Compute freezing temperature of seawater.
swTFreeze(salinity, pressure = 0, longitude = NULL, latitude = NULL,
saturation_fraction = 1, eos = getOption("oceEOS", default = "gsw"))either salinity [PSU] or a ctd object from which
salinity will be inferred.
seawater pressure [dbar]
longitude of observation (only used if eos="gsw";
see ‘Details’).
latitude of observation (only used if eos="gsw"; see
‘Details’).
saturation fraction of dissolved air in seawater
(used only if eos="gsw").
equation of state, either "unesco" [1,2] or "gsw"
[3,4].
Temperature [\(^\circ\)C], defined on the ITS-90 scale.
In the first form, the argument is a ctd object, from which the
salinity and pressure values are extracted and used to for the calculation.
[1] 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
[2] Gill, A.E., 1982. Atmosphere-ocean Dynamics, Academic Press, New York, 662 pp.
[3] IOC, SCOR, and IAPSO (2010). The international thermodynamic equation of seawater-2010: Calculation and use of thermodynamic properties. Technical Report 56, Intergovernmental Oceanographic Commission, Manuals and Guide.
[4] McDougall, T.J. and P.M. Barker, 2011: Getting started with TEOS-10 and the Gibbs Seawater (GSW) Oceanographic Toolbox, 28pp., SCOR/IAPSO WG127, ISBN 978-0-646-55621-5.
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,
swSoundSpeed, swSpecificHeat,
swSpice, swTSrho,
swThermalConductivity,
swTheta, swViscosity,
swZ
# NOT RUN {
swTFreeze(salinity=40, pressure=500, eos="unesco") # -2.588567 degC
# }
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