Fogwill et al 2017_Antarctic ice sheet discharge at LGT_NatureScReports39979.pdf (3.02 MB)
Antarctic ice sheet discharge driven by atmosphere-ocean feedbacks at the Last Glacial Termination
journal contribution
posted on 2023-05-19, 00:49 authored by Fogwill, CJ, Turney, CSM, Golledge, NR, Etheridge, DM, Rubino, M, Thornton, DP, Baker, A, Woodward, J, Winter, K, Tasman van OmmenTasman van Ommen, Andrew MoyAndrew Moy, Mark Curran, Davies, SM, Weber, ME, Bird, MI, Munksgaard, NC, Menviel, L, Rootes, CM, Ellis, B, Millman, H, Vohra, J, Rivera, A, Cooper, AReconstructing 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.
History
Publication title
Scientific ReportsVolume
7Article number
39979Number
39979Pagination
1-10ISSN
2045-2322Department/School
Institute for Marine and Antarctic StudiesPublisher
Nature Publishing GroupPlace of publication
United KingdomRights statement
Copyright 2017 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/Repository Status
- Open