Deep ocean current and its correlation with the ocean tide off the coast of northern California

Abstract

Tidal heights and currents were measured at a depth of 3903 meters off the coast of northern California for 46 days in 1966. From spectral analysis of the data, the amplitudes of various harmonics of tidal heights and current speeds and their corresponding phase differences were estimated. Good correlation between water current amplitudes and tidal heights was observed. Significant spectral peaks were found for both currents and tides corresponding to the O1, K1, N2, and M2 components. It is concluded that the measured ocean-bottom currents at this location are produced primarily by tides. The maximum spectral amplitude, 2.4 cm/sec, was obtained for the M2 component of current. The M2 component of tidal height was found to lead the M2 component of current by 45.4 degrees. Assuming two opposed traveling waves for ocean tides, theoretical amplitude relations and phase differences between tidal heights and current speeds were derived. The estimated total dissipation of energy for all the components was found to be 7.31 × 10−2 erg cm−2 sec−1.