Reconstructing extreme AMOC events through nudging of the ocean surface: a perfect model approach
International audience While the Atlantic Meridional Overturning Circulation (AMOC) is thought to be a crucial component of the North Atlantic climate, past changes in its strength are challenging to quantify, and only limited information is available. In this study, we use a perfect model approach...
Published in: | Climate Dynamics |
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Main Authors: | , , , , |
Other Authors: | , , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2017
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Subjects: | |
Online Access: | https://hal.sorbonne-universite.fr/hal-01449390 https://hal.sorbonne-universite.fr/hal-01449390/document https://hal.sorbonne-universite.fr/hal-01449390/file/reconstructing.pdf https://doi.org/10.1007/s00382-017-3521-4 |
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ftuniversailles:oai:HAL:hal-01449390v1 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Université de Versailles Saint-Quentin-en-Yvelines: HAL-UVSQ |
op_collection_id |
ftuniversailles |
language |
English |
topic |
Atlantic Meridional Overturning Circulation Decadal variability Surface nudging Coupled general circulation model [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
spellingShingle |
Atlantic Meridional Overturning Circulation Decadal variability Surface nudging Coupled general circulation model [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology Ortega, Pablo Guilyardi, Éric Swingedouw, Didier Mignot, Juliette Nguyen, Sébastien Reconstructing extreme AMOC events through nudging of the ocean surface: a perfect model approach |
topic_facet |
Atlantic Meridional Overturning Circulation Decadal variability Surface nudging Coupled general circulation model [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
description |
International audience While the Atlantic Meridional Overturning Circulation (AMOC) is thought to be a crucial component of the North Atlantic climate, past changes in its strength are challenging to quantify, and only limited information is available. In this study, we use a perfect model approach with the IPSL-CM5A-LR model to assess the performance of several surface nudging techniques in reconstructing the variability of the AMOC. Special attention is given to the reproducibility of an extreme positive AMOC peak from a preindustrial control simulation. Nudging includes standard relaxation techniques towards the sea surface temperature and salinity anomalies of this target control simulation, and/or the prescription of the wind-stress fields. Surface nudging approaches using standard fixed restoring terms succeed in reproducing most of the target AMOC variability, including the timing of the extreme event, but systematically underestimate its amplitude. A detailed analysis of the AMOC variability mechanisms reveals that the underestimation of the extreme AMOC maximum comes from a deficit in the formation of the dense water masses in the main convection region, located south of Iceland in the model. This issue is largely corrected after introducing a novel surface nudging approach, which uses a varying restoring coefficient that is proportional to the simulated mixed layer depth, which, in essence, keeps the restoring time scale constant. This new technique substantially improves water mass transformation in the regions of convection, and in particular, the formation of the densest waters, which are key for the representation of the AMOC extreme. It is therefore a promising strategy that may help to better constrain the AMOC variability and other ocean features in the models. As this restoring technique only uses surface data, for which better and longer observations are available, it opens up opportunities for improved reconstructions of the AMOC over the last few decades. |
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) NCAS-Climate Reading Department of Meteorology Reading University of Reading (UOR)-University of Reading (UOR) Processus de la variabilité climatique tropicale et impacts (PARVATI) 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)-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)) Environnements et Paléoenvironnements OCéaniques (EPOC) Observatoire aquitain des sciences de l'univers (OASU) Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) Oeschger Centre for Climate Change Research (OCCR) Universität Bern / University of Bern (UNIBE) ANR-13-SENV-0002,MORDICUS,Oscillations et rétroactions climatiques aux échelles décennales : mécanismes, sensibilité et incertitudes(2013) European Project: 308378,EC:FP7:ENV,FP7-ENV-2012-two-stage,SPECS(2012) |
format |
Article in Journal/Newspaper |
author |
Ortega, Pablo Guilyardi, Éric Swingedouw, Didier Mignot, Juliette Nguyen, Sébastien |
author_facet |
Ortega, Pablo Guilyardi, Éric Swingedouw, Didier Mignot, Juliette Nguyen, Sébastien |
author_sort |
Ortega, Pablo |
title |
Reconstructing extreme AMOC events through nudging of the ocean surface: a perfect model approach |
title_short |
Reconstructing extreme AMOC events through nudging of the ocean surface: a perfect model approach |
title_full |
Reconstructing extreme AMOC events through nudging of the ocean surface: a perfect model approach |
title_fullStr |
Reconstructing extreme AMOC events through nudging of the ocean surface: a perfect model approach |
title_full_unstemmed |
Reconstructing extreme AMOC events through nudging of the ocean surface: a perfect model approach |
title_sort |
reconstructing extreme amoc events through nudging of the ocean surface: a perfect model approach |
publisher |
HAL CCSD |
