Directionality and spread of shallow water waves along the eastern Arabian Sea

Abstract. The directional characteristics of shallow water waves are described based on measured data during 2011 at two locations spaced at 350 km along the eastern Arabian Sea. Study shows that, for high swells (significant wave height > 1 m) approaching almost parallel to the coast, the difference between mean and principal wave direction at spectral peak is negligible. The directional spreading of wind-sea-dominated wave spectrum is less than that of the swell-dominated spectrum. Average value of the ratio of the directional width at twice the peak frequency and that at the peak frequency is 1.9 indicating that the directional width increased at higher frequency. Even though both locations studied are along the eastern Arabian Sea, there are more northwest waves due to shamal events and local winds found at the northern location (27%) than at the southern location (7%).