Sea ice in the Nordic Seas: Greenland stadial to interstadial changes

Abstract

Sea ice conditions in the eastern Fram Strait between 40 and 36.5 ka b2k (thousand years before the year 2000) are reconstructed in detail, based on biomarker analyses. Following extensive sea ice conditions around the Greenland Interstadial 9/Greenland Stadial 9 transition at 39.9 ka b2k, repeated polynya activity marked Greenland Stadial 9 in the eastern Fram Strait. Nearly perennial sea ice was observed around the Greenland Stadial 9/Greenland Interstadial 8 transition at 38.22 ka b2k, followed by a gradual establishment of seasonal sea ice cover over the research area during Greenland Interstadial 8. Previous studies highlighted sea ice retreat in the southeastern Nordic Seas as a driver of abrupt Greenland Stadial to Interstadial climate change. We document intervals with less sea ice in the eastern Fram Strait during Greenland Stadial 9 and Interstadial 8 than previously suggested. By mapping the variable sea ice extent during Greenland Stadial 9 and Interstadial 8, further constraints are detected that may help define the role of the Nordic Seas sea ice cover in driving abrupt climate change during glacial times.