Abstract
Acoustical ray theory is used to analyze the three-dimensional (3-D) transmission characteristics of the propagation of sound in the Pacific Ocean. For the computer simulation, it is assumed that there is a temperature gradient caused by the warm and cold water mass. The temperature gradient also generates a non-acceleration current or the geostrophic current. The maximum flow speed of the current varies from 0 to 1.35 m/s in the area of study of 100 km square. Sound pulses projected from the source on the sound fixing and ranging (SOFAR) axis reach the cylindrical receiving plane with a curved locus, because of the influence of both temperature gradient and current. The propagation path and propagation time are more affected than shown by the estimation results by two-dimensional (2-D) simulation.