Frequency dependence and intensity fluctuations due to shallow water internal waves.

A theory and experimental results for sound propagation through an anisotropic shallow water environment are presented to examine the frequency dependence of the scintillation index in the presence of internal waves. The theory of horizontal rays and vertical modes is used to establish the azimutal and frequency behavior of the sound intensity fluctuations, specifically for shallow water broadband acoustic signals propagating through internal waves. This theory is then used to examine the frequency dependent, anisotropic acoustic field measured during the SWARM'95 experiment. The frequency dependent modal scintillation index is described for the frequency range of 30-200 Hz on the New Jersey continental shelf.

[1]  Robert H. Headrick,et al.  An overview of the 1995 SWARM shallow-water internal wave acoustic scattering experiment , 1997 .

[2]  Acoustic normal mode fluctuation statistics in the 1995 SWARM internal wave scattering experiment , 2000, The Journal of the Acoustical Society of America.

[3]  M. Badiey,et al.  Analysis and modeling of broadband airgun data influenced by nonlinear internal waves. , 2004, The Journal of the Acoustical Society of America.

[4]  S. Pereselkov,et al.  Space-frequency dependence of the Horizontal structure of a sound field in the presence of intense internal waves , 2004 .

[5]  S. A. Pereselkov,et al.  Low-frequency horizontal acoustic refraction caused by internal wave solitons in a shallow sea , 2000 .

[6]  James F. Lynch,et al.  Temporal and azimuthal dependence of sound propagation in shallow water with internal waves , 2002 .

[7]  Henry Weinberg,et al.  Horizontal ray theory for ocean acoustics , 1974 .

[8]  Lynch,et al.  Modeling mode arrivals in the 1995 SWARM experiment acoustic transmissions , 2000, The Journal of the Acoustical Society of America.

[9]  Mohsen Badiey,et al.  Measurement and modeling of three-dimensional sound intensity variations due to shallow-water internal waves. , 2005, The Journal of the Acoustical Society of America.

[10]  M. H. Brill,et al.  Acoustic Variability Due to Internal Waves and Surface Waves in Shallow Water , 1991 .

[11]  M. Badiey,et al.  Experimental evidence of three-dimensional acoustic propagation caused by nonlinear internal waves , 2005 .