The Deep Ocean's Carbon Exhaust
The deep ocean releases large amounts of old, pre-industrial carbon dioxide (CO2) to the atmosphere through upwelling in the Southern Ocean, which counters the marine carbon uptake occurring elsewhere. This Southern Ocean CO2 release is relevant to the global climate because its changes could alter...
Published in: | Global Biogeochemical Cycles |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Amer Geophysical Union
2022
|
Subjects: | |
Online Access: | https://archimer.ifremer.fr/doc/00788/90005/95569.pdf https://archimer.ifremer.fr/doc/00788/90005/95570.docx https://doi.org/10.1029/2021GB007156 https://archimer.ifremer.fr/doc/00788/90005/ |
id |
ftarchimer:oai:archimer.ifremer.fr:90005 |
---|---|
record_format |
openpolar |
spelling |
ftarchimer:oai:archimer.ifremer.fr:90005 2023-05-15T18:18:39+02:00 The Deep Ocean's Carbon Exhaust Chen, Haidi Haumann, F. Alexander Talley, Lynne D. Johnson, Kenneth S. Sarmiento, Jorge L. 2022-07 application/pdf https://archimer.ifremer.fr/doc/00788/90005/95569.pdf https://archimer.ifremer.fr/doc/00788/90005/95570.docx https://doi.org/10.1029/2021GB007156 https://archimer.ifremer.fr/doc/00788/90005/ eng eng Amer Geophysical Union https://archimer.ifremer.fr/doc/00788/90005/95569.pdf https://archimer.ifremer.fr/doc/00788/90005/95570.docx doi:10.1029/2021GB007156 https://archimer.ifremer.fr/doc/00788/90005/ info:eu-repo/semantics/openAccess restricted use Global Biogeochemical Cycles (0886-6236) (Amer Geophysical Union), 2022-07 , Vol. 36 , N. 7 , P. e2021GB007156 (21p.) carbon cycle ocean circulation Southern Ocean biogeochemistry text Publication info:eu-repo/semantics/article 2022 ftarchimer https://doi.org/10.1029/2021GB007156 2022-08-23T22:50:29Z The deep ocean releases large amounts of old, pre-industrial carbon dioxide (CO2) to the atmosphere through upwelling in the Southern Ocean, which counters the marine carbon uptake occurring elsewhere. This Southern Ocean CO2 release is relevant to the global climate because its changes could alter atmospheric CO2 levels on long time scales, and also affects the present-day potential of the Southern Ocean to take up anthropogenic CO2. Here, year-round profiling float measurements show that this CO2 release arises from a zonal band of upwelling waters between the Subantarctic Front and wintertime sea-ice edge. This band of high CO2 subsurface water coincides with the outcropping of the 27.8 kg m(-3) isoneutral density surface that characterizes Indo-Pacific Deep Water (IPDW). It has a potential partial pressure of CO2 exceeding current atmospheric CO2 levels ( increment PCO2) by 175 +/- 32 mu atm. Ship-based measurements reveal that IPDW exhibits a distinct increment PCO2 maximum in the ocean, which is set by remineralization of organic carbon and originates from the northern Pacific and Indian Ocean basins. Below this IPDW layer, the carbon content increases downwards, whereas increment PCO2 decreases. Most of this vertical increment PCO2 decline results from decreasing temperatures and increasing alkalinity due to an increased fraction of calcium carbonate dissolution. These two factors limit the CO2 outgassing from the high-carbon content deep waters on more southerly surface outcrops. Our results imply that the response of Southern Ocean CO2 fluxes to possible future changes in upwelling are sensitive to the subsurface carbon chemistry set by the vertical remineralization and dissolution profiles. Article in Journal/Newspaper Sea ice Southern Ocean Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Indian Pacific Southern Ocean Global Biogeochemical Cycles 36 7 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
carbon cycle ocean circulation Southern Ocean biogeochemistry |
spellingShingle |
carbon cycle ocean circulation Southern Ocean biogeochemistry Chen, Haidi Haumann, F. Alexander Talley, Lynne D. Johnson, Kenneth S. Sarmiento, Jorge L. The Deep Ocean's Carbon Exhaust |
topic_facet |
carbon cycle ocean circulation Southern Ocean biogeochemistry |
description |
The deep ocean releases large amounts of old, pre-industrial carbon dioxide (CO2) to the atmosphere through upwelling in the Southern Ocean, which counters the marine carbon uptake occurring elsewhere. This Southern Ocean CO2 release is relevant to the global climate because its changes could alter atmospheric CO2 levels on long time scales, and also affects the present-day potential of the Southern Ocean to take up anthropogenic CO2. Here, year-round profiling float measurements show that this CO2 release arises from a zonal band of upwelling waters between the Subantarctic Front and wintertime sea-ice edge. This band of high CO2 subsurface water coincides with the outcropping of the 27.8 kg m(-3) isoneutral density surface that characterizes Indo-Pacific Deep Water (IPDW). It has a potential partial pressure of CO2 exceeding current atmospheric CO2 levels ( increment PCO2) by 175 +/- 32 mu atm. Ship-based measurements reveal that IPDW exhibits a distinct increment PCO2 maximum in the ocean, which is set by remineralization of organic carbon and originates from the northern Pacific and Indian Ocean basins. Below this IPDW layer, the carbon content increases downwards, whereas increment PCO2 decreases. Most of this vertical increment PCO2 decline results from decreasing temperatures and increasing alkalinity due to an increased fraction of calcium carbonate dissolution. These two factors limit the CO2 outgassing from the high-carbon content deep waters on more southerly surface outcrops. Our results imply that the response of Southern Ocean CO2 fluxes to possible future changes in upwelling are sensitive to the subsurface carbon chemistry set by the vertical remineralization and dissolution profiles. |
format |
Article in Journal/Newspaper |
author |
Chen, Haidi Haumann, F. Alexander Talley, Lynne D. Johnson, Kenneth S. Sarmiento, Jorge L. |
author_facet |
Chen, Haidi Haumann, F. Alexander Talley, Lynne D. Johnson, Kenneth S. Sarmiento, Jorge L. |
author_sort |
Chen, Haidi |
title |
The Deep Ocean's Carbon Exhaust |
title_short |
The Deep Ocean's Carbon Exhaust |
title_full |
The Deep Ocean's Carbon Exhaust |
title_fullStr |
The Deep Ocean's Carbon Exhaust |
title_full_unstemmed |
The Deep Ocean's Carbon Exhaust |
title_sort |
deep ocean's carbon exhaust |
publisher |
Amer Geophysical Union |
publishDate |
2022 |
url |
https://archimer.ifremer.fr/doc/00788/90005/95569.pdf https://archimer.ifremer.fr/doc/00788/90005/95570.docx https://doi.org/10.1029/2021GB007156 https://archimer.ifremer.fr/doc/00788/90005/ |
geographic |
Indian Pacific Southern Ocean |
geographic_facet |
Indian Pacific Southern Ocean |
genre |
Sea ice Southern Ocean |
genre_facet |
Sea ice Southern Ocean |
op_source |
Global Biogeochemical Cycles (0886-6236) (Amer Geophysical Union), 2022-07 , Vol. 36 , N. 7 , P. e2021GB007156 (21p.) |
op_relation |
https://archimer.ifremer.fr/doc/00788/90005/95569.pdf https://archimer.ifremer.fr/doc/00788/90005/95570.docx doi:10.1029/2021GB007156 https://archimer.ifremer.fr/doc/00788/90005/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1029/2021GB007156 |
container_title |
Global Biogeochemical Cycles |
container_volume |
36 |
container_issue |
7 |
_version_ |
1766195299050586112 |