oce (version 0.9-18)

swSigmaT: Seawater quasi-potential density anomaly

Description

Compute $\sigma_t$, a rough estimate of potential density of seawater, minus 1000 kg/m$^3$.

Usage

swSigmaT(salinity, temperature=NULL, pressure=NULL, longitude=300,
  latitude=30, eos=getOption("oceEOS", default="gsw"))

Arguments

salinity

either salinity [PSU] (in which case temperature and pressure must be provided) or a ctd object (in which case salinity, temperature and pressure ar

temperature

in-situ temperature [$^\circ$C], defined on the ITS-90 scale; see Temperature units in the documentation for swRho, and the examples below.

pressure

pressure [dbar]

longitude

longitude of observation (only used if eos="gsw").

latitude

latitude of observation (only used if eos="gsw").

eos

name of equation of state to be used, either "unesco" or "gsw".

Value

• Quasi-potential density anomaly [kg/m$^3$], defined as the density calculated with pressure set to zero.

Details

If the first argument is an oce object, then salinity, etc., are extracted from it, and used for the calculation.

References

See citations provided in the swRho documentation.

See Also

Related density routines include: swRho, swSigma, swSigmaTheta, swSigma0, etc.

Examples

swSigmaT(35, 13, 1000, eos="gsw")                # 26.396816
swSigmaT(35, T90fromT68(13), 1000, eos="unesco") # 26.393538