Southern Ocean Sea Ice – what happened and what happens next?

Sea ice plays a crucial role in the global climate and also provides habitat for krill, which underpin the Southern Ocean food web. Despite the importance of sea ice, there is much we do not know; sea ice in the Southern Ocean has a baffling history and an uncertain future. From the beginning of the satellite record in 1979 sea ice extent increased even as the world warmed, until suddenly in 2016 it shrank dramatically. Antarctic sea ice extent rebounded towards the long-term mean until the 2021/22 summer when it once again fell to record low levels, raising the possibility of a recent regime shift in Antarctic sea ice behaviour. Are these sudden changes part of the long-term natural variability, or a response to anthropogenic influences? Our project is motivated by the need to answer such questions and to improve future projections of sea ice.

This project will address the low confidence in projections of Antarctic sea ice change, by identifying the mechanisms of recent sea ice variability, and by focussing on the sea ice response to expected future atmospheric changes.