The Pacific Arctic Region Has Become a Sink for Multiyear Sea Ice Coverage

Abstract The Pacific sector (PAC) is critical for both dynamic transport and thermodynamic melting of Arctic multiyear ice (MYI). Long‐term observations from 1980 to 2023 reveal an unprecedented decline (−3.87 × 10 4 km 2 yr −1 ) in PAC MYI area (MYIA) during winter, surpassing the summer loss. Net MYI flux reveals that the PAC has transitioned into a MYI import region, particularly in the Beaufort Sea, driving more positive seasonal MYIA changes. The Dipole Anomaly pattern is shown to modulate the MYI transport and thermodynamic growth, contributing to winter MYIA variability on interannual to decadal timescales. Since 2001, the PAC has witnessed a dramatic increase in melting area, with some years experiencing complete MYI depletion. Concurrently, the replenishment from first‐year ice (FYI) surviving the melt season shrank by half. Recent enhanced winter‐summer coupling further indicates that MYIA retained in the PAC during the cold season is deleterious for the pan‐Arctic MYI reservoir.