Post-1990s warming of Circumpolar Deep Water off West Antarctica and its drivers

Damini, Brendon Y., Dotto, Tiago S., Heywood, Karen J. ORCID: https://orcid.org/0000-0001-9859-0026, Naveira Garabato, Alberto C., Hall, Rob A. ORCID: https://orcid.org/0000-0002-3665-6322, Mata, Mauricio M. and Kerr, Rodrigo (2026) Post-1990s warming of Circumpolar Deep Water off West Antarctica and its drivers. Journal of Geophysical Research - Oceans. ISSN 2169-9275 (In Press)

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Abstract

Ice loss off East Antarctica has been linked to the warming of Circumpolar Deep Water (CDW) associated with a poleward shift of the southern boundary of the Antarctic Circumpolar Current (ACC). In West Antarctica, where the fastest ice-shelf melting occurs, it has been proposed that off-shelf CDW warming could be additionally driven by enhanced lateral heat transport by a strengthened Ross Gyre and increased isopycnal heat transfer across the ACC. Although previous studies have proposed links between Ross Gyre variability, cross-ACC exchange, and off-shelf CDW warming around West Antarctica, their relative contributions have not yet been quantified. Here, we document an interdecadal (1990s–2010s) warming of off-shelf CDW around West Antarctica driven by two processes: (i) ~90% results from enhanced lateral heat transport along isopycnals at the ACC’s southern boundary, linked to an intensification of the Ross Gyre and cross-ACC isopycnal heat transfer; and (ii) ~10% arises from a poleward expansion of the ACC’s hydrographic structure, analogous to that observed off East Antarctica. Both sets of processes were concurrent to a strengthening and poleward shift of westerly winds over the Southern Ocean, suggesting a causal link. As climate projections indicate that such wind trends will continue through the 21st century, the ongoing off-shelf CDW warming may also persist in future. bolstering the shelf-break source of oceanic heat supply to the West Antarctic Ice Sheet.

Item Type:	Article
Faculty \ School:	Faculty of Science > School of Environmental Sciences University of East Anglia Research Groups/Centres > Theme - ClimateUEA
UEA Research Groups:	Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences Faculty of Science > Research Groups > Collaborative Centre for Sustainable Use of the Seas
Depositing User:	LivePure Connector
Date Deposited:	16 Jul 2026 12:48
Last Modified:	16 Jul 2026 12:48
URI:	https://ueaeprints.uea.ac.uk/id/eprint/103893
DOI:	issn:2169-9275

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