Direct measurements of vertical water motions were made in the Oregon coastal region during the 1972 summer upwelling season. The instruments used were the Webb-Voorhis vertical current meters which are freely drifting neutrally buoyant floats capable of sensing vertical motion. It was found that in the region studied, water tended to sink at depths of 40 to 60 meters under the influence of strong northward and southward winds but that water tended to rise during the slackening periods of a southward wind. Techniques used in processing the data, some problems encountered, and the results of four good dives are presented along with possible correlations of vertical water movements with wind, sea Level, and isopycnal movements. / Graduation date: 1974

Moored instrument records, drogue displacements, and hydrographic observations are used in describing the coastal currents and upwelling off Peru. The data were obtained over the continental shelf near 15°S. during a two week study in late March and early April of 1969. First order statistics and graphical representations of current meter time series indicate that the longshore flow was poleward during most of the study period, interrupted by a three day 'event' of equatorward flow. The similarity of flow at all current meters indicates that the field of flow as quasi-barotropic. The depth, extent, and transport of poleward flow indicated by current meter time series and geostrophic sections were similar to those described in the literature for the Peru-Chile Undercurrent. The observations suggest that this flow moved further offshore as equatorward flow appeared over the shelf. Power spectral analyses performed on current meter records indicate the existence of semidiurnal tidal currents in the longshore direction. The magnitude of these currents is estimated at 10% to 15% of period mean speeds. Ten meter drogue displacements are compared with 25 m recorded currents and with winds. The observations indicate that: the drogues were affected by both the 25 m flow and the wind; the depth of the wind drift layer was between 10 m and 25 m; the drogue displacements were in the sense expected from the Ekman model. Vertical sections of sigma-t, oxygen, and nitrate indicate the existence of conditions consistent with upwelling. Surface maps of temperature, nitrate, and chlorophyll 'a' over the shelf are used to define the horizontal field of upwelling and its variations in time. The distributions suggest that upwelling existed throughout the period and underwent temporal and spatial modulations in intensity. The possibility of a causal mechanism between observed current and upwelling variations is examined. Vertical salinity sections indicated the presence of a weak salinity minimum between the surface and 100 m. It is suggested that this minimum manifests the remnants of a tongue of Subantarctic Water embedded in a much larger mass of Equatorial Subsurface Water. The occurrence of the minimum only in conjunction with poleward flow suggests that the water was advected or mixed coastward somewhere north of the area studied, was entrained in the Peru-Chile Undercurrent, and was carried south again. / Graduation date: 1970

Graduation date: 1962

Graduation date: 1963

Little has been published about the shelf circulation off the coast of Nigeria. Due to increased activity and associated incidents in the shallow waters offshore Nigeria, there is a need to more clearly define the near-shore circulation patterns. An oil spill occurred in January of 1998, the slick drifted in the opposite direction at twice the speed as was anticipated. It was believed that the heavy discharge from the Niger River Delta would have a strong influence on the near-shore circulation patterns and was the reason for this unexpected drift. This thesis investigates the river discharge by examining hydrographic data taken along the coastline. Using Acoustic Doppler Current Profilers, this thesis also investigates other possible forcing factors to gain an overall understanding of Nigeria??s shallow water circulation. Indeed river discharge plays an important role in the near-shore circulation as the coastal waters are highly stratified; however, the coastal waters are also strongly influenced by a cross-shelf semidiurnal tide, weather events and seasonal events, such as eddies and coastal upwelling. The resulting currents are a combination of a strong bi-directional cross-shelf tidal current with a strong bi-directional alongshelf current. The waters off Nigeria are highly stratified; they have spatial coherence and a uniform vertical structure along the coastline. These coastal waters may also be influenced by a remotely forced upwelling event and by northerly drift from the Congo River. The shelf circulation is clearly a complicated system and will require further investigation to be fully defined.

Little has been published about the shelf circulation off the coast of Nigeria. Due to increased activity and associated incidents in the shallow waters offshore Nigeria, there is a need to more clearly define the near-shore circulation patterns. An oil spill occurred in January of 1998, the slick drifted in the opposite direction at twice the speed as was anticipated. It was believed that the heavy discharge from the Niger River Delta would have a strong influence on the near-shore circulation patterns and was the reason for this unexpected drift. This thesis investigates the river discharge by examining hydrographic data taken along the coastline. Using Acoustic Doppler Current Profilers, this thesis also investigates other possible forcing factors to gain an overall understanding of Nigeria??s shallow water circulation. Indeed river discharge plays an important role in the near-shore circulation as the coastal waters are highly stratified; however, the coastal waters are also strongly influenced by a cross-shelf semidiurnal tide, weather events and seasonal events, such as eddies and coastal upwelling. The resulting currents are a combination of a strong bi-directional cross-shelf tidal current with a strong bi-directional alongshelf current. The waters off Nigeria are highly stratified; they have spatial coherence and a uniform vertical structure along the coastline. These coastal waters may also be influenced by a remotely forced upwelling event and by northerly drift from the Congo River. The shelf circulation is clearly a complicated system and will require further investigation to be fully defined.

Thesis (M.S.)--Naval Postgraduate School, 2002. / Thesis advisor(s): Timothy P. Stanton, Edward B. Thornton. Includes bibliographical references (p. 71-73). Also available online.

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, December 2009. / Thesis Advisor(s): Papoulias, Fotis ; Rice, Joseph. "December 2009." Author(s) subject terms: Acoustic modem, Cable, Steady state, Undersea sensors, Catenary, Mooring. Includes bibliographical references (p. 41). Also available in print.

Thesis (S.M.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences and the Woods Hole Oceanographic Institution), February 2001. / Includes bibliographical references (p. 116-118).

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 162-170).