Sea ice distribution in the northeastern Nordic Seas during the Dansgaard-Oeschger events

Sea ice conditions in the eastern Fram Strait during the Dansgaard-Oeschger (D-O) events are reconstructed using biomarkers. The role of the Nordic Seas sea ice has long been recognized as a significant factor influencing the D-O climate changes. Two full D-O cycles between 40 and 34 ka b2k, covering Greenland Stadial (GS) 9, also known as Heinrich Stadial (HS) 4, to Greenland Interstadial (GI) 7 are investigated in high resolution (20-40 yr/sample). Preliminary results suggest an extended sea ice cover in the eastern Fram Strait during both stadials. Repeated polynyas were present during GS-9/HS-4, but not during GS-8. The retreat of the extended sea ice cover in the eastern Fram Strait occurred later during the GS-9/HS-4 to GI-8 transition than during the GS-8 to GI-7 transition. Both interstadials were characterized by a seasonal sea ice cover, with the summer/fall sea ice edge occasionally moving farther north than the study site. Our findings provide new insights on the importance of ocean-ice processes in driving the D-O events.