Evolution of the stable carbon isotope composition of atmospheric CO₂ over the last glacial cycle
We present new δ¹³C measurements of atmospheric CO₂ covering the last glacial/interglacial cycle, complementing previous records covering Terminations I and II. Most prominent in the new record is a significant depletion in δ¹³C(atm) of 0.5‰ occurring during marine isotope stage (MIS) 4, followed by...
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2016
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ftunivbern:oai:boris.unibe.ch:83817 2023-08-20T04:09:58+02:00 Evolution of the stable carbon isotope composition of atmospheric CO₂ over the last glacial cycle Eggleston, S. Schmitt, J. Bereiter, B. Schneider, R. Fischer, H. 2016 application/pdf https://boris.unibe.ch/83817/1/eggleston16po.pdf https://boris.unibe.ch/83817/ eng eng American Geophysical Union https://boris.unibe.ch/83817/ info:eu-repo/semantics/openAccess Eggleston, S.; Schmitt, J.; Bereiter, B.; Schneider, R.; Fischer, H. (2016). Evolution of the stable carbon isotope composition of atmospheric CO₂ over the last glacial cycle. Paleoceanography, 31(3), pp. 434-452. American Geophysical Union 10.1002/2015PA002874 <http://dx.doi.org/10.1002/2015PA002874> 530 Physics info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion PeerReviewed 2016 ftunivbern https://doi.org/10.1002/2015PA002874 2023-07-31T21:26:55Z We present new δ¹³C measurements of atmospheric CO₂ covering the last glacial/interglacial cycle, complementing previous records covering Terminations I and II. Most prominent in the new record is a significant depletion in δ¹³C(atm) of 0.5‰ occurring during marine isotope stage (MIS) 4, followed by an enrichment of the same magnitude at the beginning of MIS 3. Such a significant excursion in the record is otherwise only observed at glacial terminations, suggesting that similar processes were at play, such as changing sea surface temperatures, changes in marine biological export in the Southern Ocean (SO) due to variations in aeolian iron fluxes, changes in the Atlantic meridional overturning circulation, upwelling of deep water in the SO, and long-term trends in terrestrial carbon storage. Based on previous modeling studies, we propose constraints on some of these processes during specific time intervals. The decrease in δ¹³C(atm) at the end of MIS 4 starting approximately 64 kyr B.P. was accompanied by increasing [CO₂]. This period is also marked by a decrease in aeolian iron flux to the SO, followed by an increase in SO upwelling during Heinrich event 6, indicating that it is likely that a large amount of δ¹³C-depleted carbon was transferred to the deep oceans previously, i.e., at the onset of MIS 4. Apart from the upwelling event at the end of MIS 4 (and potentially smaller events during Heinrich events in MIS 3), upwelling of deep water in the SO remained reduced until the last glacial termination, whereupon a second pulse of isotopically light carbon was released into the atmosphere. Article in Journal/Newspaper Southern Ocean BORIS (Bern Open Repository and Information System, University of Bern) Southern Ocean Paleoceanography 31 3 434 452 |
institution |
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 Eggleston, S. Schmitt, J. Bereiter, B. Schneider, R. Fischer, H. Evolution of the stable carbon isotope composition of atmospheric CO₂ over the last glacial cycle |
topic_facet |
530 Physics |
description |
We present new δ¹³C measurements of atmospheric CO₂ covering the last glacial/interglacial cycle, complementing previous records covering Terminations I and II. Most prominent in the new record is a significant depletion in δ¹³C(atm) of 0.5‰ occurring during marine isotope stage (MIS) 4, followed by an enrichment of the same magnitude at the beginning of MIS 3. Such a significant excursion in the record is otherwise only observed at glacial terminations, suggesting that similar processes were at play, such as changing sea surface temperatures, changes in marine biological export in the Southern Ocean (SO) due to variations in aeolian iron fluxes, changes in the Atlantic meridional overturning circulation, upwelling of deep water in the SO, and long-term trends in terrestrial carbon storage. Based on previous modeling studies, we propose constraints on some of these processes during specific time intervals. The decrease in δ¹³C(atm) at the end of MIS 4 starting approximately 64 kyr B.P. was accompanied by increasing [CO₂]. This period is also marked by a decrease in aeolian iron flux to the SO, followed by an increase in SO upwelling during Heinrich event 6, indicating that it is likely that a large amount of δ¹³C-depleted carbon was transferred to the deep oceans previously, i.e., at the onset of MIS 4. Apart from the upwelling event at the end of MIS 4 (and potentially smaller events during Heinrich events in MIS 3), upwelling of deep water in the SO remained reduced until the last glacial termination, whereupon a second pulse of isotopically light carbon was released into the atmosphere. |
format |
Article in Journal/Newspaper |
author |
Eggleston, S. Schmitt, J. Bereiter, B. Schneider, R. Fischer, H. |
author_facet |
Eggleston, S. Schmitt, J. Bereiter, B. Schneider, R. Fischer, H. |
author_sort |
Eggleston, S. |
title |
Evolution of the stable carbon isotope composition of atmospheric CO₂ over the last glacial cycle |
title_short |
Evolution of the stable carbon isotope composition of atmospheric CO₂ over the last glacial cycle |
title_full |
Evolution of the stable carbon isotope composition of atmospheric CO₂ over the last glacial cycle |
title_fullStr |
Evolution of the stable carbon isotope composition of atmospheric CO₂ over the last glacial cycle |
title_full_unstemmed |
Evolution of the stable carbon isotope composition of atmospheric CO₂ over the last glacial cycle |
title_sort |
evolution of the stable carbon isotope composition of atmospheric co₂ over the last glacial cycle |
publisher |
American Geophysical Union |
publishDate |
2016 |
url |
https://boris.unibe.ch/83817/1/eggleston16po.pdf https://boris.unibe.ch/83817/ |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Eggleston, S.; Schmitt, J.; Bereiter, B.; Schneider, R.; Fischer, H. (2016). Evolution of the stable carbon isotope composition of atmospheric CO₂ over the last glacial cycle. Paleoceanography, 31(3), pp. 434-452. American Geophysical Union 10.1002/2015PA002874 <http://dx.doi.org/10.1002/2015PA002874> |
op_relation |
https://boris.unibe.ch/83817/ |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1002/2015PA002874 |
container_title |
Paleoceanography |
container_volume |
31 |
container_issue |
3 |
container_start_page |
434 |
op_container_end_page |
452 |
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1774723775429869568 |