Reconciling two alternative mechanisms behind bi-decadal variability in the North Atlantic
Understanding the preferential timescales of variability in the North Atlantic, usually associated with the Atlantic meridional overturning circulation (AMOC), is essential for the prospects for decadal prediction. However, the wide variety of mechanisms proposed from the analysis of climate simulat...
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ftunivbern:oai:boris.unibe.ch:73419 2023-08-20T04:07:27+02:00 Reconciling two alternative mechanisms behind bi-decadal variability in the North Atlantic Ortega, Pablo Mignot, Juliette Swingedouw, Didier Sévellec, Florian Guilyardi, Eric 2015 application/pdf https://boris.unibe.ch/73419/1/1-s2.0-S0079661115001482-main.pdf https://boris.unibe.ch/73419/ eng eng Elsevier https://boris.unibe.ch/73419/ info:eu-repo/semantics/restrictedAccess Ortega, Pablo; Mignot, Juliette; Swingedouw, Didier; Sévellec, Florian; Guilyardi, Eric (2015). Reconciling two alternative mechanisms behind bi-decadal variability in the North Atlantic. Progress in Oceanography, 137, pp. 237-249. Elsevier 10.1016/j.pocean.2015.06.009 <http://dx.doi.org/10.1016/j.pocean.2015.06.009> 530 Physics info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion PeerReviewed 2015 ftunivbern https://doi.org/10.1016/j.pocean.2015.06.009 2023-07-31T21:21:00Z Understanding the preferential timescales of variability in the North Atlantic, usually associated with the Atlantic meridional overturning circulation (AMOC), is essential for the prospects for decadal prediction. However, the wide variety of mechanisms proposed from the analysis of climate simulations, potentially dependent on the models themselves, has stimulated the debate of which processes take place in reality. One mechanism receiving increasing attention, identified both in idealized models and observations, is a westward propagation of subsurface buoyancy anomalies that impact the AMOC through a basin-scale intensification of the zonal density gradient, enhancing the northward transport via thermal wind balance. In this study, we revisit a control simulation from the Institut Pierre-Simon Laplace Coupled Model 5A (IPSL-CM5A), characterized by a strong AMOC periodicity at 20 years, previously explained by an upper ocean–atmosphere–sea ice coupled mode driving convection activity south of Iceland. Our study shows that this mechanism interacts constructively with the basin-wide propagation in the subsurface. This constructive feedback may explain why bi-decadal variability is so intense in this coupled model as compared to others. Article in Journal/Newspaper Iceland North Atlantic Sea ice BORIS (Bern Open Repository and Information System, University of Bern) Laplace ENVELOPE(141.467,141.467,-66.782,-66.782) Progress in Oceanography 137 237 249 |
institution |
Open Polar |
collection |
BORIS (Bern Open Repository and Information System, University of Bern) |
op_collection_id |
ftunivbern |
language |
English |
topic |
530 Physics |
spellingShingle |
530 Physics Ortega, Pablo Mignot, Juliette Swingedouw, Didier Sévellec, Florian Guilyardi, Eric Reconciling two alternative mechanisms behind bi-decadal variability in the North Atlantic |
topic_facet |
530 Physics |
description |
Understanding the preferential timescales of variability in the North Atlantic, usually associated with the Atlantic meridional overturning circulation (AMOC), is essential for the prospects for decadal prediction. However, the wide variety of mechanisms proposed from the analysis of climate simulations, potentially dependent on the models themselves, has stimulated the debate of which processes take place in reality. One mechanism receiving increasing attention, identified both in idealized models and observations, is a westward propagation of subsurface buoyancy anomalies that impact the AMOC through a basin-scale intensification of the zonal density gradient, enhancing the northward transport via thermal wind balance. In this study, we revisit a control simulation from the Institut Pierre-Simon Laplace Coupled Model 5A (IPSL-CM5A), characterized by a strong AMOC periodicity at 20 years, previously explained by an upper ocean–atmosphere–sea ice coupled mode driving convection activity south of Iceland. Our study shows that this mechanism interacts constructively with the basin-wide propagation in the subsurface. This constructive feedback may explain why bi-decadal variability is so intense in this coupled model as compared to others. |
format |
Article in Journal/Newspaper |
author |
Ortega, Pablo Mignot, Juliette Swingedouw, Didier Sévellec, Florian Guilyardi, Eric |
author_facet |
Ortega, Pablo Mignot, Juliette Swingedouw, Didier Sévellec, Florian Guilyardi, Eric |
author_sort |
Ortega, Pablo |
title |
Reconciling two alternative mechanisms behind bi-decadal variability in the North Atlantic |
title_short |
Reconciling two alternative mechanisms behind bi-decadal variability in the North Atlantic |
title_full |
Reconciling two alternative mechanisms behind bi-decadal variability in the North Atlantic |
title_fullStr |
Reconciling two alternative mechanisms behind bi-decadal variability in the North Atlantic |
title_full_unstemmed |
Reconciling two alternative mechanisms behind bi-decadal variability in the North Atlantic |
title_sort |
reconciling two alternative mechanisms behind bi-decadal variability in the north atlantic |
publisher |
Elsevier |
publishDate |
2015 |
url |
https://boris.unibe.ch/73419/1/1-s2.0-S0079661115001482-main.pdf https://boris.unibe.ch/73419/ |
long_lat |
ENVELOPE(141.467,141.467,-66.782,-66.782) |
geographic |
Laplace |
geographic_facet |
Laplace |
genre |
Iceland North Atlantic Sea ice |
genre_facet |
Iceland North Atlantic Sea ice |
op_source |
Ortega, Pablo; Mignot, Juliette; Swingedouw, Didier; Sévellec, Florian; Guilyardi, Eric (2015). Reconciling two alternative mechanisms behind bi-decadal variability in the North Atlantic. Progress in Oceanography, 137, pp. 237-249. Elsevier 10.1016/j.pocean.2015.06.009 <http://dx.doi.org/10.1016/j.pocean.2015.06.009> |
op_relation |
https://boris.unibe.ch/73419/ |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.pocean.2015.06.009 |
container_title |
Progress in Oceanography |
container_volume |
137 |
container_start_page |
237 |
op_container_end_page |
249 |
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1774719109969215488 |