Leading role of outer-Arctic circulation transport in AMOC response to global warming over a century

• Published in: Environmental Research Letters
• Main Authors: Chen, Jiao, Wang, Xidong, Wang, Xuezhu, Semmler, Tido
• Other Authors: the Opening Project of Key Laboratory of Marine Science and Numerical Modeling, the Opening Project of Key Laboratory of Marine Environmental Information Technology, National Key Research and Development Program of China, National Natural Science Foundation of China
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: IOP Publishing 2023
• Subjects: Arctic; Global warming; Labrador Sea; Nordic Seas
• Online Access: http://dx.doi.org/10.1088/1748-9326/acfb25; https://iopscience.iop.org/article/10.1088/1748-9326/acfb25; https://iopscience.iop.org/article/10.1088/1748-9326/acfb25/pdf

Abstract Using the Alfred Wegener Institute Climate Model (AWI-CM 1.1 LR), we explored how Arctic and extra-Arctic warming affect the response of Atlantic meridional overturning circulation (AMOC) to quadruple carbon dioxide (4 × CO 2 ) forcing. The results suggest that AMOC weakening is mainly affected by circulation adjustment caused by extra-Arctic warming, while Arctic warming has a limited local impact and a relatively small contribution to AMOC weakening. Due to the warming outside the Arctic, the increase in northward advective heat transport dominates the weakening of deep convection in Nordic Seas. While in the Labrador Sea, the decrease in advection heat transport is compensated by a more significant decrease in ocean heat loss to the atmosphere, leading to an enhancement of the upper ocean stratification. Besides, the weakening of deep convection associated with AMOC response under global warming is more pronounced in Nordic Seas than in Labrador Sea.