Ocean control on sea ice in the Nordic Seas

Abstract. To better understand the processes in the Nordic Seas and their connection to large-scale climate changes during Dansgaard-Oeschger (D-O) events, we reconstruct sea ice extent (SIE) and subsurface temperatures (SubSTs) in the eastern Fram Strait between 40 and 33.5 ka b2k. Our new proxy data from MD99-2304 reveal pronounced fluctuations in SIE and SubSTs both between and within each investigated Greenland Stadial (GS) and Greenland Interstadials (GIs). Consequently, variations in SIE and SubSTs in the eastern Fram Strait show a weaker connection to climate oscillations in Greenland ice cores, in comparison to changes observed in the southeastern Nordic Seas and the North Atlantic.

Integrating our results with AMOC strength reconstructions and sea ice records from the southeastern Nordic Seas, we identify different sea ice regimes between the eastern Fram Strait and the southeastern Nordic Seas. These findings suggest that fluctuations in the eastern Fram Strait were primarily driven by shifts in northward oceanic heat transport, which were regulated by changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC).