OBSERVATIONS OF SEA AND SWELL USING DIRECTIONAL WAVE BUOY

Directional wave data collected during an experiment at a location on the continental shelf of the south west coast of India using a WAVEC b uoy, have been analysed based on the technique of Kuik et al (1988). T he observed wave spectra indicate that the wave field is composed of s ea waves (with peaks around 0.18 and 0.23 Hz) travelling nearly in the wind direction (WNW-N), and lower frequency (0.09 Hz) swell waves fro m the South. The parameterization of the wave directional spread shows that both local wind conditions and nonlinear wave-wave interactions control the shape of the directional distribution. The directional dis tribution is generally bimodal in the transition region between sea an d swell and at higher frequencies when rapid changes in wind speed and direction occur.