Projected West Antarctic Ocean Warming Caused by an Expansion of the Ross Gyre

• Published in: Geophysical Research Letters
• Main Authors: Gómez‐Valdivia, Felipe, Holland, Paul, Siahaan, Antony, Dutrieux, Pierre, Young, Emma
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2023
• Subjects: Antarc*; Antarctic; Antarctic Ocean; Ice Sheet; Sea ice
• Online Access: http://nora.nerc.ac.uk/id/eprint/534254/; https://nora.nerc.ac.uk/id/eprint/534254/1/Geophysical%20Research%20Letters%20-%202023%20-%20G%C3%B3mez%E2%80%90Valdivia%20-%20Projected%20West%20Antarctic%20Ocean%20Warming%20Caused%20by%20an%20Expansion%20of%20the.pdf; https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL102978

We use United Kingdom Earth System Model simulations from the Coupled Model Intercomparison Project 6 to analyze the Ross Gyre (RG) dynamics during the historical 1850–2014 period and under two contrasting future climate-change scenarios. The modeled RG is relatively stable, with an extent and strength that agree with observations. The projections exhibit an eastward gyre expansion into the Amundsen-Bellingshausen Seas that starts during the 2040s. The associated cyclonic ocean circulation enhances the onshore transport of warm Circumpolar Deep Water into the inner regional shelf, a regime change that increases the local subsurface shelf temperatures by up to 1.2°C and is independent of future forcing scenario. The RG expansion is generated by a regional ocean surface stress curl intensification associated with anthropogenic sea ice loss. If realised in reality, such a warming would strongly influence the future stability of the West Antarctic Ice Sheet.