Measurements Of Ocean Currents Across The Continental Margin Off Point Sur California During March 1989

Mean currents and density were measured off Point Sur, California in March 1989 using Pegasus and CTD instruments. Velocity, temperature, salinity, and density fields are examined to discern the structure of the California and Davidson currents. Velocities measured by Pegasus are compared to flow fields derived from geostrophy. The Davidson Current flows poleward at the surface in its winter configuration despite northerly winds and coastal upwelling which normally drive the flow subsurface in the summer months.

Ocean currents and density were measured off Point Sur, California in February 1989 using Pegasus (an acoustically tracked velocity profiler), ADCP (a ship-mounted acoustic doppler current profiler), and CTD (conductivity, temperature, depth profiler). Absolute velocities are compared with geostrophy and various flow regimes are analyzed with respect to prominent features and historical and other recent data. Geostrophic cross-sections based on various levels of no motion (LNM) are compared. Temperature, salinity, and density fields are examined and correlated to velocity features. The California Current is a weak southeastward flow starting about 60 kilometers from the coast. The Davidson Inshore Current is a strong surface-intensified core of warm, fresh water centered 30 kilometers offshore, and located in the top 100 meters. A subsurface maximum of westward flow exists in a well-defined jet 100 meters deep about 30 kilometers off Point Sur. There is a trench jet located along the bottom between the continental slope and a seamount 33 kilometers from the coast, which could either be topographically steered out of Monterey Canyon or recirculated from further offshore. Word processing, Script, GML, Text processing, Ocean currents, California, Davidson inshore current, Geostrophic currents, Thesis.

Direct measurements by moored current meters and indirect measurements from geostrophy are compared and discussed for a region over the continental slope off central California during the Davidson Current period. During that same period vertical temperature and salinity profiles were made at 23 stations on four separate cruises in the study area south of Monterey, California. These arrays of moored current meters simultaneously recorded the flow of the current at specified levels. The California Countercurrent was found to be present in the region of study during the entire observation period. Its offshore position and extent, its intensity and its vertical location and extent varied in a way largely consistent with its reported behavior in other locations along the U.S. West Coast. (Author).

This thesis describes results from moored current meters, 150-350 m, for a region over the continental slope off Cape San Martin, California, from January 1979 to April 1980. Current vector time series were constructed from the data and compared to a local coastal upwelling index. Progressive vector diagrams were also constructed, and spectrum analysis was performed for alongshore and cross-slope currents. The California Countercurrent was found to be present in the study area during the entire period. Seasonally, the countercurrent was substantially stronger during the spring. Frequent current reversals and oscillations occurred between equatorward and poleward flow, less often at the nearshore station. Preferred low frequency energy peaks were found at periods of about 10 days. The intensity of the countercurrent increased with increasing coastal upwelling index, and the cross-slope flow also appeared to be related to the local coastal upwelling index. Keywords include: California undercurrent; Davidson current; California current; Eastern boundary currents; and metered currents.

Ocean Currents is a derivative of the Encyclopedia of Ocean Sciences, 2nd Edition and serves as an important reference on current ocean current knowledge and expertise in one convenient and accessible source. Its selection of articles—all written by experts in their field—focuses on key ocean current concepts. Its topics include ocean currents, the circulation of deep water, the contrasting circulations of the seas, the circulation in fjords, estuaries and the effects of rivers, and the intermittency and variability of the oceans. Ocean Currents serves as an ideal reference for topical research. References related articles on ocean currents to facilitate further research Richly illustrated with figures and tables that aid in understanding key concepts Includes an introductory overview of ocean currents and then explores each topic in detail, making it useful to experts and graduate-level researchers Topical arrangement makes it the perfect desk reference