Oceanographic dynamics and the end of the last interglacial in the subpolar North Atlantic
The last interglacial interval was terminated by the inception of a long, progressive glaciation that is attributed to astronomically influenced changes in the seasonal distribution of sunlight over the earth. However, the feedbacks, internal dynamics, and global teleconnections associated with decl...
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ftdatacite:10.7916/d83j3bq5 2023-05-15T15:07:11+02:00 Oceanographic dynamics and the end of the last interglacial in the subpolar North Atlantic Mokeddem, Zohra McManus, Jerry F. Oppo, Delia W. 2014 https://dx.doi.org/10.7916/d83j3bq5 https://academiccommons.columbia.edu/doi/10.7916/D83J3BQ5 unknown Columbia University https://dx.doi.org/10.1073/pnas.1322103111 Climatic changes Ocean circulation Geochemistry Text Articles article-journal ScholarlyArticle 2014 ftdatacite https://doi.org/10.7916/d83j3bq5 https://doi.org/10.1073/pnas.1322103111 2021-11-05T12:55:41Z The last interglacial interval was terminated by the inception of a long, progressive glaciation that is attributed to astronomically influenced changes in the seasonal distribution of sunlight over the earth. However, the feedbacks, internal dynamics, and global teleconnections associated with declining northern summer insolation remain incompletely understood. Here we show that a crucial early step in glacial inception involves the weakening of the subpolar gyre (SPG) circulation of the North Atlantic Ocean. Detailed new records of microfossil foraminifera abundance and stable isotope ratios in deep sea sediments from Ocean Drilling Program site 984 south of Iceland reveal repeated, progressive cold water-mass expansions into subpolar latitudes during the last peak interglacial interval, marine isotope substage 5e. These movements are expressed as a sequence of progressively extensive southward advances and subsequent retreats of a hydrographic boundary that may have been analogous to the modern Arctic front, and associated with rapid changes in the strength of the SPG. This persistent millennial-scale oceanographic oscillation accompanied a long-term cooling trend at a time of slowly declining northern summer insolation, providing an early link in the propagation of those insolation changes globally, and resulting in a rapid transition from extensive regional warmth to the dramatic instability of the subsequent ∼100 ka. Text Arctic Foraminifera* Iceland North Atlantic DataCite Metadata Store (German National Library of Science and Technology) Arctic Last Peak ENVELOPE(-134.221,-134.221,61.599,61.599) |
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DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
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language |
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topic |
Climatic changes Ocean circulation Geochemistry |
spellingShingle |
Climatic changes Ocean circulation Geochemistry Mokeddem, Zohra McManus, Jerry F. Oppo, Delia W. Oceanographic dynamics and the end of the last interglacial in the subpolar North Atlantic |
topic_facet |
Climatic changes Ocean circulation Geochemistry |
description |
The last interglacial interval was terminated by the inception of a long, progressive glaciation that is attributed to astronomically influenced changes in the seasonal distribution of sunlight over the earth. However, the feedbacks, internal dynamics, and global teleconnections associated with declining northern summer insolation remain incompletely understood. Here we show that a crucial early step in glacial inception involves the weakening of the subpolar gyre (SPG) circulation of the North Atlantic Ocean. Detailed new records of microfossil foraminifera abundance and stable isotope ratios in deep sea sediments from Ocean Drilling Program site 984 south of Iceland reveal repeated, progressive cold water-mass expansions into subpolar latitudes during the last peak interglacial interval, marine isotope substage 5e. These movements are expressed as a sequence of progressively extensive southward advances and subsequent retreats of a hydrographic boundary that may have been analogous to the modern Arctic front, and associated with rapid changes in the strength of the SPG. This persistent millennial-scale oceanographic oscillation accompanied a long-term cooling trend at a time of slowly declining northern summer insolation, providing an early link in the propagation of those insolation changes globally, and resulting in a rapid transition from extensive regional warmth to the dramatic instability of the subsequent ∼100 ka. |
format |
Text |
author |
Mokeddem, Zohra McManus, Jerry F. Oppo, Delia W. |
author_facet |
Mokeddem, Zohra McManus, Jerry F. Oppo, Delia W. |
author_sort |
Mokeddem, Zohra |
title |
Oceanographic dynamics and the end of the last interglacial in the subpolar North Atlantic |
title_short |
Oceanographic dynamics and the end of the last interglacial in the subpolar North Atlantic |
title_full |
Oceanographic dynamics and the end of the last interglacial in the subpolar North Atlantic |
title_fullStr |
Oceanographic dynamics and the end of the last interglacial in the subpolar North Atlantic |
title_full_unstemmed |
Oceanographic dynamics and the end of the last interglacial in the subpolar North Atlantic |
title_sort |
oceanographic dynamics and the end of the last interglacial in the subpolar north atlantic |
publisher |
Columbia University |
publishDate |
2014 |
url |
https://dx.doi.org/10.7916/d83j3bq5 https://academiccommons.columbia.edu/doi/10.7916/D83J3BQ5 |
long_lat |
ENVELOPE(-134.221,-134.221,61.599,61.599) |
geographic |
Arctic Last Peak |
geographic_facet |
Arctic Last Peak |
genre |
Arctic Foraminifera* Iceland North Atlantic |
genre_facet |
Arctic Foraminifera* Iceland North Atlantic |
op_relation |
https://dx.doi.org/10.1073/pnas.1322103111 |
op_doi |
https://doi.org/10.7916/d83j3bq5 https://doi.org/10.1073/pnas.1322103111 |
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1766338745934544896 |