# gsw_sigma0_pt

    potential density anomaly

## Contents

- USAGE:
- DESCRIPTION:
- INPUT:
- OUTPUT:
- EXAMPLE:
- AUTHOR:
- VERSION NUMBER:
- REFERENCES:

## USAGE:

    sigma0_pt = gsw_sigma0_pt(SA,pt0)

## DESCRIPTION:

    Calculates potential density anomaly with reference sea pressure of
    zero (0) dbar.

    Click for a more detailed description of potential
    density anomaly with pr of 0 dbar (sigma_0).

## INPUT:

    SA   =   Absolute Salinity                                      [ g/kg ]
    pt0  =   potential temperature with respect to a               [ deg C ]
             reference sea pressure of 0 dbar (ITS-90)

    SA & pt0 need to have the same dimensions.

## OUTPUT:

    sigma0_pt  =  potential density anomaly with                  [ kg/m^3 ]
                  respect to a reference pressure of 0 dbar,
                  that is, potential density minus 1000 kg/m^3.

## EXAMPLE:

    SA = [34.7118; 34.8915; 35.0256; 34.8472; 34.7366; 34.7324;]
    pt0 = [28.7832; 28.4209; 22.7850; 10.2305;  6.8292;  4.3245;]

    sigma0_pt = gsw_sigma0_pt(SA,pt0)

    sigma0_pt =

     21.798144753257930
     22.052511933456117
     23.893563694775708
     26.667625207411902
     27.107234985050809
     27.409632401587487

## AUTHOR:

    Trevor McDougall & Paul Barker  [ help_gsw@csiro.au ]

## VERSION NUMBER:

    2.0 (26th August, 2010)

## REFERENCES:

    IOC, SCOR and IAPSO, 2010: The international thermodynamic equation of
     seawater - 2010: Calculation and use of thermodynamic properties.
     Intergovernmental Oceanographic Commission, Manuals and Guides No. 56,
     UNESCO (English), 196 pp.  Available from the TEOS-10 web site.
      See Eqn. (3.6.1) of this TEOS-10 Manual.

    The software is available from http://www.TEOS-10.org