Equilibrium‐range constant in wind‐generated wave spectra

The equilibrium range in wind‐driven wave spectra is characterized to have an f −4 form in deep water (k −5/2 shallow‐water form). Absolute energy levels for six physically diverse sites are shown to be well fit by an expression involving the wind speed measured at a fraction of a wavelength above the sea surface in combination with the phase speed of the spectral peak. Observed energy levels suggest that nonlinear wave‐wave interactions are capable of maintaining the observed energy‐flux balance in the equilibrium range.