Abstract
Over recent decades, the Arctic has warmed four times faster than the global average, associated with a decline in sea ice and accelerating Greenland Ice Sheet mass loss, which has contributed to episodic freshening of the subpolar North Atlantic. Here, we show that a 0.05 Sv North Atlantic meltwater flux induces ~ 1°C subsurface warming within a decade in Baffin Bay, Hudson Strait, and along Greenland’s southern and western coasts. This warming arises from enhanced stratification, weakened deep convection in the subpolar gyre, and a weaker Labrador Current. Freshening also alters horizontal density gradients, strengthening cyclonic circulation in the Nordic Seas and causing transient regional warming. The temperature response significantly depends on the location of deep-ocean convection, highlighting the need for simulations with accurate deep-ocean convection. This warming may create a positive feedback, accelerating Greenland and Arctic glacier melt with implications for ice-sheet stability and the strength of the Atlantic Meridional Overturning Circulation.
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The data underpinning this work is available on the public UNSWorks repository: https://doi.org/10.26190/unsworks/31839.
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Acknowledgements
Laurie Menviel and Gabriel Pontes acknowledge funding from the Australian Research Council (ARC) grant SR200100008. Himadri Saini and Laurie Menviel acknowledge funding from the ARC grant DP220102134. This research was supported by the Australian Government’s National Collaborative Research Infrastructure Strategy (NCRIS), with access to computational resources provided by the National Computational Infrastructure (NCI) through the National Computational Merit Allocation Scheme, and through UNSW. The authors thank CSIRO for developing the ACCESS-ESM1.5 model configuration and making it freely available to researchers, and thank COSIMA for developing the ACCESS-OM2-025 and making it available. This research used the ACCESS-ESM1.5 and ACCESS-OM2-025 model infrastructures provided by ACCESS-NRI, which is enabled by the Australian Government’s NCRIS. The authors would like to thank Peter Dobrohotoff for retrieving the CMIP6 data. The author(s) wish to acknowledge the use of the Ferret program for analysis and graphics in this paper. Ferret is a product of NOAA’s Pacific Marine Environmental Laboratory. (Information is available at http://ferret.pmel.noaa.gov/Ferret/).
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L.M. conceived the study, G.P. performed the experiments, L.M. analyzed the results with help from M.L., G.P., and H.S. L.M. made the figures with the help of G.P. L.M. wrote the manuscript with contributions from G.P., H.S., and M.L.
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Menviel, L.C., Pontes, G., Lapeze, M. et al. Rapid subsurface warming in the subpolar North Atlantic from freshening. Nat Commun (2026). https://doi.org/10.1038/s41467-026-70635-5
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DOI: https://doi.org/10.1038/s41467-026-70635-5
