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Abstract

Reconstructing the dynamic response of the Antarctic ice sheets to warming during the Last Glacial Termination (LGT; 18,000–11,650 yrs ago) allows us to disentangle ice-climate feedbacks that are key to improving future projections. Whilst the sequence of events during this period is reasonably well-known, relatively poor chronological control has precluded precise alignment of ice, atmospheric and marine records, making it difficult to assess relationships between Antarctic ice-sheet (AIS) dynamics, climate change and sea level. Here we present results from a highly-resolved ‘horizontal ice core’ from the Weddell Sea Embayment, which records millennial-scale AIS dynamics across this extensive region. Counterintuitively, we find AIS mass-loss across the full duration of the Antarctic Cold Reversal (ACR; 14,600–12,700 yrs ago), with stabilisation during the subsequent millennia of atmospheric warming. Earth-system and ice-sheet modelling suggests these contrasting trends were likely Antarctic-wide, sustained by feedbacks amplified by the delivery of Circumpolar Deep Water onto the continental shelf. Given the anti-phase relationship between inter-hemispheric climate trends across the LGT our findings demonstrate that Southern Ocean-AIS feedbacks were controlled by global atmospheric teleconnections. With increasing stratification of the Southern Ocean and intensification of mid-latitude westerly winds today, such teleconnections could amplify AIS mass loss and accelerate global sea-level rise.

Item Type:	Article
Authors/Creators:	Fogwill, CJ and Turney, CSM and Golledge, NR and Etheridge, DM and Rubino, M and Thornton, DP and Baker, A and Woodward, J and Winter, K and van Ommen, TD and Moy, AD and Curran, MAJ and Davies, SM and Weber, ME and Bird, MI and Munksgaard, NC and Menviel, L and Rootes, CM and Ellis, B and Millman, H and Vohra, J and Rivera, A and Cooper, A
Keywords:	Antarctic ice sheet, Last Glacial Termination, Patriot Hills
Journal or Publication Title:	Scientific Reports
Publisher:	Nature Publishing Group
ISSN:	2045-2322
DOI / ID Number:	10.1038/srep39979
Copyright Information:	Copyright 2017 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/
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