Alongshore Sub-Thermocline Current Variability in the Central California Current System
Abstract
Moored current meter observations were made along the central California continental slope from Pt. Piedras Blancas to the Farallon Islands. The study area covered an alongshore distance of approximately 290 km and examined the data from off Pt. Piedras Blancas (P4), Pt. Sur (P2 and P3), Monterey Bay (MBl and MB2) and the Farallon Islands (D and E). Time and frequency domain analyses were performed on three time segments that included data from combinations of the above mooring locations based on common time periods and depths (350 m - 500 m). Segment 1 revealed a mean poleward flow attributed to the California Undercurrent at all moorings. Segment 2 had a similar mean poleward flow but also exhibited an equatorward reversal at periods between 19.5 and 58.5 days at P2 and MB2 that was less apparent at P3 further offshore and appeared to be coastally trapped. Observed wavelengths were compared with simple wave theory indicating that the observed signal may have resulted from a combination of two theories i.e. a coastally trapped wave. The complex bottom topography between Pt. Sur and the Monterey Bay prohibited more rigorous comparison between theory and the observations. Satellite sea surface temperature imagery during Segment 3 showed an anti-cyclonic meander with a 65 km radius outside of the Monterey Bay. Current and temperature records at P2 and MB2 indicated that the surface feature's position varied and influenced the currents at depths down to 500 m. Time domain empirical orthogonal functions were calculated for alongshore and across-shore components separately. ... California Current, California Undercurrent, Coastal Trapping, Monterey Bay Meander.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1992
- Accession Number
- ADA262150
Entities
People
- Michael R. Hicks
Organizations
- Naval Postgraduate School