# gsw_pt_from_pot_enthalpy_ice

    potential temperature of ice with a reference sea
    pressure of zero dbar from the potential enthalpy
    of ice

## Contents

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

## USAGE:

    pt0_ice = gsw_pt_from_pot_enthalpy_ice(pot_enthalpy_ice)

## DESCRIPTION:

    Calculates the potential temperature of ice from the potential enthalpy
    of ice.  The reference sea pressure of both the potential temperature
    and the potential enthalpy is zero dbar.

## INPUT:

    pot_enthalpy_ice  =  potential enthalpy of ice                  [ J/kg ]

## OUTPUT:

    pt0_ice   =  potential temperature of ice                      [ deg C ]
            with reference sea pressure (pr) = 0 dbar.
    Note. The reference sea pressure of the output, pt, is zero dbar.

## EXAMPLE:

    pot_enthalpy_ice = [-3.5544e5; -3.6033e5; -3.5830e5; -3.5589e5; -3.4948e5; -3.4027e5;]

    pt0_ice = gsw_pt_from_pot_enthalpy_ice(pot_enthalpy_ice)

    pt0_ice =

      -10.733087588125384
      -13.167397822300588
      -12.154205899172704
      -10.956202704066083
       -7.794963180206421
       -3.314905214262531

## AUTHOR:

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

## VERSION NUMBER:

    3.05 (16th February, 2015)

## 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.

    McDougall, T.J. and S.J. Wotherspoon, 2013: A simple modification of
     Newton’s method to achieve convergence of order "1 + sqrt(2)". Applied
     Mathematics Letters, 29, 20-25.
     http://dx.doi.org/10.1016/j.aml.2013.10.008

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