Multimodel analysis on the response of the AMOC under an increase of radiative forcing and its symmetrical reversal
The response of the Atlantic meridional overturning circulation (AMOC) to an increase of radiative forcing (ramp-up) and a subsequent reversal of radiative forcing (ramp-down) is analyzed for four different global climate models. Due to changes in ocean temperature and hydrological cycle, all models...
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Online Access: | https://oskar-bordeaux.fr/handle/20.500.12278/200343 https://hdl.handle.net/20.500.12278/200343 https://www.researchgate.net/publication/268094364_Multimodel_analysis_on_the_response_of_the_AMOC_under_an_increase_of_radiative_forcing_and_its_symmetrical_reversal https://doi.org/10.1007/s00382-014-2391-2 |
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ftoskarbordeaux:oai:oskar-bordeaux.fr:20.500.12278/200343 2024-06-23T07:55:17+00:00 Multimodel analysis on the response of the AMOC under an increase of radiative forcing and its symmetrical reversal SGUBIN, Giovanni SWINGEDOUW, Didier DRIJFHOUT, Sybren HAGEMANN, Stefan ROBERTSON, Eddy 2014-11-05 https://oskar-bordeaux.fr/handle/20.500.12278/200343 https://hdl.handle.net/20.500.12278/200343 https://www.researchgate.net/publication/268094364_Multimodel_analysis_on_the_response_of_the_AMOC_under_an_increase_of_radiative_forcing_and_its_symmetrical_reversal https://doi.org/10.1007/s00382-014-2391-2 EN eng 0930-7575 https://www.researchgate.net/publication/268094364_Multimodel_analysis_on_the_response_of_the_AMOC_under_an_increase_of_radiative_forcing_and_its_symmetrical_reversal oai:crossref.org:10.1007/s00382-014-2391-2 oai:researchgate.net:268094364 https://oskar-bordeaux.fr/handle/20.500.12278/200343 doi:10.1007/s00382-014-2391-2 open Pas de Licence CC crossref researchgate Sciences de l'environnement Article de revue 2014 ftoskarbordeaux https://doi.org/20.500.12278/20034310.1007/s00382-014-2391-2 2024-06-10T14:02:26Z The response of the Atlantic meridional overturning circulation (AMOC) to an increase of radiative forcing (ramp-up) and a subsequent reversal of radiative forcing (ramp-down) is analyzed for four different global climate models. Due to changes in ocean temperature and hydrological cycle, all models show a weakening of the AMOC during the ramp-up phase. Once the external forcing is reversed, the results become model dependent. For IPSL-CM5A-LR, the AMOC continues its weakening trend for most of the ramp-down experiment. For HadGEM2-ES, the AMOC trend reverses once the external forcing also reverses, without recovering its initial value. For EC-EARTH and MPI-ESM-LR the recovery is anomalously strong yielding an AMOC overshoot. A robust linear dependency can be established between AMOC and density difference between North Atlantic (NA) deep water formation region and South Atlantic (SA). In particular, AMOC evolution is primarily controlled by a meridional salinity contrast between these regions. During the warming scenario, the subtropical Atlantic becomes saltier while the NA experiences a net freshening which favours an AMOC weakening. The different behaviour in the models during the ramp-down is dependent on the response of the ocean at the boundaries of NA and SA. The way in which the positive salinity anomaly stored in the subtropical Atlantic during the ramp-up is subsequently released elsewhere, characterizes the recovery. An out-of-phase response of the salinity transport at 48° N and 34°S boundaries is able to control the meridional density contrast between NA and SA during the transient experiments. Such a non-synchronized response is mainly controlled by changes in gyre salinity transport rather than by changes in overturning transport, thus suggesting a small role of the salt advection feedback in the evolution of the AMOC. Article in Journal/Newspaper North Atlantic OSKAR Bordeaux (Open Science Knowledge ARchive) The Ramp ENVELOPE(-38.305,-38.305,-53.990,-53.990) Climate Dynamics 45 5-6 1429 1450 |
institution |
Open Polar |
collection |
OSKAR Bordeaux (Open Science Knowledge ARchive) |
op_collection_id |
ftoskarbordeaux |
language |
English |
topic |
Sciences de l'environnement |
spellingShingle |
