Carbon export in the naturally iron-fertilized Kerguelen area of the Southern Ocean based on the 234Th approach
International audience This study examined upper-ocean particulate organic carbon (POC) export using the 234Th approach as part of the second KErguelen Ocean and Plateau compared Study expedition (KEOPS2). Our aim was to characterize the spatial and the temporal variability of POC export during aust...
Published in: | Biogeosciences |
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Main Authors: | , , , , , , , , |
Other Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2015
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Subjects: | |
Online Access: | https://hal.science/hal-02559414 https://hal.science/hal-02559414/document https://hal.science/hal-02559414/file/bg-12-3831-2015.pdf https://doi.org/10.5194/bg-12-3831-2015 |
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ftinsu:oai:HAL:hal-02559414v1 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
NITROGEN UPTAKE SPRING BLOOM ACL PARTICULATE ORGANIC-CARBON ANTARCTIC POLAR FRONT PHYTOPLANKTON BLOOM DISSOLVED IRON ATLANTIC SECTOR PARTICLE EXPORT PLATEAU REGION [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
spellingShingle |
NITROGEN UPTAKE SPRING BLOOM ACL PARTICULATE ORGANIC-CARBON ANTARCTIC POLAR FRONT PHYTOPLANKTON BLOOM DISSOLVED IRON ATLANTIC SECTOR PARTICLE EXPORT PLATEAU REGION [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere Planchon, Frédéric Ballas, D. Cavagna, A.-J. Bowie, A. R. Davies, D. Trull, T. Laurenceau-Cornec, E. C. van Der Merwe, P. Dehairs, F. Carbon export in the naturally iron-fertilized Kerguelen area of the Southern Ocean based on the 234Th approach |
topic_facet |
NITROGEN UPTAKE SPRING BLOOM ACL PARTICULATE ORGANIC-CARBON ANTARCTIC POLAR FRONT PHYTOPLANKTON BLOOM DISSOLVED IRON ATLANTIC SECTOR PARTICLE EXPORT PLATEAU REGION [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
description |
International audience This study examined upper-ocean particulate organic carbon (POC) export using the 234Th approach as part of the second KErguelen Ocean and Plateau compared Study expedition (KEOPS2). Our aim was to characterize the spatial and the temporal variability of POC export during austral spring (October–November 2011) in the Fe-fertilized area of the Kerguelen Plateau region. POC export fluxes were estimated at high productivity sites over and downstream of the plateau and compared to a high-nutrient low-chlorophyll (HNLC) area upstream of the plateau in order to assess the impact of iron-induced productivity on the vertical export of carbon. Deficits in 234Th activities were observed at all stations in surface waters, indicating early scavenging by particles in austral spring. 234Th export was lowest at the reference station R-2 and highest in the recirculation region (E stations) where a pseudo-Lagrangian survey was conducted. In comparison 234Th export over the central plateau and north of the polar front (PF) was relatively limited throughout the survey. However, the 234Th results support that Fe fertilization increased particle export in all iron-fertilized waters. The impact was greatest in the recirculation feature (3–4 fold at 200 m depth, relative to the reference station), but more moderate over the central Kerguelen Plateau and in the northern plume of the Kerguelen bloom (~2-fold at 200 m depth). The C : Th ratio of large (\textgreater53 μm) potentially sinking particles collected via sequential filtration using in situ pumping (ISP) systems was used to convert the 234Th flux into a POC export flux. The C : Th ratios of sinking particles were highly variable (3.1 ± 0.1 to 10.5 ± 0.2 μmol dpm−1) with no clear site-related trend, despite the variety of ecosystem responses in the fertilized regions. C : Th ratios showed a decreasing trend between 100 and 200 m depth suggesting preferential carbon loss relative to 234Th possibly due to heterotrophic degradation and/or grazing activity. C ... |
author2 |
Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) Analytical, Environmental and Geo- Chemistry Vrije Universiteit Brussel (VUB) Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC) Institute for Marine and Antarctic Studies Hobart (IMAS) University of Tasmania Hobart, Australia (UTAS) CSIRO Marine and Atmosphere Research Hobart Commonwealth Scientific and Industrial Research Organisation Canberra (CSIRO) ANR-10-BLAN-0614,KEOPS 2,Kerguelen : Comparaison plateau Ocean2(2010) |
format |
Article in Journal/Newspaper |
author |
Planchon, Frédéric Ballas, D. Cavagna, A.-J. Bowie, A. R. Davies, D. Trull, T. Laurenceau-Cornec, E. C. van Der Merwe, P. Dehairs, F. |
author_facet |
Planchon, Frédéric Ballas, D. Cavagna, A.-J. Bowie, A. R. Davies, D. Trull, T. Laurenceau-Cornec, E. C. van Der Merwe, P. Dehairs, F. |
author_sort |
Planchon, Frédéric |
title |
Carbon export in the naturally iron-fertilized Kerguelen area of the Southern Ocean based on the 234Th approach |
title_short |
Carbon export in the naturally iron-fertilized Kerguelen area of the Southern Ocean based on the 234Th approach |
title_full |
Carbon export in the naturally iron-fertilized Kerguelen area of the Southern Ocean based on the 234Th approach |
title_fullStr |
Carbon export in the naturally iron-fertilized Kerguelen area of the Southern Ocean based on the 234Th approach |
