An intensive chemical investigation, that includes the determinations of salinity, oxygen, nutrients, pH, alkalinity, and total carbon dioxide of the Columbia River plume off the Oregon coast in July 1967 shows the following unique features: 1. Along the axis of the river plume both the salinity minimum and temperature maximum occur. The location of these extrema at zero, ten, twenty meters depths differ considerably, suggesting different patterns of water flow at different depths. 2. Throughout the plume region, at salinities less than 32.5%, the plume water is supersaturated with respect to dissolved oxygen, and a subsurface oxygen maximum exists at the depths of 3.0-50 meters. 3. The relationship between apparent oxygen production by marine organisms and nutrient concentrations shows biological production of dissolved oxygen is a definite cause for the oxygen supersaturation in the plume region. 4. The plume area off Oregon is a source of oxygen transfer from the ocean into the atmosphere. / Graduation date: 1969

Hydrographic and bathythermograph data taken off the Oregon coast during a two week period in August of 1969 were analyzed to determine if heat content and mixed layer depth may be used as indicators of Columbia River plume water. Heat content was found to be a poor indicator of plume water because of large additions of heat to the plume as the waters flowed southward and because the layer over which heat content was integrated (0 to 20 meters) was inconsistent with the depth of the plume. High variability among observations made analysis of mixed layer depth difficult and reduced its utility as an indicator of plume waters. Hydrographic sections taken during the summer months off Oregon from 1960 through 1969 were also examined. The axis of the Columbia River plume was located in 70 instances. The salinity axis was found to lie inshore of the temperature axis by a mean distance of 8.5 nautical miles. This displacement increased downstream and was most pronounced in July and August. A simple model showed the displacement to be the result of a large temperature gradient across the nearshore portion of the plume pynocline. / Graduation date: 1972

In this study methods were developed for the prediction of wave conditions that are hazardous to navigation at river entrances, with emphasis on applicability to the Columbia River. There are two basic components to the prediction system: (1) a semi-automated spectral method for forecasting the significant height and average period of waves in deep water, and (2) an index of navigation hazard at river entrances that depends on the significant height and average period in deep water and on the mean current and water depth at the entrance. The computerized, deep water forecast method is a hybrid scheme that combines the spectral principles of the Pierson-Neumann-James method with the graphical input techniques of Wilson and the fetch limited spectrum of Liu. The significant heights generated by the method are well verified by winter wave measurements at Newport, Oregon. The hazard index is based on the probability of wave-breaking in water of arbitrary depth and current. The breaking probability is derived under the assumption that wave heights and squared periods are statistically independent and distributed according to a Rayleigh probability density function. The breaking-wave probability and the hazard index depend on the wave steepness in deep slack water and on the depth (relative to the wave period squared) and current (relative to the period) at the river entrance. The dependence on depth and current is achieved in two ways: (1) the limiting steepness (breaking index) k found as a function of relative depth and relative current, and (2) the wave spectrum in water of arbitrary depth and current is found by transformation of the spectrum in deep slack water. The transformation is performed by requiring that the rate of wave energy propagation remain constant. The hazard index is closely related to the probability of breaking swell. At water depths that are typical of river entrances, the hazard index depends strongly on the significant wave height, mean current and depth, but only weakly on the mean wave period (since the breaking height of swell at such depths is only weakly dependent on period). Hindcasts of deep water significant wave heights and hazard indices compared reasonably well with measured heights and Columbia River bar closure periods. Forecasts based on accurate prognostic weather charts should provide similar results. / Graduation date: 1974

Radioactive chromium-51, a waste byproduct from operation of nuclear reactors at Hanford, Washington, has been followed down the Columbia River and into the Pacific Ocean. Chemical factors influencing the partitioning of ⁵¹Cr between solution and sediment have been considered. Chromium-5l, in a hexavalent oxyanion when introduced into the Columbia River, largely remains in solution in a hexavalent anion during its passage through the lower river and after its entrance into the Pacific Ocean. A minor fraction of Hanford-induced ⁵¹Cr becomes attached to suspended particles and bottom sediments. Reduction of Cr(VI) to Cr(III) apparently precedes or accompanies sorption. Iron oxides appear to be the most important sorption substrate. Sediment organic matter acts both as a reducing agent, making ⁵¹Cr less soluble, and as a sorption substrate. Ion exchange on sediment particles is not important in retention of ⁵¹Cr by Columbia River sediment. Chromium-51 is a sensitive and unique tracer for Columbia River water at sea and has been used to trace the Columbia River plume up to 525 km away from the mouth of the river. Dispersion of ⁵¹Cr by the Columbia River system would be adversely affected by: 1) lowered pH; 2) presence of particulate organic wastes; 3) increased temperature; 4) increased biological oxygen demand. These factors would increase the rate of uptake of ⁵¹Cr by sediments and thus increase the steady-state inventory of ⁵¹Cr on the bottom of the river. / Graduation date: 1967

The Columbia River plume region was investigated during the period of 20 June to 3 July, 1968 by light scattering measurements and standard hydrographic station observations. The Columbia River plume was traced by the light scattering particles of the plume water. The light scattering particles are estimated to be contained in the plume water for 30 to 50 days. On the basis of the data taken in the Columbia River plume region, a conceptual model is made to describe the flow of river originated particles to the ocean water. In the distribution of the light scattering particles a northward deep current under the plume near the river mouth and a subsurface offshore flow near the bottom of the Columbia River plume are shown. / Graduation date: 1970

Graduation date: 1970

Thesis (Ph. D.)--Oregon State University, 1967. / Typescript (photocopy). Includes bibliographical references (p. 99-109). Also available online.

Thesis (Ph. D.)--Oregon State University, 1974. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1988. / Includes bibliographical references (leaves 183-185).

Thesis (Ph. D., Natural Resources)--University of Idaho, 2009. / Major professor: George LaBar. Includes bibliographical references. Also available online (PDF file) by subscription or by purchasing the individual file.