gsw_rho_first_derivatives

SA, CT and p partial derivatives of density
(48-term equation)

Contents

USAGE:

[drho_dSA, drho_dCT, drho_dP] = gsw_rho_first_derivatives(SA,CT,p)

DESCRIPTION:

Calculates the three (3) partial derivatives of in situ density with 
respect to Absolute Salinity, Conservative Temperature and pressure.  
Note that the pressure derivative is done with respect to pressure in 
Pa, not dbar.  This function uses the computationally-efficient 48-term 
expression for density in terms of SA, CT and p.
Note that the 48-term equation has been fitted in a restricted range of 
parameter space, and is most accurate inside the "oceanographic funnel" 
described in IOC et al. (2010).  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".
TEOS-10 
Click for a more detailed description of three (3)
partial derivatives of in situ density with respect 
to Absolute Salinity, Conservative Temperature and
pressure.

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:

drho_dSA  =  partial derivatives of density             [ kg^2/(g m^3) ]
             with respect to Absolute Salinity
drho_dCT  =  partial derivatives of density               [ kg/(K m^3) ]
             with respect to Conservative Temperature
drho_dP   =  partial derivatives of density              [ kg/(Pa m^3) ]
             with respect to pressure in Pa

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;]
[drho_dSA, drho_dCT, drho_dP] = gsw_rho_first_derivatives(SA,CT,p)
drho_dSA =
   0.733213518869108
   0.733680726153097
   0.744004504721854
   0.771450239175361
   0.777682888539079
   0.781381240968611
drho_dCT =
  -0.331745785850892
  -0.329852042010685
  -0.288019853222119
  -0.177963249929159
  -0.150582707661951
  -0.133481065091957
drho_dP =
  1.0e-006 *
   0.420305747137598
   0.420249518076609
   0.426747374547013
   0.447719879751583
   0.451969476434040
   0.454082698501517

AUTHOR:

Paul Barker and Trevor McDougall          [ help@teos-10.org ]

VERSION NUMBER:

3.04 (10th December, 2013)

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.
The software is available from http://www.TEOS-10.org