Upper-ocean-to-atmosphere radiocarbon offsets imply fast deglacial carbon dioxide release.
Radiocarbon in the atmosphere is regulated largely by ocean circulation, which controls the sequestration of carbon dioxide (CO(2)) in the deep sea through atmosphere-ocean carbon exchange. During the last glaciation, lower atmospheric CO(2) levels were accompanied by increased atmospheric radiocarb...
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ftcdlib:oai:escholarship.org:ark:/13030/qt5486407b 2023-05-15T18:25:03+02:00 Upper-ocean-to-atmosphere radiocarbon offsets imply fast deglacial carbon dioxide release. Rose, Kathryn A Sikes, Elisabeth L Guilderson, Thomas P Shane, Phil Hill, Tessa M Zahn, Rainer Spero, Howard J 1093 - 1097 2010-08-01 application/pdf https://escholarship.org/uc/item/5486407b unknown eScholarship, University of California qt5486407b https://escholarship.org/uc/item/5486407b public Nature, vol 466, iss 7310 Plankton Carbon Dioxide Carbon Radioisotopes Atmosphere Ice Cover Seawater Water Movements Environmental Monitoring Geologic Sediments Oceans and Seas Foraminifera Global Warming General Science & Technology article 2010 ftcdlib 2022-10-10T17:30:51Z Radiocarbon in the atmosphere is regulated largely by ocean circulation, which controls the sequestration of carbon dioxide (CO(2)) in the deep sea through atmosphere-ocean carbon exchange. During the last glaciation, lower atmospheric CO(2) levels were accompanied by increased atmospheric radiocarbon concentrations that have been attributed to greater storage of CO(2) in a poorly ventilated abyssal ocean. The end of the ice age was marked by a rapid increase in atmospheric CO(2) concentrations that coincided with reduced (14)C/(12)C ratios (Delta(14)C) in the atmosphere, suggesting the release of very 'old' ((14)C-depleted) CO(2) from the deep ocean to the atmosphere. Here we present radiocarbon records of surface and intermediate-depth waters from two sediment cores in the southwest Pacific and Southern oceans. We find a steady 170 per mil decrease in Delta(14)C that precedes and roughly equals in magnitude the decrease in the atmospheric radiocarbon signal during the early stages of the glacial-interglacial climatic transition. The atmospheric decrease in the radiocarbon signal coincides with regionally intensified upwelling and marine biological productivity, suggesting that CO(2) released by means of deep water upwelling in the Southern Ocean lost most of its original depleted-(14)C imprint as a result of exchange and isotopic equilibration with the atmosphere. Our data imply that the deglacial (14)C depletion previously identified in the eastern tropical North Pacific must have involved contributions from sources other than the previously suggested carbon release by way of a deep Southern Ocean pathway, and may reflect the expanded influence of the (14)C-depleted North Pacific carbon reservoir across this interval. Accordingly, shallow water masses advecting north across the South Pacific in the early deglaciation had little or no residual (14)C-depleted signals owing to degassing of CO(2) and biological uptake in the Southern Ocean. Article in Journal/Newspaper Southern Ocean University of California: eScholarship Pacific Southern Ocean |
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Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Plankton Carbon Dioxide Carbon Radioisotopes Atmosphere Ice Cover Seawater Water Movements Environmental Monitoring Geologic Sediments Oceans and Seas Foraminifera Global Warming General Science & Technology |
spellingShingle |
Plankton Carbon Dioxide Carbon Radioisotopes Atmosphere Ice Cover Seawater Water Movements Environmental Monitoring Geologic Sediments Oceans and Seas Foraminifera Global Warming General Science & Technology Rose, Kathryn A Sikes, Elisabeth L Guilderson, Thomas P Shane, Phil Hill, Tessa M Zahn, Rainer Spero, Howard J Upper-ocean-to-atmosphere radiocarbon offsets imply fast deglacial carbon dioxide release. |
topic_facet |
Plankton Carbon Dioxide Carbon Radioisotopes Atmosphere Ice Cover Seawater Water Movements Environmental Monitoring Geologic Sediments Oceans and Seas Foraminifera Global Warming General Science & Technology |
description |
Radiocarbon in the atmosphere is regulated largely by ocean circulation, which controls the sequestration of carbon dioxide (CO(2)) in the deep sea through atmosphere-ocean carbon exchange. During the last glaciation, lower atmospheric CO(2) levels were accompanied by increased atmospheric radiocarbon concentrations that have been attributed to greater storage of CO(2) in a poorly ventilated abyssal ocean. The end of the ice age was marked by a rapid increase in atmospheric CO(2) concentrations that coincided with reduced (14)C/(12)C ratios (Delta(14)C) in the atmosphere, suggesting the release of very 'old' ((14)C-depleted) CO(2) from the deep ocean to the atmosphere. Here we present radiocarbon records of surface and intermediate-depth waters from two sediment cores in the southwest Pacific and Southern oceans. We find a steady 170 per mil decrease in Delta(14)C that precedes and roughly equals in magnitude the decrease in the atmospheric radiocarbon signal during the early stages of the glacial-interglacial climatic transition. The atmospheric decrease in the radiocarbon signal coincides with regionally intensified upwelling and marine biological productivity, suggesting that CO(2) released by means of deep water upwelling in the Southern Ocean lost most of its original depleted-(14)C imprint as a result of exchange and isotopic equilibration with the atmosphere. Our data imply that the deglacial (14)C depletion previously identified in the eastern tropical North Pacific must have involved contributions from sources other than the previously suggested carbon release by way of a deep Southern Ocean pathway, and may reflect the expanded influence of the (14)C-depleted North Pacific carbon reservoir across this interval. Accordingly, shallow water masses advecting north across the South Pacific in the early deglaciation had little or no residual (14)C-depleted signals owing to degassing of CO(2) and biological uptake in the Southern Ocean. |
format |
Article in Journal/Newspaper |
author |
Rose, Kathryn A Sikes, Elisabeth L Guilderson, Thomas P Shane, Phil Hill, Tessa M Zahn, Rainer Spero, Howard J |
author_facet |
Rose, Kathryn A Sikes, Elisabeth L Guilderson, Thomas P Shane, Phil Hill, Tessa M Zahn, Rainer Spero, Howard J |
author_sort |
Rose, Kathryn A |
title |
Upper-ocean-to-atmosphere radiocarbon offsets imply fast deglacial carbon dioxide release. |
title_short |
Upper-ocean-to-atmosphere radiocarbon offsets imply fast deglacial carbon dioxide release. |
title_full |
Upper-ocean-to-atmosphere radiocarbon offsets imply fast deglacial carbon dioxide release. |
title_fullStr |
Upper-ocean-to-atmosphere radiocarbon offsets imply fast deglacial carbon dioxide release. |
title_full_unstemmed |
Upper-ocean-to-atmosphere radiocarbon offsets imply fast deglacial carbon dioxide release. |
title_sort |
upper-ocean-to-atmosphere radiocarbon offsets imply fast deglacial carbon dioxide release. |
publisher |
eScholarship, University of California |
publishDate |
2010 |
url |
https://escholarship.org/uc/item/5486407b |
op_coverage |
1093 - 1097 |
geographic |
Pacific Southern Ocean |
geographic_facet |
Pacific Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Nature, vol 466, iss 7310 |
op_relation |
qt5486407b https://escholarship.org/uc/item/5486407b |
op_rights |
public |
_version_ |
1766206201659392000 |