Iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep Southern Ocean
International audience As an essential micronutrient, iron plays a key role in oceanic biogeochemistry. It is therefore linked to the global carbon cycle and climate. Here, we report a dissolved iron (DFe) isotope section in the South Atlantic and Southern Ocean. Throughout the section, a striking D...
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Online Access: | https://insu.hal.science/insu-03661381 https://doi.org/10.1073/pnas.1603107114 |
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ftinsu:oai:HAL:insu-03661381v1 2024-04-28T08:39:21+00:00 Iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep Southern Ocean Abadie, Cyril Lacan, Francois Radic, Amandine Pradoux, Catherine Poitrasson, Franck Géosciences Environnement Toulouse (GET) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) 2017 https://insu.hal.science/insu-03661381 https://doi.org/10.1073/pnas.1603107114 en eng HAL CCSD National Academy of Sciences info:eu-repo/semantics/altIdentifier/doi/10.1073/pnas.1603107114 insu-03661381 https://insu.hal.science/insu-03661381 BIBCODE: 2017PNAS.114.858A doi:10.1073/pnas.1603107114 PUBMEDCENTRAL: PMC5293069 ISSN: 0027-8424 EISSN: 1091-6490 Proceedings of the National Academy of Sciences of the United States of America https://insu.hal.science/insu-03661381 Proceedings of the National Academy of Sciences of the United States of America, 2017, 114, pp.858-863. ⟨10.1073/pnas.1603107114⟩ iron isotopes GEOTRACES South Atlantic Southern Ocean remineralization [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2017 ftinsu https://doi.org/10.1073/pnas.1603107114 2024-04-05T00:33:38Z International audience As an essential micronutrient, iron plays a key role in oceanic biogeochemistry. It is therefore linked to the global carbon cycle and climate. Here, we report a dissolved iron (DFe) isotope section in the South Atlantic and Southern Ocean. Throughout the section, a striking DFe isotope minimum (light iron) is observed at intermediate depths (200-1,300 m), contrasting with heavier isotopic composition in deep waters. This unambiguously demonstrates distinct DFe sources and processes dominating the iron cycle in the intermediate and deep layers, a feature impossible to see with only iron concentration data largely used thus far in chemical oceanography. At intermediate depths, the data suggest that the dominant DFe sources are linked to organic matter remineralization, either in the water column or at continental margins. In deeper layers, however, abiotic non-reductive release of Fe (desorption, dissolution) from particulate iron—notably lithogenic—likely dominates. These results go against the common but oversimplified view that remineralization of organic matter is the major pathway releasing DFe throughout the water column in the open ocean. They suggest that the oceanic iron cycle, and therefore oceanic primary production and climate, could be more sensitive than previously thought to continental erosion (providing lithogenic particles to the ocean), particle transport within the ocean, dissolved/particle interactions, and deep water upwelling. These processes could also impact the cycles of other elements, including nutrients. Article in Journal/Newspaper Southern Ocean Institut national des sciences de l'Univers: HAL-INSU Proceedings of the National Academy of Sciences 114 5 858 863 |
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Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
iron isotopes GEOTRACES South Atlantic Southern Ocean remineralization [SDU]Sciences of the Universe [physics] |
spellingShingle |
iron isotopes GEOTRACES South Atlantic Southern Ocean remineralization [SDU]Sciences of the Universe [physics] Abadie, Cyril Lacan, Francois Radic, Amandine Pradoux, Catherine Poitrasson, Franck Iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep Southern Ocean |
topic_facet |
iron isotopes GEOTRACES South Atlantic Southern Ocean remineralization [SDU]Sciences of the Universe [physics] |
description |
International audience As an essential micronutrient, iron plays a key role in oceanic biogeochemistry. It is therefore linked to the global carbon cycle and climate. Here, we report a dissolved iron (DFe) isotope section in the South Atlantic and Southern Ocean. Throughout the section, a striking DFe isotope minimum (light iron) is observed at intermediate depths (200-1,300 m), contrasting with heavier isotopic composition in deep waters. This unambiguously demonstrates distinct DFe sources and processes dominating the iron cycle in the intermediate and deep layers, a feature impossible to see with only iron concentration data largely used thus far in chemical oceanography. At intermediate depths, the data suggest that the dominant DFe sources are linked to organic matter remineralization, either in the water column or at continental margins. In deeper layers, however, abiotic non-reductive release of Fe (desorption, dissolution) from particulate iron—notably lithogenic—likely dominates. These results go against the common but oversimplified view that remineralization of organic matter is the major pathway releasing DFe throughout the water column in the open ocean. They suggest that the oceanic iron cycle, and therefore oceanic primary production and climate, could be more sensitive than previously thought to continental erosion (providing lithogenic particles to the ocean), particle transport within the ocean, dissolved/particle interactions, and deep water upwelling. These processes could also impact the cycles of other elements, including nutrients. |
author2 |
Géosciences Environnement Toulouse (GET) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Abadie, Cyril Lacan, Francois Radic, Amandine Pradoux, Catherine Poitrasson, Franck |
author_facet |
Abadie, Cyril Lacan, Francois Radic, Amandine Pradoux, Catherine Poitrasson, Franck |
author_sort |
Abadie, Cyril |
title |
Iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep Southern Ocean |
title_short |
Iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep Southern Ocean |
title_full |
Iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep Southern Ocean |
title_fullStr |
Iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep Southern Ocean |
title_full_unstemmed |
Iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep Southern Ocean |
title_sort |
iron isotopes reveal distinct dissolved iron sources and pathways in the intermediate versus deep southern ocean |
publisher |
HAL CCSD |
publishDate |
2017 |
url |
https://insu.hal.science/insu-03661381 https://doi.org/10.1073/pnas.1603107114 |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
ISSN: 0027-8424 EISSN: 1091-6490 Proceedings of the National Academy of Sciences of the United States of America https://insu.hal.science/insu-03661381 Proceedings of the National Academy of Sciences of the United States of America, 2017, 114, pp.858-863. ⟨10.1073/pnas.1603107114⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1073/pnas.1603107114 insu-03661381 https://insu.hal.science/insu-03661381 BIBCODE: 2017PNAS.114.858A doi:10.1073/pnas.1603107114 PUBMEDCENTRAL: PMC5293069 |
op_doi |
https://doi.org/10.1073/pnas.1603107114 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
114 |
container_issue |
5 |
container_start_page |
858 |
op_container_end_page |
863 |
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1797570430958043136 |