“…It is clear that most of the energy of WPF is concentrated around the convective peak and then any correlation data is mainly the representation of the convective character of the TBL. Unfortunately, only few experimental data concerning direct measurements of the wavenumber-frequency spectrum are available (Abraham, 1998;Choi and Moin, 1990;Panton and Robert, 1994;Farabee and Geib, 1991;Manoha, 1996) and, among them, a big spread of the spectra magnitude at low wavenumbers is present as reported for example by Hwang and Maidanik (1990).…”