Untangling the relationship between AMOC variability and North Atlantic upper‐ocean temperature and salinity

• Published in: Geophysical Research Letters
• Other Authors: Chiang, J. C. H. (author), Cheng, W. (author), Kim, Who M. (author), Kim, S. (author)
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2021
• Subjects: North Atlantic
• Online Access: https://doi.org/10.1029/2021GL093496

The relationship between Atlantic meridional overturning circulation (AMOC) variability and high-latitude North Atlantic buoyancy changes is complicated by the latter both driving, and responding to, AMOC changes. A maximum covariance analysis applied to a 1,201-year preindustrial control simulation reveals two leading modes that separate these two distinct roles of North Atlantic temperature and salinity as related to AMOC variability. A linear combination of the two modes accounts for most of the variation of a widely used AMOC index. The same analysis applied to another control simulation known to possess two distinct regimes of AMOC variability-oscillatory and red-noise-suggests that the North Atlantic buoyancy-forced AMOC variability is present in both regimes but is weaker in the latter, and moreover there is pronounced multidecadal/centennial AMOC behavior in the latter regime that is unrelated to North Atlantic buoyancy forcing. 1852977 NA16OAR4310170 OCE1243015