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, 131 (7). ISSN 2169-9275

	Microsoft Word (OpenXML) (Damini_et_al_2025 - reviewed) - Accepted Version Available under License Creative Commons Attribution. Download (9MB)
Preview	PDF (JGR Oceans - 2026 - Damini - Post‐1990s Warming of Circumpolar Deep Water Off West Antarctica and Its Drivers) - Published Version Available under License Creative Commons Attribution. Download (3MB) | Preview

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
Additional Information:	Data availability statement: Hydrographic seawater temperature and salinity data (1990–2020) were obtained from the following publiclyavailable repositories: World Ocean Database 2023 (WOD23; https://www.ncei.noaa.gov/products/world‐ocean‐database; Mishonov et al., 2024); Thwaites‐Amundsen Regional Survey and Network (TARSAN; https://www.bodc.ac.uk/data/bodc_database/nodb/project/54319/); Argo float data (Argo, 2000; https://argo.ucsd.edu); CLI-VAR and Carbon Hydrographic Data Office (CCHDO; https://cchdo.ucsd.edu/); and Marine Mammals Exploringthe Ocean Pole to Pole (MEOP; https://www.meop.net/; Roquet et al., 2011). Ocean reanalysis temperature andsalinity fields were obtained from the GLORYS12v1 global ocean reanalysis (https://doi.org/10.48670/moi‐00021; Fernandez & Lellouche, 2021). Monthly wind stress and sea level pressure fields were obtained from theERA5 reanalysis (https://doi.org/10.24381/cds.f17050d7; Hersbach et al., 2020). ADT fields were obtained fromthe Copernicus Marine Service (https://doi.org/10.48670/moi‐00148). The Antarctic Circumpolar Current frontpositions are based on Orsi et al. (1995) and are available from the Australian Antarctic Data Centre (https://data.aad.gov.au/metadata/records/antarctic_circumpolar_current_fronts/; Orsi & Harris, 2019). Bathymetric datawere obtained from R–Topo2 data set (https://doi.org/10.1594/PANGAEA.85684; Schaffer et al., 2016).
Uncontrolled Keywords:	sdg 13 - climate action ,/dk/atira/pure/sustainabledevelopmentgoals/climate_action
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
Related URLs:	https://www.scopus.com/pages/publication...
Depositing User:	LivePure Connector
Date Deposited:	16 Jul 2026 12:48
Last Modified:	07 Aug 2026 12:21
URI:	https://ueaeprints.uea.ac.uk/id/eprint/103893
DOI:	10.1029/2025JC023856

Downloads

Actions (login required)

View Item