Sound Speed calculation in Seawater

To use the calculator below, enter the  values of water temperature , salinity and depth . When a calculation button is pushed, the values for the sound speed in seawater are displayed on a screen. The four alternatives are derived using algorithms from the sources specified.

(1)The Equation of  Mackenzie   Mackenzie, K.V. "Nine-term Equation for Sound Speed in the Oceans", J. Acoust. Soc. Am. 70 (1981), 807-812.

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

(3)The Equation of  Del Grosso   Del Grosso, "A New Equation for the speed of sound in Natural Waters", J. Acoust. Soc. Am. 56#4 (1974).

(4)The Equation of UNESCO (Chen and Millero)   Chen and Millero, "The Sound Speed in Seawater", J. Acoust. Soc. Am. 62 (1977), 1129-1135

The UNESCO equation is true for the oceanographers' standard ocean, defined as an ideal medium with a temperature of  0 degrees Celsius and salinity of 35 parts per thousand.
 Leroy and Parthiot (1998) give a table of corrections which are needed when the standard formula is applied to specific oceans and seas. The equation and interactive version do not apply any corrections.

The calculation of the speed of sound profile of the depth direction.  A CSV file for STD is necessary for the calculation. The sample files are prepared.

When T,S,D value is input into the following columns, sound speed in seawater by each equation is calculated.

Latitude  (degrees)  The north and the south latitude are not distinguished. When you do not have a value, input 45.

Temperature (degrees Celsius)

Salinity  (parts per thousand )

Depth (meters)