A flip-flopping, yearslong pattern of winds helps control the fate of the Arctic’s sea ice — by regulating how much of the Atlantic Ocean’s relatively warm, salty water sneaks northward into the Arctic Ocean.
From 2007 to 2021, winds over North America and Eurasia were circulating in such a way that they reduced the influx of warmer Atlantic water into the Arctic, researchers report in the Sept. 1 Science. That helped slow the rate of sea ice loss during that time period — even as atmospheric warming ramped up (SN: 8/11/22). But that grace period may come to an end within just a few years. When the winds shift back, enhanced “Atlantification” of the Arctic may speed up sea ice loss, by giving an extra oomph of warming from below.