Origin and mechanism of Subantarctic Mode Water formation and transformation in the Southern Indian Ocean
International audience The sources and pathways of mode waters and lower thermocline waters entering the subtropical gyre of the Indian Ocean are examined. A Lagrangian analysis is performed on an eddy-admitting simulation of the Global Ocean performed by the DRAKKAR Group (NEMO/OPA), which captures...
Published in: | Ocean Dynamics |
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Main Authors: | , , , |
Other Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2010
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-00570155 https://doi.org/10.1007/s10236-010-0276-4 |
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ftsorbonneuniv:oai:HAL:hal-00570155v1 |
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openpolar |
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Open Polar |
collection |
HAL Sorbonne Université |
op_collection_id |
ftsorbonneuniv |
language |
English |
topic |
Eddy mixing Transformation Formation OGCM ARGO Winter mixed layers Subantarctic mode water Pathways Southern Indian Ocean [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
Eddy mixing Transformation Formation OGCM ARGO Winter mixed layers Subantarctic mode water Pathways Southern Indian Ocean [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Koch-Larrouy, Ariane Morrow, Rosemary Penduff, Thierry Juza, Mélanie Origin and mechanism of Subantarctic Mode Water formation and transformation in the Southern Indian Ocean |
topic_facet |
Eddy mixing Transformation Formation OGCM ARGO Winter mixed layers Subantarctic mode water Pathways Southern Indian Ocean [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience The sources and pathways of mode waters and lower thermocline waters entering the subtropical gyre of the Indian Ocean are examined. A Lagrangian analysis is performed on an eddy-admitting simulation of the Global Ocean performed by the DRAKKAR Group (NEMO/OPA), which captures the main observed features. We trace the subducted mode water's pathways, identify their formation regions and trace whether their source waters come from the Atlantic, Pacific or Indian sectors of the Southern Ocean. Three main sites for mode waters ventilation in the Indian sector are identified with different circulation pathways and source water masses: (a) just north of Kerguelen, where 4.2 Sv of lighter Subantarctic Mode Waters (SAMW); σ 0 ∼ 26.5) are exported--originating in the Atlantic and Agulhas Retroflection regions; (b) SW of Australia, where 6.5 Sv of medium SAMW (σ 0 ∼ 26.6) are ventilated--originating in the southern and denser Agulhas Retroflection region; (c) SW of Tasmania and along the South Australian coast, where 3 Sv of denser SAMW (σ 0 ∼ 26.75) are ventilated--originating from three sources: Leeuwin Current waters, Tasman Sea (Pacific) waters and Antarctic Surface Waters. In all cases, modelled mode waters were last ventilated in the Indian Ocean just north of the deepest winter-mixed layers. For the waters subducted SW of Australia, the last ventilation site extends even further north. Waters ventilated in the deepest mixed layers north of the Subantarctic Front are then re-ventilated 5 years later southwest of Australia. The model results raise new hypotheses that revisit the classical picture of the SAMW formation and transformation, where a large homogeneous mixed layer is subducted and 'slides' equatorward, essentially maintaining the T/S characteristics acquired at the surface. Firstly, the last ventilation of the modelled mode waters is not in the region of the deepest mixed layers, as previously thought, but further north in regions of moderate meso-scale eddy activity. Secondly, the ... |
author2 |
Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) 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)-Université Fédérale Toulouse Midi-Pyrénées-Météo-France -Institut de Recherche pour le Développement (IRD)-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 Écoulements Géophysiques et Industriels Grenoble (LEGI) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Koch-Larrouy, Ariane Morrow, Rosemary Penduff, Thierry Juza, Mélanie |
author_facet |
Koch-Larrouy, Ariane Morrow, Rosemary Penduff, Thierry Juza, Mélanie |
author_sort |
Koch-Larrouy, Ariane |
title |
Origin and mechanism of Subantarctic Mode Water formation and transformation in the Southern Indian Ocean |
title_short |
Origin and mechanism of Subantarctic Mode Water formation and transformation in the Southern Indian Ocean |
title_full |
Origin and mechanism of Subantarctic Mode Water formation and transformation in the Southern Indian Ocean |
title_fullStr |
Origin and mechanism of Subantarctic Mode Water formation and transformation in the Southern Indian Ocean |
