Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 58-62). Also available on the World Wide Web.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1979. / Supervised by Robert C. Beardsley. Vita. Includes bibliographical references (leaves 121-122).

Thesis (Ph.D.)--Brown University, 2005. / Vita. Thesis advisor: Donald W. Forsyth. Includes bibliographical references (leaves 61-69, 98-103, 176-182, 224-229). Also available online.

Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.

No description available.

An acoustic array was deployed in the nearsurface layer in Saanich Inlet, B.C. to image breaking waves using only the naturally occurring acoustical radiation from the breaking region over the band [160 Hz, 2000 Hz]. The 1.5-element array was configured as a horizontal cross with an 8 m aperture, bottom-moored, and positioned nominally 3 m beneath the surface. Due to sensor sparseness, the array PSF at any particular frequency was badly contaminated by grating lobes. A novel broadband scheme was devised to combine information at multiple independent frequencies to yield unambiguous images with resolution of about 0.2 m at the sea surface. The broadband scheme assumed space-time separability in the source mutual spectral density. This is only considered valid for breaking waves above about 400 Hz. Nonstationarity and time-bandwidth constraints yielded at most six independent frequency bands within the system passband. A parametric image analysis showed that the images align closely with the wind and can be observed moving downwind with a speed about two-thirds the phase speed of the dominant component of the wind waves. Absolute power levels were found to be consistent with previously published results. The absolute power levels were parameterized by where [special characters omitted] and λ (f) is well-described by a simple first order relation [special characters omitted], where [special characters omitted] varied depending on the size of the wave but b1 appeared to be a more universal constant estimated at -4.55 ± 0.47. The source mechanism for frequencies below about, 400 Hz was modeled two ways: (1) as a point source (which would follow if an acoustically compact “collective oscillation" region had formed), and (2) as due to off-peak spectral contributions from bubbles resonant at 400 Hz. Neither model achieved a satisfactory fit to the observed data. This seems to imply that the mechanism below about 400 Hz was acoustically extended and radiating as energetically as any resonant bubbles. / Graduate

The dynamics of the Arctic ocean are studied on a polar projection of the sphere. The density structure is idealized as a two-layer system, and a general formulation is developed which allows inclusion of latitudinal and longitudinal depth variations as well as asymmetries in the boundaries of the ocean. For simplicity, the density structure is neglected when depth variations are present. Time dependent displacements from equilibrium levels are assumed to be waves of constant zonal wave number; no radial propagation is considered. Amplitude equations are derived for these displacements, subject to the assumption that the polar basin is small enough to keep only a first approximation to the curvature of the Earth. A semi-qualitative investigation of the possible solutions is made in the case of a symmetrical basin, using the Method of Signatures, and existence criteria are found for the solutions in the presence of radial depth variations. Concentrating thereafter on planetary waves, explicit solution for such motions in the simplest case (depth constant, symmetrical boundaries) allows comparison with the results of other investigators (Longuet-Higgins, 1964 b; Goldsbrough, 1914 a) . It is found that the polar projection and first approximation to the curvature give quite good results, so that this method may be applied to polar regions in the same way as the β-plane is used in mid-latitudes. The general effects of radial bottom slopes are discussed and a simple example treated more explicitly. Some theorems of Ball (1963) on the motions of shallow rotating fluids in paraboloidal basins are found to hold for such basins in the polar plane approximation to the sphere. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

A mathematical model is developed which extends the theory of rip currents developed by Bowen (1969b) for a straight beach to curved beaches where radii of curvature are large relative to the width of the surf zone. Nine forcing terms are found to cause rip current systems. The terms are functions of the longshore variation in wave height and angle of incidence of the incoming waves at the breakers. The model is applied to the case of a circular beach with conical nearshore bottom topography. A large rip current component is found to exist which is inversely proportional to the radius of curvature of the beach. Another significant rip current component is found to be proportional to the variation in the angle of incidence of the waves at the breakers. This component would cause rip currents on a straight beach where some irregular offshore topography caused some variation in the incident angle of the incoming waves. Another component rip current was found which was essentially the same as the one predicted by Bowen (1969b). / Science, Faculty of / Physics and Astronomy, Department of / Graduate

This thesis contains a manuscript describing the implementation of a high resolution wave forecasting model for the coasts of Washington and Oregon. The purpose of this project was to advance the wave predictive capabilities of the states of Oregon and the southwest part of Washington by including the effects of local bathymetric features in the operational forecasts. A 30 arc-second resolution wave forecasting model was implemented making use of the WAVEWATCH III numerical code covering the coastal region from Klamath, CA to Taholah, WA. The wave forecasts extend to the continental shelf at this resolution. To assess the performance of the model, its output was compared against in situ data, with normalized root-mean-squared errors in significant wave height in the vicinity of 0.20 and linear correlation coefficients greater than 0.80. Making use of the resulting validated regional scale wave forecasting system, an evaluation of the model sensitivity to the inclusion of bottom friction and wind input at the shelf level was performed. Results suggest that neither dissipation due to bottom friction or wind generation are significant for long term forecasting/hindcasting in the region. Results from a series of hindcasts suggest that several significant offshore features may affect the nearshore wave field. To evaluate it, a shelf scale SWAN model was implemented and a series of numerical experiments performed. Results suggest that the Astoria and McArthur Canyons; the Stonewall, Perpetua, and Heceta Banks; and Cape Blanco are significant bathymetric features that are capable of producing significant alongshore variability in wave heights nearshore. / Graduation date: 2013

Graduation date: 1998