Late quaternary variations of elemental ratios (C/Si and N/Si) in diatom-bound organic matter from the Southern Ocean
International audience The carbon cycle in the Southern Ocean is considered as a major factor controlling past atmospheric CO 2 concentration variations. However, accumulation rates of biogenic opal are not linearly related to carbon burial rates. Here, we show that it is possible to measure the car...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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ftinsu:oai:HAL:insu-03619007v1 2023-08-20T04:09:55+02:00 Late quaternary variations of elemental ratios (C/Si and N/Si) in diatom-bound organic matter from the Southern Ocean Crosta, Xavier Shemesh, Aldo Salvignac, Marie-Eve Gildor, Hezi Yam, Ruth 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) 2002 https://insu.hal.science/insu-03619007 https://doi.org/10.1016/S0967-0645(02)00019-X en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/S0967-0645(02)00019-X insu-03619007 https://insu.hal.science/insu-03619007 BIBCODE: 2002DSRII.49.1939C doi:10.1016/S0967-0645(02)00019-X ISSN: 0967-0645 Deep Sea Research Part II: Topical Studies in Oceanography https://insu.hal.science/insu-03619007 Deep Sea Research Part II: Topical Studies in Oceanography, 2002, 49, pp.1939-1952. ⟨10.1016/S0967-0645(02)00019-X⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2002 ftinsu https://doi.org/10.1016/S0967-0645(02)00019-X 2023-07-26T16:22:20Z International audience The carbon cycle in the Southern Ocean is considered as a major factor controlling past atmospheric CO 2 concentration variations. However, accumulation rates of biogenic opal are not linearly related to carbon burial rates. Here, we show that it is possible to measure the carbon and nitrogen content of diatom-bound organic matter (%C diat and %N diat , respectively) and that the signals recorded do not appear to be analytical artifacts. Analyses of two cores from the Atlantic and Indian sectors of the Southern Ocean show that %C diat and %N diat change on glacial-interglacial cycles by 30-40% and 120-175%, respectively. Accordingly, C/N ratios vary between 3 and 7 on glacial-interglacial timescales. If changes recorded in the occluded organic matter are representative of the changes in the diatom bulk organic matter, this provides a new tool to document the carbon cycle in the Southern Ocean and to determine its role on past atmospheric pCO 2 variations. Laboratory experiments on diatom cultures are needed to validate the use of diatom organic bound C and N as a tracer of diatom physiology and of carbon export from surface waters. Article in Journal/Newspaper Southern Ocean Institut national des sciences de l'Univers: HAL-INSU Southern Ocean Indian Deep Sea Research Part II: Topical Studies in Oceanography 49 9-10 1939 1952 |
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collection |
Institut national des sciences de l'Univers: HAL-INSU |
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ftinsu |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
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[SDU]Sciences of the Universe [physics] Crosta, Xavier Shemesh, Aldo Salvignac, Marie-Eve Gildor, Hezi Yam, Ruth Late quaternary variations of elemental ratios (C/Si and N/Si) in diatom-bound organic matter from the Southern Ocean |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience The carbon cycle in the Southern Ocean is considered as a major factor controlling past atmospheric CO 2 concentration variations. However, accumulation rates of biogenic opal are not linearly related to carbon burial rates. Here, we show that it is possible to measure the carbon and nitrogen content of diatom-bound organic matter (%C diat and %N diat , respectively) and that the signals recorded do not appear to be analytical artifacts. Analyses of two cores from the Atlantic and Indian sectors of the Southern Ocean show that %C diat and %N diat change on glacial-interglacial cycles by 30-40% and 120-175%, respectively. Accordingly, C/N ratios vary between 3 and 7 on glacial-interglacial timescales. If changes recorded in the occluded organic matter are representative of the changes in the diatom bulk organic matter, this provides a new tool to document the carbon cycle in the Southern Ocean and to determine its role on past atmospheric pCO 2 variations. Laboratory experiments on diatom cultures are needed to validate the use of diatom organic bound C and N as a tracer of diatom physiology and of carbon export from surface waters. |
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) |
format |
Article in Journal/Newspaper |
author |
Crosta, Xavier Shemesh, Aldo Salvignac, Marie-Eve Gildor, Hezi Yam, Ruth |
author_facet |
Crosta, Xavier Shemesh, Aldo Salvignac, Marie-Eve Gildor, Hezi Yam, Ruth |
author_sort |
Crosta, Xavier |
title |
Late quaternary variations of elemental ratios (C/Si and N/Si) in diatom-bound organic matter from the Southern Ocean |
title_short |
Late quaternary variations of elemental ratios (C/Si and N/Si) in diatom-bound organic matter from the Southern Ocean |
title_full |
Late quaternary variations of elemental ratios (C/Si and N/Si) in diatom-bound organic matter from the Southern Ocean |
title_fullStr |
Late quaternary variations of elemental ratios (C/Si and N/Si) in diatom-bound organic matter from the Southern Ocean |
title_full_unstemmed |
Late quaternary variations of elemental ratios (C/Si and N/Si) in diatom-bound organic matter from the Southern Ocean |
title_sort |
late quaternary variations of elemental ratios (c/si and n/si) in diatom-bound organic matter from the southern ocean |
publisher |
HAL CCSD |
publishDate |
2002 |
url |
https://insu.hal.science/insu-03619007 https://doi.org/10.1016/S0967-0645(02)00019-X |
geographic |
Southern Ocean Indian |
geographic_facet |
Southern Ocean Indian |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
ISSN: 0967-0645 Deep Sea Research Part II: Topical Studies in Oceanography https://insu.hal.science/insu-03619007 Deep Sea Research Part II: Topical Studies in Oceanography, 2002, 49, pp.1939-1952. ⟨10.1016/S0967-0645(02)00019-X⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/S0967-0645(02)00019-X insu-03619007 https://insu.hal.science/insu-03619007 BIBCODE: 2002DSRII.49.1939C doi:10.1016/S0967-0645(02)00019-X |
op_doi |
https://doi.org/10.1016/S0967-0645(02)00019-X |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
49 |
container_issue |
9-10 |
container_start_page |
1939 |
op_container_end_page |
1952 |
_version_ |
1774723671389110272 |