Nutrient cycling in the Indian sector of the Southern Ocean over the last 50,000 years
International audience Most high-southern latitude records of carbon and nitrogen isotopic ratios and elemental ratios are from the Antarctic and Polar Front zones, thus hindering a comprehensive view of nutrient cycling in the Southern Ocean. We present, for the first time, two records from the Sub...
Published in: | Global Biogeochemical Cycles |
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Online Access: | https://hal.science/hal-02105692 https://hal.science/hal-02105692/document https://hal.science/hal-02105692/file/Crosta_GBC2005a.pdf https://doi.org/10.1029/2004GB002344 |
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ftunivnantes:oai:HAL:hal-02105692v1 2023-05-15T13:40:19+02:00 Nutrient cycling in the Indian sector of the Southern Ocean over the last 50,000 years Crosta, Xavier Shemesh, A. Etourneau, J. Yam, R. Billy, I. Pichon, J. Environnements et Paléoenvironnements OCéaniques (EPOC) Observatoire aquitain des sciences de l'univers (OASU) Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) Department of Earth and Planetary Science Rehovot Weizmann Institute of Science Rehovot, Israël Institut national des sciences de l'Univers (INSU - CNRS) Departement de Géologie et Océanographie Université Sciences et Technologies - Bordeaux 1 (UB) 2005 https://hal.science/hal-02105692 https://hal.science/hal-02105692/document https://hal.science/hal-02105692/file/Crosta_GBC2005a.pdf https://doi.org/10.1029/2004GB002344 en eng HAL CCSD American Geophysical Union info:eu-repo/semantics/altIdentifier/doi/10.1029/2004GB002344 hal-02105692 https://hal.science/hal-02105692 https://hal.science/hal-02105692/document https://hal.science/hal-02105692/file/Crosta_GBC2005a.pdf doi:10.1029/2004GB002344 info:eu-repo/semantics/OpenAccess ISSN: 0886-6236 EISSN: 1944-8224 Global Biogeochemical Cycles https://hal.science/hal-02105692 Global Biogeochemical Cycles, 2005, 19 (3), pp.GB3007. ⟨10.1029/2004GB002344⟩ [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology info:eu-repo/semantics/article Journal articles 2005 ftunivnantes https://doi.org/10.1029/2004GB002344 2023-02-08T07:43:57Z International audience Most high-southern latitude records of carbon and nitrogen isotopic ratios and elemental ratios are from the Antarctic and Polar Front zones, thus hindering a comprehensive view of nutrient cycling in the Southern Ocean. We present, for the first time, two records from the Subantarctic Zone and the southern Subtropical Zone of the Indian Ocean. These records provide a latitudinal transect covering the main oceanographic systems of the Southern Ocean. Carbon and nitrogen content of the diatom-bound organic matter increases during the last glacial in the Antarctic and Subantarctic zones but does not show a clear climate-related signal in the Subtropical Zone. Comparison of these records with sea-surface temperatures reconstructed at the core locations and record of dust deposition over Antarctica suggests that eolian iron input possibly switched diatom physiology toward higher carbon to silica and nitrogen to silica uptake and storage south of the Subantarctic Front due to the dependency of photosynthesis on iron concentration levels. Conversely, the northernmost core was too remote from any iron source over the last 50,000 years. Antarctic diatoms therefore have the sole potential to change the nutrient content of the waters escaping from the Southern Ocean, hence providing partial support to the silicic leakage hypothesis as a potential cause of lower glacial atmospheric CO 2 . Article in Journal/Newspaper Antarc* Antarctic Antarctica Southern Ocean Université de Nantes: HAL-UNIV-NANTES Antarctic Indian Southern Ocean The Antarctic Global Biogeochemical Cycles 19 3 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology Crosta, Xavier Shemesh, A. Etourneau, J. Yam, R. Billy, I. Pichon, J. Nutrient cycling in the Indian sector of the Southern Ocean over the last 50,000 years |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
description |
International audience Most high-southern latitude records of carbon and nitrogen isotopic ratios and elemental ratios are from the Antarctic and Polar Front zones, thus hindering a comprehensive view of nutrient cycling in the Southern Ocean. We present, for the first time, two records from the Subantarctic Zone and the southern Subtropical Zone of the Indian Ocean. These records provide a latitudinal transect covering the main oceanographic systems of the Southern Ocean. Carbon and nitrogen content of the diatom-bound organic matter increases during the last glacial in the Antarctic and Subantarctic zones but does not show a clear climate-related signal in the Subtropical Zone. Comparison of these records with sea-surface temperatures reconstructed at the core locations and record of dust deposition over Antarctica suggests that eolian iron input possibly switched diatom physiology toward higher carbon to silica and nitrogen to silica uptake and storage south of the Subantarctic Front due to the dependency of photosynthesis on iron concentration levels. Conversely, the northernmost core was too remote from any iron source over the last 50,000 years. Antarctic diatoms therefore have the sole potential to change the nutrient content of the waters escaping from the Southern Ocean, hence providing partial support to the silicic leakage hypothesis as a potential cause of lower glacial atmospheric CO 2 . |
author2 |
Environnements et Paléoenvironnements OCéaniques (EPOC) Observatoire aquitain des sciences de l'univers (OASU) Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) Department of Earth and Planetary Science Rehovot Weizmann Institute of Science Rehovot, Israël Institut national des sciences de l'Univers (INSU - CNRS) Departement de Géologie et Océanographie Université Sciences et Technologies - Bordeaux 1 (UB) |
format |
Article in Journal/Newspaper |
author |
Crosta, Xavier Shemesh, A. Etourneau, J. Yam, R. Billy, I. Pichon, J. |
author_facet |
Crosta, Xavier Shemesh, A. Etourneau, J. Yam, R. Billy, I. Pichon, J. |
author_sort |
Crosta, Xavier |
title |
Nutrient cycling in the Indian sector of the Southern Ocean over the last 50,000 years |
title_short |
Nutrient cycling in the Indian sector of the Southern Ocean over the last 50,000 years |
title_full |
Nutrient cycling in the Indian sector of the Southern Ocean over the last 50,000 years |
title_fullStr |
Nutrient cycling in the Indian sector of the Southern Ocean over the last 50,000 years |
title_full_unstemmed |
Nutrient cycling in the Indian sector of the Southern Ocean over the last 50,000 years |
title_sort |
nutrient cycling in the indian sector of the southern ocean over the last 50,000 years |
publisher |
HAL CCSD |
publishDate |
2005 |
url |
https://hal.science/hal-02105692 https://hal.science/hal-02105692/document https://hal.science/hal-02105692/file/Crosta_GBC2005a.pdf https://doi.org/10.1029/2004GB002344 |
geographic |
Antarctic Indian Southern Ocean The Antarctic |
geographic_facet |
Antarctic Indian Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Southern Ocean |
op_source |
ISSN: 0886-6236 EISSN: 1944-8224 Global Biogeochemical Cycles https://hal.science/hal-02105692 Global Biogeochemical Cycles, 2005, 19 (3), pp.GB3007. ⟨10.1029/2004GB002344⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2004GB002344 hal-02105692 https://hal.science/hal-02105692 https://hal.science/hal-02105692/document https://hal.science/hal-02105692/file/Crosta_GBC2005a.pdf doi:10.1029/2004GB002344 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/2004GB002344 |
container_title |
Global Biogeochemical Cycles |
container_volume |
19 |
container_issue |
3 |
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1766132337294180352 |