Evaluation of Wind Wave Growth Parameters Basing on Spectral Fluxes

Resumo

We describe the main regimes of the wind wave dynamics, which correspond to the continuity of the fluxes of the wave momentum, energy, and action, on the basis of the wave turbulence theory. Basing on the experimental data about the wave growth, the energy flux into the largescale range (inverse cascade within the wave turbulence theory) is evaluated. The intensity of the direct energy cascade to the short-wave range is estimated basing on experimental parameterization of the wind wave frequency spectra, which corresponds to the Kolmogorov—Zakharov spectrum E(ω) ∝ ω⁻⁴. The obtained estimates show that intensity of the direct cascade exceeds that of the inverse one by two orders of magnitude. An approximate solution for the direct energy cascade is found as a perturbation of the classical Zakharov—Zaslavsky solution for the inverse cascade with a zero energy flux. The results are discussed in correlation with the development of spectral wind wave models.