Caesar, Levke and Rahmstorf, S and Feulner, G (2020) On the relationship between Atlantic meridional overturning circulation slowdown and global surface warming. Environmental Research Letters, 15 (2). 024003. ISSN 1748-9326

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Abstract

According to established understanding, deep-water formation in the North Atlantic and Southern Ocean keeps the deep ocean cold, counter-acting the downward mixing of heat from the warmer surface waters in the bulk of the world ocean. Therefore, periods of strong Atlantic meridional overturning circulation (AMOC) are expected to coincide with cooling of the deep ocean and warming of the surface waters. It has recently been proposed that this relation may have reversed due to global warming, and that during the past decades a strong AMOC coincides with warming of the deep ocean and relative cooling of the surface, by transporting increasingly warmer waters downward. Here we present multiple lines of evidence, including a statistical evaluation of the observed global mean temperature, ocean heat content, and different AMOC proxies, that lead to the opposite conclusion: even during the current ongoing global temperature rise a strong AMOC warms the surface. The observed weakening of the AMOC has therefore delayed global surface warming rather than enhancing it

Item Type:	Article
Additional Information:	Cite as:L Caesar et al 2020 Environ. Res. Lett. 15 024003
Keywords:	Atlantic meridional overturning circulation; global surface warming; ocean heat uptake;
Academic Unit:	Faculty of Social Sciences > Geography Faculty of Social Sciences > Research Institutes > Irish Climate Analysis and Research Units, ICARUS
Item ID:	15746
Identification Number:	https://doi.org/10.1088/1748-9326/ab63e3
Depositing User:	Levke Caesar
Date Deposited:	29 Mar 2022 13:03
Journal or Publication Title:	Environmental Research Letters
Publisher:	IOP Publishing
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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