Compute the seawater speed of sound.
swSoundSpeed(salinity, temperature = NULL, pressure = NULL,
longitude = NULL, latitude = NULL, eos = getOption("oceEOS",
default = "gsw"))either practical salinity (in which case temperature
and pressure must be provided) or an oce object, in
which case salinity, temperature (in the ITS-90 scale; see
next item), etc. are inferred from the object.
in-situ temperature [\(^\circ\)C], defined
on the ITS-90 scale. This scale is used by GSW-style calculation (as
requested by setting eos="gsw"), and is the value contained within
ctd objects (and probably most other objects created with data
acquired in the past decade or two). Since the UNESCO-style calculation is
based on IPTS-68, the temperature is converted within the present function,
using T68fromT90.
pressure [dbar]
longitude of observation (only used if eos="gsw";
see ‘Details’).
latitude of observation (only used if eos="gsw"; see
‘Details’).
equation of state, either "unesco" [1,2] or "gsw"
[3,4].
Sound speed [m/s].
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.
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.)
Other functions that calculate seawater properties: T68fromT90,
T90fromT48, T90fromT68,
swAbsoluteSalinity,
swAlphaOverBeta, swAlpha,
swBeta, swCSTp,
swConservativeTemperature,
swDepth, swDynamicHeight,
swLapseRate, swN2,
swPressure, swRho,
swRrho, swSCTp,
swSTrho, swSigma0,
swSigma1, swSigma2,
swSigma3, swSigma4,
swSigmaTheta, swSigmaT,
swSigma, swSoundAbsorption,
swSpecificHeat, swSpice,
swTFreeze, swTSrho,
swThermalConductivity,
swTheta, swViscosity,
swZ
# NOT RUN {
swSoundSpeed(40, T90fromT68(40), 10000) # 1731.995 (p48 of Fofonoff + Millard 1983)
# }
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