Abstract: A new minimum Antarctic sea ice extent was recorded in February 2023, and it is predicted that Antarctic sea ice area will significantly decrease by the end of the century. Recent studies have assessed the global ocean-atmosphere coupled model response to Antarctic sea-ice loss, and emerging evidence has shown that the global climate response would be just as consequential as that of ice loss in the well-studied Arctic. The Weddell Sea Polynya is a seasonal opening within the sea ice cover of the Weddell Sea sector, typically found over the Maud Rise and inside the Weddell Gyre. It has been a rare occurrence in the satellite period, appearing in austral spring between 1973 and 1976 and again in 2016/17. The polynya formation has been shown to be complex, requiring a combination of ocean and atmospheric mechanisms to develop. The region is often poorly resolved in global climate models, with little agreement in ocean or sea ice dynamics. When Weddell Sea polynyas have occurred in models without forcing, it is not understood how they occur within the model, or why some models produce frequent polynyas and others produce none. Some studies have shown that increasing horizontal resolution improves the dynamics of the Southern Ocean, allowing for better parameterisation of small-scale features. This seminar will explore Antarctic sea ice trends and the interactions with the climate, in addition to the Weddell Sea Polynya and its ocean and atmospheric processes, modelled using different resolutions as part of the European SO-CHIC project.