Compute \(\alpha\), the thermal expansion coefficient for seawater.
swAlpha(
salinity,
temperature = NULL,
pressure = 0,
longitude = NULL,
latitude = NULL,
eos = getOption("oceEOS", default = "gsw")
)Value in 1/degC.
either practical salinity (in which case temperature
and pressure must be provided) or an oce object (in
which case salinity, etc. are inferred from the object).
in-situ temperature (\(^\circ\)C), defined
on the ITS-90 scale; see “Temperature units” in the documentation for
swRho().
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" or "gsw".
Dan Kelley
The eos="unesco" formulae are based on the UNESCO
equation of state, but are formulated empirically by Trevor J. McDougall,
1987, Neutral Surfaces, Journal of Physical Oceanography, volume 17, pages
1950-1964. The eos="gsw" formulae come from GSW; see references in
the swRho() documentation.
Other functions that calculate seawater properties:
T68fromT90(),
T90fromT48(),
T90fromT68(),
computableWaterProperties(),
locationForGsw(),
swAbsoluteSalinity(),
swAlphaOverBeta(),
swBeta(),
swCSTp(),
swConservativeTemperature(),
swDepth(),
swDynamicHeight(),
swLapseRate(),
swN2(),
swPressure(),
swRho(),
swRrho(),
swSCTp(),
swSR(),
swSTrho(),
swSigma(),
swSigma0(),
swSigma1(),
swSigma2(),
swSigma3(),
swSigma4(),
swSigmaT(),
swSigmaTheta(),
swSoundAbsorption(),
swSoundSpeed(),
swSpecificHeat(),
swSpice(),
swSpiciness0(),
swSpiciness1(),
swSpiciness2(),
swSstar(),
swTFreeze(),
swTSrho(),
swThermalConductivity(),
swTheta(),
swViscosity(),
swZ()