Sound Field in a Coastal Wedge in the Area of a Thermocline’s Contact with the Sea Bottom

Sound field propagation across a coastal wedge toward the deep sea in the area of a thermocline is considered. It is shown that where the thermocline touches the bottom when the sea depth is equal to the thickness of the thermocline, the character of propagation changes notably when the bottom–surface modes become near-bottom ones and nonadiabatic interaction of the modes is possible as they propagate down the slope. This situation is modeled using the ray theory and the parabolic equation.