SOFAR transmission fluctuations produced by a Rossby wave

SOFAR ray geometry, travel time, and spreading loss are considered for a still−ocean region in which the sound speed is a bilinear function of depth. A sound source is placed above and a receiver below the SOFAR axis at depths corresponding to the same sound speed. Next, an assumed Rossby wave is introduced, and its effect on the phase of the total acoustic field is determined. It is found that the amplitude of phase variation can vary by a factor of three as the source and receiver depths are altered. Our theory is applied to sound transmission in the Sargasso Sea area, and phase variation values are determined which are in general agreement with experimental results. Subject Classification: 30.20.