Extreme deepening of the Atlantic overturning circulation during deglaciation
Glacial terminations during the late Pleistocene epoch are associated with changes in insolation. They are also punctuated by millennial-scale climate shifts, characterized by a weakening and subsequent strengthening of the Atlantic meridional overturning circulation. This ubiquitous association sug...
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ftnerc:oai:nora.nerc.ac.uk:11222 2023-05-15T17:25:26+02:00 Extreme deepening of the Atlantic overturning circulation during deglaciation Barker, Stephen Knorr, Gregor Vautravers, Maryline J. Diz, Paula Skinner, Luke C. 2010 http://nora.nerc.ac.uk/id/eprint/11222/ http://www.nature.com/ngeo/journal/v3/n8/pdf/ngeo921.pdf unknown Nature Publishing Group Barker, Stephen; Knorr, Gregor; Vautravers, Maryline J.; Diz, Paula; Skinner, Luke C. 2010 Extreme deepening of the Atlantic overturning circulation during deglaciation. Nature Geoscience, 3 (8). 567-571. https://doi.org/10.1038/ngeo921 <https://doi.org/10.1038/ngeo921> Marine Sciences Meteorology and Climatology Glaciology Publication - Article PeerReviewed 2010 ftnerc https://doi.org/10.1038/ngeo921 2023-02-04T19:27:12Z Glacial terminations during the late Pleistocene epoch are associated with changes in insolation. They are also punctuated by millennial-scale climate shifts, characterized by a weakening and subsequent strengthening of the Atlantic meridional overturning circulation. This ubiquitous association suggests that these oscillations may be a necessary component of deglaciation. Model simulations have suggested that the period of weakened circulation during these terminal oscillations would be followed by an overshoot of the circulation on its resumption, but this phenomenon has not yet been observed. Here we use radiocarbon measurements of benthic foraminifera and carbonate preservation indices to reconstruct ventilation changes in the deep South Atlantic Ocean over the past 40,000 years. We find evidence for a particularly deep expansion of the Atlantic overturning cell directly following the weak mode associated with Heinrich Stadial 1. Our analysis of an ocean general circulation model simulation suggests that North Atlantic Deep Water export during the expansion was greater than that of interglacial conditions. We find a similar deep expansion duringDansgaard-Oeschger Interstadial Event 8, 38,000 years ago, which followed Heinrich Stadial 4. We conclude that the rise in atmospheric CO2 concentrations and resultant warming associated with an especially weak overturning circulation are sufficient to trigger a switch to a vigorous circulation, but a full transition to interglacial conditions requires additional forcing at an orbital scale. Article in Journal/Newspaper North Atlantic Deep Water North Atlantic South Atlantic Ocean Natural Environment Research Council: NERC Open Research Archive Nature Geoscience 3 8 567 571 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
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unknown |
topic |
Marine Sciences Meteorology and Climatology Glaciology |
spellingShingle |
Marine Sciences Meteorology and Climatology Glaciology Barker, Stephen Knorr, Gregor Vautravers, Maryline J. Diz, Paula Skinner, Luke C. Extreme deepening of the Atlantic overturning circulation during deglaciation |
topic_facet |
Marine Sciences Meteorology and Climatology Glaciology |
description |
Glacial terminations during the late Pleistocene epoch are associated with changes in insolation. They are also punctuated by millennial-scale climate shifts, characterized by a weakening and subsequent strengthening of the Atlantic meridional overturning circulation. This ubiquitous association suggests that these oscillations may be a necessary component of deglaciation. Model simulations have suggested that the period of weakened circulation during these terminal oscillations would be followed by an overshoot of the circulation on its resumption, but this phenomenon has not yet been observed. Here we use radiocarbon measurements of benthic foraminifera and carbonate preservation indices to reconstruct ventilation changes in the deep South Atlantic Ocean over the past 40,000 years. We find evidence for a particularly deep expansion of the Atlantic overturning cell directly following the weak mode associated with Heinrich Stadial 1. Our analysis of an ocean general circulation model simulation suggests that North Atlantic Deep Water export during the expansion was greater than that of interglacial conditions. We find a similar deep expansion duringDansgaard-Oeschger Interstadial Event 8, 38,000 years ago, which followed Heinrich Stadial 4. We conclude that the rise in atmospheric CO2 concentrations and resultant warming associated with an especially weak overturning circulation are sufficient to trigger a switch to a vigorous circulation, but a full transition to interglacial conditions requires additional forcing at an orbital scale. |
format |
Article in Journal/Newspaper |
author |
Barker, Stephen Knorr, Gregor Vautravers, Maryline J. Diz, Paula Skinner, Luke C. |
author_facet |
Barker, Stephen Knorr, Gregor Vautravers, Maryline J. Diz, Paula Skinner, Luke C. |
author_sort |
Barker, Stephen |
title |
Extreme deepening of the Atlantic overturning circulation during deglaciation |
title_short |
Extreme deepening of the Atlantic overturning circulation during deglaciation |
title_full |
Extreme deepening of the Atlantic overturning circulation during deglaciation |
title_fullStr |
Extreme deepening of the Atlantic overturning circulation during deglaciation |
title_full_unstemmed |
Extreme deepening of the Atlantic overturning circulation during deglaciation |
title_sort |
extreme deepening of the atlantic overturning circulation during deglaciation |
publisher |
Nature Publishing Group |
publishDate |
2010 |
url |
http://nora.nerc.ac.uk/id/eprint/11222/ http://www.nature.com/ngeo/journal/v3/n8/pdf/ngeo921.pdf |
genre |
North Atlantic Deep Water North Atlantic South Atlantic Ocean |
genre_facet |
North Atlantic Deep Water North Atlantic South Atlantic Ocean |
op_relation |
Barker, Stephen; Knorr, Gregor; Vautravers, Maryline J.; Diz, Paula; Skinner, Luke C. 2010 Extreme deepening of the Atlantic overturning circulation during deglaciation. Nature Geoscience, 3 (8). 567-571. https://doi.org/10.1038/ngeo921 <https://doi.org/10.1038/ngeo921> |
op_doi |
https://doi.org/10.1038/ngeo921 |
container_title |
Nature Geoscience |
container_volume |
3 |
container_issue |
8 |
container_start_page |
567 |
op_container_end_page |
571 |
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1766116854418374656 |