Contents
USAGE:
[SA_final, CT_final, w_Ih_final] = ...
gsw_frazil_properties(SA_bulk,h_bulk,p)
DESCRIPTION:
Calculates the mass fraction of ice (mass of ice divided by mass of ice
plus seawater), w_Ih_final, which results from given values of the bulk
Absolute Salinity, SA_bulk, bulk enthalpy, h_bulk, occuring at pressure
p. The final values of Absolute Salinity, SA_final, and Conservative
Temperature, CT_final, of the interstitial seawater phase are also
returned. This code assumes that there is no dissolved air in the
seawater (that is, saturation_fraction is assumed to be zero
throughout the code).
When the mass fraction w_Ih_final is calculated as being a positive
value, the seawater-ice mixture is at thermodynamic equlibrium.
This code returns w_Ih_final = 0 when the input bulk enthalpy, h_bulk,
is sufficiently large (i.e. sufficiently "warm") so that there is no ice
present in the final state. In this case the final state consists of
only seawater rather than being an equlibrium mixture of seawater and
ice which occurs when w_Ih_final is positive. Note that when
w_Ih_final = 0, the final seawater is not at the freezing temperature.
Note that there is another GSW code,
gsw_frazil_properties_potential_poly(SA_bulk,h_pot_bulk,p) which
treats potential enthalpy as the conservative variable, while, in
contrast, the present code treats in situ enthalpy as the conservative
variable during the interaction of seawater and ice Ih.
INPUT:
SA_bulk = bulk Absolute Salinity of the seawater and ice mixture
[ g/kg ]
h_bulk = bulk enthalpy of the seawater and ice mixture [ J/kg ]
p = sea pressure [ dbar ]
( i.e. absolute pressure - 10.1325 dbar )
SA_bulk and h_bulk must have the same dimensions.
p may have dimensions 1x1 or Mx1 or 1xN or MxN, where SA_bulk and
h_bulk are MxN.
OUTPUT:
SA_final = Absolute Salinity of the seawater in the final state,
whether or not any ice is present. [ g/kg ]
CT_final = Conservative Temperature of the seawater in the the final
state, whether or not any ice is present. [ deg C ]
w_Ih_final = mass fraction of ice in the final seawater-ice mixture.
If this ice mass fraction is positive, the system is at
thermodynamic equilibrium. If this ice mass fraction is
zero there is no ice in the final state which consists
only of seawater which is warmer than the freezing
temperature. [unitless]
EXAMPLE:
SA_bulk = [34.7118; 34.8915; 35.0256; 34.8472; 34.7366; 34.7324;]
h_bulk = [-4.5544e4;-4.6033e4;-4.5830e4;-4.5589e4;-4.4948e4;-4.4027e4;]
p = [ 10; 50; 125; 250; 600; 1000;]
[SA_final, CT_final, w_Ih_final] = ...
gsw_frazil_properties(SA_bulk,h_bulk,p)
SA_final =
39.111030663000442
39.407625769681573
39.595789974885108
39.481230045372889
39.591177095552503
39.826467709177123
CT_final =
-2.156311126114311
-2.204672298963783
-2.273689262333450
-2.363714136353600
-2.644541000680772
-2.977651291726651
w_Ih_final =
0.112480560814322
0.114600300867556
0.115421108602301
0.117372990660305
0.122617649983886
0.127906590822347
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., 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
