The Arctic Oscillation (AO) is a dominant atmospheric mode in the Northern Hemisphere, influencing weather and climate. Its variations are driven by numerous factors, including Arctic sea ice, particularly autumn Barents-Kara Sea ice concentration (SIC), which can significantly impact the AO through planetary wave dynamics. However, the interdecadal stability of this relationship remains unclear. This study detected the weakened November Barents-Kara SIC-AO connection after the mid-1990s. Observational analysis shows that from 1979 to 1994, this relationship was driven by the North Atlantic tripole (NAT) sea surface temperature (SST) anomalies, which influenced storm track activity over North Atlantic and Eurasia, thus inducing a Scandinavian-like wave train. After the mid-1990s, weakened NAT SST variability disrupted this mechanism. These findings highlight the critical role of mid-latitude ocean-atmosphere interactions in Arctic climate variability and emphasize the need for further research on long-term AO-SIC linkages.
 

Arctic Oscillation; Barents-Kara Sea ice; Interdecadal change, North Atlantic tripole SST