Revisiting the Interaction Between Antarctic Sea Ice and Southern Ocean Cyclones

Abstract

The seasonal cycle of Antarctic sea ice—characterized by slow advance and rapid retreat—does not align with the seasonal north-south shift of Southern Ocean storm tracks. This misalignment introduces spatial and temporal complexity into cyclone-sea ice interactions. To gain deeper insights, we apply cyclone tracking to identify cyclones near the sea ice edge and examine both their characteristics and the sea ice's response. Our analysis reveals a significant increase in the frequency of these cyclones across most subregions of the Southern Ocean. To quantify their impact, we introduce an exposure index that encompasses cyclone intensity, local sea ice concentration (SIC), and interaction duration to identify key seasons and regions of cyclone-ice interactions. Furthermore, categorizing cyclones by SIC anomalies reveals that cyclone strength and moving direction are primary drivers of SIC variability. In particular, composite analyses highlight surface temperature advection and sensible heat flux as critical mechanisms linking cyclone circulation to SIC anomalies. These findings highlight the role of cyclones in driving short-term sea ice variability, offering new insights into Antarctic climate system feedbacks.