The sound field structure in the subsurface channel

Results of an experimental study of the sound field formed in the subsurface channel of the ocean are presented. The subsurface channel exists in deep-water areas of the ocean, near the upper boundary, in the wind-agitated water layer. Experiments were performed in two regions of the central Atlantic, near the coast of Portugal and near the coast of Guiana. The angular and energy structures of the field produced by a noise source are studied in the frequency band from 1 to 10 kHz at distances of up to 25–30 km. The results of the experiments are compared with theoretical calculations. For several specific frequencies, the values of the attenuation of the additional field compared to the cylindrical law of the decay of sound intensity with distance are determined. The influence of the surface of the rough ocean on the details of the structure of the sound field is estimated.