Carbonate system in the water masses of the Southeast Atlantic sector of the Southern Ocean during February and March 2008
peer reviewed Carbonate system variables were measured in the South Atlantic sector of the Southern Ocean along a transect from South Africa to the southern limit of the Antarctic Circumpolar Current (ACC) from February to March 2008. Eddies detached from the retroflection of the Agulhas Current inc...
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Language: | English |
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European Geosciences Union
2011
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Online Access: | https://orbi.uliege.be/handle/2268/115096 https://orbi.uliege.be/bitstream/2268/115096/1/bg-8-1401-2011.pdf https://doi.org/10.5194/bg-8-1401-2011 |
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ftorbi:oai:orbi.ulg.ac.be:2268/115096 2024-10-13T14:03:26+00:00 Carbonate system in the water masses of the Southeast Atlantic sector of the Southern Ocean during February and March 2008 Gonzalez-Davila, M. Santana-Casiano, J. M. Fine, R. A. Happell, J. Delille, Bruno Speich, S. 2011 https://orbi.uliege.be/handle/2268/115096 https://orbi.uliege.be/bitstream/2268/115096/1/bg-8-1401-2011.pdf https://doi.org/10.5194/bg-8-1401-2011 en eng European Geosciences Union http://www.biogeosciences.net/8/1401/2011/bg-8-1401-2011.html urn:issn:1726-4170 urn:issn:1726-4189 https://orbi.uliege.be/handle/2268/115096 info:hdl:2268/115096 open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess Biogeosciences, 8, 1401-1413 (2011) Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique journal article http://purl.org/coar/resource_type/c_6501 info:eu-repo/semantics/article peer reviewed 2011 ftorbi https://doi.org/10.5194/bg-8-1401-2011 2024-09-27T07:01:51Z peer reviewed Carbonate system variables were measured in the South Atlantic sector of the Southern Ocean along a transect from South Africa to the southern limit of the Antarctic Circumpolar Current (ACC) from February to March 2008. Eddies detached from the retroflection of the Agulhas Current increased the gradients observed along the fronts. Minima in the fugacity of CO2, fCO2, and maxima in pH on either side of the frontal zone were observed, noting that within the frontal zone fCO2 reached maximum values and pH was at a minimum. Vertical distributions of water masses were described by their carbonate system properties and their relationship to CFC concentrations. Upper Circumpolar Deep Water (UCDW) and Lower Circumpolar Deep Water (LCDW) offered pHT,25 values of 7.56 and 7.61, respectively. The UCDW also had higher concentrations of CFC-12 (>0.2 pmol kg−1) as compared to deeper waters, revealing that UCDW was mixed with recently ventilated waters. Calcite and aragonite saturation states (Ω) were also affected by the presence of these two water masses with high carbonate concentrations. The aragonite saturation horizon was observed at 1000 m in the subtropical area and north of the Subantarctic Front. At the position of the Polar Front, and under the influence of UCDW and LCDW, the aragonite saturation horizon deepened from 800 m to 1500 m at 50.37° S, and reached 700 m south of 57.5° S. High latitudes proved to be the most sensitive areas to predicted anthropogenic carbon increase. Buffer coefficients related to changes in [CO2], [H+] and Ω with changes in dissolved inorganic carbon (CT) and total alkalinity (AT) offered minima values in the Antarctic Intermediate Water and UCDW layers. These coefficients suggest that a small increase in CT will sharply decrease the status of pH and carbonate saturation. Here we present data that suggest that south of 55° S, surface water will be under-saturated with respect to aragonite within the next few decades. Belcanto Article in Journal/Newspaper Antarc* Antarctic Southern Ocean University of Liège: ORBi (Open Repository and Bibliography) Antarctic Southern Ocean The Antarctic Biogeosciences 8 5 1401 1413 |
institution |
Open Polar |
collection |
University of Liège: ORBi (Open Repository and Bibliography) |
op_collection_id |
ftorbi |
language |
English |
topic |
Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
spellingShingle |
Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique Gonzalez-Davila, M. Santana-Casiano, J. M. Fine, R. A. Happell, J. Delille, Bruno Speich, S. Carbonate system in the water masses of the Southeast Atlantic sector of the Southern Ocean during February and March 2008 |
topic_facet |
Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
description |
peer reviewed Carbonate system variables were measured in the South Atlantic sector of the Southern Ocean along a transect from South Africa to the southern limit of the Antarctic Circumpolar Current (ACC) from February to March 2008. Eddies detached from the retroflection of the Agulhas Current increased the gradients observed along the fronts. Minima in the fugacity of CO2, fCO2, and maxima in pH on either side of the frontal zone were observed, noting that within the frontal zone fCO2 reached maximum values and pH was at a minimum. Vertical distributions of water masses were described by their carbonate system properties and their relationship to CFC concentrations. Upper Circumpolar Deep Water (UCDW) and Lower Circumpolar Deep Water (LCDW) offered pHT,25 values of 7.56 and 7.61, respectively. The UCDW also had higher concentrations of CFC-12 (>0.2 pmol kg−1) as compared to deeper waters, revealing that UCDW was mixed with recently ventilated waters. Calcite and aragonite saturation states (Ω) were also affected by the presence of these two water masses with high carbonate concentrations. The aragonite saturation horizon was observed at 1000 m in the subtropical area and north of the Subantarctic Front. At the position of the Polar Front, and under the influence of UCDW and LCDW, the aragonite saturation horizon deepened from 800 m to 1500 m at 50.37° S, and reached 700 m south of 57.5° S. High latitudes proved to be the most sensitive areas to predicted anthropogenic carbon increase. Buffer coefficients related to changes in [CO2], [H+] and Ω with changes in dissolved inorganic carbon (CT) and total alkalinity (AT) offered minima values in the Antarctic Intermediate Water and UCDW layers. These coefficients suggest that a small increase in CT will sharply decrease the status of pH and carbonate saturation. Here we present data that suggest that south of 55° S, surface water will be under-saturated with respect to aragonite within the next few decades. Belcanto |
format |
Article in Journal/Newspaper |
author |
Gonzalez-Davila, M. Santana-Casiano, J. M. Fine, R. A. Happell, J. Delille, Bruno Speich, S. |
author_facet |
Gonzalez-Davila, M. Santana-Casiano, J. M. Fine, R. A. Happell, J. Delille, Bruno Speich, S. |
author_sort |
Gonzalez-Davila, M. |
title |
Carbonate system in the water masses of the Southeast Atlantic sector of the Southern Ocean during February and March 2008 |
title_short |
Carbonate system in the water masses of the Southeast Atlantic sector of the Southern Ocean during February and March 2008 |
title_full |
Carbonate system in the water masses of the Southeast Atlantic sector of the Southern Ocean during February and March 2008 |
title_fullStr |
Carbonate system in the water masses of the Southeast Atlantic sector of the Southern Ocean during February and March 2008 |
title_full_unstemmed |
Carbonate system in the water masses of the Southeast Atlantic sector of the Southern Ocean during February and March 2008 |
title_sort |
carbonate system in the water masses of the southeast atlantic sector of the southern ocean during february and march 2008 |
publisher |
European Geosciences Union |
publishDate |
2011 |
url |
https://orbi.uliege.be/handle/2268/115096 https://orbi.uliege.be/bitstream/2268/115096/1/bg-8-1401-2011.pdf https://doi.org/10.5194/bg-8-1401-2011 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
Biogeosciences, 8, 1401-1413 (2011) |
op_relation |
http://www.biogeosciences.net/8/1401/2011/bg-8-1401-2011.html urn:issn:1726-4170 urn:issn:1726-4189 https://orbi.uliege.be/handle/2268/115096 info:hdl:2268/115096 |
op_rights |
open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/bg-8-1401-2011 |
container_title |
Biogeosciences |
container_volume |
8 |
container_issue |
5 |
container_start_page |
1401 |
op_container_end_page |
1413 |
_version_ |
1812808421863325696 |