gsw_specvol_first_derivatives_wrt_enthalpy

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

Contents

USAGE:

[v_SA_wrt_h, v_h] = gsw_specvol_first_derivatives_wrt_enthalpy(SA,CT,p)

DESCRIPTION:

Calculates the following two first-order derivatives of specific
volume (v),
 (1) v_SA_wrt_h, first-order derivative with respect to Absolute Salinity 
     at constant h & p.
 (2) v_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:

v_SA_wrt_h  =  The first derivative of specific volume with respect to 
            Absolute Salinity at constant CT & p.   
                                         [ (m^3/kg)(g/kg)^-1 (J/kg)^-1 ]
v_h  =  The first derivative of specific volume with respect to 
            SA and CT at constant p.               [ (m^3/kg)(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;]
[v_SA_wrt_h, v_h] = gsw_specvol_first_derivatives_wrt_enthalpy(SA,CT,p)
v_SA_wrt_h =
   1.0e-06 *
  -0.702143511679586
  -0.701991101310494
  -0.708834353735310
  -0.730130919555592
  -0.733018321892082
  -0.733342002723321
v_h =
   1.0e-10 *
   0.795862623587769
   0.790648383268264
   0.687443468257647
   0.422105846942233
   0.355778874334799
   0.314053366403993

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.
  See appendix A.20 and appendix K of this TEOS-10 Manual.
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