Article | Published:

Latitudinal shift of the Atlantic Meridional Overturning Circulation source regions under a warming climate

Nature Climate Changevolume 8pages10131020 (2018) | Download Citation

Abstract

The strength of the Atlantic Meridional Overturning Circulation, a key indicator of the climate state, is maintained by the subduction of dense water that feeds the deep southwards branch. At present, this subduction occurs almost entirely in the subpolar region, in the Labrador, Irminger and Nordic seas; however, whether this will continue under climate change is unknown. Here we use a quantitative Lagrangian diagnostic applied to climate model output to show that, in response to warming, the main source regions of this mixed-layer subduction shift northwards to the Arctic Basin and southwards to the subtropical gyre. These shifts are explained by changes in background stratification, mixed-layer depth and ocean circulation, highlighting the need to consider the full three-dimensionality of the circulation and its changes to accurately predict the future climate state.

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The data sets generated and analysed during the current study are available upon request from the corresponding author.

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Acknowledgements

We are deeply grateful to A. Voldoire and R. Séférian (CNRM, Toulouse, France) for making the model outputs from the different simulations available, and providing guidance on their use.

Author information

Affiliations

  1. IFREMER, Univ. Brest, CNRS, IRD, LOPS, Plouzané, France

    • Camille Lique
  2. Department of Geology and Geophysics, Yale University, New Haven, CT, USA

    • Matthew D. Thomas

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Contributions

C.L. and M.T. designed the study. M.T. performed the Lagrangian analysis. C.L. and M.T. analysed the results. C.L. wrote the manuscript with input from M.T.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to Camille Lique.

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  1. Supplementary Information

    Supplementary figures 1–3, Supplementary references

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https://doi.org/10.1038/s41558-018-0316-5

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