Southern Ocean circulation’s impact on atmospheric CO2 concentration
In the context of past and present climate change, the Southern Ocean (SO) has been identified as a crucial region modulating the concentration of atmospheric CO 2 . The sustained upwelling of carbon-rich deep waters and inefficient nutrient utilization at the surface of the SO leads to an outgassin...
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Online Access: | http://dx.doi.org/10.3389/fmars.2023.1328534 https://www.frontiersin.org/articles/10.3389/fmars.2023.1328534/full |
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crfrontiers:10.3389/fmars.2023.1328534 2024-02-11T09:57:47+01:00 Southern Ocean circulation’s impact on atmospheric CO2 concentration Menviel, Laurie Spence, Paul 2024 http://dx.doi.org/10.3389/fmars.2023.1328534 https://www.frontiersin.org/articles/10.3389/fmars.2023.1328534/full unknown Frontiers Media SA https://creativecommons.org/licenses/by/4.0/ Frontiers in Marine Science volume 10 ISSN 2296-7745 Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography journal-article 2024 crfrontiers https://doi.org/10.3389/fmars.2023.1328534 2024-01-26T09:56:41Z In the context of past and present climate change, the Southern Ocean (SO) has been identified as a crucial region modulating the concentration of atmospheric CO 2 . The sustained upwelling of carbon-rich deep waters and inefficient nutrient utilization at the surface of the SO leads to an outgassing of natural CO 2 , while anthropogenic CO 2 is entrained to depth during the formation of Antarctic Bottom water (AABW), Antarctic intermediate water (AAIW) and sub-Antarctic mode water (SAMW). Changes to the SO circulation resulting from both dynamic and buoyancy forcing can alter the rate of upwelling as well as formation and subsequent transport of AABW, AAIW and SAMW, thus impacting the air-sea CO 2 exchange in the SO. Models of all complexity robustly show that stronger southern hemispheric (SH) westerlies enhance SO upwelling, thus leading to stronger natural CO 2 outgassing, with a sensitivity of 0.13 GtC/yr for a 10% increase in SH westerly windstress. While the impact of changes in the position of the SH westerly winds was previously unclear, recent simulations with high-resolution ocean/sea-ice/carbon cycle models show that a poleward shift of the SH westerlies also enhances natural CO 2 outgassing with a sensitivity of 0.08GtC/yr for a 5° poleward shift. While enhanced AABW transport reduces deep ocean natural DIC concentration and increases surface natural DIC concentration, it acts on a multi-decadal timescale. Future work should better constrain both the natural and anthropogenic carbon cycle response to changes in AABW and the compound impacts of dynamic and buoyancy changes on the SO marine carbon cycle. Article in Journal/Newspaper Antarc* Antarctic Sea ice Southern Ocean Frontiers (Publisher) Antarctic Southern Ocean Frontiers in Marine Science 10 |
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Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography |
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Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography Menviel, Laurie Spence, Paul Southern Ocean circulation’s impact on atmospheric CO2 concentration |
topic_facet |
Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography |
description |
In the context of past and present climate change, the Southern Ocean (SO) has been identified as a crucial region modulating the concentration of atmospheric CO 2 . The sustained upwelling of carbon-rich deep waters and inefficient nutrient utilization at the surface of the SO leads to an outgassing of natural CO 2 , while anthropogenic CO 2 is entrained to depth during the formation of Antarctic Bottom water (AABW), Antarctic intermediate water (AAIW) and sub-Antarctic mode water (SAMW). Changes to the SO circulation resulting from both dynamic and buoyancy forcing can alter the rate of upwelling as well as formation and subsequent transport of AABW, AAIW and SAMW, thus impacting the air-sea CO 2 exchange in the SO. Models of all complexity robustly show that stronger southern hemispheric (SH) westerlies enhance SO upwelling, thus leading to stronger natural CO 2 outgassing, with a sensitivity of 0.13 GtC/yr for a 10% increase in SH westerly windstress. While the impact of changes in the position of the SH westerly winds was previously unclear, recent simulations with high-resolution ocean/sea-ice/carbon cycle models show that a poleward shift of the SH westerlies also enhances natural CO 2 outgassing with a sensitivity of 0.08GtC/yr for a 5° poleward shift. While enhanced AABW transport reduces deep ocean natural DIC concentration and increases surface natural DIC concentration, it acts on a multi-decadal timescale. Future work should better constrain both the natural and anthropogenic carbon cycle response to changes in AABW and the compound impacts of dynamic and buoyancy changes on the SO marine carbon cycle. |
format |
Article in Journal/Newspaper |
author |
Menviel, Laurie Spence, Paul |
author_facet |
Menviel, Laurie Spence, Paul |
author_sort |
Menviel, Laurie |
title |
Southern Ocean circulation’s impact on atmospheric CO2 concentration |
title_short |
Southern Ocean circulation’s impact on atmospheric CO2 concentration |
title_full |
Southern Ocean circulation’s impact on atmospheric CO2 concentration |
title_fullStr |
Southern Ocean circulation’s impact on atmospheric CO2 concentration |
title_full_unstemmed |
Southern Ocean circulation’s impact on atmospheric CO2 concentration |
title_sort |
southern ocean circulation’s impact on atmospheric co2 concentration |
publisher |
Frontiers Media SA |
publishDate |
2024 |
url |
http://dx.doi.org/10.3389/fmars.2023.1328534 https://www.frontiersin.org/articles/10.3389/fmars.2023.1328534/full |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Sea ice Southern Ocean |
op_source |
Frontiers in Marine Science volume 10 ISSN 2296-7745 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3389/fmars.2023.1328534 |
container_title |
Frontiers in Marine Science |
container_volume |
10 |
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1790593328477110272 |