The effect of transverse canyons on coastal trapped waves : a modeling study /
The presence of a transverse canyon on the continental shelf/slope scatters the energy of encroaching coastal trapped waves (CTWs) and perturbs the flow in the area of the canyon. Analytical work has shown that forward scattering is preferentially into nearby allowable higher modes and backward sca...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739641001&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The presence of a transverse canyon on the continental shelf/slope scatters the energy of encroaching coastal trapped waves (CTWs) and perturbs the flow in the area of the canyon. Analytical work has shown that forward scattering is preferentially into nearby allowable higher modes and backward scattering into the fundamental mode, with the energy density increased in and near the canyon. In this research the scattering of CTWs from transverse canyons is investigated with a numerical model which allows the specification of arbitrary canyon bathymetry and density stratification. A canyon bathymetry similar to those typically found off the eastern coast of the United States is used. The strength of forward and backward scattering of wave energy decreases and increases, respectively, with canyon width due to the canyon being seen by the CTWs as a pair of narrowing and broadening shelves rather than as an abrupt transition. Increasing stratification strength for a constant width canyon shows a decrease in backward scattered wave energy and an concomitant increase in forward scattered energy as a stratification strength sufficiently strong to disallow backscattering is reached. Increased stratification opens baroclinic avenues of adjustment and thus qualitatively changes the nature of flow in the canyon area. The numerical simulation of CTW scattering should be undertaken only with a keen awareness of the limitations of the methods used. The usefulness of methods commonly used for performing orthogonal decompositions in order to ascertain how incoming wave energy is partitioned into scattered modes is a function of the frequency of the CTW wave being simulated, with lower frequency waves more amenable to the use of these methods than higher frequency waves. Great care should also be taken when using sigma coordinate models in regions that combine strong stratification with steep bathymetry, especially when the relative magnitudes of the velocity fields being simulated and the velocity fields induced by numerical errors are similar. |
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| Item Description: | Vita. "Major Subject: Oceanography." |
| Physical Description: | ix, 124 leaves : illustrations, maps ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 120-123. |