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Natural variability of the Arctic Ocean sea ice during the present interglacial.

https://arctichealth.org/en/permalink/ahliterature304542
Source
Proc Natl Acad Sci U S A. 2020 10 20; 117(42):26069-26075
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
10-20-2020
Author
Anne de Vernal
Claude Hillaire-Marcel
Cynthia Le Duc
Philippe Roberge
Camille Brice
Jens Matthiessen
Robert F Spielhagen
Ruediger Stein
Author Affiliation
Geotop-Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada; devernal.anne@uqam.ca.
Source
Proc Natl Acad Sci U S A. 2020 10 20; 117(42):26069-26075
Date
10-20-2020
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Abstract
The impact of the ongoing anthropogenic warming on the Arctic Ocean sea ice is ascertained and closely monitored. However, its long-term fate remains an open question as its natural variability on centennial to millennial timescales is not well documented. Here, we use marine sedimentary records to reconstruct Arctic sea-ice fluctuations. Cores collected along the Lomonosov Ridge that extends across the Arctic Ocean from northern Greenland to the Laptev Sea were radiocarbon dated and analyzed for their micropaleontological and palynological contents, both bearing information on the past sea-ice cover. Results demonstrate that multiyear pack ice remained a robust feature of the western and central Lomonosov Ridge and that perennial sea ice remained present throughout the present interglacial, even during the climate optimum of the middle Holocene that globally peaked ~6,500 y ago. In contradistinction, the southeastern Lomonosov Ridge area experienced seasonally sea-ice-free conditions, at least, sporadically, until about 4,000 y ago. They were marked by relatively high phytoplanktonic productivity and organic carbon fluxes at the seafloor resulting in low biogenic carbonate preservation. These results point to contrasted west-east surface ocean conditions in the Arctic Ocean, not unlike those of the Arctic dipole linked to the recent loss of Arctic sea ice. Hence, our data suggest that seasonally ice-free conditions in the southeastern Arctic Ocean with a dominant Arctic dipolar pattern, may be a recurrent feature under "warm world" climate.
PubMed ID
33020299 View in PubMed
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