Accurate prediction of nearshore waves and currents is of critical importance in littoral naval operations. This study examines the effects of complex bathymetry on nearshore currents. Data collected by an array of 12 pressure and velocity sensors in the Nearshore Canyon Experiment (NCEX), conducted near La Jolla, California in 2003, were analyzed to investigate the variability of nearshore currents near a submarine canyon. Time series of pressure, 3-component velocity, and wave heights along the 10 meter depth contour were analyzed to determine the relative importance of tides, waves, and winds in the forcing of nearshore currents outside the surf zone. Additionally, the spatial variability of the observed currents was investigated in relation to the nearby canyon head. Case studies are examined to determine how different wave and tide conditions affect the currents near the canyon. In low-moderate wave conditions, tides dominate longshore currents, whereas cross-shore currents show the passage of irregular bore-like features. The currents are coherent away from the submarine canyon and decay towards the canyon head. Strong longshore currents were observed near the canyon head during a large wave event that were likely driven by an alongshore pressure gradient associated with wave set-up variations.
| Identifer | oai:union.ndltd.org:nps.edu/oai:calhoun.nps.edu:10945/2165 |
| Date | 06 1900 |
| Creators | Cushanick, Matthew Stephan |
| Contributors | Herbers, Thomas H.C., Thornton, Edward B., Naval Postgraduate School (U.S.)., Oceanography |
| Publisher | Monterey, California. Naval Postgraduate School |
| Source Sets | Naval Postgraduate School |
| Detected Language | English |
| Type | Thesis |
| Format | xiv, 47 p. : col. ill., application/pdf |
| Rights | Approved for public release, distribution unlimited |
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