Short wave modulation, wave breaking and shapes of wave spectra
A preliminary parameterization combined with a saturation-based dissipation of this effect provides an effective explanation for the empirical dissipation used in the energy balance and effectively enhances the bimodality around 1 m wavelength, making the modeled spectra closer to observed young wave spectra, and modulation of short wave breaking. This parameterized preferred breaking is found to have a strong impact on cross-wind and down-wind slope statistics and thus air-sea exchanges and remote sensing.
Simulations of the conservative short wave action evolution shows that the growth rate of this instability is a function of the initial modulation of the short waves by the longer wave. Work is underway to include a wave dissipation effect in these simulations, examine the response to narrow-band random long waves and refine the expected impact on the wave spectrum shape, and produce a seamless parameterization of dissipation that can be used to represent the full range of surface gravity waves for remote sensing and air-sea fluxes applications. It is also expected that further analysis of stereo-video data should support the non-Rayleigh distribution of short wave steepnesses predicted for this type of modulation.