Locally and Remotely Forced Subtropical AMOC Variability: A Matter of Time Scales
International audience Mechanisms driving the North Atlantic meridional overturning circulation (AMOC) variability at low frequency are of central interest for accurate climate predictions. Although the subpolar gyre region has been identified as a preferred place for generating climate timescale si...
Published in: | Journal of Climate |
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Main Authors: | , , , , , |
Other Authors: | , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2020
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Online Access: | https://hal.science/hal-02879821 https://hal.science/hal-02879821/document https://hal.science/hal-02879821/file/Jamet2020.pdf https://doi.org/10.1175/JCLI-D-19-0844.1 |
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openpolar |
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Open Polar |
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École Polytechnique, Université Paris-Saclay: HAL |
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ftepunivpsaclay |
language |
English |
topic |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
spellingShingle |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Jamet, Quentin Dewar, William, K Wienders, Nicolas Deremble, Bruno Close, Sally Penduff, Thierry Locally and Remotely Forced Subtropical AMOC Variability: A Matter of Time Scales |
topic_facet |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
International audience Mechanisms driving the North Atlantic meridional overturning circulation (AMOC) variability at low frequency are of central interest for accurate climate predictions. Although the subpolar gyre region has been identified as a preferred place for generating climate timescale signals, their southward propagation remains under consideration, complicating the interpretation of the observed time series provided by the Rapid Climate Change-Meridional Overturning Circulation and Heatflux Array-Western Boundary Time Series (RAPID-MOCHA-WBTS) program. In this study, we aim at disentangling the respective contribution of the local atmospheric forcing from signals of remote origin for the subtropical low-frequency AMOC variability. We analyze for this a set of four ensembles of a regional (208S-558N), eddy-resolving (1/128) North Atlantic oceanic configuration, where surface forcing and open boundary conditions are alternatively permuted from fully varying (realistic) to yearly repeating signals. Their analysis reveals the predominance of local, atmospherically forced signal at interannual time scales (2-10 years), whereas signals imposed by the boundaries are responsible for the decadal (10-30 years) part of the spectrum. Due to this marked timescale separation, we show that, although the intergyre region exhibits peculiarities, most of the subtropical AMOC variability can be understood as a linear superposition of these two signals. Finally, we find that the decadal-scale, boundary-forced AMOC variability has both northern and southern origins, although the former dominates over the latter, including at the site of the RAPID array (26.58N). |
author2 |
Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Université Grenoble Alpes (UGA) Florida State University Tallahassee (FSU) Department of Earth, Ocean and Atmospheric Science Tallahassee (FSU Laboratoire de Météorologie Dynamique (UMR 8539) (LMD) Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL) Laboratoire d'Océanographie Physique et Spatiale (LOPS) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) Laboratoire des Écoulements Géophysiques et Industriels Grenoble (LEGI) Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) ANR-18-MPGA-0002,CONTACTS,Turbulence homogène de l'océan pour les simulateurs climatiques(2018) |
format |
Article in Journal/Newspaper |
author |
Jamet, Quentin Dewar, William, K Wienders, Nicolas Deremble, Bruno Close, Sally Penduff, Thierry |
author_facet |
Jamet, Quentin Dewar, William, K Wienders, Nicolas Deremble, Bruno Close, Sally Penduff, Thierry |
author_sort |
Jamet, Quentin |
title |
Locally and Remotely Forced Subtropical AMOC Variability: A Matter of Time Scales |
title_short |
Locally and Remotely Forced Subtropical AMOC Variability: A Matter of Time Scales |
title_full |
Locally and Remotely Forced Subtropical AMOC Variability: A Matter of Time Scales |
title_fullStr |
Locally and Remotely Forced Subtropical AMOC Variability: A Matter of Time Scales |
title_full_unstemmed |
