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Modelling of ocean tides

In this thesis three independent studies of tidal dynamics have been pesented. The first is an analytical study of continental shelf tides forced at the ocean boundary. Earlier studies have shown that the response for a sloping shelf and a flat shelf differ and that the response for a flat shelf changes when tides are incident at an angle. Other studies considered a sloping shelf but they did not take into account a possible non-zero depth at a coastal wall. This study shows that the effects of a sloping shelf, a coastal wall and obliquely incident tides an all significantly modify the response on the shelf. The modification increases with the width of the shelf, and in a wide shelf scenario, near resonance, it greatly modifies the response. Secondly, the Princeton Ocean Model in barotropic mode along with a tracer transport module has been used to study the tides of Sydney Harbour. The tidally induced residual circulation due to the semi-diurnal tide consists of a series of recirculating gyres which are due to the interaction of flow with topography. This study shows that in the harbour it is the Lagrangian residual velocity not the Eulerian residual velocity which determines the net transport of material over a tidal cycle. In addition, the flushing time of the harbour varies significantly in space, and the tidal mixing is restricted in the vicinity of the entrance. The third is a theoretical study of forced oscillations in a rotating, flat-bottomed, circular basin. This study shows that the direction of propagation of waves in a basin depends on the ratio of its radius to depth. At each latitude there is a critical value of this ratio and this value decreases with increase in latitude. Beyond this value, waves start to propagate around the basin in the opposite direction to the earth ???s rotation (clockwise in the northern hemisphere and anti-clockwise in the southern hemisphere).The presence of friction increases this critical value which shows that friction plays an important role in determining the response.

Identiferoai:union.ndltd.org:ADTP/274345
Date January 1998
CreatorsDas, Pritha, School of Methematics, UNSW
PublisherAwarded by:University of New South Wales. School of Methematics
Source SetsAustraliasian Digital Theses Program
LanguageEnglish
Detected LanguageEnglish
RightsCopyright Pritha Das, http://unsworks.unsw.edu.au/copyright

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