In late winter, a significant eastward shift (up to 20° longitude) of NAO south center during 1980–2001 was observed in both observation and CMIP6, accompanied by the eastward expansion of NAO north center. Spatial shift of the NAO forced the region of strong air‐sea interactions to shift and resulting in the collapse of NAO‐related SST_tri. These findings deepen our understanding of the NAO on the subseasonal scale.