April 2003 729 Simonnet Et Al.
The time-dependent wind-driven ocean circulation is investigated for both a rectangular and a North Atlantic-- shaped basin. Multiple steady states in a 2-layer shallow-water model and their dependence on various parameters and other model properties were studied in Part I for the rectangular basin....
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.8.5150 http://www.atmos.ucla.edu/tcd/MG/./PREPRINTS/SGITW2.pdf |
| Summary: | The time-dependent wind-driven ocean circulation is investigated for both a rectangular and a North Atlantic-- shaped basin. Multiple steady states in a 2-layer shallow-water model and their dependence on various parameters and other model properties were studied in Part I for the rectangular basin. As the wind stress on the rectangular basin is increased, each steady-state branch is destabilized by a Hopf bifurcation. The periodic solutions that arise off the subpolar branch have a robust subannual periodicity of 4--5 months. For the subtropical branch, the period varies between sub- and interannual, depending on the inverse Froude number F 2 defined with respect to the lower active layer's thickness H 2 .AsF 2 is lowered, the perturbed-symmetric branch is destabilized baroclinically, before the perturbed pitchfork bifurcation examined in detail in Part I occurs. Transition to aperiodic behavior arises at first by a homoclinic explosion off the isolated branch that exists only for sufficiently high wind stress. |
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