Eddy Formation in the Tropical Atlantic Induced by Abrupt Changes in the Meridional Overturning Circulation
The variability of the meridional overturning circulation (MOC) in the upper tropical Atlantic basin is investigated using a reduced-gravity model in a simplified domain. Four sets of idealized numerical experiments are performed: (i) switch-on of the MOC until a fixed value when a constant northwar...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
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2009
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| _version_ | 1826260471205855232 |
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| author | Goes, M Marshall, D Wainer, I |
| author_facet | Goes, M Marshall, D Wainer, I |
| author_sort | Goes, M |
| collection | OXFORD |
| description | The variability of the meridional overturning circulation (MOC) in the upper tropical Atlantic basin is investigated using a reduced-gravity model in a simplified domain. Four sets of idealized numerical experiments are performed: (i) switch-on of the MOC until a fixed value when a constant northward flow is applied along the western boundary; (ii) MOC with a variable flow; (iii) MOC in a quasi-steady flow; and (iv) shutdown of the MOC in the Northern Hemisphere. Results from experiments (i) show that eddies are generated at the equatorial region by shear instability and detached northward; eddies are responsible for an enhancement of the mean flow and the variability of the MOC. Results from experiments (ii) show a transitional behavior of the MOC related to the eddy generation in interannual-decadal time scales as the Reynolds number varies due to the variations in the MOC. In experiments (iii), a critical Reynolds number Rec around 30 is found, above which eddies are generated. Experiments (iv) demonstrate that even after the collapse of MOC in the Northern Hemisphere, eddies can still be generated and carry energy across the equator into the Northern Hemisphere; these eddies act to attenuate the impact of the MOC shutdown on short time scales. The results described here may be particularly pertinent to ocean general circulation models in which the Reynolds number lies close to the bifurcation point separating the laminar and turbulent regimes. © 2009 American Meteorological Society. |
| first_indexed | 2024-03-06T19:06:10Z |
| format | Journal article |
| id | oxford-uuid:1535bab5-d919-4bc3-81a8-6738da20746d |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:06:10Z |
| publishDate | 2009 |
| record_format | dspace |
| spelling | oxford-uuid:1535bab5-d919-4bc3-81a8-6738da20746d2022-03-26T10:24:09ZEddy Formation in the Tropical Atlantic Induced by Abrupt Changes in the Meridional Overturning CirculationJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:1535bab5-d919-4bc3-81a8-6738da20746dEnglishSymplectic Elements at Oxford2009Goes, MMarshall, DWainer, IThe variability of the meridional overturning circulation (MOC) in the upper tropical Atlantic basin is investigated using a reduced-gravity model in a simplified domain. Four sets of idealized numerical experiments are performed: (i) switch-on of the MOC until a fixed value when a constant northward flow is applied along the western boundary; (ii) MOC with a variable flow; (iii) MOC in a quasi-steady flow; and (iv) shutdown of the MOC in the Northern Hemisphere. Results from experiments (i) show that eddies are generated at the equatorial region by shear instability and detached northward; eddies are responsible for an enhancement of the mean flow and the variability of the MOC. Results from experiments (ii) show a transitional behavior of the MOC related to the eddy generation in interannual-decadal time scales as the Reynolds number varies due to the variations in the MOC. In experiments (iii), a critical Reynolds number Rec around 30 is found, above which eddies are generated. Experiments (iv) demonstrate that even after the collapse of MOC in the Northern Hemisphere, eddies can still be generated and carry energy across the equator into the Northern Hemisphere; these eddies act to attenuate the impact of the MOC shutdown on short time scales. The results described here may be particularly pertinent to ocean general circulation models in which the Reynolds number lies close to the bifurcation point separating the laminar and turbulent regimes. © 2009 American Meteorological Society. |
| spellingShingle | Goes, M Marshall, D Wainer, I Eddy Formation in the Tropical Atlantic Induced by Abrupt Changes in the Meridional Overturning Circulation |
| title | Eddy Formation in the Tropical Atlantic Induced by Abrupt Changes in the Meridional Overturning Circulation |
| title_full | Eddy Formation in the Tropical Atlantic Induced by Abrupt Changes in the Meridional Overturning Circulation |
| title_fullStr | Eddy Formation in the Tropical Atlantic Induced by Abrupt Changes in the Meridional Overturning Circulation |
| title_full_unstemmed | Eddy Formation in the Tropical Atlantic Induced by Abrupt Changes in the Meridional Overturning Circulation |
| title_short | Eddy Formation in the Tropical Atlantic Induced by Abrupt Changes in the Meridional Overturning Circulation |
| title_sort | eddy formation in the tropical atlantic induced by abrupt changes in the meridional overturning circulation |
| work_keys_str_mv | AT goesm eddyformationinthetropicalatlanticinducedbyabruptchangesinthemeridionaloverturningcirculation AT marshalld eddyformationinthetropicalatlanticinducedbyabruptchangesinthemeridionaloverturningcirculation AT waineri eddyformationinthetropicalatlanticinducedbyabruptchangesinthemeridionaloverturningcirculation |