Abstract/Summary

The sea ice around Antarctica undergoes a natural seasonal cycle of slow advance and rapid retreat, which does not align with the seasonal north-south shift of the storm track over the Southern Ocean. In particular, cyclones near the sea ice edge have a stronger impact on the sea ice compared to those occurring elsewhere across the Southern Ocean. Despite the increasing long-term trend of sea ice reversing after 2015, further investigation shows a significant increase in the number of ice-linked cyclones in almost all subregions. To better understand the seasonal and regional relationship between sea ice and cyclones, an exposure index is introduced, encompassing various features of cyclones, local sea ice concentration (SIC), and their interaction time. This index helps identify key seasons for each subregion. Analyzing cyclones categorized by local SIC anomaly, we observe that cyclone strength and movement direction significantly influence SIC anomalies. Composite results highlight the critical role of temperature advection and surface sensible heat flux in SIC changes driven by cyclone circulation. Though these results depend on the cyclone’s interaction with the background circulation and its position relative to the sea ice edge, they offer a new perspective on short-term sea ice changes from a cyclone perspective and improve the representation of cyclone-sea ice interactions in climate models, enhancing predictions of future Antarctic sea ice trends.