Abstract

The northern coastline of Greenland, spanning from the Lincoln Sea to northern Baffin Bay, is a unique sea-ice regime. It is part of the Last Ice Area, where the dominant surface currents in the Arctic Ocean push sea ice towards the coastlines of northern Greenland and the Canadian Arctic Archipelago. Research indicates that, under continued and future climate warming, the Last Ice Area is expected to remain the final refuge of multi-year sea ice in the Arctic, important for sea-ice dependent ecosystems. However, prolonged periods of open water observed in the Lincoln Sea and elsewhere in the Last Ice Area during recent years raise concerns about its long-term stability. From the Lincoln Sea, the Nares Strait connects the perennially sea-ice covered Last Ice Area to the Pikialasorsuaq or North Water Polynya (NOW), the Arctic’s largest and most productive polynya. The NOW is influenced by both sensible and latent heat processes, with the latter driven by strong northeasterly winds and aided by the formation of ice arches in the narrow passages of Nares Strait. Recurrent failure of ice arches in Nares Strait during recent years influence the extent, ice cover, and stratification of the NOW and with it its ecosystem.

Using sea-ice biomarkers on a transect of marine sediment cores spanning from the Lincoln Sea to northern Baffin Bay, we can investigate the stability of perennial sea ice in the Last Ice Area, understand the evolution of ice arching in Nares Strait, and explore the extent of the NOW throughout the Holocene. In the context of regional climate variability and ocean circulation, this can provide insights into the mechanisms governing sea-ice dynamics in this region and improve our understanding of their spatiotemporal links to ecosystem shifts.