Contribution of enhanced Antarctic Bottom Water formation to Antarctic warm events and millennial-scale atmospheric CO 2 increase
During Marine Isotope Stage 3, the Atlantic Meridional Overturning Circulation (AMOC) weakened significantly on a millennial time-scale leading to Greenland stadials. Ice core records reveal that each Greenland stadial is associated with a warming over Antarctica, so-called Antarctic Isotope Maximum...
Published in: | Earth and Planetary Science Letters |
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ftunswworks:oai:unsworks.library.unsw.edu.au:1959.4/unsworks_13641 2024-05-12T07:53:14+00:00 Contribution of enhanced Antarctic Bottom Water formation to Antarctic warm events and millennial-scale atmospheric CO 2 increase Menviel, L Spence, P England, MH Spence, Paul 2015-03-01 http://hdl.handle.net/1959.4/unsworks_13641 https://doi.org/10.1016/j.epsl.2014.12.050 unknown Elsevier http://purl.org/au-research/grants/arc/FL100100214 http://purl.org/au-research/grants/arc/CE110001028 http://hdl.handle.net/1959.4/unsworks_13641 https://doi.org/10.1016/j.epsl.2014.12.050 metadata only access http://purl.org/coar/access_right/c_14cb CC-BY-NC-ND https://creativecommons.org/licenses/by-nc-nd/4.0/ urn:ISSN:0012-821X urn:ISSN:1385-013X Earth and Planetary Science Letters, 413, 37-50 13 Climate Action anzsrc-for: 02 Physical Sciences anzsrc-for: 04 Earth Sciences journal article http://purl.org/coar/resource_type/c_6501 2015 ftunswworks https://doi.org/10.1016/j.epsl.2014.12.050 2024-04-17T15:29:07Z During Marine Isotope Stage 3, the Atlantic Meridional Overturning Circulation (AMOC) weakened significantly on a millennial time-scale leading to Greenland stadials. Ice core records reveal that each Greenland stadial is associated with a warming over Antarctica, so-called Antarctic Isotope Maximum (AIM), and that atmospheric CO2 increases with Antarctic temperature during the long Greenland stadials. Here we perform transient simulations spanning the period 50-34 ka B.P. with two Earth System Models (LOVECLIM and the UVic ESCM) to understand the possible link between changes in the AMOC, changes in high latitude Southern Hemispheric climate and evolution of atmospheric CO2. We find that oceanic carbon releases due to the AMOC resumption during stadial/interstadial transitions lead to an atmospheric CO2 increase. However, the atmospheric CO2 increases observed during the first parts of AIM12 (~47.6 ka B.P.) and AIM8 (~39.8 ka B.P.) occur during periods of weak AMOC (HS5 and HS4 respectively) and could instead be explained by enhanced Antarctic Bottom Water transport. Enhanced Antarctic Bottom Water formation is shown to effectively ventilate the deep Pacific carbon and lead to CO2 outgassing into the atmosphere. In addition, changes in the AMOC alone are not sufficient to explain the largest Antarctic Isotope Maxima (namely AIM12 and AIM8). Stronger formation of Antarctic Bottom Water during AIM12 and AIM8 would enhance the southern high latitude warming and lead to a better agreement with high southern latitude paleoproxy records. The robustness of this southern warming response is tested using an eddy-permitting coupled ocean sea-ice model. We show that stronger Antarctic Bottom Water formation contributes to Southern Ocean surface warming by increasing the Southern Ocean meridional heat transport. Article in Journal/Newspaper Antarc* Antarctic Antarctica Greenland ice core Sea ice Southern Ocean UNSW Sydney (The University of New South Wales): UNSWorks Antarctic Southern Ocean Greenland Pacific Earth and Planetary Science Letters 413 37 50 |
institution |
Open Polar |
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UNSW Sydney (The University of New South Wales): UNSWorks |
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ftunswworks |
language |
unknown |
topic |
13 Climate Action anzsrc-for: 02 Physical Sciences anzsrc-for: 04 Earth Sciences |
spellingShingle |
13 Climate Action anzsrc-for: 02 Physical Sciences anzsrc-for: 04 Earth Sciences Menviel, L Spence, P England, MH Spence, Paul Contribution of enhanced Antarctic Bottom Water formation to Antarctic warm events and millennial-scale atmospheric CO 2 increase |
