c(D,S,t) = ^{ } |
c(0,S,t) + (16.23 + 0.253t)D +
(0.213-0.1t)D^{2} + [0.016 + 0.0002(S-35)](S - 35)tD |

c(0,S,t) = ^{ } |
1449.05 + 45.7t - 5.21t^{2} +
0.23t^{3} + (1.333 - 0.126t + 0.009t^{2})(S - 35) |

t = T/10 where T = temperature in
degrees Celsius S = salinity in parts per thousand D = depth in kilometres |

*Range of validity: temperature 0 to
35 C, salinity 0 to 45 parts per thousand, depth 0 to 4000 m*

The above equation for the speed of sound in sea-water as a function of temperature, salinity and depth is given by Coppens equation (1981).

@

Reference

A.B. Coppens, Simple equations for the speed of sound in Neptunian waters (1981) J. Acoust. Soc. Am. 69(3), pp 862-863