Badulin S.I., Ivonin D.V.
The simplest weakly nonlinear models of three-dimensional water waves are presented. The spatio-temporal spectral estimates of the New Year Wave record show a pronounced effect of the harmonic f3/2 = 3/2 fm, fm – spectral peak frequency) that corresponds to the maximum of five-wave instability and a harmonic with an intermediate frequency that can be related to the well-known modulational four-wave instability. The results are discussed in the context of possible scenarios of freak wave occurrence.