[3] The speed of sound in the ocean at different depths can be measured directly, e.g., by using a velocimeter, or, using measurements of temperature and salinity at different depths, it can be calculated using a number of different sound speed formulae which have been developed.
[7] There are software solutions that ease the adoption of such formulas, e.g., the open-source Sound Speed Manager.
At a certain point, however, the effect of depth, i.e., pressure, begins to dominate, and the sound speed increases to the ocean floor.
[9] Also visible in figure 1 is a common feature in sound speed profiles: the SOFAR channel.
[2] Sound speed profile data are necessary for underwater acoustic propagation models, especially those based on ray tracing theory.