In the first part of this thesis I investigated the surface layer dynamics of Knight Inlet to see which of the governing forces: inertial accelerations, pressure gradient, or stress, dominated the momentum balance for a steady two-layer flow. I estimated the inertial terms and pressure term in the momentum equation, which had been integrated over the surface layer, from conductivity, temperature, and depth data measured in Knight Inlet in the springs of 1986 and 1987. I solved for the coefficient of interfacial friction, k, so that an estimate of the interfacial stress, Tί = pkΔu², could be made. I obtained the idea of the Knight Inlet analysis from an earlier attempt I had made at resolving the balance of forces in the Fraser River plume. I found an estimate of the friction coefficient at the interface for the plume; k = 1.55 x 10¯⁴, which was much smaller than an assumed value used by Cordes, et al. (1980). The results of the Knight Inlet study showed that within the inlet (inside the sill), the pressure gradient, and the stress dominated the balance for high runoff conditions. Estimates of the coefficient of friction were on the order of 10⁻² and 10⁻³. The depth of the interface appeared to be constant inland of the sill. The second part of this thesis was a qualitative study of fine structure in Knight Inlet. I processed the CTD data measured in 1986 and 1987 to find the first differences of temperature and salinity. I used the profiles of ΔT and ΔS to describe features present in the upper and lower water. Later, data that had been measured with a special microprofiler at the same time as the 1987 CTD data were sampled, were compared to the CTD data. For this comparison, I studied profiles of [formula omitted] (calculated as a centered first difference), and the log of the variance of [formula omitted]. Results of this study were that the upper water (< 30 m) appeared more highly active than the deeper water (> 30 m), especially at the head of the inlet, at the sill, and in the region of the interface. The deeper water contained fluctuations of temperature and salinity that were concentrated in patches which were several meters thick. For the year, 1987, the microprofiler revealed the existence of temperature variations that were more significant than I had originally judged from the profiles of ΔT and ΔS. Values of the variance of the temperature gradient, [formula omitted] in some areas of the deeper water were almost as large as values in the upper water. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Measurements of the distributions of temperature, salinity and oxygen in Burrard Inlet and Indian Arm, British Columbia from May 1974 to October 1975 have been analysed to determine features of the large scale circulation in this system. Observations at roughly four-week intervals were supplemented by serial CSTD casts taken over intervals of a few hours, and by 93-day records of near-bottom currents, temperature, and salinity on the Indian Arm sill. Short-term tidal fluctuations in property distributions have been shown to be small compared to seasonal changes. Circulation in the Burrard Inlet - Indian Arm system is basically estuarine: relatively fresh surface waters normally flow down the inlet overlying more saline waters which enter from the Strait of Georgia. Turbulent mixing associated with estuarine and tidal flow through the shallow constrictions at both First and Second Narrows yields surface waters between the narrows which are more saline and cooler than those which would be found in a simpler estuarine environment. In a complementary sense, bottom waters are fresher and warmer. Significant exchange and overturn of deep water in Indian Arm was recorded between October 1974 and April 1975. Intruding waters were shown to have originated west of First Narrows. In one instance exchange of at least 80% of the volume of the Arm, over an interval of 33 days, was inferred from property distributions, compared to exchange estimates of 111% and 74% deduced from the current meter record for the same event. Exchange was shown to be intermittent, with fresh water runoff volume into Indian Arm, tidal mixing (particularly at Second Narrows) and density of Georgia Strait water being identified as some of the controlling factors. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Unknown

