Surface predictor of overturning circulation and heat content change in the subpolar North Atlantic

Type Article
Date 2019-06
Language English
Author(s) Desbruyères DamienORCID1, Mercier HerleORCID3, Maze GuillaumeORCID1, Daniault Nathalie2
Affiliation(s) 1 : Ifremer, University of Brest, CNRS, IRD, Laboratoire d'Océanographie Physique et Spatiale, IUEM, Ifremer centre de Bretagne, Plouzané, 29280, France
2 : University of Brest, CNRS, Ifremer, IRD, Laboratoire d'Océanographie Physique et Spatiale, IUEM, Ifremer centre de Bretagne, Plouzané, 29280, France
Source Ocean Science (1812-0784) (Copernicus GmbH), 2019-06 , Vol. 15 , N. 3 , P. 809-817
DOI 10.5194/os-15-809-2019
WOS© Times Cited 4
Abstract

The Atlantic Meridional Overturning Circulation (AMOC) impacts ocean and atmosphere temperatures on a wide range of temporal and spatial scales. Here we use observational datasets to validate model-based inferences on the usefulness of thermodynamics theory in reconstructing AMOC variability at low frequency, and further build on this reconstruction to provide prediction of the near-future (2019–2022) North Atlantic state. An easily observed surface quantity – the rate of warm to cold transformation of water masses at high latitudes – is found to lead the observed AMOC at 45∘ N by 5–6 years and to drive its 1993–2010 decline and its ongoing recovery, with suggestive prediction of extreme intensities for the early 2020s. We further demonstrate that AMOC variability drove a bi-decadal warming-to-cooling reversal in the subpolar North Atlantic before triggering a recent return to warming conditions that should prevail at least until 2021. Overall, this mechanistic approach of AMOC variability and its impact on ocean temperature brings new key aspects for understanding and predicting climatic conditions in the North Atlantic and beyond.

Full Text
File Pages Size Access
Publisher's official version 9 2 MB Open access
Supplement 9 519 KB Open access
Discussion paper 21 823 KB Open access
Supplement to the discussion paper 5 643 KB Open access
Top of the page