# gsw_pt_from_entropy

    potential temperature with a reference sea
    pressure of zero dbar as a function of entropy

## Contents

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

## USAGE:

    pt = gsw_pt_from_entropy(SA,entropy)

## DESCRIPTION:

    Calculates potential temperature with reference pressure pr = 0 dbar and
    with entropy as an input variable.

    Click for a more detailed description of calculating
    potential temperature from entropy.

## INPUT:

    SA       =   Absolute Salinity                                  [ g/kg ]
    entropy  =   specific entropy                               [ J/(kg*K) ]

    SA & entropy need to have the same dimensions.

## OUTPUT:

    pt   =  potential temperature                                  [ deg C ]
            with reference sea pressure (pr) = 0 dbar.
    Note. The reference sea pressure of the output, pt, is zero dbar.

## EXAMPLE:

    SA = [34.7118; 34.8915; 35.0256; 34.8472; 34.7366; 34.7324;]
    entropy = [400.3892; 395.4378; 319.8668; 146.7910; 98.6471; 62.7919;]

    pt = gsw_pt_from_entropy(SA,entropy)

    pt =

      28.783179828078666
      28.420954825949291
      22.784952736245351
      10.230532066931868
       6.829213325916900
       4.324537782985845

## AUTHOR:

    Trevor McDougall and Paul Barker                    [ help@teos-10.org ]

## VERSION NUMBER:

    3.05 (20th March, 2017)

## 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 appendix  A.10 of this TEOS-10 Manual.

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