Nonlinear scattering of acoustic waves by natural and artificially generated subsurface bubble layers in sea.
The paper describes nonlinear effects due to a biharmonic acoustic signal scattering from air bubbles in the sea. The results of field experiments in a shallow sea are presented. Two waves radiated at frequencies 30 and 31-37 kHz generated backscattered signals at sum and difference frequencies in a bubble layer. A motorboat propeller was used to generate bubbles with different concentrations at different times, up to the return to the natural subsurface layer. Theoretical consideration is given for these effects. The experimental data are in a reasonably good agreement with theoretical predictions.
Ostrovsky
Lev A
LA
Zel Technologies/NOAA Environmental Technology Laboratory, Boulder, Colorado 80303, USA.
Sutin
Alexander M
AM
Soustova
Irina A
IA
Matveyev
Alexander L
AL
Potapov
Andrey I
AI
Kluzek
Zigmund
Z