The Permanent Downshifting at Later Stages of Benjamin–Feir Instability of Waves

Frequency Downshifting in Wave Spectra in Coastal Zone and Its Influence on Mudbank Formation

“…It occurs discretely with a frequency step equal to the difference between the peak frequency and the most unstable low-frequency mode. Dissipation of wave energy during wave propagation accelerates the downshift of the peak frequency [7,8]. As shown by numerical and laboratory experiments, for steep waves, a cascade frequency downshift is possible, and that occurs at a spatial distance of less than 10 wavelengths.…”

“…Wave transformation leads to changes in the shape of the wave spectrum. Sometimes, the major peak frequency shifts to the low-frequency region-where so-called "frequency downshifting" is observed [4][5][6][7]. It is not completely understood in detail how the frequency downshift occurs.…”

Spatial evolution of young wind waves: numerical modelling verified by experiments

“…The broad frequency spectra characterizing the stationary wind-wave field under steady forcing in the present experiments suggest selection of the deterministic spatial version of the Zakharov (1968) equation (Shemer et al 2001; Kit & Shemer 2002) as a basis for developing an evolution model for the growth of wind waves along the tank. This equation has no limitations on the spectral width; it has been successfully applied to study wave evolution along test sections of laboratory facilities with a wide range of scales (Shemer, Goulitski & Kit 2007; Shemer & Chernyshova 2017; Shugan et al 2019). The measured evolution patterns of deterministic wavemaker-generated nonlinear wavetrains with various envelopes and spectral shapes investigated in those studies were found to be in a very good agreement with simulations based on the spatial Zakharov equation.…”