Modulation of regional carbon uptake by AMOC and alkalinity changes in the subpolar North Atlantic under a warming climate
The slowdown of the Atlantic Meridional Overturning Circulation (AMOC) and associated consequences on ocean carbon uptake could have large implications for the Earth's climate system and its global carbon cycle. This study analyzes ten Earth System Models from the Coupled Model Intercomparison...
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Online Access: | http://dx.doi.org/10.3389/fmars.2024.1304193 https://www.frontiersin.org/articles/10.3389/fmars.2024.1304193/full |
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crfrontiers:10.3389/fmars.2024.1304193 2024-05-12T08:07:40+00:00 Modulation of regional carbon uptake by AMOC and alkalinity changes in the subpolar North Atlantic under a warming climate Zhang, Qi Ito, Takamitsu Bracco, Annalisa 2024 http://dx.doi.org/10.3389/fmars.2024.1304193 https://www.frontiersin.org/articles/10.3389/fmars.2024.1304193/full unknown Frontiers Media SA https://creativecommons.org/licenses/by/4.0/ Frontiers in Marine Science volume 11 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.2024.1304193 2024-04-18T07:57:44Z The slowdown of the Atlantic Meridional Overturning Circulation (AMOC) and associated consequences on ocean carbon uptake could have large implications for the Earth's climate system and its global carbon cycle. This study analyzes ten Earth System Models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) and reveals that the regional carbon uptake in the subpolar North Atlantic under a high CO 2 emission scenario moderately correlates with the decline in AMOC at 40°N. AMOC transports warm and salty subtropical waters to the subpolar regions. Models with stronger AMOC slowdown generally exhibit weaker surface warming and larger decline of surface salinity and alkalinity. We consider two plausible mechanisms linking the AMOC slowdown to the decline of regional CO 2 uptake: the reduction in surface alkalinity and diminished subduction. The decline of surface salinity and alkalinity reduces the ocean's capacity to buffer acids leading to a reduced CO 2 uptake. This important contribution is unique to the North Atlantic. Diminished convective mixing and subduction of surface water can further decrease the downward transport of anthropogenic carbon, as also shown in previous research. The centennial trends of p CO 2 are decomposed into four components driven by temperature, salinity, alkalinity and dissolved inorganic carbon, revealing that alkalinity and dissolved inorganic carbon are both significant contributors. The alkalinity-driven p CO 2 essentially follows surface salinity, establishing the linkage between AMOC slowdown and alkalinity decline. Our results indicate that alkalinity changes are important for the interplay between AMOC and the regional carbon sequestration ability across the late 20 th and the entirety of the 21 st century in the subpolar North Atlantic. Article in Journal/Newspaper North Atlantic Frontiers (Publisher) Frontiers in Marine Science 11 |
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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 Zhang, Qi Ito, Takamitsu Bracco, Annalisa Modulation of regional carbon uptake by AMOC and alkalinity changes in the subpolar North Atlantic under a warming climate |
topic_facet |
Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography |
description |
The slowdown of the Atlantic Meridional Overturning Circulation (AMOC) and associated consequences on ocean carbon uptake could have large implications for the Earth's climate system and its global carbon cycle. This study analyzes ten Earth System Models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) and reveals that the regional carbon uptake in the subpolar North Atlantic under a high CO 2 emission scenario moderately correlates with the decline in AMOC at 40°N. AMOC transports warm and salty subtropical waters to the subpolar regions. Models with stronger AMOC slowdown generally exhibit weaker surface warming and larger decline of surface salinity and alkalinity. We consider two plausible mechanisms linking the AMOC slowdown to the decline of regional CO 2 uptake: the reduction in surface alkalinity and diminished subduction. The decline of surface salinity and alkalinity reduces the ocean's capacity to buffer acids leading to a reduced CO 2 uptake. This important contribution is unique to the North Atlantic. Diminished convective mixing and subduction of surface water can further decrease the downward transport of anthropogenic carbon, as also shown in previous research. The centennial trends of p CO 2 are decomposed into four components driven by temperature, salinity, alkalinity and dissolved inorganic carbon, revealing that alkalinity and dissolved inorganic carbon are both significant contributors. The alkalinity-driven p CO 2 essentially follows surface salinity, establishing the linkage between AMOC slowdown and alkalinity decline. Our results indicate that alkalinity changes are important for the interplay between AMOC and the regional carbon sequestration ability across the late 20 th and the entirety of the 21 st century in the subpolar North Atlantic. |
format |
Article in Journal/Newspaper |
author |
Zhang, Qi Ito, Takamitsu Bracco, Annalisa |
author_facet |
Zhang, Qi Ito, Takamitsu Bracco, Annalisa |
author_sort |
Zhang, Qi |
title |
Modulation of regional carbon uptake by AMOC and alkalinity changes in the subpolar North Atlantic under a warming climate |
title_short |
Modulation of regional carbon uptake by AMOC and alkalinity changes in the subpolar North Atlantic under a warming climate |
title_full |
Modulation of regional carbon uptake by AMOC and alkalinity changes in the subpolar North Atlantic under a warming climate |
title_fullStr |
Modulation of regional carbon uptake by AMOC and alkalinity changes in the subpolar North Atlantic under a warming climate |
title_full_unstemmed |
Modulation of regional carbon uptake by AMOC and alkalinity changes in the subpolar North Atlantic under a warming climate |
title_sort |
modulation of regional carbon uptake by amoc and alkalinity changes in the subpolar north atlantic under a warming climate |
publisher |
Frontiers Media SA |
publishDate |
2024 |
url |
http://dx.doi.org/10.3389/fmars.2024.1304193 https://www.frontiersin.org/articles/10.3389/fmars.2024.1304193/full |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Frontiers in Marine Science volume 11 ISSN 2296-7745 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3389/fmars.2024.1304193 |
container_title |
Frontiers in Marine Science |
container_volume |
11 |
_version_ |
1798850415641493504 |