Influence of Thermocline on Sound Propagation in Shallow Water

摘要

The thermocline has an important influence on sound propagation or underwater acoustic detection in shallow water. The beam-displacement ray-mode theory is used to analyze the influence of thermocline on sound propagation. The peculiarity of this method is that the boundary effects on the sound field can be expressed by the equivalent boundary reflection coefficient. An improved new method for computing the upper boundary reflection coefficient in the theory is proposed based on the generalized phase integral eigenfunction and an univocal formulation of upper boundary reflection coefficient is deduced. An ocean environment model of thermocline is established. The influence of therrnocline's depth, thickness and intensity on sound transmission loss is discussed. The research results shows that thermocline has an important effect on sound transmission loss. It is of practical guiding significance in sonar detection and underwater warfare.