in-situ temperature freezing point



t_freezing = gsw_t_freezing(SA,p,saturation_fraction)


Calculates the in-situ temperature at which seawater freezes. The 
in-situ temperature freezing point is calculated from the exact 
in-situ freezing temperature which is found by a modified Newton-Raphson
iteration (McDougall and Wotherspoon, 2013) of the equality of the 
chemical potentials of water in seawater and in ice.
An alternative GSW function, gsw_t_freezing_poly, it is based on a 
computationally-efficient polynomial, and is accurate to within -5e-4 K 
and 6e-4 K, when compared with this function.


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

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.


t_freezing = in-situ temperature at which seawater freezes.    [ deg C ]


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


Paul Barker, Trevor McDougall and Rainer Feistal    [ ]


3.05 (16th February, 2015)


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., P.M. Barker, R. Feistel and B.K. Galton-Fenzi, 2014: 
 Melting of Ice and Sea Ice into Seawater and Frazil Ice Formation. 
 Journal of Physical Oceanography, 44, 1751-1775.
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. 
The software is available from