The Effect of Fetch on the Directional Spectrum of Celtic Sea Storm Waves

This paper describes measurements of the directional spectrum of storm waves obtained using the PISCES high-frequency radar. The storm occurred during the Netherlands UK Radar Wavebuoy Experimental Comparison 2 experiment in March 1987. Wind direction changes from southerly to northwesterly over a period of five hours led to a rapid change in short-wave direction but did not lead to changes in the mean direction of the long energetic wind waves. Wind waves generated in the changed wind direction are shown to be fetch limited, and the spectrum is shown to be dominated by long-fetch wind waves generated by the component of wind blowing from the southwest.