oce (version 0.9-20)

swSCTp: Salinity from electrical conductivity, temperature and pressure

Description

Compute salinity based on electrical conductivity, temperature, and pressure.

Usage

swSCTp(conductivity, temperature = NULL, pressure = 0, conductivityUnit = c("", "mS/cm", "S/m"), eos = getOption("oceEOS", default = "gsw"))

Arguments

conductivity

a measure of conductivity (see also conductivityUnit) or an oce object holding hydrographic information. In the second case, all the other arguments to swSCTp are ignored.

temperature

in-situ temperature [$deg$C], defined on the ITS-90 scale; see “Temperature units” in the documentation for swRho.

pressure

pressure [dbar]

conductivityUnit

string indicating the unit used for conductivity. This may be "ratio" or "" (meaning conductivity ratio), "mS/cm" or "S/m". Note that the ratio mode assumes that measured conductivity has been divided by the standard conductivity of 4.2914 S/m.

eos

equation of state, either "unesco" or "gsw".

Value

Practical salinity.

Details

Calculate salinity from what is actually measured by a CTD, i.e. conductivity, in-situ temperature and pressure. Often this is done by the CTD processing software, but sometimes it is helpful to do this directly, e.g. when there is a concern about mismatches in sensor response times. If eos="unesco" then salinity is calculated using the UNESCO algorithm described by Fofonoff and Millard (1983); if it is "gsw" then the Gibbs-SeaWater formulation is used, via gsw_SP_from_C.

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 Also

For thermal (as opposed to electrical) conductivity, see swThermalConductivity. For computation of electrical conductivity from salinity, see swCSTp.

Other functions that calculate seawater properties: T68fromT90, T90fromT48, T90fromT68, swAbsoluteSalinity, swAlphaOverBeta, swAlpha, swBeta, swCSTp, swConservativeTemperature, swDepth, swDynamicHeight, swLapseRate, swN2, swPressure, swRho, swRrho, swSTrho, swSigma0, swSigma1, swSigma2, swSigma3, swSigma4, swSigmaTheta, swSigmaT, swSigma, swSoundAbsorption, swSoundSpeed, swSpecificHeat, swSpice, swTFreeze, swTSrho, swThermalConductivity, swTheta, swViscosity, swZ

Examples

swSCTp(1, T90fromT68(15), 0, eos="unesco") # 35
swSCTp( 1,            15, 0, eos="gsw") # 35