# gsw_SA_freezing_from_t_poly

`Absolute Salinity of seawater at the freezing point (poly)`

## USAGE:

`SA_freezing = gsw_SA_freezing_from_t_poly(t,p,saturation_fraction)`

## DESCRIPTION:

```Calculates the Absolute Salinity of seawater at the freezing temperature.
That is, the output is the Absolute Salinity of seawater, with the
fraction saturation_fraction of dissolved air, that is in equilibrium
with ice at in-situ temperature t and pressure p.  If the input
values are such that there is no positive value of Absolute Salinity for
which seawater is frozen, the output, SA_freezing, is put equal to NaN.```
 ```Click for a more detailed description of calculating Absolute Salinity of seawater at the freezing point.```

## INPUT:

```t  =  in-situ temperature (ITS-90)                             [ deg C ]
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 t is MxN.```

## OUTPUT:

```SA_freezing  =  Absolute Salinity of seawater when it freezes, for
given input values of in-situ temperature
pressure and air saturation fraction.             [ g/kg ]```

## EXAMPLE:

```t = [-0.11901; -0.15608;  -0.72138; -1.97738;  -2.31728;  -2.56764;]
p =  [     10;      50;     125;     250;     600;    1000;]
saturation_fraction = 1```
`SA_freezing = gsw_SA_freezing_from_t_poly(t,p,saturation_fraction)`
`SA_freezing =`
```  2.017072489768256
2.151989342038462
11.677649626115608
32.843128114999026
34.136459306273451
33.097427522625182```

## AUTHOR:

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

## VERSION NUMBER:

`3.05 (28th May, 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., 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.```
`The software is available from http://www.TEOS-10.org`