A shift to predominant multi-year sea ice conditions in the Baffin Bay and North Atlantic Ocean during the Holocene-Glacial transition inferred from the EGRIP ice core
- 1Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Venice, Italy
- 2CNR-Institute of Polar Sciences (ISP-CNR), Venice, Italy
- 3Laboratory of Environmental Chemistry, Paul Scherrer Institute, Villigen, Switzerland
- 4Institute of Atmospheric Sciences and Climate, National Research Council, Lecce, Italy
- 5Center for the Built Environment, University of California, Berkeley, CA USA
- 6Geophysical Institute, University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway
- 7Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerharven, Germany
- 8Physics Institute and Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland
- 9Atmospheric Chemistry and Climate Group, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain
- 10Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- 11Centre for Earth Observation Science, University of Manitoba, Winnipeg, MB R3T 2N2 Canada
Arctic sea ice has been melting at unprecedented rates in the past decades. Understanding past sea ice variability is of paramount importance to contextualize recent changes and constrain global climate models. Bromine enrichment (Brenr), relative to sea-water ratio, has been introduced as a proxy of first-year sea ice conditions within the ocean region influencing the ice core location (Spolaor et al., 2013). Brenr has been measured in ice cores from Greenland, that is the NEEM and RECAP cores. NEEM sea ice proxies are influenced by the region of the Canadian Arctic and Baffin Bay, while for the RECAP core it is mainly the North Atlantic Ocean. In this study we present the first high-resolution record of bromine enrichment from the EGRIP ice core in Greenland for the last 15.7 kyr BP, covering the Holocene-Glacial transition.
From preliminary back-trajectory analyses we suggest that EGRIP sea ice proxy sources are located in a wide region in the Baffin Bay and North Atlantic Ocean. We find EGRIP Brenr values of ~1 during cold periods, that is the Younger Dryas (12.9 – 11.7 kyr BP) and the last part of the Oldest Dryas (15.7 – 14.7 kyr BP), which we associate with predominant multi-year sea ice conditions. During warmer periods, instead, we observe higher Brenr values, ~3 for the Bølling-Allerød period (14.7 – 12.9 kyr BP) and progressively higher values from the early Holocene onwards, likely associated with an increased seasonal sea ice area. EGRIP Brenr is consistent with NEEM and RECAP records and it has the potential to extend our knowledge on Arctic past sea ice variability.
Bibliography
Spolaor, A., Vallelonga, P., Plane, J. M. C., Kehrwald, N., Gabrieli, J., Varin, C., Turetta, C., Cozzi, G., Kumar, R., Boutron, C., and Barbante, C.: Halogen species record Antarctic sea ice extent over glacial–interglacial periods, Atmos. Chem. Phys., 13, 6623–6635, https://doi.org/10.5194/acp-13-6623-2013, 2013.
How to cite: Segato, D., Burgay, F., Maffezzoli, N., Spagnesi, A., Turetta, C., Scoto, F., Dallo, F., Zannoni, D., Erhardt, T., Jensen, C. M., Saiz-Lopez, A., Kjær, H. A., Dahl-Jensen, D., Barbante, C., and Spolaor, A.: A shift to predominant multi-year sea ice conditions in the Baffin Bay and North Atlantic Ocean during the Holocene-Glacial transition inferred from the EGRIP ice core, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6278, https://doi.org/10.5194/egusphere-egu21-6278, 2021.
