The Role of Anthropogenic Aerosol Forcing in the 1850–1985 Strengthening of the AMOC in CMIP6 Historical Simulations
International audience Abstract Previous work has shown that anthropogenic aerosol (AA) forcing drives a strengthening in the Atlantic meridional overturning circulation (AMOC) in CMIP6 historical simulations over 1850–1985, but the mechanisms have not been fully understood. Across CMIP6 models, it...
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
2022
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Online Access: | https://hal.science/hal-03952762 https://hal.science/hal-03952762/document https://hal.science/hal-03952762/file/1520-0442-JCLI-D-22-0124.1.pdf https://doi.org/10.1175/jcli-d-22-0124.1 |
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Université de Nantes: HAL-UNIV-NANTES |
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English |
topic |
[SDU]Sciences of the Universe [physics] |
spellingShingle |
[SDU]Sciences of the Universe [physics] Robson, Jon Menary, Matthew, Sutton, Rowan Mecking, Jenny Gregory, Jonathan Jones, Colin Sinha, Bablu Stevens, David Wilcox, Laura The Role of Anthropogenic Aerosol Forcing in the 1850–1985 Strengthening of the AMOC in CMIP6 Historical Simulations |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience Abstract Previous work has shown that anthropogenic aerosol (AA) forcing drives a strengthening in the Atlantic meridional overturning circulation (AMOC) in CMIP6 historical simulations over 1850–1985, but the mechanisms have not been fully understood. Across CMIP6 models, it is shown that there is a strong correlation between surface heat loss over the subpolar North Atlantic (SPNA) and the forced strengthening of the AMOC. Despite the link to AA forcing, the AMOC response is not strongly related to the contribution of anomalous downwelling surface shortwave radiation to SPNA heat loss. Rather, the spread in AMOC response is primarily due to the spread in turbulent heat loss. We hypothesize that turbulent heat loss is larger in models with strong AA forcing because the air advected over the ocean is colder and drier, in turn because of greater AA-forced cooling over the continents upwind, especially North America. The strengthening of the AMOC also feeds back on itself positively in two distinct ways: by raising the sea surface temperature and hence further increasing turbulent heat loss in the SPNA, and by increasing the sea surface density across the SPNA due to increased northward transport of saline water. A comparison of key indices suggests that the AMOC response in models with strong AA forcing is not likely to be consistent with observations. |
author2 |
National Centre for Atmospheric Science University of Reading (UOR) Océan et variabilité du climat (VARCLIM) Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) 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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) National Oceanography Centre Southampton (NOC) University of Southampton Met Office Hadley Centre for Climate Change (MOHC) United Kingdom Met Office Exeter National Centre for Atmospheric Science Leeds (NCAS) Natural Environment Research Council (NERC) Centre for Ocean and Atmospheric Sciences Norwich (COAS) School of Environmental Sciences Norwich University of East Anglia Norwich (UEA)-University of East Anglia Norwich (UEA) |
format |
Article in Journal/Newspaper |
author |
Robson, Jon Menary, Matthew, Sutton, Rowan Mecking, Jenny Gregory, Jonathan Jones, Colin Sinha, Bablu Stevens, David Wilcox, Laura |
author_facet |
Robson, Jon Menary, Matthew, Sutton, Rowan Mecking, Jenny Gregory, Jonathan Jones, Colin Sinha, Bablu Stevens, David Wilcox, Laura |
author_sort |
Robson, Jon |
title |
The Role of Anthropogenic Aerosol Forcing in the 1850–1985 Strengthening of the AMOC in CMIP6 Historical Simulations |
title_short |
The Role of Anthropogenic Aerosol Forcing in the 1850–1985 Strengthening of the AMOC in CMIP6 Historical Simulations |
title_full |
The Role of Anthropogenic Aerosol Forcing in the 1850–1985 Strengthening of the AMOC in CMIP6 Historical Simulations |
title_fullStr |
The Role of Anthropogenic Aerosol Forcing in the 1850–1985 Strengthening of the AMOC in CMIP6 Historical Simulations |
title_full_unstemmed |
The Role of Anthropogenic Aerosol Forcing in the 1850–1985 Strengthening of the AMOC in CMIP6 Historical Simulations |
title_sort |
role of anthropogenic aerosol forcing in the 1850–1985 strengthening of the amoc in cmip6 historical simulations |