Locally and Remotely Forced Subtropical AMOC Variability: A Matter of Time Scales |
title_sort |
locally and remotely forced subtropical amoc variability: a matter of time scales |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://hal.science/hal-02879821 https://hal.science/hal-02879821/document https://hal.science/hal-02879821/file/Jamet2020.pdf https://doi.org/10.1175/JCLI-D-19-0844.1 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
ISSN: 0894-8755 EISSN: 1520-0442 Journal of Climate https://hal.science/hal-02879821 Journal of Climate, 2020, ⟨10.1175/JCLI-D-19-0844.1⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1175/JCLI-D-19-0844.1 hal-02879821 https://hal.science/hal-02879821 https://hal.science/hal-02879821/document https://hal.science/hal-02879821/file/Jamet2020.pdf doi:10.1175/JCLI-D-19-0844.1 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1175/JCLI-D-19-0844.1 |
container_title |
Journal of Climate |
container_volume |
33 |
container_issue |
12 |
container_start_page |
5155 |
op_container_end_page |
5172 |
_version_ |
1801379715736403968 |
spelling |
ftepunivpsaclay:oai:HAL:hal-02879821v1 2024-06-09T07:48:08+00:00 Locally and Remotely Forced Subtropical AMOC Variability: A Matter of Time Scales Jamet, Quentin Dewar, William, K Wienders, Nicolas Deremble, Bruno Close, Sally Penduff, Thierry Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Université Grenoble Alpes (UGA) Florida State University Tallahassee (FSU) Department of Earth, Ocean and Atmospheric Science Tallahassee (FSU Laboratoire de Météorologie Dynamique (UMR 8539) (LMD) Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL) Laboratoire d'Océanographie Physique et Spatiale (LOPS) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) Laboratoire des Écoulements Géophysiques et Industriels Grenoble (LEGI) Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) ANR-18-MPGA-0002,CONTACTS,Turbulence homogène de l'océan pour les simulateurs climatiques(2018) 2020 https://hal.science/hal-02879821 https://hal.science/hal-02879821/document https://hal.science/hal-02879821/file/Jamet2020.pdf https://doi.org/10.1175/JCLI-D-19-0844.1 en eng HAL CCSD American Meteorological Society info:eu-repo/semantics/altIdentifier/doi/10.1175/JCLI-D-19-0844.1 hal-02879821 https://hal.science/hal-02879821 https://hal.science/hal-02879821/document https://hal.science/hal-02879821/file/Jamet2020.pdf doi:10.1175/JCLI-D-19-0844.1 info:eu-repo/semantics/OpenAccess ISSN: 0894-8755 EISSN: 1520-0442 Journal of Climate https://hal.science/hal-02879821 Journal of Climate, 2020, ⟨10.1175/JCLI-D-19-0844.1⟩ [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 2020 ftepunivpsaclay https://doi.org/10.1175/JCLI-D-19-0844.1 2024-05-16T12:18:45Z International audience Mechanisms driving the North Atlantic meridional overturning circulation (AMOC) variability at low frequency are of central interest for accurate climate predictions. Although the subpolar gyre region has been identified as a preferred place for generating climate timescale signals, their southward propagation remains under consideration, complicating the interpretation of the observed time series provided by the Rapid Climate Change-Meridional Overturning Circulation and Heatflux Array-Western Boundary Time Series (RAPID-MOCHA-WBTS) program. In this study, we aim at disentangling the respective contribution of the local atmospheric forcing from signals of remote origin for the subtropical low-frequency AMOC variability. We analyze for this a set of four ensembles of a regional (208S-558N), eddy-resolving (1/128) North Atlantic oceanic configuration, where surface forcing and open boundary conditions are alternatively permuted from fully varying (realistic) to yearly repeating signals. Their analysis reveals the predominance of local, atmospherically forced signal at interannual time scales (2-10 years), whereas signals imposed by the boundaries are responsible for the decadal (10-30 years) part of the spectrum. Due to this marked timescale separation, we show that, although the intergyre region exhibits peculiarities, most of the subtropical AMOC variability can be understood as a linear superposition of these two signals. Finally, we find that the decadal-scale, boundary-forced AMOC variability has both northern and southern origins, although the former dominates over the latter, including at the site of the RAPID array (26.58N). Article in Journal/Newspaper North Atlantic École Polytechnique, Université Paris-Saclay: HAL Journal of Climate 33 12 5155 5172 |