Sea ice fluctuations in the Baffin Bay and the Labrador Sea during glacial abrupt climate changes

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Scoto, Federico, Sadatzki, Henrik, Maffezzoli, Niccolò, Barbante, Carlo, Gagliardi, Alessandro, Varin, Cristiano, Vallelonga, Paul, Gkinis, Vasileios, Dahl-Jensen, Dorthe, Kjær, Helle Astrid, Burgay, François, Saiz-Lopez, A., Stein, Ruediger, Spolaor, Andrea
• Other Authors: European Commission, National Science Foundation (US), Fonds de La Recherche Scientifique (Belgique), Research Foundation - Flanders, National Research Council of Canada, Chinese Academy of Sciences, Innovation Fund Denmark, Institut Polaire Français Paul Emile Victor, Centre National de la Recherche Scientifique (France), Commissariat à l'Ènergie Atomique et aux Ènergies Alternatives (France), Agence Nationale de la Recherche (France), Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (Germany), Icelandic Centre for Research, National Institute of Polar Research (Japan), Korea Polar Research Institute, Dutch Research Council, Swedish Research Council, Swiss National Science Foundation, Natural Environment Research Council (UK)
• Format: Article in Journal/Newspaper
• Language: English
• Published: National Academy of Sciences (U.S.) 2022
• Subjects: Baffin Bay; Dansgaard-Oeschger events; Labrador Sea; Abrupt climate changes; Sea ice reconstruction; Greenland; Baffin; Greenland ice cores; ice core; Nordic Seas; North Atlantic; Sea ice
• Online Access: http://hdl.handle.net/10261/296059; https://doi.org/10.1073/pnas.2203468119; https://doi.org/10.13039/501100003130; https://doi.org/10.13039/501100000046; https://doi.org/10.13039/100000001; https://doi.org/10.13039/501100000270; https://doi.org/10.13039/501100001665; https://doi.org/10.13039/501100003207; https://doi.org/10.13039/501100004794; https://doi.org/10.13039/501100002367; https://doi.org/10.13039/501100006489; https://doi.org/10.13039/501100000780; https://doi.org/10.13039/501100002661; https://doi.org/10.13039/501100001840; https://doi.org/10.13039/501100004796; https://api.elsevier.com/content/abstract/scopus_id/85140561832

9 pags., 5 figs., 2 tabs. Sea ice decline in the North Atlantic and Nordic Seas has been proposed to contribute to the repeated abrupt atmospheric warmings recorded in Greenland ice cores during the last glacial period, known as Dansgaard-Oeschger (D-O) events. However, the understanding of how sea ice changes were coupled with abrupt climate changes during D-O events has remained incomplete due to a lack of suitable high-resolution sea ice proxy records from northwestern North Atlantic regions. Here, we present a subdecadal-scale bromine enrichment (Brenr) record from the NEEM ice core (Northwest Greenland) and sediment core biomarker records to reconstruct the variability of seasonal sea ice in the Baffin Bay and Labrador Sea over a suite of D-O events between 34 and 42 ka. Our results reveal repeated shifts between stable, multiyear sea ice (MYSI) conditions during cold stadials and unstable, seasonal sea ice conditions during warmer interstadials. The shift from stadial to interstadial sea ice conditions occurred rapidly and synchronously with the atmospheric warming over Greenland, while the amplitude of high-frequency sea ice fluctuations increased through interstadials. Our findings suggest that the rapid replacement of widespread MYSI with seasonal sea ice amplified the abrupt climate warming over the course of D-O events and highlight the role of feedbacks associated with late-interstadial seasonal sea ice expansion in driving the North Atlantic ocean-climate system back to stadial conditions. The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013) grant agreements #243908 “Past4Future. Climate change—Learning from the past climate” and #610055 “Ice2ice”. We thank our colleagues at Centre for Ice and Climate (Copenhagen, Denmark) for their generous contribution and providing the NEEM ice core samples. NEEM is directed and organized by the Center of Ice and Climate at the Niels Bohr Institute ...