gsw_enthalpy_first_derivatives
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.
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).
EXAMPLE:
SA = [34.7118; 34.8915; 35.0256; 34.8472; 34.7366; 34.7324;]
t = [28.7856; 28.4329; 22.8103; 10.2600; 6.8863; 4.4036;]
p = [ 10; 50; 125; 250; 600; 1000;]
[h_SA, h_CT, h_P] = gsw_enthalpy_first_derivatives(SA,CT,p)
h_SA =
-0.070221017857321
-0.351155742717708
-0.887081852469166
-1.829811186103484
-4.424369449732652
-7.407229217110896
h_CT =
1.0e+003 *
3.991899729625529
3.992025696743769
3.992210168035032
3.992283178760239
3.992681641668387
3.993005774345293
h_P =
1.0e-003 *
0.978626618725186
0.978222134953103
0.976154774939840
0.972961213383549
0.971026778012244
0.968989993773259
AUTHOR:
Trevor McDougall. [ help_gsw@csiro.au ]
VERSION NUMBER:
2.0 (17th August, 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. (A.11.18), (A.11.15) and (A.11.12) of this TEOS-10 Manual.
This software is available from http://www.TEOS-10.org