Untangling the Relationship Between AMOC Variability and North Atlantic Upper-Ocean Temperature and Salinity

• Main Authors: Chiang, JCH, Cheng, W, Kim, WM, Kim, S
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: eScholarship, University of California 2021
• Subjects: Meteorology & Atmospheric Sciences; North Atlantic
• Online Access: https://escholarship.org/uc/item/9bk973wd

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.