Impeded Arctic sea ice recovery: The role of declining southeastern North Atlantic atmospheric rivers

The increasing frequency of Arctic atmospheric rivers has significantly slowed the recovery of Arctic sea ice in recent decades. However, existing studies primarily focused on the local impacts of Arctic-internal atmospheric rivers, while how polar-external atmospheric rivers influence Arctic sea ice remains largely unexplored. This study reveals a significant decline in the genesis and poleward tracks of southeastern North Atlantic atmospheric rivers (NAARs) during the sea ice recovery season (October to March) since the mid-2000s. Both reanalysis and simulations suggest that large-scale atmospheric teleconnection wave trains associated with southeastern NAARs play a critical role in Barents Sea ice recovery by enhancing local Arctic cooling. However, the decline in southeastern NAARs activity after the mid-2000s has weakened this restorative effect, leading to a 31% slowdown in Barents Sea ice growth. These findings highlight the important influence of mid- to low-latitude climate changes on Arctic sea ice decline.