What should one expect at high wave frequencies?
The high frequency contents of the spectrum can be split between bound and free waves. Since one cannot think of any generating mechanism for free high frequency waves that could compete with the non linear composition of lower frequency waves into bound waves, it is a sensible assumption that the linear spectrum will exhibit a high rate of decay, and that most energy in any high frequency band will be the result of wave-wave interaction. Moreover, the results of Forristall and Prevosto in the WACSIS JIP have shown that as far as water surface elevation is concerned, second-order reconstruction of the high frequency energy contents starting from a linear spectrum is quite satisfactory. Linear spectra can be obtained with standard buoys, but may still differ significantly from the JONSWAP model, especially by featuring several peaks. Yet, it is very likely that using a correct shape of the free waves spectrum in its most energetic frequency range, and computing the second-order energy c
