Rapid reductions and millennial-scale variability in Nordic Seas sea ice cover during abrupt glacial climate changes

Constraining the past sea ice variability in the Nordic Seas is critical for a comprehensive understanding of the abrupt DansgaardOeschger (D-O) climate changes during the last glacial. Here we present unprecedentedly detailed sea ice proxy evidence from two Norwegian Sea sediment cores and an East...

Full description

Bibliographic Details
Published in:Proceedings of the National Academy of Sciences
Main Authors: Sadatzki, Henrik, Maffezzoli, Niccolo, Dokken, Trond M., Simon, Margit H., Berben, Sarah M. P., Fahl, Kirsten, Kjor, Helle A., Spolaor, Andrea, Stein, Ruediger, Vallelonga, Paul, Vinther, Bo M., Jansen, Eystein
Format: Article in Journal/Newspaper
Language:English
Published: 2020
Subjects:
sea ice
Nordic Seas
Dansgaard-Oeschger events
abrupt climate change
HIGH-RESOLUTION RECORD
NORTH-ATLANTIC
HALOGEN DEPOSITION
OCEAN CIRCULATION
BIOMARKER
MARINE
RECONSTRUCTIONS
INSTABILITY
CONVECTION
ANOMALIES
East Greenland
Greenland
Greenland ice core
ice core
North Atlantic
Norwegian Sea
Sea ice
Online Access:https://curis.ku.dk/portal/da/publications/rapid-reductions-and-millennialscale-variability-in-nordic-seas-sea-ice-cover-during-abrupt-glacial-climate-changes(3cc7b753-fba8-42c9-b7e3-4b3926e24857).html
https://doi.org/10.1073/pnas.2005849117
https://curis.ku.dk/ws/files/253650212/29478.full.pdf
Description
Summary:Constraining the past sea ice variability in the Nordic Seas is critical for a comprehensive understanding of the abrupt DansgaardOeschger (D-O) climate changes during the last glacial. Here we present unprecedentedly detailed sea ice proxy evidence from two Norwegian Sea sediment cores and an East Greenland ice core to resolve and constrain sea ice variations during four D-O events between 32 and 41 ka. Our independent sea ice records consistently reveal a millennial-scale variability and threshold response between an extensive seasonal sea ice cover in the Nordic Seas during cold stadials and reduced seasonal sea ice conditions during warmer interstadials. They document substantial and rapid sea ice reductions that may have happened within 250 y or less, concomitant with reinvigoration of deep convection in the Nordic Seas and the abrupt warming transitions in Greenland. Our empirical evidence thus underpins the cardinal role of rapid sea ice decline and related feedbacks to trigger abrupt and large-amplitude climate change of the glacial D-O events.

Similar Items