HR: 0830h
AN: OS41A-04    [Abstracts]
TI: Simulation the Effect of Internal Wave on the Acoustic Propagation
AU: * Ko, D S
EM: ko@nrlssc.navy.mil
AF: Naval Research Laboratory, NRL Code 7320 , Stennis Space Center, MS 39529 United States
AB: An acoustic radiation transport model with the Monte Carlo solution has been developed and applied to study the effect of internal wave induced random oceanic fluctuations on the deep ocean acoustic propagation. Refraction in the ocean sound channel is performed by means of bi-cubic spline interpolation of discrete deterministic ray paths in the angle(energy)-range-depth coordinates. Scattering by random internal wave fluctuations is accomplished by sampling a power law scattering kernel applying the rejection method. Results from numerical experiments show that the mean positions of acoustic rays are significantly displaced tending toward the sound channel axis due to the asymmetry of the scattering kernel. The spreading of ray depths and angles about the means depends strongly on frequency. The envelope of the ray displacement spreading is found to be proportional to the square root of range which is different from "3/2 law" found in the non-channel case. Suppression of the spreading is due to the anisotropy of fluctuations and especially due to the presence of sound channel itself.
DE: 4255 Numerical modeling
DE: 4259 Ocean acoustics
DE: 4544 Internal and inertial waves
SC: Ocean Sciences [OS]
MN: 2005 Joint Assembly