Dipolar Distribution of Cyclones and Its Influence on Sea Ice Extremes in the Amundsen‐Bellingshausen Seas

Abstract The Amundsen‐Bellingshausn Seas (ABS) have experienced a notable decline in sea ice extent (SIE) since 1979, alongside strengthening cyclone activity. This study examines the role of cyclones in driving extreme SIE events using satellite observations and atmospheric reanalysis data. A comparison between two years with the highest and lowest annual minimum SIE (1980 and 2010) reveals a significant relationship between cyclone intensity and retreat‐season SIE fluctuations, with cyclone intensity leading to sea ice changes. Relative to high SIE years, low SIE years are characterized by more frequent, stronger, and slower‐moving cyclones over the Amundsen Sea, and weaker, faster‐moving systems over the Bellingshausen Sea. Composite analysis of the five highest and lowest SIE years, together with a 44‐year EOF analysis of cyclone intensity, show a robust zonal dipole pattern across the ABS. Based on this pattern, a Dipole Cyclone Index (DCI) is constructed to represent the east‐west contrast in cyclone intensity, which shows limited interannual covariability with SIE after removing the long‐term trend. These results highlight a scale dependence in cyclone‐ice interactions and emphasize the importance of synoptic‐scale cyclones during sea ice extremes in this rapidly changing region.