EGU2020-17959, updated on 12 Jun 2020
https://doi.org/10.5194/egusphere-egu2020-17959
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

High Arctic Polynyas in a Changing Climate

Rebecca Jackson1, Anna Bang Kvorning2, Christof Pearce3, Marit-Solveig Seidenkrantz3, and Sofia Ribeiro1
Rebecca Jackson et al.
  • 1Department of Glaciology and Climate, Geological Survey of Denmark and Greenland, , Copenhagen, Denmark
  • 2Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
  • 3Department of Geoscience, Aarhus University, Aarhus, Denmark

Polynyas, areas of open water in the otherwise sea-ice dominated high Arctic, are vital oases for biological productivity, supporting a plethora of marine mammals and birds that in turn sustain indigenous communities. Polynyas are not, however, consistent features. Beyond the observational era, little to nothing is known about their past dynamics and equally, about their resilience to emerging changes in Arctic sea-ice conditions.

Recent paleoceanographic reconstructions of the North Water in northern Baffin Bay, the largest of the high Arctic polynyas, indicate that the polynya contracted in response to warm climatic intervals during the Holocene (e.g. Roman Warm Period). In contrast, the onset of stable North Water polynya formation acted to suppress northward incursion of warm Atlantic-sourced waters. This highlighted not only the sensitivity of polynyas to past climatic changes, but the role their formation plays in mediating water column dynamics and ocean circulation.

These new findings provided the rationale for the MSCA project ‘POLARC: High Arctic Polynyas in a Changing Climate’, to investigate the Holocene dynamics of other high Arctic polynyas forming off the east Greenland coast. New marine sedimentary archives and a multiproxy approach will be used to reconstruct productivity, sea-ice conditions and bottom water conditions, capturing a holistic view of these systems and their interaction with climatic and oceanographic variation during the Holocene (11,700 years BP to present). We present here preliminary paleoceanographic reconstructions of the Sirius Water, the first Holocene record from this polynya region, as well as plans for model-data comparisons in key polynya regions with the aim of constraining the past and better predicting the future of these phenomena.

How to cite: Jackson, R., Bang Kvorning, A., Pearce, C., Seidenkrantz, M.-S., and Ribeiro, S.: High Arctic Polynyas in a Changing Climate, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-17959, https://doi.org/10.5194/egusphere-egu2020-17959, 2020

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Presentation version 1 – uploaded on 29 Apr 2020
  • CC1: Comment on EGU2020-17959, Antoon Kuijpers, 03 May 2020

    Any link with N-Atlantic subpolar gyre strength and/or (long-term) NAO Index changes ?