Influence of intense scavenging on Pa-Th fractionation in the wake of Kerguelen Island (Southern Ocean)
International audience Dissolved and particulate excess 230 Th and 231 Pa concentrations (noted 230 Th xs and 231 Pa xs respectively) and 231 Pa xs / 230 Th xs activity ratios were investigated on and out of the Kerguelen plateau (Southern Ocean) in the framework of the Kerguelen Ocean and Plateau c...
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Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2011
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Online Access: | https://hal.science/hal-04113877 https://doi.org/10.5194/bg-8-3187-201110.5194/bgd-8-4871-2011 |
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ftccsdartic:oai:HAL:hal-04113877v1 |
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openpolar |
institution |
Open Polar |
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Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
Earth Science [SDU]Sciences of the Universe [physics] |
spellingShingle |
Earth Science [SDU]Sciences of the Universe [physics] Venchiarutti, C. Roy-Barman, M. Freydier, R. van Beek, P. Souhaut, M. Jeandel, C. Influence of intense scavenging on Pa-Th fractionation in the wake of Kerguelen Island (Southern Ocean) |
topic_facet |
Earth Science [SDU]Sciences of the Universe [physics] |
description |
International audience Dissolved and particulate excess 230 Th and 231 Pa concentrations (noted 230 Th xs and 231 Pa xs respectively) and 231 Pa xs / 230 Th xs activity ratios were investigated on and out of the Kerguelen plateau (Southern Ocean) in the framework of the Kerguelen Ocean and Plateau compared Study project in order to better understand the influence of particle flux and particle chemistry and advection on the scavenging of 231 Pa. In the wake of Kerguelen, particulate 231 Pa xs is relatively abundant compared to its content in the dissolved phase. This, together with the low fractionation observed between 230 Th and 231 Pa (F Th/Pa ranging from 0.06 ± 0.01 to 1.6 ± 0.2) reflects the domination of the biogenic silica in the particle pool. Along the eastern escarpment of the Kerguelen plateau, the strong 231 Pa xs horizontal gradient in the deep waters highlights the intense removal of 231 Pa at depth, as already observed for 230 Th xs . This local boundary scavenging was attributed to re-suspension of opal-rich particles by nepheloid layers, resulting in fractionation factors F Th/Pa ≤ 1 along the Kerguelen plateau slope. Therefore, both the composition (biogenic opal) and the flux (intense along the margin) of particles control the scavenging of the two radionuclides in the Kerguelen wake. The modelling of 231 Pa distribution with an advection-scavenging model demonstrates that lateral advection of open ocean water on the Kerguelen plateau could supply most of the 231 Pa, which is then efficiently scavenged on the highly productive plateau, as previously proposed for 230 Th xs . It stresses that lateral advection can play a significant role in the overall budget of particle reactive trace elements in a coastal-open ocean system. |
author2 |
Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS) 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) Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) Hydrosciences Montpellier (HSM) Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Venchiarutti, C. Roy-Barman, M. Freydier, R. van Beek, P. Souhaut, M. Jeandel, C. |
author_facet |
Venchiarutti, C. Roy-Barman, M. Freydier, R. van Beek, P. Souhaut, M. Jeandel, C. |
author_sort |
Venchiarutti, C. |
title |
Influence of intense scavenging on Pa-Th fractionation in the wake of Kerguelen Island (Southern Ocean) |
title_short |
Influence of intense scavenging on Pa-Th fractionation in the wake of Kerguelen Island (Southern Ocean) |
title_full |
Influence of intense scavenging on Pa-Th fractionation in the wake of Kerguelen Island (Southern Ocean) |
title_fullStr |
Influence of intense scavenging on Pa-Th fractionation in the wake of Kerguelen Island (Southern Ocean) |
title_full_unstemmed |