Fresh water entering the inlets moves seaward, mixing with and entraining salt water from below. On the assumption that horizontal advection of salt is balanced by vertical diffusion, the magnitude and variation in time and space of the diffusion coefficient are determined by numerical evaluation of the differential equation describing this process. A method of systematically smoothing the data is established by solving the differential equation analytically. These solutions yield further information on the diffusion coefficient which is found to be nearly constant in the upper reaches of an inlet but increases rapidly towards the mouth in the brackish layer. A technique is developed for determining the total fresh water inflow to the inlets using precipitation observations and available river flow measurements. The results indicate that a significant proportion of fresh water enters from the sides at all times. The importance of this in theoretical studies is emphasized. The results are also analyzed for a possible relationship between inlet dimensions and intensity of mixing. A new method, based on the heat budget, is developed to determine the mean seaward movement of the brackish layer. This method is also applied to determine the depth from which salt water is entrained into the surface layer. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Wind-driven up welling events near Brooks Peninsula off the west coast of Vancouver Island have been identified during the summers of 1988 and 1989 from sea surface NOAA AVHRR thermal imagery obtained at the UBC Satellite Oceanography and Meteorology Laboratory. Software has been developed to characterize the strength and extent of the surface cooling associated with the upwelling. A two-dimensional, 2-layer finite difference model with 1 km resolution has been formulated to examine the small-scale dynamics of the upwelling events. The model uses local wind and includes realistic coastline and bathymetry. The wind-stress and coastline configuration appear to be the main factors contributing to favourable upwelling regions. The results of the model compare favourably to the observed starting location of the upwelling. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Data from five conductivity-temperature-depth (CTD) surveys collected during 1985 and 1986 in support of project MOIST -Meteorological and Oceanographic Influences on Sockeye Tracks- are used to describe the salient oceanographic features of the waters lying between Vancouver Island and the British Columbia mainland coast. Using these data, four oceanographic regimes are clearly defined on the basis of salinity structure. Temperature-Salinity diagrams are used to discuss water types and mixing ratios in these regimes. Vigorous tidal mixing over shallow sills and/or in narrow channels produces tidally mixed fronts that separate oceanographic regimes. The tidal evolution of two of these fronts located near Weynton Passage and Cape Mudge are discussed by means of 24-hour CTD stations. Seasonal variability of the residual estuarine circulation is examined and estimates of the seaward flow in the upper layer of a very simple two-layer geostrophic model were found to be in reasonable agreement with the few direct measurements made in this region. Seasonal variability of the general hydrography is described. Ultrasonic telemetry provided horizontal and vertical distribution time series data for return migrating sockeye salmon (Oncorhynchus nerka). Concurrent high spatial resolution CTD data was used to specify the ambient temperature and salinity fields in the immediate vicinity of the tagged sockeye. Spectral analysis of the depth and ambient oceanographic data time series revealed periodic vertical movements at approximately 15 and 33 minutes per cycle for fish tracked in the slightly stratified regimes of Queen Charlotte Strait, western Johnstone Strait and the Strait of Georgia. High frequency large amplitude periodic vertical movements were characteristic of fish that did not make significant progress towards the Fraser River: low frequency small amplitude vertical movements were characteristic of well oriented fish. Aspect ratio, defined as the horizontal distance travelled divided by the vertical distance travelled, gave an indication of the relative degree of homeward orientation. Vertical distribution and orientation were also related to the frequency and duration of successive vertical excursions. Fish depth and vertical swimming velocity were found to be positively correlated in regions of weak stratification and/or for well oriented fish. Ambient density gradients were not found to inhibit vertical movements as the rate of doing work against hydrodynamic drag was several orders of magnitude greater than that of doing work against a varying buoyancy force. In the presence of strong temperature and salinity gradients, tracked sockeye were most often observed at depths not associated with the maximum gradients. In stratification regimes where temperature and salinity gradients were nearly uniform with depth, tracked sockeye were observed at depths uniformally distributed throughout the thermo- and haloclines. Minimum vertical swimming velocities were generally associated with minimum vertical gradients. These observations suggest that the tracked sockeye frequently swam through but did not reside in the region of the maximum gradients. Dimensional analysis suggested that physical variables alone are insufficient to specify the vertical distribution of the tracked sockeye. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

An anodic stripping voltammetric technique was developed for the simultaneous determination of Cu and Pb in seawater. Mercuric ion added to the sample is plated out with the metals of interest onto a highly polished glassy carbon electrode. The thin mercury films obtained by this procedure gave excellent resolution and sensitivity although a non-linear response resulted in the case of Cu, presumably as a result of saturation of the mercury, at concentrations in excess of 4 μg/1. The technique was applied to a short term study of the distribution of Cu and Pb in Indian Arm and Burrard Inlet. Large fluctuations in the concentrations of both metals were observed during the sampling period, July to October, 1972. Although dissolved Pb concentrations were lower than might be expected near a large urban area, there was, nevertheless, an overall enrichment of the subsurface waters of the inlets relative to Georgia Strait by as much as an order of magnitude. Dissolved Cu concentrations were not, however, significantly higher than those reported for other B.C. coastal waters. Although study of metal speciation by the method employed here was limited by the excess of mercuric ions added to the samples and interferences from surface active agents, evidence was obtained indicating that a portion of Cu in some British Columbia coastal seawater samples is complexed with dissolved organic matter. The experimental conditions indicate that these complexes are either inert to displacement by mercuric ions or have a high degree of specificity for Cu. / Science, Faculty of / Chemistry, Department of / Graduate

Knowledge of the surface heat transfer in coastal inlets would permit studies of their thermal structure and circulation. An assessment is made of data available for calculating the surface heat transfer for the coastal regions of British Columbia and S.E. Alaska. Monthly means of meteorological and oceanographic observations for the years 1961 and 1963 are critically examined for their representativness of conditions that exist over the open water. The location of the observation point is found to be important in choosing values for dew point and wind speed. Formulae for calculating surface heat transfer are examined for their potential applicability to a coastal climate. The calculated net annual surface heat transfer is found to be highest in the southern regions, approximately 90 langleys/day in the Strait of Georgia, and to decrease for more northerly regions, to an approximate balance with no net input in northern Chatham Strait. The annual cycle is found to be strongly modified by fine structure, the radiation balance dominating in summer, the convective losses in winter. Comparison of the calculated surface heat transfer with heat storage indicates that the calculations may be accurate to within 20% of the peak values. The range and shape of the surface temperature cycle was found to reflect the influence of advection, and deep water temperature, as well as the surface heat transfer. / Science, Faculty of / Physics and Astronomy, Department of / Graduate