Observations of sea and swell using directional wave buoy

Abstract

Directional wave data collected during an experiment at a location on the continental shelf of the south west coast of India using a WAVEC buoy, have been analysed based on the technique of Kuiket al (1988). The observed wave spectra indicate that the wave field is composed of sea 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 from 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 distribution is generally bimodal in the transition region between sea and swell and at higher frequencies when rapid changes in wind speed and direction occur.