North Atlantic climate and deep-ocean flow speed changes during the last 230 years

Variations in the near-bottom flow speed of Iceland-Scotland Overflow Water (ISOW) are documented in a 230-year-long deep-sea sediment record from the eastern flank of Reykjanes Ridge in the subpolar North Atlantic at (sub) decadal time scales. For recent decades, the ISOW palaeocurrent reconstructi...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Boessenkool, K. P., Hall, I. R., Elderfield, H., Yashayaev, I.
Format: Article in Journal/Newspaper
Language:English
Published: Amer Geophysical Union 2007
Subjects:
deep ocean circulation
North Atlantic Oscillation
drift sediments
Reykjanes
Iceland
Labrador Sea
North Atlantic
North Atlantic oscillation
Online Access:https://archimer.ifremer.fr/doc/00235/34646/33007.pdf
https://doi.org/10.1029/2007GL030285
https://archimer.ifremer.fr/doc/00235/34646/
Description
Summary:Variations in the near-bottom flow speed of Iceland-Scotland Overflow Water (ISOW) are documented in a 230-year-long deep-sea sediment record from the eastern flank of Reykjanes Ridge in the subpolar North Atlantic at (sub) decadal time scales. For recent decades, the ISOW palaeocurrent reconstructions show similarities with observational hydrographic data. Furthermore, recent ISOW flow changes fall mostly within the range of its variability of the past 230 years. The record also reveals a hitherto unrecognized coupling of deep flow speeds in the subpolar North Atlantic with the North Atlantic Oscillation (NAO) index, with more (less) vigorous ISOW flow during negative (positive) phases of the NAO. Our results suggest that the changes in ISOW vigor are largely controlled by the transport and characteristics of Labrador Sea Water rather than variations in the overflow itself, with implications for the meridional overturning of the Atlantic Ocean and climate.

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