The related TEOS-10 quantity ``conservative temperature'' may be
computed with swConservativeTemperature.  For a ctd object,
absolute salinity may also be recovered by indexing as e.g.
ctd[["absoluteSalinity"]] or ctd[["SA"]].
Other functions that calculate seawater properties: T68fromT90,
  T90fromT48, T90fromT68,
  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, swTFreeze,
  swTSrho,
  swThermalConductivity,
  swTheta, swViscosity,
  swZ