publisher |
HAL CCSD |
publishDate |
2022 |
url |
https://hal.science/hal-03952762 https://hal.science/hal-03952762/document https://hal.science/hal-03952762/file/1520-0442-JCLI-D-22-0124.1.pdf https://doi.org/10.1175/jcli-d-22-0124.1 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
ISSN: 0894-8755 EISSN: 1520-0442 Journal of Climate https://hal.science/hal-03952762 Journal of Climate, 2022, 35 (20), pp.3243-3263. ⟨10.1175/jcli-d-22-0124.1⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1175/jcli-d-22-0124.1 hal-03952762 https://hal.science/hal-03952762 https://hal.science/hal-03952762/document https://hal.science/hal-03952762/file/1520-0442-JCLI-D-22-0124.1.pdf doi:10.1175/jcli-d-22-0124.1 WOS: 000888269400020 |
op_rights |
http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1175/jcli-d-22-0124.1 |
container_title |
Journal of Climate |
container_volume |
35 |
container_issue |
20 |
container_start_page |
3243 |
op_container_end_page |
3263 |
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1766132934998228992 |
spelling |
ftunivnantes:oai:HAL:hal-03952762v1 2023-05-15T17:34:11+02:00 The Role of Anthropogenic Aerosol Forcing in the 1850–1985 Strengthening of the AMOC in CMIP6 Historical Simulations Robson, Jon Menary, Matthew, Sutton, Rowan Mecking, Jenny Gregory, Jonathan Jones, Colin Sinha, Bablu Stevens, David Wilcox, Laura National Centre for Atmospheric Science University of Reading (UOR) Océan et variabilité du climat (VARCLIM) Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) 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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) National Oceanography Centre Southampton (NOC) University of Southampton Met Office Hadley Centre for Climate Change (MOHC) United Kingdom Met Office Exeter National Centre for Atmospheric Science Leeds (NCAS) Natural Environment Research Council (NERC) Centre for Ocean and Atmospheric Sciences Norwich (COAS) School of Environmental Sciences Norwich University of East Anglia Norwich (UEA)-University of East Anglia Norwich (UEA) 2022-10-15 https://hal.science/hal-03952762 https://hal.science/hal-03952762/document https://hal.science/hal-03952762/file/1520-0442-JCLI-D-22-0124.1.pdf https://doi.org/10.1175/jcli-d-22-0124.1 en eng HAL CCSD American Meteorological Society info:eu-repo/semantics/altIdentifier/doi/10.1175/jcli-d-22-0124.1 hal-03952762 https://hal.science/hal-03952762 https://hal.science/hal-03952762/document https://hal.science/hal-03952762/file/1520-0442-JCLI-D-22-0124.1.pdf doi:10.1175/jcli-d-22-0124.1 WOS: 000888269400020 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess ISSN: 0894-8755 EISSN: 1520-0442 Journal of Climate https://hal.science/hal-03952762 Journal of Climate, 2022, 35 (20), pp.3243-3263. ⟨10.1175/jcli-d-22-0124.1⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2022 ftunivnantes https://doi.org/10.1175/jcli-d-22-0124.1 2023-02-08T01:47:20Z International audience Abstract Previous work has shown that anthropogenic aerosol (AA) forcing drives a strengthening in the Atlantic meridional overturning circulation (AMOC) in CMIP6 historical simulations over 1850–1985, but the mechanisms have not been fully understood. Across CMIP6 models, it is shown that there is a strong correlation between surface heat loss over the subpolar North Atlantic (SPNA) and the forced strengthening of the AMOC. Despite the link to AA forcing, the AMOC response is not strongly related to the contribution of anomalous downwelling surface shortwave radiation to SPNA heat loss. Rather, the spread in AMOC response is primarily due to the spread in turbulent heat loss. We hypothesize that turbulent heat loss is larger in models with strong AA forcing because the air advected over the ocean is colder and drier, in turn because of greater AA-forced cooling over the continents upwind, especially North America. The strengthening of the AMOC also feeds back on itself positively in two distinct ways: by raising the sea surface temperature and hence further increasing turbulent heat loss in the SPNA, and by increasing the sea surface density across the SPNA due to increased northward transport of saline water. A comparison of key indices suggests that the AMOC response in models with strong AA forcing is not likely to be consistent with observations. Article in Journal/Newspaper North Atlantic Université de Nantes: HAL-UNIV-NANTES Journal of Climate 35 20 3243 3263 |