Impact of ocean resolution and mean state on the rate of AMOC weakening
We examine the weakening of the Atlantic Meridional Overturning Circulation (AMOC) in response to increasing CO2 at different horizontal resolutions in a state-of-the-art climate model and in a small ensemble of models with differing resolutions. There is a strong influence of the ocean mean state o...
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Format: | Article in Journal/Newspaper |
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Online Access: | http://hdl.handle.net/2117/192990 https://doi.org/10.1007/s00382-020-05345-9 |
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ftupcatalunyair:oai:upcommons.upc.edu:2117/192990 2023-05-15T16:30:29+02:00 Impact of ocean resolution and mean state on the rate of AMOC weakening Jackson, Laura C. Roberts, Mark J. Hewit, Helene T. Iovino, Doroteaciro Koenigk, Torben Meccia, Virna L. Roberts, Chris D. Ruprich Robert, Yohan Wood, Richard A. Barcelona Supercomputing Center 2020 22 p. application/pdf http://hdl.handle.net/2117/192990 https://doi.org/10.1007/s00382-020-05345-9 eng eng Springer Link https://link.springer.com/article/10.1007/s00382-020-05345-9 info:eu-repo/grantAgreement/EC/H2020/641727/EU/PRocess-based climate sIMulation: AdVances in high resolution modelling and European climate Risk Assessment/PRIMAVERA Jackson, L. C. [et al.]. Impact of ocean resolution and mean state on the rate of AMOC weakening. "Climate Dynamics", 2020. 1432-0894 http://hdl.handle.net/2117/192990 doi:10.1007/s00382-020-05345-9 Attribution 3.0 Spain Attribution 4.0 International (CC BY 4.0) http://creativecommons.org/licenses/by/3.0/es/ https://creativecommons.org/licenses/by/4.0/ Open Access CC-BY Àrees temàtiques de la UPC::Desenvolupament humà i sostenible Databases Atlantic Ocean Ocean temperature Climate Atlantic Meridional Overturning Circulation (AMOC) Weakening ocean heat Climate models Bases de dades Article 2020 ftupcatalunyair https://doi.org/10.1007/s00382-020-05345-9 2021-02-26T15:11:29Z We examine the weakening of the Atlantic Meridional Overturning Circulation (AMOC) in response to increasing CO2 at different horizontal resolutions in a state-of-the-art climate model and in a small ensemble of models with differing resolutions. There is a strong influence of the ocean mean state on the AMOC weakening: models with a more saline western subpolar gyre have a greater formation of deep water there. This makes the AMOC more susceptible to weakening from an increase in CO2 since weakening ocean heat transports weaken the contrast between ocean and atmospheric temperatures and hence weaken the buoyancy loss. In models with a greater proportion of deep water formation further north (in the Greenland-Iceland-Norwegian basin), deep-water formation can be maintained by shifting further north to where there is a greater ocean-atmosphere temperature contrast. We show that ocean horizontal resolution can have an impact on the mean state, and hence AMOC weakening. In the models examined, those with higher resolutions tend to have a more westerly location of the North Atlantic Current and stronger subpolar gyre. This likely leads to a greater impact of the warm, saline subtropical Atlantic waters on the western subpolar gyre resulting in greater dense water formation there. Although there is some improvement of the higher resolution models over the lower resolution models in terms of the mean state, both still have biases and it is not clear which biases are the most important for influencing the AMOC strength and response to increasing CO2. LJ, MR, DI, TK, VM, CR, YR-R were funded by the PRIMAVERA project, funded by the European Union’s Horizon 2020 programme under grant agreement 641727. LJ, HH, MR, RW were supported by the Met Office Hadley Centre Climate Programme funded by BEIS and Defra (GA01101). We wish to thank two anonymous reviewers for their comments which improved this manuscript. Peer Reviewed Postprint (published version) Article in Journal/Newspaper Greenland Iceland north atlantic current North Atlantic Universitat Politècnica de Catalunya, BarcelonaTech: UPCommons - Global access to UPC knowledge Greenland Climate Dynamics 55 7-8 1711 1732 |
institution |
Open Polar |
collection |
Universitat Politècnica de Catalunya, BarcelonaTech: UPCommons - Global access to UPC knowledge |
op_collection_id |
ftupcatalunyair |
language |
English |
topic |
Àrees temàtiques de la UPC::Desenvolupament humà i sostenible Databases Atlantic Ocean Ocean temperature Climate Atlantic Meridional Overturning Circulation (AMOC) Weakening ocean heat Climate models Bases de dades |
spellingShingle |
