Models incorporating a single baroclinic mode and realistic coastline geometry are used to analyze the linear, dynamic response to estimates of the interannual wind field over the tropical Pacific and the seasonally varying winds of the tropical Atlantic. The interannual variability of the tropical Pacific is studied for the period January, 1961 to December, 1978. Model pycnocline variations at several locations are similar to the observed sea level fluctuations. El Nino events are depicted as periods when the pycnocline is persistently deep along the eastern boundary. Remotely forced equatorial Kelvin waves are responsible for this response. The character of each simulated El Nisno is strongly dependent on the relation between zonal wind stress changes in the western an central equatorial Pacific. A rapid shoaling of the pycnocline in the western tropical Pacific during each El Nino is caused by westward-propagating Rossby waves. Interannual pycnocline displacements in the central equatorial Pacific are determined by the superposition of Kelvin waves excited to the west and first-mode Rossby waves generated to the east. / The forced periodic response to the seasonal wind field of the tropical Atlantic is a spatially dependent combination of a locally forced response, Kelvin waves, Rossby waves, and multiple wave reflections. The seasonal displacements of the model pycnocline are compared with observed dynamic height. Annual and semiannual fluctuations dominate the seasonal signal throughout the basin. In general, the distribution of amplitude and phase are similar for annual changes in dynamic height and pycnocline depth. Major features of the seasonal response are reproduced, e.g. an east-west tilting of the equatorial pycnocline about a pivot point, the seasonal pycnocline movement along the northern and southern coast of the Guinea Gulf, and a significant change of phase in the ocean variability north and south of the ITCZ. The relative importance between local and remote forcing is determined for several parts of the basin. The wind-driven annual signal in the Gulf of Guinea is due to zonal wind stress fluctuations west of the gulf. The seasonal response in the western equatorial and northernmost parts of the basin are primarily local. / Source: Dissertation Abstracts International, Volume: 43-10, Section: B, page: 3173. / Thesis (Ph.D.)--The Florida State University, 1982.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_74959 |
| Contributors | BUSALACCHI, ANTONIO JAMES, JR., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 149 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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