Rapid changes in ocean circulation and atmospheric radiocarbon
A latitude-depth, coupled global ocean-ice-atmosphere model is extended to include a simple biosphere component. A physically reasonable adjustment of runoff into the North Atlantic is invoked to achieve a transient response to glacial meltwater perturbations, which closely resembles the Younger Dry...
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American Geophysical Union
1996
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Online Access: | https://boris.unibe.ch/158216/1/stocker96po.pdf https://boris.unibe.ch/158216/ |
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ftunivbern:oai:boris.unibe.ch:158216 2023-08-20T04:08:14+02:00 Rapid changes in ocean circulation and atmospheric radiocarbon Stocker, Thomas F. Wright, Daniel 1996 application/pdf https://boris.unibe.ch/158216/1/stocker96po.pdf https://boris.unibe.ch/158216/ eng eng American Geophysical Union https://boris.unibe.ch/158216/ info:eu-repo/semantics/openAccess Stocker, Thomas F.; Wright, Daniel (1996). Rapid changes in ocean circulation and atmospheric radiocarbon. Paleoceanography, 11(6), pp. 773-795. American Geophysical Union 10.1029/96PA02640 <http://dx.doi.org/10.1029/96PA02640> 530 Physics info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion PeerReviewed 1996 ftunivbern https://doi.org/10.1029/96PA02640 2023-07-31T22:07:57Z A latitude-depth, coupled global ocean-ice-atmosphere model is extended to include a simple biosphere component. A physically reasonable adjustment of runoff into the North Atlantic is invoked to achieve a transient response to glacial meltwater perturbations, which closely resembles the Younger Dryas climate event. We then investigate the evolution of the isotopic ratio of atmospheric radiocarbon, Δ14C, due to the rapid changes of deep ocean circulation. When the North Atlantic branch of the conveyor belt circulation is interrupted, the oceanic uptake of radiocarbon is reduced, resulting in an increase of atmospheric Δ14C by about 35 ‰. The reduction of ventilation in the North Atlantic is partly compensated by an increase of the 14C ratios of the biosphere, the Southern Ocean, and the upper ocean above 1000 m depth. A plateau of the 14C year/calendar year relation can be generated at the time of the rapid reinitiation of deep ocean ventilation which begins coincident with the major temperature increase and lasts for about 60 years. It is hence significantly shorter than that found by analyzing tree rings during the termination of Younger Dryas (longer than 400 years). A sensitivity study reveals that the duration of the plateau depends strongly on the transient evolution of the gas exchange rate and can increase to 150–300 years if changes of pCO2 or sea ice coverage are taken into account. Article in Journal/Newspaper North Atlantic Sea ice Southern Ocean BORIS (Bern Open Repository and Information System, University of Bern) Southern Ocean Paleoceanography 11 6 773 795 |
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Open Polar |
collection |
BORIS (Bern Open Repository and Information System, University of Bern) |
op_collection_id |
ftunivbern |
language |
English |
topic |
530 Physics |
spellingShingle |
530 Physics Stocker, Thomas F. Wright, Daniel Rapid changes in ocean circulation and atmospheric radiocarbon |
topic_facet |
530 Physics |
description |
A latitude-depth, coupled global ocean-ice-atmosphere model is extended to include a simple biosphere component. A physically reasonable adjustment of runoff into the North Atlantic is invoked to achieve a transient response to glacial meltwater perturbations, which closely resembles the Younger Dryas climate event. We then investigate the evolution of the isotopic ratio of atmospheric radiocarbon, Δ14C, due to the rapid changes of deep ocean circulation. When the North Atlantic branch of the conveyor belt circulation is interrupted, the oceanic uptake of radiocarbon is reduced, resulting in an increase of atmospheric Δ14C by about 35 ‰. The reduction of ventilation in the North Atlantic is partly compensated by an increase of the 14C ratios of the biosphere, the Southern Ocean, and the upper ocean above 1000 m depth. A plateau of the 14C year/calendar year relation can be generated at the time of the rapid reinitiation of deep ocean ventilation which begins coincident with the major temperature increase and lasts for about 60 years. It is hence significantly shorter than that found by analyzing tree rings during the termination of Younger Dryas (longer than 400 years). A sensitivity study reveals that the duration of the plateau depends strongly on the transient evolution of the gas exchange rate and can increase to 150–300 years if changes of pCO2 or sea ice coverage are taken into account. |
format |
Article in Journal/Newspaper |
author |
Stocker, Thomas F. Wright, Daniel |
author_facet |
Stocker, Thomas F. Wright, Daniel |
author_sort |
Stocker, Thomas F. |
title |
Rapid changes in ocean circulation and atmospheric radiocarbon |
title_short |
Rapid changes in ocean circulation and atmospheric radiocarbon |
title_full |
Rapid changes in ocean circulation and atmospheric radiocarbon |
title_fullStr |
Rapid changes in ocean circulation and atmospheric radiocarbon |
title_full_unstemmed |
Rapid changes in ocean circulation and atmospheric radiocarbon |
title_sort |
rapid changes in ocean circulation and atmospheric radiocarbon |
publisher |
American Geophysical Union |
publishDate |
1996 |
url |
https://boris.unibe.ch/158216/1/stocker96po.pdf https://boris.unibe.ch/158216/ |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
North Atlantic Sea ice Southern Ocean |
genre_facet |
North Atlantic Sea ice Southern Ocean |
op_source |
Stocker, Thomas F.; Wright, Daniel (1996). Rapid changes in ocean circulation and atmospheric radiocarbon. Paleoceanography, 11(6), pp. 773-795. American Geophysical Union 10.1029/96PA02640 <http://dx.doi.org/10.1029/96PA02640> |
op_relation |
https://boris.unibe.ch/158216/ |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/96PA02640 |
container_title |
Paleoceanography |
container_volume |
11 |
container_issue |
6 |
container_start_page |
773 |
op_container_end_page |
795 |
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1774720386425946112 |