Decadal biogeochemical changes in the subtropical Indian Ocean associated with Subantarctic Mode Water
International audience Within the Subantarctic Mode Water (SAMW) density level, we study temporal changes in salinity, nutrients, oxygen and TTD (Transit Time Distribution) ages in the western (W) and eastern (E) subtropical gyre of the Indian Ocean (IO) from 1987 to 2002. Additionally, changes in T...
Published in: | Journal of Geophysical Research |
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Main Authors: | , , , , , , |
Other Authors: | , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2011
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-00758303 https://hal.archives-ouvertes.fr/hal-00758303/document https://hal.archives-ouvertes.fr/hal-00758303/file/2010JC006475.pdf https://doi.org/10.1029/2010JC006475 |
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Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
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ftccsdartic |
language |
English |
topic |
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] |
spellingShingle |
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] Álvarez, M. Tanhua, Toste Brix, H. Lo Monaco, Claire Metzl, Nicolas Mcdonagh, E. L. Bryden, H. L. Decadal biogeochemical changes in the subtropical Indian Ocean associated with Subantarctic Mode Water |
topic_facet |
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] |
description |
International audience Within the Subantarctic Mode Water (SAMW) density level, we study temporal changes in salinity, nutrients, oxygen and TTD (Transit Time Distribution) ages in the western (W) and eastern (E) subtropical gyre of the Indian Ocean (IO) from 1987 to 2002. Additionally, changes in Total Alkalinity (TA) and Dissolved Inorganic Carbon (DIC) are evaluated between 1995 and 2002. The mechanisms behind the detected changes are discussed along with the results from a hindcast model run (Community Climate System Model). The increasing salinity and decreasing oxygen trends from 1960 to 1987 reversed from 1987 to 2002 along the gyre. In the W-IO a decreasing trend in TTD ages points to a faster delivery of SAMW, thus less biogenic matter remineralization, explaining the oxygen increase and noisier nutrients decrease. In the E-IO SAMW, no change in TTD ages was detected, therefore the trends in oxygen and inorganic nutrients relate to changes in the Antarctic Surface Water transported into the E-IO SAMW formation area. In the W-IO between 1995 and 2002, the DIC increase is equal or even less than the anthropogenic input as the reduction in remineralization contributes to mask the increasing trend. In the E-IO between 1995 and 2002, DIC decreases slightly despite the increase in the anthropogenic input. Differences in the preformed E-IO SAMW conditions would explain this behavior. Trends in the W and E IO SAMW are decoupled and related to different forcing mechanisms in the two main sites of SAMW formation in the IO, at 40°S-70°E and 45°S-90°E, respectively. |
author2 |
Instituto Español de Oceanografía (IEO), Málaga. Leibniz Institute of Marine Science at the University of Kiel (IFM-GEOMAR) Kiel University Department of Atmospheric and Oceanic Sciences Los Angeles (AOS) University of California Los Angeles (UCLA) University of California-University of California Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS Paris) 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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris) 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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU) National Oceanographic Centre Southampton (NOCS) |
format |
Article in Journal/Newspaper |
author |
Álvarez, M. Tanhua, Toste Brix, H. Lo Monaco, Claire Metzl, Nicolas Mcdonagh, E. L. Bryden, H. L. |
author_facet |
Álvarez, M. Tanhua, Toste Brix, H. Lo Monaco, Claire Metzl, Nicolas Mcdonagh, E. L. Bryden, H. L. |
author_sort |
Álvarez, M. |
title |
Decadal biogeochemical changes in the subtropical Indian Ocean associated with Subantarctic Mode Water |
title_short |
Decadal biogeochemical changes in the subtropical Indian Ocean associated with Subantarctic Mode Water |
title_full |
Decadal biogeochemical changes in the subtropical Indian Ocean associated with Subantarctic Mode Water |
title_fullStr |
Decadal biogeochemical changes in the subtropical Indian Ocean associated with Subantarctic Mode Water |
title_full_unstemmed |
Decadal biogeochemical changes in the subtropical Indian Ocean associated with Subantarctic Mode Water |
title_sort |
decadal biogeochemical changes in the subtropical indian ocean associated with subantarctic mode water |
publisher |
HAL CCSD |
publishDate |
2011 |
url |
