Fig. 1: Periods of large sea ice loss in the Arctic coincident with large midlatitude cooling.

Time series of winter average (December, January and February) sea ice extent averaged over the Barents–Kara Sea (black curve; left axis) and surface air temperature averaged over Eurasia (blue curve; right axis). Linear trends have been removed to accentuate winter-to-winter fluctuations. The grey shadings and thicker lines illustrate periods within which large Arctic sea ice loss is coincident with large midlatitude cooling.