The purpose of this work is to study the interaction of two oceanic eddies in contact with each other, and to investigate the long-time evolution of the merged state when merging occurs. The emphasis is put on strong eddies for which the interfaces rise to the surface. We use a reduced-gravity shallow-water model in two distinct dynamical regimes: the frontal-geostrophic approximation, and the full primitive equations. In both cases, equations are solved numerically by a particle-in-cell method in order to handle interfacial surfacing. / A series of experiments shows that the eddy-eddy interaction leads to merging in most situations. However, a marked reluctance to merge was observed with: zero-potential-vorticity eddies, cold-core rings, and vortices of unequal sizes even on a beta-plane. When merging takes place, the resulting state is a single elongated vortex which, depending on the physics at play in that particular experiment, may or may not become axisymmetric. Namely, axisymmetrization occurs in the frontal-geostrophic experiment, while the merged state remains elliptical in the primitive-equation case. A comparison with results of intermediate models sheds some light on this difference. The special case of interaction via eddy pulsation is also simulated with the primitive-equation model to find that two non-touching but pulsating eddies can still merge. The work concludes with a study of the stability of filaments, which are observed to form and break during eddy axisymmetrization. It is found that frontal filaments always break up into a series of eddies. Conservation of mass, energy and potential vorticity explains their number and sizes. Results also show that the eddies accommodate a surplus in angular momentum by either taking a staggered position with respect to the zonal axis of the filament, or acquiring an elliptical shape, or both. / Source: Dissertation Abstracts International, Volume: 51-01, Section: B, page: 0125. / Major Professor: Benoit Cushman-Roisin. / Thesis (Ph.D.)--The Florida State University, 1989.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_78159 |
| Contributors | Pavia, Edgar Gerardo., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 100 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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