Graduation date: 1979

Hydrographic, tidal, and meteorological data collected near Newport, Oregon, were analyzed to determine the relative contributions of temperature, salinity, and air pressure variations to the recorded departures of sea level from mean sea level. Nearshore the steric and recorded sea levels exhibited a similar seasonal oscillation, with high sea levels in winter and low sea levels in summer. Analysis of the steric topography indicated the presence of two distinct regions off Oregon, one extending from shore to 45 nm, and the other from 65 nm offshore to seaward of NH 165. The seasonal oscillations of sea level were approximately six months out of phase in the two regions. The nearshore region was greatly influenced by upwelling and local runoff, while the offshore region was dominated by the Columbia River plume which flows south during the summer months. Redacted for privacy Steric departures were of greater magnitude than air pressure departures, but no single dominant cause of sea level oscillation could be identified, thus justifying the labeling of this region as a transition zone from steric to pressure dominance in sea level determination. Thermal and haline components of the steric departure were shown to be of comparable magnitude and in phase. The range of steric departures was approximately 16 cm, a figure compatible with ranges reported for stations of similar latitude. / Graduation date: 1973

Graduation date: 1973

Two beaches with significant differences in grain size and thus in beach profile morphology and response to wave conditions were studied on the Oregon coast. Gleneden Beach, just south of Siletz Spit and Lincoln City, has a median grain size of 0.36 mm (medium sand) and a steep beach face slope, while Devil's Punchbowl Beach has a median grain size of 0.23 mm (fine sand) and low concave-up beach face slope. Eleven beach profile surveys were obtained at Gleneden Beach and twelve at Devil's Punchbowl Beach between August 1976 and April 1977; on average once every two weeks during spring tides. Gleneden Beach showed the typical change from a swell profile with a wide berm that prevails during summer months to a storm profile with little or no berm that exists during the stormy winter months. This transition occurred in August and September, being completed by early November. The finer-grained Devil's Punchbowl Beach also showed general erosion during the fall. However, a transition from a swell profile to a storm profile is not as clear there as the beach has little berm, even in mid-summer, and always has a concave-up appearance typical of the winter storm profile. Gleneden Beach and Devil's Punchbowl Beach did not always agree in their responses to the changing wave conditions. One may be eroding at the same time the other is accreting. These differences in response to changing wave conditions appear to result from their differences in grain size. Volume changes of the erosion or deposition at the two beaches were computed from successive beach profiles. The coarser-grained Gleneden Beach showed larger changes in erosion and deposition, the maximum erosion being 0.71 m³ per meter of profile length, while the finer-grained Devil's Punchbowl Beach showed a maximum erosion of 0.25 m³ per meter of profile length. Attempts were made at relating the erosion or deposition and the volumes of erosion/deposition to the wave breaker heights and deep-water wave steepness that occurred between the beach profile sequences. There is only a vague relationship between the volumes of beach erosion/deposition and the wave heights, the probability of erosion increasing and the volume of sand eroded increasing with increasing wave breaker heights. The maximum wave heights that occur during the time interval appear to be most important to the volume of erosion, erosion volumes being large if storm breaker heights reach 5 to 6 meters or greater. Deposition prevails when the average breaker heights fall below 4 meters and storms are limited to breaker heights less than 5 meters. The deep-water wave steepness shows little relationship to the erosion or deposition volumes, indicating that the wave period is not as important a parameter as the wave height to beach erosion. / Graduation date: 1977

Observations of wind, currents, sea level and hydrography obtained during the 1972 Coastal Upwelling Experiment (CUE-I) are described. Only phenomena with periods longer than a day are considered. One section describes the changes observed during a period of variable winds in early July 1972. Another describes a ribbon of relatively cool water observed early in the upwelling season and attributes its existence to advection of Subarctic water by the coastal jet associated with upwelling. A third section describes the seasonal development of the upwelling regime between April and October 1972. These studies are combined with other studies of CUE-I data to provide a partial description of the upwelling regime which is compared to the conceptual model developed prior to CUE-I. It is concluded that the vertical and onshore velocity fields are as yet largely unknown. The alongshore velocity field includes southward surface flow with a coastal jet, a persistent vertical shear with deeper velocities northward relative to the surface and high coherence with the wind and sea level at periods of several days. A poleward undercurrent is observed, but it may not be an integral part of the upwelling regime. The hydrography has a strong seasonal cycle. Differences between any two sections between April and October l972 are smaller than between any of these and a section occupied in January 1973. Oscillations in the wind with periods of several days cause significant changes in the region inshore of 10 km and in the upper 20 m further offshore. Subsurface temperature observations are not coherent with the wind at periods of several days. / Graduation date: 1974

The oceanic phenomenon of upwelling along the Oregon coast is examined. Upwelling in both the open ocean and coastal regions is discussed. An idealized model is used, envisaging the ocean off Oregon to consist of homogeneous surface and deep layers separated by a pycnocline. The equations of motion are solved to yield the vertical velocity at the base of the surface layer. A comparison is made between the model and results inferred from hydrographic data. In the open ocean region qualitative agreement is observed between the wind stress curl and the depth of the surface layer. Geostrophic meridional transports relative to the 1000 decibar surface were computed and found to be of the order of the uncertainty. In the coastal upwelling region surface layer zonal transports were computed from the meridional component of the mean wind stress and compared with values inferred from oceanographic data. Coastal upwelling along the Oregon coast is clearly associated with the northerly (longshore) component of the wind stress. / Graduation date: 1964

Graduation date: 1966

Graduation date: 1999 / Best scan available for figures. Original has a moray pattern.

Graduation date: 1964

Using the hydrographic data collected by the ACONA from June 1961 to May 1963, the Oregon coastal front has been examined. Representative sigma-t surfaces were chosen to delineate the front, and changes in position of these surfaces with time were used to obtain zonal flow rates for the frontal and surface layers. From May to early October upwelling resulted in offshore flow. Onshore flow was indicated from late October to January, and indeterminate zonal flow occurred during the remainder of the year. Flow within the front agreed with these surface flows in ten of the fourteen observational periods. / Graduation date: 1964