sound channel

8.31  sound channel. Zone or duct in the sea within which horizontally propagating sound is trapped by alternating upward and downward refraction or reflection. The vertical sound speed profile includes a minimum at the sound channel axis....

surface layer

8.30  surface layer. Zone just below the ocean surface in which the velocity of sound is susceptible to daily and local changes due to heating, cooling, and wind action. Annotation             ...

limiting ray

8.29  limiting ray. Ray tangential to a horizontal plane at which the propagation velocity goes through a maximum or a step...

refraction

8.28  refraction. Phenomenon by which the direction of propagation of a sound wave is changed as a result of a spatial variation in the speed of sound. Annotation   Factors influencing the speed of sound in sea water include temperature, salinity,...

underwater radiated noise

8.27  underwater radiated noise. Sound radiated into water by surface vessels, submarines, fixed installations, or marine...