East Antarctic warming forced by ice loss during the Last Interglacial

David K Hutchinson; Laurie Menviel; Katrin J Meissner; Andrew McC Hogg

doi:10.1038/s41467-024-45501-x

East Antarctic warming forced by ice loss during the Last Interglacial

Nat Commun. 2024 Feb 3;15(1):1026. doi: 10.1038/s41467-024-45501-x.

Authors

David K Hutchinson^{1

2}, Laurie Menviel^{3

4}, Katrin J Meissner^{3

5}, Andrew McC Hogg^{5

6}

Affiliations

¹ Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia. david.hutchinson@unsw.edu.au.
² The Australian Centre for Excellence in Antarctic Science, University of New South Wales, Sydney, NSW, Australia. david.hutchinson@unsw.edu.au.
³ Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia.
⁴ The Australian Centre for Excellence in Antarctic Science, University of New South Wales, Sydney, NSW, Australia.
⁵ ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, Australia.
⁶ Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia.

Abstract

During the Last Interglacial (LIG; 129-116 thousand years before present), the Antarctic ice sheet (AIS) was 1 to 7 m sea level equivalent smaller than at pre-industrial. Here, we assess the climatic impact of partial AIS melting at the LIG by forcing a coupled climate model with a smaller AIS and the equivalent meltwater input around the Antarctic coast. We find that changes in surface elevation induce surface warming over East Antarctica of 2 to 4 °C, and sea surface temperature (SST) increases in the Weddell and Ross Seas by up to 2 °C. Meltwater forcing causes a high latitude SST decrease and a subsurface (100-500 m) ocean temperature increase by up to 2 °C in the Ross Sea. Our results suggest that the combination of a smaller AIS and enhanced meltwater input leads to a larger sub-surface warming than meltwater alone and induces further Antarctic warming than each perturbation separately.