Compute the seawater Absolute Salinity, according to the GSW/TEOS-10 formulation with gsw::gsw_SA_from_SP() in the gsw package. Typically, this is a fraction of a unit higher than practical salinity as defined in the UNESCO formulae.

  pressure = NULL,
  longitude = NULL,
  latitude = NULL,
  debug = getOption("oceDebug")



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).


pressure in dbar.


longitude of observation.


latitude of observation.


an integer specifying whether debugging information is to be printed during the processing. This is a general parameter that is used by many oce functions. Generally, setting debug=0 turns off the printing, while higher values suggest that more information be printed. If one function calls another, it usually reduces the value of debug first, so that a user can often obtain deeper debugging by specifying higher debug values.


Absolute Salinity in \(g/kg\).


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.

See also

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(), computableWaterProperties(), locationForGsw(), swAlpha(), 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()


Dan Kelley


swAbsoluteSalinity(35.5, 300, 260, 16) # 35.67136
#> [1] 35.67136