Thesis (M.S.)--Naval Postgraduate School, 1971. / Includes bibliographical references (leaves 141-142).

Thesis (M.S.)--Naval Postgraduate School, 1970. / Includes bibliographical references (p. 196-197).

Small amounts of carbon from glucose and leucine added at natural concentrations to seawater were biologically transformed to higher molecular weight (MW) dissolved materials which persisted through six months of incubation. These materials were resistant to biological utilization: only 1 to 17% of the higher MW carbon was respired when re-incubated with seawater microbial populations. Over the same time span, 40 to 75% of the monomers were respired. In situ transformations of biologically-available carbon may be important mechanisms for the production of refractory dissolved organic carbon in the oceans. / Graduation date: 1987

Graduation date: 1969

The apparent dissociation constants of carbonic acid were determined as functions of temperature and salinity in seawater at atmospheric pressure. There is fair agreement between my values of K'₁ and those of Buch et al. (1932), Lyman (1956), and Hansson (1971). My values, on the average, are 6.7% lower than Buch et al.'s (1932), 4.6% smaller than Lyman's (1956), and 4.0% higher than Hansson's (1972). My values for K'₂ are smaller than those reported by other workers. They differ by 3.4% from Hansson's (1972) values, and 26% from Buch's (1938). Lyman's (1956) values are larger than mine by 3.2% at temperatures of 25°C and below, and greater by 13.4% at 35°C. / Graduation date: 1973

Dissolved oxygen profiles made with an in situ polarographic device reveal structure in the form of inversions and gradient changes in the 100-600 meter depth zone off Oregon. Inversions 10-70 meters thick are traced over distances of 40 miles in some cases and are bracketed by a distance of 8 miles in others. The horizontal extent of these features agrees with observations of similarly-sized temperature and salinity structure reported by Stommel and Federov (1967) and by Hamon (1967). Oxygen maxima are correlated with changes in the vertical temperature gradient. Corresponding salinity minima are sometimes found. This relationship between properties is consistent with the formation of oxygen structure by a horizontal mixing process off Oregon. The existence of significant horizontal gradients in properties over distances of tens of miles favors the interleaving of dissimilar waters along density surfaces. A quantitative example of the horizontal mixing process yields temperature gradient changes near oxygen maxima similar to those observed. The in situ production of oxygen structure by layers of oxygen-consuming materials is considered unlikely in the size range studied. A transient state vertical model indicates that the consumption layers required for this mechanism are more intense than is consistent with recent biomass measurements. Diffusion calculations are used to model the decay of oxygen maxima. Calculated lifetimes range from 2.6 days for features 15 meters thick to 48.1 days for features 60 meters thick. These are considered estimates of the time scales associated with the stratification process. / Graduation date: 1973

Graduation date: 1973

Graduation date: 1974

Graduation date: 1976

The stoichiometric model of organic decomposition in seawater (Redfield, Ketchum, and Richards, 1963) was used to describe the oceanic distribution of total carbon dioxide. It was assumed that the concentration of total carbon dioxide was the sum of three terms: (1) the initial concentration of carbon dioxide, (2) the increase in carbon dioxide due to the oxidation of organic matter, and (3) the increase in carbon dioxide due to the solution of calcium carbonate. The initial concentration of carbon dioxide was calculated by assuming that surface seawater is in equilibrium with atmospheric carbon dioxide. This assumption allowed the temperature dependence of the initial concentration to be estimated. The vertical and horizontal distribution of total carbon dioxide in the Pacific, Indian, and South Atlantic Oceans was shown to conform to this model. In particular, values of the oxidative ratio (ΔC/ΔO) calculated from field data agreed with the theoretical value of Redfield et al. (1963). The model for the distribution of total carbon dioxide was applied to the vertical distribution of carbon-13 at the North Pacific (1969) GEOSECS intercalibration station (Kroopnick, Deuser, and Craig, 1970). Values of δC¹³ calculated from the stoichiometric model agreed to within ± 0.3‰ with the measured values at this station. Near-bottom chemical measurements were made on three cruises: YALOC-69 to the Eastern Tropical Pacific, Y6908F off the Oregon Coast, and TT-46 to the Caribbean Sea and North Atlantic. The emphasis during these cruises was on chemical gradients in deep water, and 39 stations were occupied at depths greater than 2000 m. Salinity, oxygen, pH, alkalinity, silicate, phosphate, nitrate, and nitrite were measured at heights from 0.5 to 300 m above the bottom. No measurable salinity, oxygen, silicate, phosphate, nitrate, or nitrite gradients were observed. A statistically significant near-bottom increase in pH and alkalinity was found. However, the increase was small and could have resulted from undetected analytical and/or sampling errors. / Graduation date: 1972