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ABSTRACT The Atlantic meridional overturning circulation (AMOC) transports warm salty surface waters to high latitudes, where they cool, sink and return southwards at depth. Through its

attendant meridional heat transport, the AMOC helps maintain a warm northwestern European climate, and acts as a control on the global climate. Past climate fluctuations during the Holocene

epoch (∼11,700 years ago to the present) have been linked with changes in North Atlantic Ocean circulation1,2. The behaviour of the surface flowing salty water that helped drive overturning

during past climatic changes is, however, not well known. Here we investigate the temperature and salinity changes of a substantial surface inflow to a region of deep-water formation

throughout the Holocene. We find that the inflow has undergone millennial-scale variations in temperature and salinity (∼3.5 °C and ∼1.5 practical salinity units, respectively) most probably

controlled by subpolar gyre dynamics. The temperature and salinity variations correlate with previously reported periods of rapid climate change3. The inflow becomes more saline during

enhanced freshwater flux to the subpolar North Atlantic. Model studies predict a weakening of AMOC in response to enhanced Arctic freshwater fluxes4, although the inflow can compensate on

decadal timescales by becoming more saline5. Our data suggest that such a negative feedback mechanism may have operated during past intervals of climate change. Access through your

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BEING VIEWED BY OTHERS WEAKENING OF THE ATLANTIC MERIDIONAL OVERTURNING CIRCULATION ABYSSAL LIMB IN THE NORTH ATLANTIC Article 19 April 2024 WEAKENING OF THE ATLANTIC MERIDIONAL OVERTURNING

CIRCULATION DRIVEN BY SUBARCTIC FRESHENING SINCE THE MID-TWENTIETH CENTURY Article 18 November 2024 FRESHWATER FORCING OF THE ATLANTIC MERIDIONAL OVERTURNING CIRCULATION REVISITED Article 07

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references ACKNOWLEDGEMENTS We thank the crew of RV _Charles Darwin 159_; M. Greaves, A. Huckle and L. Booth for laboratory assistance; J. Rolfe and M. Hall for stable isotope analyses; J.

Hillier for the Atlantic base map; and S. Crowhurst, T. Dokken, M. Schulz and L. Skinner for discussions. Radiocarbon dates were run by the UK Natural Environment Research Council (NERC)

radiocarbon laboratory. Labrador Sea data was provided by A. de Vernal. Funding was provided by the NERC Rapid Climate Change programme. AUTHOR CONTRIBUTIONS H.E. and I.N.M. were responsible

for initiating the study, and D.J.R.T. collected data, performed analyses and interpreted data. The manuscript was written by D.J.R.T. H.E. and I.N.M. contributed equally to the study. All

authors contributed to the work at sea on RV _Charles Darwin 159_, discussed the results and commented on the manuscript. AUTHOR INFORMATION Author notes * David J. R. Thornalley Present

address: Present address: School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3YE, UK., AUTHORS AND AFFILIATIONS * Department of Earth Sciences,

The Godwin Laboratory for Palaeoclimate Research, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK, David J. R. Thornalley, Harry Elderfield & I. Nick McCave Authors *

David J. R. Thornalley View author publications You can also search for this author inPubMed Google Scholar * Harry Elderfield View author publications You can also search for this author

inPubMed Google Scholar * I. Nick McCave View author publications You can also search for this author inPubMed Google Scholar CORRESPONDING AUTHOR Correspondence to David J. R. Thornalley.

SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION This file contains Supplementary Methods, Supplementary Figures 1-3 with Legends, Supplementary Table 1, a Supplementary Discussion,

Supplementary Notes and Supplementary References (PDF 237 kb) POWERPOINT SLIDES POWERPOINT SLIDE FOR FIG. 1 POWERPOINT SLIDE FOR FIG. 2 POWERPOINT SLIDE FOR FIG. 3 RIGHTS AND PERMISSIONS

Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Thornalley, D., Elderfield, H. & McCave, I. Holocene oscillations in temperature and salinity of the surface subpolar North

Atlantic. _Nature_ 457, 711–714 (2009). https://doi.org/10.1038/nature07717 Download citation * Received: 17 March 2008 * Accepted: 09 December 2008 * Issue Date: 05 February 2009 * DOI:

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