gsw_rho_first_derivatives_wrt_enthalpy

partial derivatives of density 
with respect to enthalpy (75-term equation)

Contents

USAGE:

[rho_SA_wrt_h, rho_h] = gsw_rho_first_derivatives_wrt_enthalpy(SA,CT,p)

DESCRIPTION:

Calculates the following two first-order derivatives of density
(rho),
 (1) rho_SA_wrt_h, first-order derivative with respect to Absolute Salinity 
     at constant h & p.
 (2) rho_h, first-order derivative with respect to h at 
     constant SA & p. 
This function uses the computationally-efficient 75-term
expression for specific volume in terms of SA, CT and p (Roquet et al.,
2015).
Note that the 75-term equation has been fitted in a restricted range of 
parameter space, and is most accurate inside the "oceanographic funnel" 
described in McDougall et al. (2003).  The GSW library function 
"gsw_infunnel(SA,CT,p)" is avaialble to be used if one wants to test if 
some of one's data lies outside this "funnel". 

INPUT:

SA  =  Absolute Salinity                                        [ g/kg ]
CT  =  Conservative Temperature                                [ deg C ]
p   =  sea pressure                                             [ dbar ]
       (ie. 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:

rho_SA_wrt_h  =  The first derivative of density with respect to 
                 Absolute Salinity at constant CT & p.   
                                         [ (kg/m^3)(g/kg)^-1 (J/kg)^-1 ]
rho_h  =  The first derivative of density with respect to 
          SA and CT at constant p.                 [ (kg/m^3)(J/kg)^-1 ]

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 =  [     10;      50;     125;     250;     600;    1000;]
[rho_SA_wrt_h, rho_h] = gsw_rho_first_derivatives_wrt_enthalpy(SA,CT,p)
rho_SA_wrt_h =
   0.733147960400929
   0.733595114830609
   0.743886977148835
   0.771275693831993
   0.777414200397148
   0.781030546357425
v_h =
   1.0e-04 *
  -0.831005413475887
  -0.826243794873652
  -0.721438289309903
  -0.445892608094272
  -0.377326924646647
  -0.334475962698187

AUTHOR:

Paul Barker and 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.
McDougall, T.J., D.R. Jackett, D.G. Wright and R. Feistel, 2003: 
 Accurate and computationally efficient algorithms for potential 
 temperature and density of seawater.  J. Atmosph. Ocean. Tech., 20,
 pp. 730-741.
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.
The software is available from http://www.TEOS-10.org