A series of intermittent interval wave events were observed at a single site in 133 m of water on the northern California continental shelf during the Coastal Ocean Dynamics Experiment 1981. Simultaneous time-series observations of temperature and conductivity were used to infer isotherm and isopycnal depths which were combined with current observations to developed a kinematic description of an average internal wave event. The event described consists of a downward displacement of the middepth isopycnals and a corresponding increase of upper-layer minus lower-layer velocity in the ratio R=105¿33 s. The observed value of R is in excellent agreement with the prediction of the two-layer internal soliton theory for which the theoretical value of R, given the hydrographic conditions of the observation site, is 105 s. Predicted values of upper-layer onshore velocity (0.15 m s-1), lower-layer offshore velocity (0.12 m s-1), and time scale (24.6 min) compare well with corresponding observations of 0.14¿0.02 m s-1, 0.14¿0.02 m s-1, and 28¿4 min, respectively, for a 29-m internal wave of depression. Based on these results and similar observations of others, we conclude that internal solitary waves, generated in the region of the continental slope, evolve into packets of solitons as they propagate shoreward before dissipating their energy of about 8.23¿105 J per meter of wave crest. |