Influence of intense scavenging on Pa-Th fractionation in the wake of Kerguelen Island (Southern Ocean) |
title_sort |
influence of intense scavenging on pa-th fractionation in the wake of kerguelen island (southern ocean) |
publisher |
HAL CCSD |
publishDate |
2011 |
url |
https://hal.science/hal-04113877 https://doi.org/10.5194/bg-8-3187-201110.5194/bgd-8-4871-2011 |
long_lat |
ENVELOPE(69.500,69.500,-49.250,-49.250) |
geographic |
Southern Ocean Kerguelen Kerguelen Island |
geographic_facet |
Southern Ocean Kerguelen Kerguelen Island |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Biogeosciences https://hal.science/hal-04113877 Biogeosciences, 2011, 8, pp.3187-3201. ⟨10.5194/bg-8-3187-201110.5194/bgd-8-4871-2011⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-8-3187-201110.5194/bgd-8-4871-2011 hal-04113877 https://hal.science/hal-04113877 BIBCODE: 2011BGeo.8.3187V doi:10.5194/bg-8-3187-201110.5194/bgd-8-4871-2011 |
op_doi |
https://doi.org/10.5194/bg-8-3187-201110.5194/bgd-8-4871-2011 |
_version_ |
1769009465776930816 |
spelling |
ftccsdartic:oai:HAL:hal-04113877v1 2023-06-18T03:43:11+02:00 Influence of intense scavenging on Pa-Th fractionation in the wake of Kerguelen Island (Southern Ocean) Venchiarutti, C. Roy-Barman, M. Freydier, R. van Beek, P. Souhaut, M. Jeandel, C. Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS) 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) Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) Hydrosciences Montpellier (HSM) Institut de Recherche pour le Développement (IRD)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) 2011 https://hal.science/hal-04113877 https://doi.org/10.5194/bg-8-3187-201110.5194/bgd-8-4871-2011 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-8-3187-201110.5194/bgd-8-4871-2011 hal-04113877 https://hal.science/hal-04113877 BIBCODE: 2011BGeo.8.3187V doi:10.5194/bg-8-3187-201110.5194/bgd-8-4871-2011 Biogeosciences https://hal.science/hal-04113877 Biogeosciences, 2011, 8, pp.3187-3201. ⟨10.5194/bg-8-3187-201110.5194/bgd-8-4871-2011⟩ Earth Science [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2011 ftccsdartic https://doi.org/10.5194/bg-8-3187-201110.5194/bgd-8-4871-2011 2023-06-03T23:50:36Z International audience Dissolved and particulate excess 230 Th and 231 Pa concentrations (noted 230 Th xs and 231 Pa xs respectively) and 231 Pa xs / 230 Th xs activity ratios were investigated on and out of the Kerguelen plateau (Southern Ocean) in the framework of the Kerguelen Ocean and Plateau compared Study project in order to better understand the influence of particle flux and particle chemistry and advection on the scavenging of 231 Pa. In the wake of Kerguelen, particulate 231 Pa xs is relatively abundant compared to its content in the dissolved phase. This, together with the low fractionation observed between 230 Th and 231 Pa (F Th/Pa ranging from 0.06 ± 0.01 to 1.6 ± 0.2) reflects the domination of the biogenic silica in the particle pool. Along the eastern escarpment of the Kerguelen plateau, the strong 231 Pa xs horizontal gradient in the deep waters highlights the intense removal of 231 Pa at depth, as already observed for 230 Th xs . This local boundary scavenging was attributed to re-suspension of opal-rich particles by nepheloid layers, resulting in fractionation factors F Th/Pa ≤ 1 along the Kerguelen plateau slope. Therefore, both the composition (biogenic opal) and the flux (intense along the margin) of particles control the scavenging of the two radionuclides in the Kerguelen wake. The modelling of 231 Pa distribution with an advection-scavenging model demonstrates that lateral advection of open ocean water on the Kerguelen plateau could supply most of the 231 Pa, which is then efficiently scavenged on the highly productive plateau, as previously proposed for 230 Th xs . It stresses that lateral advection can play a significant role in the overall budget of particle reactive trace elements in a coastal-open ocean system. Article in Journal/Newspaper Southern Ocean Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Southern Ocean Kerguelen Kerguelen Island ENVELOPE(69.500,69.500,-49.250,-49.250) |