The surfaee film effeet 00 uoderwater ooise of raio

Stanislaw Pogorzel
1997 International Symposium on HYDROACOUSTICS AND ULTRASONICS EAA Symposium (formerly 13 th FASE Symposium) Gdańsk-Jurata   unpublished
The spectrum of rain noise shows a peak at 13.5-15 kHz, stronger wind s smear the peak. The spectralievel (SL) at 15 kHz shows a linear dependence on the log of the rain rate with wind speed as a parameter. The presenee of a monomoleeular film on the sea surfaee results in a pronouneed reduetion of SL beneath the film by 10 log K. The damping ratio K(= ae / ao, where ae, ao are water wave damping eoefficiants for film-covered and c1ean surfaces) is related to the viseoelastic properties,
more » ... properties, surface activity, concentration and diffusional coefficient of the surface-active substances composing the film.