Cyclonic ring interaction with the Gulf Stream recirculation is studied numerically using a two-layer quasigeostrophic model. Rings shed by the Gulf Stream in previous eddy-resolving general circulation experiments of Holland move westward, embedded in the recirculation. We find that these rings, when transferred to quiescent surroundings, have a nearly steady northward translation component, suggesting steering by the recirculation. Quasi-Lagrangian vorticity balances show that, if an isolated ring decays by Rossby wave dispersion, northward translation is required for potential vorticity conservation. / Although stable westward channel flows comparable to the recirculation failed to inhibit northward translation, a current that appeared to be barotropically unstable substantially reduced it. Energy extraction probably offset decay, reducing the need for planetary vorticity addition. / The trajectories in the general circulation model comprise two phases. Southward translation, after apparent separation, occurs in a region found baroclinically unstable by previous investigators. The ring continues to grow in area and relative vorticity. Decay characterizes the later phase. / The channel rings adjusted after a month to a quasi-steady deep potential vorticity configuration. A wedge of fluid intrudes the region below the ring from the south. The exiting fluid overshoots its undisturbed latitude, leaving a well-mixed wake. A somewhat weaker "deep eddy wedge" appears in general circulation experiments. / We find that moderate bottom slope can alter the deep potential vorticity distribution, preventing wedge formation. Deep potential vorticity influence on upper eddy dynamics may be critically related to potential vorticity homogenization and the structure of the thermocline. / Source: Dissertation Abstracts International, Volume: 45-11, Section: B, page: 3454. / Thesis (Ph.D.)--The Florida State University, 1984.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_75456 |
| Contributors | EVANS, JAMES CHRISTOPHER., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 238 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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