# gsw_pt_from_entropy

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

## Contents

## 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.

## 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