Bottom trapped waves at tidal frequencies off Point Sur, California.

Abstract

Current meter data were collected from moorings on the 800 and 1800 m isobaths on the continental slope off Point Sur, California at 100, 350, and 500 m depth and at 1000 m depth on the 1800 m isobath. Complex demodulation and spectral techniques were used to study the distribution of tidal energy at the diurnal and semidiurnal frequencies, and to study the size, rotation and orientation of the tidal current ellipses. At mooring P2 (800 m) the observed diurnal energy increased with depth for each of the 17 months of data analyzed, and the semidiurnal energy likewise increased with depth for 14 of the 17 months. The observations were studied using the theory of bottom trapped waves in a rotating stratified fluid (Rhines, 1970).