Can the boundary profiles at 26° N be used to extract buoyancy-forced Atlantic Meridional Overturning Circulation signals?
The temporal variability of the Atlantic Meridional Overturning Circulation (AMOC) is driven both by direct wind stresses and by the buoyancy-driven formation of North Atlantic Deep Water over the Labrador Sea and Nordic Seas. In many models, low-frequency density variability down the western bounda...
Published in: | Ocean Science |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2020
|
Subjects: | |
Online Access: | https://doi.org/10.5194/os-16-1067-2020 https://noa.gwlb.de/receive/cop_mods_00053168 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052821/os-16-1067-2020.pdf https://os.copernicus.org/articles/16/1067/2020/os-16-1067-2020.pdf |
id |
ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00053168 |
---|---|
record_format |
openpolar |
spelling |
ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00053168 2023-05-15T17:06:12+02:00 Can the boundary profiles at 26° N be used to extract buoyancy-forced Atlantic Meridional Overturning Circulation signals? Polo, Irene Haines, Keith Robson, Jon Thomas, Christopher 2020-09 electronic https://doi.org/10.5194/os-16-1067-2020 https://noa.gwlb.de/receive/cop_mods_00053168 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052821/os-16-1067-2020.pdf https://os.copernicus.org/articles/16/1067/2020/os-16-1067-2020.pdf eng eng Copernicus Publications Ocean Science -- http://www.bibliothek.uni-regensburg.de/ezeit/?2183769 -- http://www.copernicus.org/EGU/os/os.html -- 1812-0792 https://doi.org/10.5194/os-16-1067-2020 https://noa.gwlb.de/receive/cop_mods_00053168 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052821/os-16-1067-2020.pdf https://os.copernicus.org/articles/16/1067/2020/os-16-1067-2020.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2020 ftnonlinearchiv https://doi.org/10.5194/os-16-1067-2020 2022-02-08T22:35:36Z The temporal variability of the Atlantic Meridional Overturning Circulation (AMOC) is driven both by direct wind stresses and by the buoyancy-driven formation of North Atlantic Deep Water over the Labrador Sea and Nordic Seas. In many models, low-frequency density variability down the western boundary of the Atlantic basin is linked to changes in the buoyancy forcing over the Atlantic subpolar gyre (SPG) region, and this is found to explain part of the geostrophic AMOC variability at 26∘ N. In this study, using different experiments with an ocean general circulation model (OGCM), we develop statistical methods to identify characteristic vertical density profiles at 26∘ N at the western and eastern boundaries, which relate to the buoyancy-forced AMOC. We show that density anomalies due to anomalous buoyancy forcing over the SPG propagate equatorward along the western Atlantic boundary (through 26∘ N), eastward along the Equator, and then poleward up the eastern Atlantic boundary. The timing of the density anomalies appearing at the western and eastern boundaries at 26∘ N reveals ∼ 2–3-year lags between boundaries along deeper levels (2600–3000 m). Record lengths of more than 26 years are required at the western boundary (WB) to allow the buoyancy-forced signals to appear as the dominant empirical orthogonal function (EOF) mode. Results suggest that the depth structure of the signals and the lagged covariances between the boundaries at 26∘ N may both provide useful information for detecting propagating signals of high-latitude origin in more complex models and potentially in the observational RAPID (Rapid Climate Change programme) array. However, time filtering may be needed, together with the continuation of the RAPID programme, in order to extend the time period. Article in Journal/Newspaper Labrador Sea Nordic Seas North Atlantic Deep Water North Atlantic Niedersächsisches Online-Archiv NOA Ocean Science 16 5 1067 1088 |
institution |
Open Polar |
collection |
Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Polo, Irene Haines, Keith Robson, Jon Thomas, Christopher Can the boundary profiles at 26° N be used to extract buoyancy-forced Atlantic Meridional Overturning Circulation signals? |
topic_facet |
article Verlagsveröffentlichung |
description |
The temporal variability of the Atlantic Meridional Overturning Circulation (AMOC) is driven both by direct wind stresses and by the buoyancy-driven formation of North Atlantic Deep Water over the Labrador Sea and Nordic Seas. In many models, low-frequency density variability down the western boundary of the Atlantic basin is linked to changes in the buoyancy forcing over the Atlantic subpolar gyre (SPG) region, and this is found to explain part of the geostrophic AMOC variability at 26∘ N. In this study, using different experiments with an ocean general circulation model (OGCM), we develop statistical methods to identify characteristic vertical density profiles at 26∘ N at the western and eastern boundaries, which relate to the buoyancy-forced AMOC. We show that density anomalies due to anomalous buoyancy forcing over the SPG propagate equatorward along the western Atlantic boundary (through 26∘ N), eastward along the Equator, and then poleward up the eastern Atlantic boundary. The timing of the density anomalies appearing at the western and eastern boundaries at 26∘ N reveals ∼ 2–3-year lags between boundaries along deeper levels (2600–3000 m). Record lengths of more than 26 years are required at the western boundary (WB) to allow the buoyancy-forced signals to appear as the dominant empirical orthogonal function (EOF) mode. Results suggest that the depth structure of the signals and the lagged covariances between the boundaries at 26∘ N may both provide useful information for detecting propagating signals of high-latitude origin in more complex models and potentially in the observational RAPID (Rapid Climate Change programme) array. However, time filtering may be needed, together with the continuation of the RAPID programme, in order to extend the time period. |
format |
Article in Journal/Newspaper |
author |
Polo, Irene Haines, Keith Robson, Jon Thomas, Christopher |
author_facet |
Polo, Irene Haines, Keith Robson, Jon Thomas, Christopher |
author_sort |
Polo, Irene |
title |
Can the boundary profiles at 26° N be used to extract buoyancy-forced Atlantic Meridional Overturning Circulation signals? |
title_short |
Can the boundary profiles at 26° N be used to extract buoyancy-forced Atlantic Meridional Overturning Circulation signals? |
title_full |
Can the boundary profiles at 26° N be used to extract buoyancy-forced Atlantic Meridional Overturning Circulation signals? |
title_fullStr |
Can the boundary profiles at 26° N be used to extract buoyancy-forced Atlantic Meridional Overturning Circulation signals? |
title_full_unstemmed |
Can the boundary profiles at 26° N be used to extract buoyancy-forced Atlantic Meridional Overturning Circulation signals? |
title_sort |
can the boundary profiles at 26° n be used to extract buoyancy-forced atlantic meridional overturning circulation signals? |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/os-16-1067-2020 https://noa.gwlb.de/receive/cop_mods_00053168 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052821/os-16-1067-2020.pdf https://os.copernicus.org/articles/16/1067/2020/os-16-1067-2020.pdf |
genre |
Labrador Sea Nordic Seas North Atlantic Deep Water North Atlantic |
genre_facet |
Labrador Sea Nordic Seas North Atlantic Deep Water North Atlantic |
op_relation |
Ocean Science -- http://www.bibliothek.uni-regensburg.de/ezeit/?2183769 -- http://www.copernicus.org/EGU/os/os.html -- 1812-0792 https://doi.org/10.5194/os-16-1067-2020 https://noa.gwlb.de/receive/cop_mods_00053168 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052821/os-16-1067-2020.pdf https://os.copernicus.org/articles/16/1067/2020/os-16-1067-2020.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/os-16-1067-2020 |
container_title |
Ocean Science |
container_volume |
16 |
container_issue |
5 |
container_start_page |
1067 |
op_container_end_page |
1088 |
_version_ |
1766061238354182144 |