https://hal.archives-ouvertes.fr/hal-00758303 https://hal.archives-ouvertes.fr/hal-00758303/document https://hal.archives-ouvertes.fr/hal-00758303/file/2010JC006475.pdf https://doi.org/10.1029/2010JC006475 |
geographic |
Antarctic The Antarctic Indian |
geographic_facet |
Antarctic The Antarctic Indian |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
ISSN: 0148-0227 EISSN: 2156-2202 Journal of Geophysical Research https://hal.archives-ouvertes.fr/hal-00758303 Journal of Geophysical Research, American Geophysical Union, 2011, 116, pp.C09016. ⟨10.1029/2010JC006475⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2010JC006475 hal-00758303 https://hal.archives-ouvertes.fr/hal-00758303 https://hal.archives-ouvertes.fr/hal-00758303/document https://hal.archives-ouvertes.fr/hal-00758303/file/2010JC006475.pdf BIBCODE: 2011JGRC.11609016A doi:10.1029/2010JC006475 WOS: 000295132800001 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/2010JC006475 |
container_title |
Journal of Geophysical Research |
container_volume |
116 |
container_issue |
C9 |
_version_ |
1766260978772606976 |
spelling |
ftccsdartic:oai:HAL:hal-00758303v1 2023-05-15T13:54:50+02:00 Decadal biogeochemical changes in the subtropical Indian Ocean associated with Subantarctic Mode Water Álvarez, M. Tanhua, Toste Brix, H. Lo Monaco, Claire Metzl, Nicolas Mcdonagh, E. L. Bryden, H. L. Instituto Español de Oceanografía (IEO), Málaga. Leibniz Institute of Marine Science at the University of Kiel (IFM-GEOMAR) Kiel University Department of Atmospheric and Oceanic Sciences Los Angeles (AOS) University of California Los Angeles (UCLA) University of California-University of California Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS Paris) 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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris) 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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU) National Oceanographic Centre Southampton (NOCS) 2011-09 https://hal.archives-ouvertes.fr/hal-00758303 https://hal.archives-ouvertes.fr/hal-00758303/document https://hal.archives-ouvertes.fr/hal-00758303/file/2010JC006475.pdf https://doi.org/10.1029/2010JC006475 en eng HAL CCSD American Geophysical Union info:eu-repo/semantics/altIdentifier/doi/10.1029/2010JC006475 hal-00758303 https://hal.archives-ouvertes.fr/hal-00758303 https://hal.archives-ouvertes.fr/hal-00758303/document https://hal.archives-ouvertes.fr/hal-00758303/file/2010JC006475.pdf BIBCODE: 2011JGRC.11609016A doi:10.1029/2010JC006475 WOS: 000295132800001 info:eu-repo/semantics/OpenAccess ISSN: 0148-0227 EISSN: 2156-2202 Journal of Geophysical Research https://hal.archives-ouvertes.fr/hal-00758303 Journal of Geophysical Research, American Geophysical Union, 2011, 116, pp.C09016. ⟨10.1029/2010JC006475⟩ [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] info:eu-repo/semantics/article Journal articles 2011 ftccsdartic https://doi.org/10.1029/2010JC006475 2021-12-18T23:43:14Z International audience Within the Subantarctic Mode Water (SAMW) density level, we study temporal changes in salinity, nutrients, oxygen and TTD (Transit Time Distribution) ages in the western (W) and eastern (E) subtropical gyre of the Indian Ocean (IO) from 1987 to 2002. Additionally, changes in Total Alkalinity (TA) and Dissolved Inorganic Carbon (DIC) are evaluated between 1995 and 2002. The mechanisms behind the detected changes are discussed along with the results from a hindcast model run (Community Climate System Model). The increasing salinity and decreasing oxygen trends from 1960 to 1987 reversed from 1987 to 2002 along the gyre. In the W-IO a decreasing trend in TTD ages points to a faster delivery of SAMW, thus less biogenic matter remineralization, explaining the oxygen increase and noisier nutrients decrease. In the E-IO SAMW, no change in TTD ages was detected, therefore the trends in oxygen and inorganic nutrients relate to changes in the Antarctic Surface Water transported into the E-IO SAMW formation area. In the W-IO between 1995 and 2002, the DIC increase is equal or even less than the anthropogenic input as the reduction in remineralization contributes to mask the increasing trend. In the E-IO between 1995 and 2002, DIC decreases slightly despite the increase in the anthropogenic input. Differences in the preformed E-IO SAMW conditions would explain this behavior. Trends in the W and E IO SAMW are decoupled and related to different forcing mechanisms in the two main sites of SAMW formation in the IO, at 40°S-70°E and 45°S-90°E, respectively. Article in Journal/Newspaper Antarc* Antarctic Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Antarctic The Antarctic Indian Journal of Geophysical Research 116 C9 |