Separation of wind sea and swell from nearshore ocean wave spectra

Abstract

ABSTRACT: Coexistence of wind sea and swell often resu1ts in doub1e-peaked spectra. Separation and identification ofthe wave energies of wind sea and swell from the measured spectra allow us to have a more rea1istic description of thesea state, which is of great importance to offshore structure design, safety of marine operation, and the study of windwave dynamics. This paper describes a method based on the peak frequency of a steepness function to separate thewave energies of wind sea and swell from the omnidirectiona1 wave spectra. Using the PM spectra1 mode1 for the windsea spectrum, the separation frequency is derived from the peak frequency of the steepness function. This steepnessmethod does not re1y on the avai1abi1ity of the information of wind ve10cities and wave directions and can be easi1yimp1emented for operationa1 uses. Verification results using wave data collected of Seoguipo in Korea are presenteda state, which is of great importance to offshore structure design, safety of marine operation, and the study of windwave dynamics. This paper describes a method based on the peak frequency of a steepness function to separate thewave energies of wind sea and swell from the omnidirectiona1 wave spectra. Using the PM spectra1 mode1 for the windsea spectrum, the separation frequency is derived from the peak frequency of the steepness function. This steepnessmethod does not re1y on the avai1abi1ity of the information of wind ve10cities and wave directions and can be easi1yimp1emented for operationa1 uses. Verification results using wave data collected of Seoguipo in Korea are presented