“…For the regional and global applications, the directional wave spectrum is resolved at ever grid point across wavenumber-direction bands. By numerically solving the spectral wave action balance equation (1), the evolution of the wave field is achieved: Where, λ is longitude, φ is latitude, θ is wave propagation direction, k is wave number, t is time, σ is the intrinsic angular frequency. R is the radius of the earth, and U φ and U λ are current components in φ and λ directions.…”