Àrees temàtiques de la UPC::Desenvolupament humà i sostenible Databases Atlantic Ocean Ocean temperature Climate Atlantic Meridional Overturning Circulation (AMOC) Weakening ocean heat Climate models Bases de dades Jackson, Laura C. Roberts, Mark J. Hewit, Helene T. Iovino, Doroteaciro Koenigk, Torben Meccia, Virna L. Roberts, Chris D. Ruprich Robert, Yohan Wood, Richard A. Impact of ocean resolution and mean state on the rate of AMOC weakening |
topic_facet |
Àrees temàtiques de la UPC::Desenvolupament humà i sostenible Databases Atlantic Ocean Ocean temperature Climate Atlantic Meridional Overturning Circulation (AMOC) Weakening ocean heat Climate models Bases de dades |
description |
We examine the weakening of the Atlantic Meridional Overturning Circulation (AMOC) in response to increasing CO2 at different horizontal resolutions in a state-of-the-art climate model and in a small ensemble of models with differing resolutions. There is a strong influence of the ocean mean state on the AMOC weakening: models with a more saline western subpolar gyre have a greater formation of deep water there. This makes the AMOC more susceptible to weakening from an increase in CO2 since weakening ocean heat transports weaken the contrast between ocean and atmospheric temperatures and hence weaken the buoyancy loss. In models with a greater proportion of deep water formation further north (in the Greenland-Iceland-Norwegian basin), deep-water formation can be maintained by shifting further north to where there is a greater ocean-atmosphere temperature contrast. We show that ocean horizontal resolution can have an impact on the mean state, and hence AMOC weakening. In the models examined, those with higher resolutions tend to have a more westerly location of the North Atlantic Current and stronger subpolar gyre. This likely leads to a greater impact of the warm, saline subtropical Atlantic waters on the western subpolar gyre resulting in greater dense water formation there. Although there is some improvement of the higher resolution models over the lower resolution models in terms of the mean state, both still have biases and it is not clear which biases are the most important for influencing the AMOC strength and response to increasing CO2. LJ, MR, DI, TK, VM, CR, YR-R were funded by the PRIMAVERA project, funded by the European Union’s Horizon 2020 programme under grant agreement 641727. LJ, HH, MR, RW were supported by the Met Office Hadley Centre Climate Programme funded by BEIS and Defra (GA01101). We wish to thank two anonymous reviewers for their comments which improved this manuscript. Peer Reviewed Postprint (published version) |
author2 |
Barcelona Supercomputing Center |
format |
Article in Journal/Newspaper |
author |
Jackson, Laura C. Roberts, Mark J. Hewit, Helene T. Iovino, Doroteaciro Koenigk, Torben Meccia, Virna L. Roberts, Chris D. Ruprich Robert, Yohan Wood, Richard A. |
author_facet |
Jackson, Laura C. Roberts, Mark J. Hewit, Helene T. Iovino, Doroteaciro Koenigk, Torben Meccia, Virna L. Roberts, Chris D. Ruprich Robert, Yohan Wood, Richard A. |
author_sort |
Jackson, Laura C. |
title |
Impact of ocean resolution and mean state on the rate of AMOC weakening |
title_short |
Impact of ocean resolution and mean state on the rate of AMOC weakening |
title_full |
Impact of ocean resolution and mean state on the rate of AMOC weakening |
title_fullStr |
Impact of ocean resolution and mean state on the rate of AMOC weakening |
title_full_unstemmed |
Impact of ocean resolution and mean state on the rate of AMOC weakening |
title_sort |
impact of ocean resolution and mean state on the rate of amoc weakening |
publisher |
Springer Link |
publishDate |
2020 |
url |
http://hdl.handle.net/2117/192990 https://doi.org/10.1007/s00382-020-05345-9 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Iceland north atlantic current North Atlantic |
genre_facet |
Greenland Iceland north atlantic current North Atlantic |
op_relation |
https://link.springer.com/article/10.1007/s00382-020-05345-9 info:eu-repo/grantAgreement/EC/H2020/641727/EU/PRocess-based climate sIMulation: AdVances in high resolution modelling and European climate Risk Assessment/PRIMAVERA Jackson, L. C. [et al.]. Impact of ocean resolution and mean state on the rate of AMOC weakening. "Climate Dynamics", 2020. 1432-0894 http://hdl.handle.net/2117/192990 doi:10.1007/s00382-020-05345-9 |
op_rights |
Attribution 3.0 Spain Attribution 4.0 International (CC BY 4.0) http://creativecommons.org/licenses/by/3.0/es/ https://creativecommons.org/licenses/by/4.0/ Open Access |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1007/s00382-020-05345-9 |
container_title |
Climate Dynamics |
container_volume |
55 |
container_issue |
7-8 |
container_start_page |
1711 |
op_container_end_page |
1732 |
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1766020216861491200 |