title_full_unstemmed |
Origin and mechanism of Subantarctic Mode Water formation and transformation in the Southern Indian Ocean |
title_sort |
origin and mechanism of subantarctic mode water formation and transformation in the southern indian ocean |
publisher |
HAL CCSD |
publishDate |
2010 |
url |
https://hal.archives-ouvertes.fr/hal-00570155 https://doi.org/10.1007/s10236-010-0276-4 |
geographic |
Antarctic Indian Kerguelen Pacific Southern Ocean |
geographic_facet |
Antarctic Indian Kerguelen Pacific Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
ISSN: 1616-7341 EISSN: 1616-7228 Ocean Dynamics https://hal.archives-ouvertes.fr/hal-00570155 Ocean Dynamics, Springer Verlag, 2010, 60 (3), pp.563-583. ⟨10.1007/s10236-010-0276-4⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1007/s10236-010-0276-4 hal-00570155 https://hal.archives-ouvertes.fr/hal-00570155 doi:10.1007/s10236-010-0276-4 IRD: fdi:010050712 |
op_doi |
https://doi.org/10.1007/s10236-010-0276-4 |
container_title |
Ocean Dynamics |
container_volume |
60 |
container_issue |
3 |
container_start_page |
563 |
op_container_end_page |
583 |
_version_ |
1766133317206278144 |
spelling |
ftsorbonneuniv:oai:HAL:hal-00570155v1 2023-05-15T13:40:25+02:00 Origin and mechanism of Subantarctic Mode Water formation and transformation in the Southern Indian Ocean Koch-Larrouy, Ariane Morrow, Rosemary Penduff, Thierry Juza, Mélanie Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) 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)-Université Fédérale Toulouse Midi-Pyrénées-Météo-France -Institut de Recherche pour le Développement (IRD)-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 Écoulements Géophysiques et Industriels Grenoble (LEGI) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS) 2010-02-08 https://hal.archives-ouvertes.fr/hal-00570155 https://doi.org/10.1007/s10236-010-0276-4 en eng HAL CCSD Springer Verlag info:eu-repo/semantics/altIdentifier/doi/10.1007/s10236-010-0276-4 hal-00570155 https://hal.archives-ouvertes.fr/hal-00570155 doi:10.1007/s10236-010-0276-4 IRD: fdi:010050712 ISSN: 1616-7341 EISSN: 1616-7228 Ocean Dynamics https://hal.archives-ouvertes.fr/hal-00570155 Ocean Dynamics, Springer Verlag, 2010, 60 (3), pp.563-583. ⟨10.1007/s10236-010-0276-4⟩ Eddy mixing Transformation Formation OGCM ARGO Winter mixed layers Subantarctic mode water Pathways Southern Indian Ocean [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2010 ftsorbonneuniv https://doi.org/10.1007/s10236-010-0276-4 2022-07-05T22:34:54Z International audience The sources and pathways of mode waters and lower thermocline waters entering the subtropical gyre of the Indian Ocean are examined. A Lagrangian analysis is performed on an eddy-admitting simulation of the Global Ocean performed by the DRAKKAR Group (NEMO/OPA), which captures the main observed features. We trace the subducted mode water's pathways, identify their formation regions and trace whether their source waters come from the Atlantic, Pacific or Indian sectors of the Southern Ocean. Three main sites for mode waters ventilation in the Indian sector are identified with different circulation pathways and source water masses: (a) just north of Kerguelen, where 4.2 Sv of lighter Subantarctic Mode Waters (SAMW); σ 0 ∼ 26.5) are exported--originating in the Atlantic and Agulhas Retroflection regions; (b) SW of Australia, where 6.5 Sv of medium SAMW (σ 0 ∼ 26.6) are ventilated--originating in the southern and denser Agulhas Retroflection region; (c) SW of Tasmania and along the South Australian coast, where 3 Sv of denser SAMW (σ 0 ∼ 26.75) are ventilated--originating from three sources: Leeuwin Current waters, Tasman Sea (Pacific) waters and Antarctic Surface Waters. In all cases, modelled mode waters were last ventilated in the Indian Ocean just north of the deepest winter-mixed layers. For the waters subducted SW of Australia, the last ventilation site extends even further north. Waters ventilated in the deepest mixed layers north of the Subantarctic Front are then re-ventilated 5 years later southwest of Australia. The model results raise new hypotheses that revisit the classical picture of the SAMW formation and transformation, where a large homogeneous mixed layer is subducted and 'slides' equatorward, essentially maintaining the T/S characteristics acquired at the surface. Firstly, the last ventilation of the modelled mode waters is not in the region of the deepest mixed layers, as previously thought, but further north in regions of moderate meso-scale eddy activity. Secondly, the ... Article in Journal/Newspaper Antarc* Antarctic Southern Ocean HAL Sorbonne Université Antarctic Indian Kerguelen Pacific Southern Ocean Ocean Dynamics 60 3 563 583 |