topic_facet |
13 Climate Action anzsrc-for: 02 Physical Sciences anzsrc-for: 04 Earth Sciences |
description |
During Marine Isotope Stage 3, the Atlantic Meridional Overturning Circulation (AMOC) weakened significantly on a millennial time-scale leading to Greenland stadials. Ice core records reveal that each Greenland stadial is associated with a warming over Antarctica, so-called Antarctic Isotope Maximum (AIM), and that atmospheric CO2 increases with Antarctic temperature during the long Greenland stadials. Here we perform transient simulations spanning the period 50-34 ka B.P. with two Earth System Models (LOVECLIM and the UVic ESCM) to understand the possible link between changes in the AMOC, changes in high latitude Southern Hemispheric climate and evolution of atmospheric CO2. We find that oceanic carbon releases due to the AMOC resumption during stadial/interstadial transitions lead to an atmospheric CO2 increase. However, the atmospheric CO2 increases observed during the first parts of AIM12 (~47.6 ka B.P.) and AIM8 (~39.8 ka B.P.) occur during periods of weak AMOC (HS5 and HS4 respectively) and could instead be explained by enhanced Antarctic Bottom Water transport. Enhanced Antarctic Bottom Water formation is shown to effectively ventilate the deep Pacific carbon and lead to CO2 outgassing into the atmosphere. In addition, changes in the AMOC alone are not sufficient to explain the largest Antarctic Isotope Maxima (namely AIM12 and AIM8). Stronger formation of Antarctic Bottom Water during AIM12 and AIM8 would enhance the southern high latitude warming and lead to a better agreement with high southern latitude paleoproxy records. The robustness of this southern warming response is tested using an eddy-permitting coupled ocean sea-ice model. We show that stronger Antarctic Bottom Water formation contributes to Southern Ocean surface warming by increasing the Southern Ocean meridional heat transport. |
format |
Article in Journal/Newspaper |
author |
Menviel, L Spence, P England, MH Spence, Paul |
author_facet |
Menviel, L Spence, P England, MH Spence, Paul |
author_sort |
Menviel, L |
title |
Contribution of enhanced Antarctic Bottom Water formation to Antarctic warm events and millennial-scale atmospheric CO 2 increase |
title_short |
Contribution of enhanced Antarctic Bottom Water formation to Antarctic warm events and millennial-scale atmospheric CO 2 increase |
title_full |
Contribution of enhanced Antarctic Bottom Water formation to Antarctic warm events and millennial-scale atmospheric CO 2 increase |
title_fullStr |
Contribution of enhanced Antarctic Bottom Water formation to Antarctic warm events and millennial-scale atmospheric CO 2 increase |
title_full_unstemmed |
Contribution of enhanced Antarctic Bottom Water formation to Antarctic warm events and millennial-scale atmospheric CO 2 increase |
title_sort |
contribution of enhanced antarctic bottom water formation to antarctic warm events and millennial-scale atmospheric co 2 increase |
publisher |
Elsevier |
publishDate |
2015 |
url |
http://hdl.handle.net/1959.4/unsworks_13641 https://doi.org/10.1016/j.epsl.2014.12.050 |
geographic |
Antarctic Southern Ocean Greenland Pacific |
geographic_facet |
Antarctic Southern Ocean Greenland Pacific |
genre |
Antarc* Antarctic Antarctica Greenland ice core Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Greenland ice core Sea ice Southern Ocean |
op_source |
urn:ISSN:0012-821X urn:ISSN:1385-013X Earth and Planetary Science Letters, 413, 37-50 |
op_relation |
http://purl.org/au-research/grants/arc/FL100100214 http://purl.org/au-research/grants/arc/CE110001028 http://hdl.handle.net/1959.4/unsworks_13641 https://doi.org/10.1016/j.epsl.2014.12.050 |
op_rights |
metadata only access http://purl.org/coar/access_right/c_14cb CC-BY-NC-ND https://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_doi |
https://doi.org/10.1016/j.epsl.2014.12.050 |
container_title |
Earth and Planetary Science Letters |
container_volume |
413 |
container_start_page |
37 |
op_container_end_page |
50 |
_version_ |
1798841659573665792 |