Subannual, seasonal and interannual variability of the North Atlantic meridional overturning circulation
An eddy-permitting numerical ocean model is used to investigate the variability of the meridional overturning circulation (MOC). Both wind stress and fluctuations of the seawater density contribute to MOC changes on subannual and seasonal time scales, whereas the interannual variability mainly refle...
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ftnerc:oai:nora.nerc.ac.uk:144017 2023-05-15T17:30:22+02:00 Subannual, seasonal and interannual variability of the North Atlantic meridional overturning circulation Hirschi, J.J-M. Killworth, P.D. Blundell, J.R. 2007 http://nora.nerc.ac.uk/id/eprint/144017/ http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2FJPO3049.1 https://doi.org/10.1175/JPO3049.1 unknown Hirschi, J.J-M.; Killworth, P.D.; Blundell, J.R. 2007 Subannual, seasonal and interannual variability of the North Atlantic meridional overturning circulation. Journal of Physical Oceanography, 37 (5). 1246-1265. https://doi.org/10.1175/JPO3049.1 <https://doi.org/10.1175/JPO3049.1> Publication - Article PeerReviewed 2007 ftnerc https://doi.org/10.1175/JPO3049.1 2023-02-04T19:34:44Z An eddy-permitting numerical ocean model is used to investigate the variability of the meridional overturning circulation (MOC). Both wind stress and fluctuations of the seawater density contribute to MOC changes on subannual and seasonal time scales, whereas the interannual variability mainly reflects changes in the density field. Even on subannual and seasonal time scales, a significant fraction of the total MOC variability is due to changes of the density field in the upper 1000 m of the ocean. These changes reflect perturbations of the isopycnal structure that travel westward as Rossby waves. Because of a temporally changing phase difference between the eastern and western boundaries, the Rossby waves affect the MOC by modifying the basinwide east–west density gradient. Both the numerical model used in this study and calculations based on Rossby wave theory suggest that this effect can account for an MOC variability of several Sverdrups (Sv 106 m3 s−1). These results have implications for the interpretation of variability signals inferred from hydrographic sections and might contribute to the understanding of the results obtained from the Rapid Climate Change (RAPID) monitoring array deployed at 26°N in the North Atlantic Ocean. Article in Journal/Newspaper North Atlantic Natural Environment Research Council: NERC Open Research Archive Journal of Physical Oceanography 37 5 1246 1265 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
An eddy-permitting numerical ocean model is used to investigate the variability of the meridional overturning circulation (MOC). Both wind stress and fluctuations of the seawater density contribute to MOC changes on subannual and seasonal time scales, whereas the interannual variability mainly reflects changes in the density field. Even on subannual and seasonal time scales, a significant fraction of the total MOC variability is due to changes of the density field in the upper 1000 m of the ocean. These changes reflect perturbations of the isopycnal structure that travel westward as Rossby waves. Because of a temporally changing phase difference between the eastern and western boundaries, the Rossby waves affect the MOC by modifying the basinwide east–west density gradient. Both the numerical model used in this study and calculations based on Rossby wave theory suggest that this effect can account for an MOC variability of several Sverdrups (Sv 106 m3 s−1). These results have implications for the interpretation of variability signals inferred from hydrographic sections and might contribute to the understanding of the results obtained from the Rapid Climate Change (RAPID) monitoring array deployed at 26°N in the North Atlantic Ocean. |
format |
Article in Journal/Newspaper |
author |
Hirschi, J.J-M. Killworth, P.D. Blundell, J.R. |
spellingShingle |
Hirschi, J.J-M. Killworth, P.D. Blundell, J.R. Subannual, seasonal and interannual variability of the North Atlantic meridional overturning circulation |
author_facet |
Hirschi, J.J-M. Killworth, P.D. Blundell, J.R. |
author_sort |
Hirschi, J.J-M. |
title |
Subannual, seasonal and interannual variability of the North Atlantic meridional overturning circulation |
title_short |
Subannual, seasonal and interannual variability of the North Atlantic meridional overturning circulation |
title_full |
Subannual, seasonal and interannual variability of the North Atlantic meridional overturning circulation |
title_fullStr |
Subannual, seasonal and interannual variability of the North Atlantic meridional overturning circulation |
title_full_unstemmed |
Subannual, seasonal and interannual variability of the North Atlantic meridional overturning circulation |
title_sort |
subannual, seasonal and interannual variability of the north atlantic meridional overturning circulation |
publishDate |
2007 |
url |
http://nora.nerc.ac.uk/id/eprint/144017/ http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2FJPO3049.1 https://doi.org/10.1175/JPO3049.1 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Hirschi, J.J-M.; Killworth, P.D.; Blundell, J.R. 2007 Subannual, seasonal and interannual variability of the North Atlantic meridional overturning circulation. Journal of Physical Oceanography, 37 (5). 1246-1265. https://doi.org/10.1175/JPO3049.1 <https://doi.org/10.1175/JPO3049.1> |
op_doi |
https://doi.org/10.1175/JPO3049.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
37 |
container_issue |
5 |
container_start_page |
1246 |
op_container_end_page |
1265 |
_version_ |
1766126724947378176 |