Seasonal evolution patterns of Arctic sea ice and their connection to tropical Pacific sea surface temperature anomalies

Abstract This study applies the self-organizing map method to identify the primary modes of seasonal evolution in Arctic sea ice concentration anomalies from 1979 to 2023. The resulting patterns fall into two broad categories: negative sea ice anomalies, occurring more frequently after 2005, and positive anomalies, more common prior to 2005. Differences among the modes within each category are primarily driven by sea ice variability in the Bering Sea, Sea of Okhotsk, Labrador Sea, and Greenland Sea during boreal winter and spring. Warmer temperatures, increased longwave radiation, and southerly winds favor reduced sea ice, while cooler conditions and northerly winds support increased ice cover. These atmospheric anomalies are often linked to tropical Pacific sea surface temperature variability, which influences Arctic conditions via poleward-propagating Rossby wave trains triggered by changes in tropical convection. Our findings enhance the basis for seasonal, interannual, and decadal predictions of Arctic sea ice.