gsw_enthalpy_diff_CT

difference of enthalpy at two pressures

Contents

USAGE:

enthalpy_diff_CT = gsw_enthalpy_diff_CT(SA,CT,p_shallow,p_deep)

DESCRIPTION:

Calculates the difference of the specific enthalpy of seawater between
two different pressures, p_deep (the deeper pressure) and p_shallow
(the shallower pressure), at the same values of SA and CT.  The output
(enthalpy_diff) is the specific enthalpy evaluated at (SA,CT,p_deep)
minus the specific enthalpy at (SA,CT,p_shallow).
Note that this function uses the full Gibbs function.  There is an
alternative to calling this function, namely
gsw_enthalpy_diff_CT25(SA,CT,p), which uses the computationally
efficient 25-term expression for density in terms of SA, CT and p
(McDougall et al., (2010)).  For SA, CT and p values which fall inside
the oceanographic "funnel" (McDougall et al., 2010), this
computationally efficient (i. e. faster) 25-term version fits the
underlying laboratory density data almost as well as does the density
derived from the full TEOS-10 Gibbs function.
TEOS-10
Click for a more detailed description of the difference
of enthalpy between two pressures.

INPUT:

SA         =  Absolute Salinity                                 [ g/kg ]
CT         =  Conservative Temperature                         [ deg C ]
p_shallow  =  upper sea pressure                                [ dbar ]
              (ie. shallower absolute pressure - 10.1325 dbar)
p_deep     =  lower sea pressure                                [ dbar ]
              (ie. deeper absolute pressure - 10.1325 dbar)
p_shallow and p_deep may have dimensions Mx1 or 1xN or MxN,
where SA and CT are MxN.

OUTPUT:

enthalpy_diff_CT  =  difference of specific enthalpy          [ J/kg ]
                       (deep minus shallow)

EXAMPLE:

SA =         [34.7118; 34.8915; 35.0256; 34.8472; 34.7366; 34.7324;]
CT =         [28.8099; 28.4392; 22.7862; 10.2262;  6.8272;  4.3236;]
p_shallow =  [     10;      50;     125;     250;     600;    1000;]
p_deep    =  [    110;     150;     225;     350;     700;    1100;]
enthalpy_diff_CT = gsw_enthalpy_diff_CT(SA,CT,p_shallow,p_deep)
enthalpy_diff_CT =
1.0e+002 *
 9.784255933006788
 9.780212984387035
 9.759516776633390
 9.727494888619550
 9.708138965635516
 9.687770207718350

AUTHOR:

 Trevor McDougall and Paul Barker       [ help_gsw@csiro.au ]

VERSION NUMBER:

2.0 (29th September, 2010)

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 Eqns. (3.32.2) of this TEOS-10 Manual.
McDougall T. J., D. R. Jackett, P. M. Barker, C. Roberts-Thomson, R.
 Feistel and R. W. Hallberg, 2010:  A computationally efficient 25-term
 expression for the density of seawater in terms of Conservative
 Temperature, and related properties of seawater.  To be submitted
 to Ocean Science Discussions.
The software is available from http://www.TEOS-10.org