Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise)
The Southern Ocean (SO) is of global importance to the carbon cycle, and processes such as mesopelagic remineralisation that impact the efficiency of the biological carbon pump in this region need to be better constrained. During this study early austral winter barium excess (Baxs) concentrations we...
Published in: | Biogeosciences |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Copernicus Publications
2022
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00061820 2023-05-15T18:25:42+02:00 Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise) van Horsten, Natasha René Planquette, Hélène Sarthou, Géraldine Ryan-Keogh, Thomas James Lemaitre, Nolwenn Mtshali, Thato Nicholas Roychoudhury, Alakendra Bucciarelli, Eva 2022-07 electronic https://doi.org/10.5194/bg-19-3209-2022 https://noa.gwlb.de/receive/cop_mods_00061820 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061207/bg-19-3209-2022.pdf https://bg.copernicus.org/articles/19/3209/2022/bg-19-3209-2022.pdf eng eng Copernicus Publications Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-19-3209-2022 https://noa.gwlb.de/receive/cop_mods_00061820 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061207/bg-19-3209-2022.pdf https://bg.copernicus.org/articles/19/3209/2022/bg-19-3209-2022.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2022 ftnonlinearchiv https://doi.org/10.5194/bg-19-3209-2022 2022-07-31T23:11:47Z The Southern Ocean (SO) is of global importance to the carbon cycle, and processes such as mesopelagic remineralisation that impact the efficiency of the biological carbon pump in this region need to be better constrained. During this study early austral winter barium excess (Baxs) concentrations were measured for the first time, along 30∘ E in the southern Indian Ocean. Winter Baxs concentrations of 59 to 684 pmol L−1 were comparable to those observed throughout other seasons. The expected decline of the mesopelagic Baxs signal to background values during winter was not observed, supporting the hypothesis that this remineralisation proxy likely has a longer timescale than previously reported. A compilation of available SO mesopelagic Baxs data, including data from this study, shows an accumulation rate of ∼0.9 µmol m−2 d−1 from September to July that correlates with temporally integrated remotely sensed primary productivity (PP) throughout the SO from data spanning ∼20 years, advocating for a possible annual timescale of this proxy. The percentage of mesopelagic particulate organic carbon (POC) remineralisation as calculated from estimated POC remineralisation fluxes over integrated remotely sensed PP was ∼2-fold higher south of the polar front (19 ± 15 %, n=39) than north of the polar front (10 ± 10 %, n=29), revealing the higher surface carbon export efficiency further south. By linking integrated remotely sensed PP to mesopelagic Baxs stock, we could obtain better estimates of carbon export and remineralisation signals within the SO on annual and basin scales. Article in Journal/Newspaper Southern Ocean Niedersächsisches Online-Archiv NOA Southern Ocean Austral Indian Biogeosciences 19 13 3209 3224 |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung van Horsten, Natasha René Planquette, Hélène Sarthou, Géraldine Ryan-Keogh, Thomas James Lemaitre, Nolwenn Mtshali, Thato Nicholas Roychoudhury, Alakendra Bucciarelli, Eva Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise) |
topic_facet |
article Verlagsveröffentlichung |
description |
The Southern Ocean (SO) is of global importance to the carbon cycle, and processes such as mesopelagic remineralisation that impact the efficiency of the biological carbon pump in this region need to be better constrained. During this study early austral winter barium excess (Baxs) concentrations were measured for the first time, along 30∘ E in the southern Indian Ocean. Winter Baxs concentrations of 59 to 684 pmol L−1 were comparable to those observed throughout other seasons. The expected decline of the mesopelagic Baxs signal to background values during winter was not observed, supporting the hypothesis that this remineralisation proxy likely has a longer timescale than previously reported. A compilation of available SO mesopelagic Baxs data, including data from this study, shows an accumulation rate of ∼0.9 µmol m−2 d−1 from September to July that correlates with temporally integrated remotely sensed primary productivity (PP) throughout the SO from data spanning ∼20 years, advocating for a possible annual timescale of this proxy. The percentage of mesopelagic particulate organic carbon (POC) remineralisation as calculated from estimated POC remineralisation fluxes over integrated remotely sensed PP was ∼2-fold higher south of the polar front (19 ± 15 %, n=39) than north of the polar front (10 ± 10 %, n=29), revealing the higher surface carbon export efficiency further south. By linking integrated remotely sensed PP to mesopelagic Baxs stock, we could obtain better estimates of carbon export and remineralisation signals within the SO on annual and basin scales. |
format |
Article in Journal/Newspaper |
author |
van Horsten, Natasha René Planquette, Hélène Sarthou, Géraldine Ryan-Keogh, Thomas James Lemaitre, Nolwenn Mtshali, Thato Nicholas Roychoudhury, Alakendra Bucciarelli, Eva |
author_facet |
van Horsten, Natasha René Planquette, Hélène Sarthou, Géraldine Ryan-Keogh, Thomas James Lemaitre, Nolwenn Mtshali, Thato Nicholas Roychoudhury, Alakendra Bucciarelli, Eva |
author_sort |
van Horsten, Natasha René |
title |
Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise) |
title_short |
Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise) |
title_full |
Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise) |
title_fullStr |
Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise) |
title_full_unstemmed |
Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise) |
title_sort |
early winter barium excess in the southern indian ocean as an annual remineralisation proxy (geotraces gipr07 cruise) |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/bg-19-3209-2022 https://noa.gwlb.de/receive/cop_mods_00061820 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061207/bg-19-3209-2022.pdf https://bg.copernicus.org/articles/19/3209/2022/bg-19-3209-2022.pdf |
geographic |
Southern Ocean Austral Indian |
geographic_facet |
Southern Ocean Austral Indian |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-19-3209-2022 https://noa.gwlb.de/receive/cop_mods_00061820 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061207/bg-19-3209-2022.pdf https://bg.copernicus.org/articles/19/3209/2022/bg-19-3209-2022.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/bg-19-3209-2022 |
container_title |
Biogeosciences |
container_volume |
19 |
container_issue |
13 |
container_start_page |
3209 |
op_container_end_page |
3224 |
_version_ |
1766207318946480128 |