A coupled model study on the Atlantic Meridional Overturning Circulation under extreme atmospheric CO2 conditions
This study investigates the climate sensitivity to a strong CO2 atmospheric forcing focusing on the North Atlantic Ocean (NA). The analysis is based on a set of 600 years long experiments performed with a state-of-the-art coupled general circulation model (CGCM) with the 1990 reference value of atmo...
Published in: | Annals of Geophysics |
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Online Access: | http://hdl.handle.net/2122/12131 https://doi.org/10.4401/ag-6658 |
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ftingv:oai:www.earth-prints.org:2122/12131 2023-05-15T17:06:11+02:00 A coupled model study on the Atlantic Meridional Overturning Circulation under extreme atmospheric CO2 conditions Lecci, Rita Masina, Simona Cherchi, Annalisa Barreiro, Marcelo CMCC Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione Bologna, Bologna, Italia Uruguay University 2016 http://hdl.handle.net/2122/12131 https://doi.org/10.4401/ag-6658 en eng Annals Geophysics 2/59 (2016) http://hdl.handle.net/2122/12131 doi:10.4401/ag-6658 open article 2016 ftingv https://doi.org/10.4401/ag-6658 2022-07-29T06:05:37Z This study investigates the climate sensitivity to a strong CO2 atmospheric forcing focusing on the North Atlantic Ocean (NA). The analysis is based on a set of 600 years long experiments performed with a state-of-the-art coupled general circulation model (CGCM) with the 1990 reference value of atmospheric CO2 multiplied by 4, 8 and 16. Extreme increases in atmospheric CO2 concentration have been applied to force the climate system towards stable states with different thermo-dynamical properties and analyze how the different resulting oceanic stratification and diffusion affect the Atlantic Meridional Overturning Circulation (AMOC). The AMOC weakens in response to the induced warming with distinctive features in the extreme case: a southward shift of convective sites and the formation of a density front at mid-latitudes. The analysis of the density fluxes reveals that NA loses density at high latitudes and gains it southward of 40°N mainly due to the haline contribution. Our results indicate that the most important processes that control the AMOC are active in the high latitudes and are related to the stability of the water column. The increased ocean stratification stabilizes the ocean interior leading to a decreased vertical diffusivity, a reduction in the formation of deep water and a weaker circulation. In particular, the deep convection collapses mainly in the Labrador Sea as a consequence of the water column stratification under high latitudes freshening. Published P0215 4A. Oceanografia e clima JCR Journal Article in Journal/Newspaper Labrador Sea North Atlantic Earth-Prints (Istituto Nazionale di Geofisica e Vulcanologia) Annals of Geophysics 59 2 |
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Earth-Prints (Istituto Nazionale di Geofisica e Vulcanologia) |
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English |
description |
This study investigates the climate sensitivity to a strong CO2 atmospheric forcing focusing on the North Atlantic Ocean (NA). The analysis is based on a set of 600 years long experiments performed with a state-of-the-art coupled general circulation model (CGCM) with the 1990 reference value of atmospheric CO2 multiplied by 4, 8 and 16. Extreme increases in atmospheric CO2 concentration have been applied to force the climate system towards stable states with different thermo-dynamical properties and analyze how the different resulting oceanic stratification and diffusion affect the Atlantic Meridional Overturning Circulation (AMOC). The AMOC weakens in response to the induced warming with distinctive features in the extreme case: a southward shift of convective sites and the formation of a density front at mid-latitudes. The analysis of the density fluxes reveals that NA loses density at high latitudes and gains it southward of 40°N mainly due to the haline contribution. Our results indicate that the most important processes that control the AMOC are active in the high latitudes and are related to the stability of the water column. The increased ocean stratification stabilizes the ocean interior leading to a decreased vertical diffusivity, a reduction in the formation of deep water and a weaker circulation. In particular, the deep convection collapses mainly in the Labrador Sea as a consequence of the water column stratification under high latitudes freshening. Published P0215 4A. Oceanografia e clima JCR Journal |
author2 |
CMCC Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione Bologna, Bologna, Italia Uruguay University |
format |
Article in Journal/Newspaper |
author |
Lecci, Rita Masina, Simona Cherchi, Annalisa Barreiro, Marcelo |
spellingShingle |
Lecci, Rita Masina, Simona Cherchi, Annalisa Barreiro, Marcelo A coupled model study on the Atlantic Meridional Overturning Circulation under extreme atmospheric CO2 conditions |
author_facet |
Lecci, Rita Masina, Simona Cherchi, Annalisa Barreiro, Marcelo |
author_sort |
Lecci, Rita |
title |
A coupled model study on the Atlantic Meridional Overturning Circulation under extreme atmospheric CO2 conditions |
title_short |
A coupled model study on the Atlantic Meridional Overturning Circulation under extreme atmospheric CO2 conditions |
title_full |
A coupled model study on the Atlantic Meridional Overturning Circulation under extreme atmospheric CO2 conditions |
title_fullStr |
A coupled model study on the Atlantic Meridional Overturning Circulation under extreme atmospheric CO2 conditions |
title_full_unstemmed |
A coupled model study on the Atlantic Meridional Overturning Circulation under extreme atmospheric CO2 conditions |
title_sort |
coupled model study on the atlantic meridional overturning circulation under extreme atmospheric co2 conditions |
publishDate |
2016 |
url |
http://hdl.handle.net/2122/12131 https://doi.org/10.4401/ag-6658 |
genre |
Labrador Sea North Atlantic |
genre_facet |
Labrador Sea North Atlantic |
op_relation |
Annals Geophysics 2/59 (2016) http://hdl.handle.net/2122/12131 doi:10.4401/ag-6658 |
op_rights |
open |
op_doi |
https://doi.org/10.4401/ag-6658 |
container_title |
Annals of Geophysics |
container_volume |
59 |
container_issue |
2 |
_version_ |
1766061212199550976 |