Structure of the sound field in convergence zones of the tropical Pacific

Abstract

Experimental data are presented on the intensity and angular structures of the sound field in the first and second convergence zones for the tropical region of the Pacific Ocean, southwest of the Hawaian Islands. The experiment is carried out using continuous pseudonoise signals in one-third-octave bands around central frequencies of 1.25 and 3.15 kHz with both source and receiver positioned under the discontinuity layer at a depth of 250 m. The experimental data are compared with calculations based on the ray model. The discrepancies arising between the experimental and calculated data at the entry onto the first convergence zone are compared with the corresponding parameters obtained earlier in the tropical regions of the Atlantic and Indian oceans. The detailed intensity structure of the sound field is correlated with the parameters of internal waves observed during the acoustic measurements.