Sciences de l'environnement SGUBIN, Giovanni SWINGEDOUW, Didier DRIJFHOUT, Sybren HAGEMANN, Stefan ROBERTSON, Eddy Multimodel analysis on the response of the AMOC under an increase of radiative forcing and its symmetrical reversal |
topic_facet |
Sciences de l'environnement |
description |
The response of the Atlantic meridional overturning circulation (AMOC) to an increase of radiative forcing (ramp-up) and a subsequent reversal of radiative forcing (ramp-down) is analyzed for four different global climate models. Due to changes in ocean temperature and hydrological cycle, all models show a weakening of the AMOC during the ramp-up phase. Once the external forcing is reversed, the results become model dependent. For IPSL-CM5A-LR, the AMOC continues its weakening trend for most of the ramp-down experiment. For HadGEM2-ES, the AMOC trend reverses once the external forcing also reverses, without recovering its initial value. For EC-EARTH and MPI-ESM-LR the recovery is anomalously strong yielding an AMOC overshoot. A robust linear dependency can be established between AMOC and density difference between North Atlantic (NA) deep water formation region and South Atlantic (SA). In particular, AMOC evolution is primarily controlled by a meridional salinity contrast between these regions. During the warming scenario, the subtropical Atlantic becomes saltier while the NA experiences a net freshening which favours an AMOC weakening. The different behaviour in the models during the ramp-down is dependent on the response of the ocean at the boundaries of NA and SA. The way in which the positive salinity anomaly stored in the subtropical Atlantic during the ramp-up is subsequently released elsewhere, characterizes the recovery. An out-of-phase response of the salinity transport at 48° N and 34°S boundaries is able to control the meridional density contrast between NA and SA during the transient experiments. Such a non-synchronized response is mainly controlled by changes in gyre salinity transport rather than by changes in overturning transport, thus suggesting a small role of the salt advection feedback in the evolution of the AMOC. |
format |
Article in Journal/Newspaper |
author |
SGUBIN, Giovanni SWINGEDOUW, Didier DRIJFHOUT, Sybren HAGEMANN, Stefan ROBERTSON, Eddy |
author_facet |
SGUBIN, Giovanni SWINGEDOUW, Didier DRIJFHOUT, Sybren HAGEMANN, Stefan ROBERTSON, Eddy |
author_sort |
SGUBIN, Giovanni |
title |
Multimodel analysis on the response of the AMOC under an increase of radiative forcing and its symmetrical reversal |
title_short |
Multimodel analysis on the response of the AMOC under an increase of radiative forcing and its symmetrical reversal |
title_full |
Multimodel analysis on the response of the AMOC under an increase of radiative forcing and its symmetrical reversal |
title_fullStr |
Multimodel analysis on the response of the AMOC under an increase of radiative forcing and its symmetrical reversal |
title_full_unstemmed |
Multimodel analysis on the response of the AMOC under an increase of radiative forcing and its symmetrical reversal |
title_sort |
multimodel analysis on the response of the amoc under an increase of radiative forcing and its symmetrical reversal |
publishDate |
2014 |
url |
https://oskar-bordeaux.fr/handle/20.500.12278/200343 https://hdl.handle.net/20.500.12278/200343 https://www.researchgate.net/publication/268094364_Multimodel_analysis_on_the_response_of_the_AMOC_under_an_increase_of_radiative_forcing_and_its_symmetrical_reversal https://doi.org/10.1007/s00382-014-2391-2 |
long_lat |
ENVELOPE(-38.305,-38.305,-53.990,-53.990) |
geographic |
The Ramp |
geographic_facet |
The Ramp |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
crossref researchgate |
op_relation |
0930-7575 https://www.researchgate.net/publication/268094364_Multimodel_analysis_on_the_response_of_the_AMOC_under_an_increase_of_radiative_forcing_and_its_symmetrical_reversal oai:crossref.org:10.1007/s00382-014-2391-2 oai:researchgate.net:268094364 https://oskar-bordeaux.fr/handle/20.500.12278/200343 doi:10.1007/s00382-014-2391-2 |
op_rights |
open Pas de Licence CC |
op_doi |
https://doi.org/20.500.12278/20034310.1007/s00382-014-2391-2 |
container_title |
Climate Dynamics |
container_volume |
45 |
container_issue |
5-6 |
container_start_page |
1429 |
op_container_end_page |
1450 |
_version_ |
1802647819616518144 |