The importance of wind and buoyancy forcing for the boundary density variations and the geostrophic component of the AMOC at 26°N
It is widely thought that changes in both the surface buoyancy fluxes and wind stress drive variability in the Atlantic meridional overturning circulation (AMOC), but that they drive variability on different time scales. For example, wind forcing dominates short-term variability through its effects...
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American Meteorological Society
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ftunivreading:oai:centaur.reading.ac.uk:37550 2024-02-11T10:06:34+01:00 The importance of wind and buoyancy forcing for the boundary density variations and the geostrophic component of the AMOC at 26°N Polo, Irene Robson, Jon Sutton, Rowan Balmaseda, Magdalena Alonso 2014-09-01 text https://centaur.reading.ac.uk/37550/ https://centaur.reading.ac.uk/37550/1/Polo_etal_2014_final.pdf en eng American Meteorological Society https://centaur.reading.ac.uk/37550/1/Polo_etal_2014_final.pdf Polo, I. <https://centaur.reading.ac.uk/view/creators/90004825.html>, Robson, J. <https://centaur.reading.ac.uk/view/creators/90002607.html> orcid:0000-0002-3467-018X , Sutton, R. <https://centaur.reading.ac.uk/view/creators/90000057.html> orcid:0000-0001-8345-8583 and Balmaseda, M. A. (2014) The importance of wind and buoyancy forcing for the boundary density variations and the geostrophic component of the AMOC at 26°N. Journal of Physical Oceanography, 44 (9). pp. 2387-2408. ISSN 0022-3670 doi: https://doi.org/10.1175/JPO-D-13-0264.1 <https://doi.org/10.1175/JPO-D-13-0264.1> cc_by Article PeerReviewed 2014 ftunivreading https://doi.org/10.1175/JPO-D-13-0264.1 2024-01-25T23:59:07Z It is widely thought that changes in both the surface buoyancy fluxes and wind stress drive variability in the Atlantic meridional overturning circulation (AMOC), but that they drive variability on different time scales. For example, wind forcing dominates short-term variability through its effects on Ekman currents and coastal upwelling, whereas buoyancy forcing is important for longer time scales (multiannual and decadal). However, the role of the wind forcing on multiannual to decadal time scales is less clear. Here the authors present an analysis of simulations with the Nucleus for European Modelling of the Ocean (NEMO) ocean model with the aim of explaining the important drivers of the zonal density gradient at 26°N, which is directly related to the AMOC. In the experiments, only one of either the wind stress or the buoyancy forcing is allowed to vary in time, whereas the other remains at its seasonally varying climatology. On subannual time scales, variations in the density gradient, and in the AMOC minus Ekman, are driven largely by local wind-forced coastal upwelling at both the western and eastern boundaries. On decadal time scales, buoyancy forcing related to the North Atlantic Oscillation dominates variability in the AMOC. Interestingly, however, it is found that wind forcing also plays a role at longer time scales, primarily impacting the interannual variability through the excitation of Rossby waves in the central Atlantic, which propagate westward to interact with the western boundary, but also by modulating the decadal time-scale response to buoyancy forcing. Article in Journal/Newspaper North Atlantic North Atlantic oscillation CentAUR: Central Archive at the University of Reading Journal of Physical Oceanography 44 9 2387 2408 |
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Open Polar |
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CentAUR: Central Archive at the University of Reading |
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ftunivreading |
language |
English |
description |
It is widely thought that changes in both the surface buoyancy fluxes and wind stress drive variability in the Atlantic meridional overturning circulation (AMOC), but that they drive variability on different time scales. For example, wind forcing dominates short-term variability through its effects on Ekman currents and coastal upwelling, whereas buoyancy forcing is important for longer time scales (multiannual and decadal). However, the role of the wind forcing on multiannual to decadal time scales is less clear. Here the authors present an analysis of simulations with the Nucleus for European Modelling of the Ocean (NEMO) ocean model with the aim of explaining the important drivers of the zonal density gradient at 26°N, which is directly related to the AMOC. In the experiments, only one of either the wind stress or the buoyancy forcing is allowed to vary in time, whereas the other remains at its seasonally varying climatology. On subannual time scales, variations in the density gradient, and in the AMOC minus Ekman, are driven largely by local wind-forced coastal upwelling at both the western and eastern boundaries. On decadal time scales, buoyancy forcing related to the North Atlantic Oscillation dominates variability in the AMOC. Interestingly, however, it is found that wind forcing also plays a role at longer time scales, primarily impacting the interannual variability through the excitation of Rossby waves in the central Atlantic, which propagate westward to interact with the western boundary, but also by modulating the decadal time-scale response to buoyancy forcing. |
format |
Article in Journal/Newspaper |
author |
Polo, Irene Robson, Jon Sutton, Rowan Balmaseda, Magdalena Alonso |
spellingShingle |
Polo, Irene Robson, Jon Sutton, Rowan Balmaseda, Magdalena Alonso The importance of wind and buoyancy forcing for the boundary density variations and the geostrophic component of the AMOC at 26°N |
author_facet |
Polo, Irene Robson, Jon Sutton, Rowan Balmaseda, Magdalena Alonso |
author_sort |
Polo, Irene |
title |
The importance of wind and buoyancy forcing for the boundary density variations and the geostrophic component of the AMOC at 26°N |
title_short |
The importance of wind and buoyancy forcing for the boundary density variations and the geostrophic component of the AMOC at 26°N |
title_full |
The importance of wind and buoyancy forcing for the boundary density variations and the geostrophic component of the AMOC at 26°N |
title_fullStr |
The importance of wind and buoyancy forcing for the boundary density variations and the geostrophic component of the AMOC at 26°N |
title_full_unstemmed |
The importance of wind and buoyancy forcing for the boundary density variations and the geostrophic component of the AMOC at 26°N |
title_sort |
importance of wind and buoyancy forcing for the boundary density variations and the geostrophic component of the amoc at 26°n |
publisher |
American Meteorological Society |
publishDate |
2014 |
url |
https://centaur.reading.ac.uk/37550/ https://centaur.reading.ac.uk/37550/1/Polo_etal_2014_final.pdf |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
https://centaur.reading.ac.uk/37550/1/Polo_etal_2014_final.pdf Polo, I. <https://centaur.reading.ac.uk/view/creators/90004825.html>, Robson, J. <https://centaur.reading.ac.uk/view/creators/90002607.html> orcid:0000-0002-3467-018X , Sutton, R. <https://centaur.reading.ac.uk/view/creators/90000057.html> orcid:0000-0001-8345-8583 and Balmaseda, M. A. (2014) The importance of wind and buoyancy forcing for the boundary density variations and the geostrophic component of the AMOC at 26°N. Journal of Physical Oceanography, 44 (9). pp. 2387-2408. ISSN 0022-3670 doi: https://doi.org/10.1175/JPO-D-13-0264.1 <https://doi.org/10.1175/JPO-D-13-0264.1> |
op_rights |
cc_by |
op_doi |
https://doi.org/10.1175/JPO-D-13-0264.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
44 |
container_issue |
9 |
container_start_page |
2387 |
op_container_end_page |
2408 |
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1790604365125386240 |