title_full_unstemmed |
Carbon export in the naturally iron-fertilized Kerguelen area of the Southern Ocean based on the 234Th approach |
title_sort |
carbon export in the naturally iron-fertilized kerguelen area of the southern ocean based on the 234th approach |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://hal.science/hal-02559414 https://hal.science/hal-02559414/document https://hal.science/hal-02559414/file/bg-12-3831-2015.pdf https://doi.org/10.5194/bg-12-3831-2015 |
geographic |
Antarctic Austral Kerguelen Southern Ocean |
geographic_facet |
Antarctic Austral Kerguelen Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
ISSN: 1726-4170 EISSN: 1726-4189 Biogeosciences https://hal.science/hal-02559414 Biogeosciences, 2015, 12 (12), pp.3831-3848. ⟨10.5194/bg-12-3831-2015⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-12-3831-2015 hal-02559414 https://hal.science/hal-02559414 https://hal.science/hal-02559414/document https://hal.science/hal-02559414/file/bg-12-3831-2015.pdf doi:10.5194/bg-12-3831-2015 |
op_rights |
http://creativecommons.org/licenses/by-nd/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/bg-12-3831-2015 |
container_title |
Biogeosciences |
container_volume |
12 |
container_issue |
12 |
container_start_page |
3831 |
op_container_end_page |
3848 |
_version_ |
1790594091910692864 |
spelling |
ftinsu:oai:HAL:hal-02559414v1 2024-02-11T09:58:26+01:00 Carbon export in the naturally iron-fertilized Kerguelen area of the Southern Ocean based on the 234Th approach Planchon, Frédéric Ballas, D. Cavagna, A.-J. Bowie, A. R. Davies, D. Trull, T. Laurenceau-Cornec, E. C. van Der Merwe, P. Dehairs, F. Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) Analytical, Environmental and Geo- Chemistry Vrije Universiteit Brussel (VUB) Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC) Institute for Marine and Antarctic Studies Hobart (IMAS) University of Tasmania Hobart, Australia (UTAS) CSIRO Marine and Atmosphere Research Hobart Commonwealth Scientific and Industrial Research Organisation Canberra (CSIRO) ANR-10-BLAN-0614,KEOPS 2,Kerguelen : Comparaison plateau Ocean2(2010) 2015 https://hal.science/hal-02559414 https://hal.science/hal-02559414/document https://hal.science/hal-02559414/file/bg-12-3831-2015.pdf https://doi.org/10.5194/bg-12-3831-2015 en eng HAL CCSD European Geosciences Union info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-12-3831-2015 hal-02559414 https://hal.science/hal-02559414 https://hal.science/hal-02559414/document https://hal.science/hal-02559414/file/bg-12-3831-2015.pdf doi:10.5194/bg-12-3831-2015 http://creativecommons.org/licenses/by-nd/ info:eu-repo/semantics/OpenAccess ISSN: 1726-4170 EISSN: 1726-4189 Biogeosciences https://hal.science/hal-02559414 Biogeosciences, 2015, 12 (12), pp.3831-3848. ⟨10.5194/bg-12-3831-2015⟩ NITROGEN UPTAKE SPRING BLOOM ACL PARTICULATE ORGANIC-CARBON ANTARCTIC POLAR FRONT PHYTOPLANKTON BLOOM DISSOLVED IRON ATLANTIC SECTOR PARTICLE EXPORT PLATEAU REGION [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/article Journal articles 2015 ftinsu https://doi.org/10.5194/bg-12-3831-2015 2024-01-24T17:33:07Z International audience This study examined upper-ocean particulate organic carbon (POC) export using the 234Th approach as part of the second KErguelen Ocean and Plateau compared Study expedition (KEOPS2). Our aim was to characterize the spatial and the temporal variability of POC export during austral spring (October–November 2011) in the Fe-fertilized area of the Kerguelen Plateau region. POC export fluxes were estimated at high productivity sites over and downstream of the plateau and compared to a high-nutrient low-chlorophyll (HNLC) area upstream of the plateau in order to assess the impact of iron-induced productivity on the vertical export of carbon. Deficits in 234Th activities were observed at all stations in surface waters, indicating early scavenging by particles in austral spring. 234Th export was lowest at the reference station R-2 and highest in the recirculation region (E stations) where a pseudo-Lagrangian survey was conducted. In comparison 234Th export over the central plateau and north of the polar front (PF) was relatively limited throughout the survey. However, the 234Th results support that Fe fertilization increased particle export in all iron-fertilized waters. The impact was greatest in the recirculation feature (3–4 fold at 200 m depth, relative to the reference station), but more moderate over the central Kerguelen Plateau and in the northern plume of the Kerguelen bloom (~2-fold at 200 m depth). The C : Th ratio of large (\textgreater53 μm) potentially sinking particles collected via sequential filtration using in situ pumping (ISP) systems was used to convert the 234Th flux into a POC export flux. The C : Th ratios of sinking particles were highly variable (3.1 ± 0.1 to 10.5 ± 0.2 μmol dpm−1) with no clear site-related trend, despite the variety of ecosystem responses in the fertilized regions. C : Th ratios showed a decreasing trend between 100 and 200 m depth suggesting preferential carbon loss relative to 234Th possibly due to heterotrophic degradation and/or grazing activity. C ... Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Institut national des sciences de l'Univers: HAL-INSU Antarctic Austral Kerguelen Southern Ocean Biogeosciences 12 12 3831 3848 |