Abrupt Northern Baffin Bay Autumn Warming and Sea‐Ice Loss Since the Turn of the Twenty‐First Century

A delay in autumn sea ice formation is an important consequence of Arctic Amplification. Baffin Bay one such region impacted by delayed formation, though spatiotemporal analyses to date have not detailed the evolution and drivers changes. In this study, we document abrupt cover changes key transition month October from 1950 2021. The mean variance dramatically change 2001 onward with a largely ice-free conditions northeast thinner northwest. Ocean model experiments attribute these warming Atlantic-origin water (AOW) flowing into northeastern south. Transport upwelling above-freezing AOW has stunted area, while basin's cyclonic surface current contributed reduced cooling northwestern portion Bay.