gsw_enthalpy_first_derivatives_CT_exact

first derivatives of enthalpy

Contents

USAGE:

[h_SA, h_CT, h_P] = gsw_enthalpy_first_derivatives(SA,CT,p)

DESCRIPTION:

Calculates the following three derivatives of specific enthalpy (h)
 (1) h_SA, the derivative with respect to Absolute Salinity at
     constant CT and p, and
 (2) h_CT, derivative with respect to CT at constant SA and p.
 (3) h_P, derivative with respect to pressure (in Pa) at constant
     SA and CT.
Note that this function uses the full Gibbs function.  There is an 
alternative to calling this function, namely 
gsw_enthalpy_first_derivatives(SA,CT,p),which uses the computationally 
efficient 75-term expression for specific volume in terms of SA, CT and
p (Roquet et al., 2015).
TEOS-10 
Click for a more detailed description of the first
derivatives of specific enthalpy.

INPUT:

SA  =   Absolute Salinity                                       [ g/kg ]
CT  =   Conservative Temperature                               [ deg C ]
p   =   sea pressure                                            [ dbar ]
        (i.e. absolute pressure - 10.1325 dbar)
SA & CT need to have the same dimensions.
p may have dimensions 1x1 or Mx1 or 1xN or MxN, where SA & CT are MxN.

OUTPUT:

h_SA   =  The first derivative of specific enthalpy with respect to
          Absolute Salinity at constant CT and p.
                                          [ J/(kg (g/kg))]  i.e. [ J/g ]
h_CT   =  The first derivative of specific enthalpy with respect to
          CT at constant SA and p.                          [ J/(kg K) ]
h_P    =  The first partial derivative of specific enthalpy with
          respect to pressure (in Pa) at fixed SA and CT.  Note that
          h_P is specific volume (1/rho).                     [ m^3/kg ]

EXAMPLE:

SA = [34.7118; 34.8915; 35.0256; 34.8472; 34.7366; 34.7324;]
CT = [28.7856; 28.4329; 22.8103; 10.2600;  6.8863;  4.4036;]
p =  [     10;      50;     125;     250;     600;    1000;]
[h_SA, h_CT] = gsw_enthalpy_first_derivatives_CT_exact(SA,CT,p)
h_SA =
  -0.070224183838619
  -0.351159869043798
  -0.887036550157504
  -1.829626251448858
  -4.423522691827955
  -7.405211691293971
h_CT =
1.0e+003 *
   3.991899712269790
   3.992025674159605
   3.992210402650973
   3.992283991748418
   3.992685275917238
   3.993014370250710

AUTHOR:

Trevor McDougall.                      [ 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 Eqns. (A.11.18), (A.11.15) and (A.11.12) of this TEOS-10 Manual.
Roquet, F., G. Madec, T.J. McDougall, P.M. Barker, 2015: Accurate
 polynomial expressions for the density and specifc volume of seawater
 using the TEOS-10 standard. Ocean Modelling.
This software is available from http://www.TEOS-10.org