swSoundSpeed {oce}R Documentation

Seawater sound speed

Description

Compute the seawater speed of sound.

Usage

swSoundSpeed(salinity, temperature=NULL, pressure=NULL,
    longitude=300, latitude=30, eos=getOption("oceEOS", default="gsw"))

Arguments

salinity

either salinity [PSU] (in which case temperature and pressure must be provided) or a ctd object (in which case salinity, temperature and pressure are determined from the object, and must not be provided in the argument list).

temperature

in-situ temperature [degC], defined on the ITS-90 scale; see “Temperature units” in the documentation for swRho, and the examples below.

pressure

pressure [dbar]

longitude

longitude of observation (only used if eos="gsw"; see ‘Details’).

latitude

latitude of observation (only used if eos="gsw"; see ‘Details’).

eos

equation of state, either "unesco" [1,2] or "gsw" [3,4].

Details

If the first argument is a ctd or section object, then values for salinity, etc., are extracted from it, and used for the calculation, and the corresponding arguments to the present function are ignored.

If eos="unesco", the sound speed is calculated using the formulation in section 9 of Fofonoff and Millard (1983). If eos="gsw", then the gsw_sound_speed function from the gsw package is used.

Value

Sound speed [m/s].

Author(s)

Dan Kelley

References

Fofonoff, P. and R. C. Millard Jr, 1983. Algorithms for computation of fundamental properties of seawater. Unesco Technical Papers in Marine Science, 44, 53 pp. (See section 9.)

Examples

swSoundSpeed(40, T90fromT68(40), 10000) # 1731.995 (p48 of Fofonoff + Millard 1983)

[Package oce version 0.9-18 Index]