swSigmaTheta {oce} | R Documentation |
Compute the potential density (minus 1000 kg/m^3) that seawater would have if raised
adiabatically to the surface. In the UNESCO system, this quantity is
is denoted sigma-theta (hence the function name), but in
the GSW system, it is denoted sigma0
.
swSigmaTheta(salinity, temperature = NULL, pressure = NULL, referencePressure = 0, longitude = NULL, latitude = NULL, eos = getOption("oceEOS", default = "gsw"))
salinity |
either practical salinity (in which case |
temperature |
in-situ temperature [degC], defined
on the ITS-90 scale. This scale is used by GSW-style calculation (as
requested by setting |
pressure |
pressure [dbar] |
referencePressure |
The reference pressure, in dbar. |
longitude |
longitude of observation (only used if |
latitude |
latitude of observation (only used if |
eos |
equation of state, either |
If the first argument is an oce
object, then salinity, etc., are
extracted from it, and used for the calculation instead of any values
provided in the other arguments.
Potential density anomaly [kg/m^3], defined as sigma_theta=rho(S,theta(S,t,p),0) - 1000 kg/m^3.
Dan Kelley
See citations provided in the swRho
documentation.
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
,
swSigmaT
, swSigma
,
swSoundAbsorption
,
swSoundSpeed
, swSpecificHeat
,
swSpice
, swTFreeze
,
swTSrho
,
swThermalConductivity
,
swTheta
, swViscosity
,
swZ
expect_equal(26.42066, swSigmaTheta(35, 13, 1000, eos="unesco"), tolerance=0.00001)