publishDate |
2017 |
url |
https://hal.sorbonne-universite.fr/hal-01449390 https://hal.sorbonne-universite.fr/hal-01449390/document https://hal.sorbonne-universite.fr/hal-01449390/file/reconstructing.pdf https://doi.org/10.1007/s00382-017-3521-4 |
genre |
Iceland North Atlantic |
genre_facet |
Iceland North Atlantic |
op_source |
ISSN: 0930-7575 EISSN: 1432-0894 Climate Dynamics https://hal.sorbonne-universite.fr/hal-01449390 Climate Dynamics, 2017, pp.1-17. ⟨10.1007/s00382-017-3521-4⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1007/s00382-017-3521-4 info:eu-repo/grantAgreement/EC/FP7/308378/EU/Seasonal-to-decadal climate Prediction for the improvement of EuropeanClimate Services/SPECS hal-01449390 https://hal.sorbonne-universite.fr/hal-01449390 https://hal.sorbonne-universite.fr/hal-01449390/document https://hal.sorbonne-universite.fr/hal-01449390/file/reconstructing.pdf doi:10.1007/s00382-017-3521-4 IRD: fdi:010071330 |
op_rights |
http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1007/s00382-017-3521-4 |
container_title |
Climate Dynamics |
container_volume |
49 |
container_issue |
9-10 |
container_start_page |
3425 |
op_container_end_page |
3441 |
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1799482685041672192 |
spelling |
ftuniversailles:oai:HAL:hal-01449390v1 2024-05-19T07:42:59+00:00 Reconstructing extreme AMOC events through nudging of the ocean surface: a perfect model approach Ortega, Pablo Guilyardi, Éric Swingedouw, Didier Mignot, Juliette Nguyen, Sébastien 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) NCAS-Climate Reading Department of Meteorology Reading University of Reading (UOR)-University of Reading (UOR) Processus de la variabilité climatique tropicale et impacts (PARVATI) 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)-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)) Environnements et Paléoenvironnements OCéaniques (EPOC) Observatoire aquitain des sciences de l'univers (OASU) Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) Oeschger Centre for Climate Change Research (OCCR) Universität Bern / University of Bern (UNIBE) ANR-13-SENV-0002,MORDICUS,Oscillations et rétroactions climatiques aux échelles décennales : mécanismes, sensibilité et incertitudes(2013) European Project: 308378,EC:FP7:ENV,FP7-ENV-2012-two-stage,SPECS(2012) 2017-01-25 https://hal.sorbonne-universite.fr/hal-01449390 https://hal.sorbonne-universite.fr/hal-01449390/document https://hal.sorbonne-universite.fr/hal-01449390/file/reconstructing.pdf https://doi.org/10.1007/s00382-017-3521-4 en eng HAL CCSD Springer Verlag info:eu-repo/semantics/altIdentifier/doi/10.1007/s00382-017-3521-4 info:eu-repo/grantAgreement/EC/FP7/308378/EU/Seasonal-to-decadal climate Prediction for the improvement of EuropeanClimate Services/SPECS hal-01449390 https://hal.sorbonne-universite.fr/hal-01449390 https://hal.sorbonne-universite.fr/hal-01449390/document https://hal.sorbonne-universite.fr/hal-01449390/file/reconstructing.pdf doi:10.1007/s00382-017-3521-4 IRD: fdi:010071330 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess ISSN: 0930-7575 EISSN: 1432-0894 Climate Dynamics https://hal.sorbonne-universite.fr/hal-01449390 Climate Dynamics, 2017, pp.1-17. ⟨10.1007/s00382-017-3521-4⟩ Atlantic Meridional Overturning Circulation Decadal variability Surface nudging Coupled general circulation model [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology info:eu-repo/semantics/article Journal articles 2017 ftuniversailles https://doi.org/10.1007/s00382-017-3521-4 2024-04-25T00:35:29Z International audience While the Atlantic Meridional Overturning Circulation (AMOC) is thought to be a crucial component of the North Atlantic climate, past changes in its strength are challenging to quantify, and only limited information is available. In this study, we use a perfect model approach with the IPSL-CM5A-LR model to assess the performance of several surface nudging techniques in reconstructing the variability of the AMOC. Special attention is given to the reproducibility of an extreme positive AMOC peak from a preindustrial control simulation. Nudging includes standard relaxation techniques towards the sea surface temperature and salinity anomalies of this target control simulation, and/or the prescription of the wind-stress fields. Surface nudging approaches using standard fixed restoring terms succeed in reproducing most of the target AMOC variability, including the timing of the extreme event, but systematically underestimate its amplitude. A detailed analysis of the AMOC variability mechanisms reveals that the underestimation of the extreme AMOC maximum comes from a deficit in the formation of the dense water masses in the main convection region, located south of Iceland in the model. This issue is largely corrected after introducing a novel surface nudging approach, which uses a varying restoring coefficient that is proportional to the simulated mixed layer depth, which, in essence, keeps the restoring time scale constant. This new technique substantially improves water mass transformation in the regions of convection, and in particular, the formation of the densest waters, which are key for the representation of the AMOC extreme. It is therefore a promising strategy that may help to better constrain the AMOC variability and other ocean features in the models. As this restoring technique only uses surface data, for which better and longer observations are available, it opens up opportunities for improved reconstructions of the AMOC over the last few decades. Article in Journal/Newspaper Iceland North Atlantic Université de Versailles Saint-Quentin-en-Yvelines: HAL-UVSQ Climate Dynamics 49 9-10 3425 3441 |