# gsw_pot_enthalpy_ice_freezing

    potential enthalpy of ice at which seawater freezes

## Contents

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

## USAGE:

    pot_enthalpy_ice_freezing = ...
             gsw_pot_enthalpy_ice_freezing(SA,p,saturation_fraction)

## DESCRIPTION:

    Calculates the potential enthalpy of ice at which seawater freezes.

    An alternative GSW function, gsw_pot_enthalpy_ice_freezing_poly, it
    is based on a computationally-efficient polynomial.

## INPUT:

    SA  =  Absolute Salinity                                        [ g/kg ]
    p   =  sea pressure                                             [ dbar ]
           ( i.e. absolute pressure - 10.1325 dbar )

    OPTIONAL:

    saturation_fraction  =  the saturation fraction of dissolved air
                            in seawater
    (i.e., saturation_fraction must be between 0 and 1, and the
    default is 0, air free)

    p & saturation_fraction (if provided) may have dimensions 1x1 or Mx1
    or 1xN or MxN, where SA is MxN.

## OUTPUT:

    pot_enthalpy_ice_freezing = potential enthalpy of ice at freezing
                                  of seawater                   [ J/kg ]

## EXAMPLE:

    SA = [34.7118; 34.8915; 35.0256; 34.8472; 34.7366; 34.7324;]
    p =  [     10;      50;     125;     250;     600;    1000;]
    saturation_fraction = 1;

    pot_enthalpy_ice_freezing = ...
            gsw_pot_enthalpy_ice_freezing(SA,p,saturation_fraction)

    pot_enthalpy_ice_freezing =

      1.0e+05 *

      -3.373409558967978
      -3.374434164002012
      -3.376117536928847
      -3.378453698871986
      -3.385497832886802
      -3.393768587631489

## AUTHOR:

    Paul Barker, Trevor McDougall and Rainer Feistal   [ 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.
      See section 3.3 of this TEOS-10 Manual.

    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