gsw_enthalpy_diff

difference of enthalpy between two pressures (75-term equation)

Contents

USAGE:

enthalpy_diff = gsw_enthalpy_diff(SA,CT,p_shallow,p_deep)

DESCRIPTION:

Calculates the difference of the specific enthalpy of seawater between
two different pressures, p_deep (the deeper pressure) and p_shallow
(the shallower pressure), at the same values of SA and CT.  This
function uses the computationally-efficient 75-term expression for
specific volume in terms of SA, CT and p (Roquet et al., 2015).  The
output (enthalpy_diff) is the specific enthalpy evaluated at 
(SA, CT, p_deep) minus the specific enthalpy at (SA, CT, p_shallow).
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".
TEOS-10 
Click for a more detailed description of the difference
of enthalpy between two pressures

INPUT:

SA         =  Absolute Salinity                                 [ g/kg ]
CT         =  Conservative Temperature                         [ deg C ]
p_shallow  =  upper sea pressure                                [ dbar ]
              (ie. shallower absolute pressure - 10.1325 dbar)
p_deep     =  lower sea pressure                                [ dbar ]
              (ie. deeper absolute pressure - 10.1325 dbar)
p_shallow and p_deep may have dimensions Mx1 or 1xN or MxN,
where SA and CT are MxN.

OUTPUT:

enthalpy_diff  =  difference of specific enthalpy               [ J/kg ]
                  (deep minus shallow)

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_shallow =  [     10;      50;     125;     250;     600;    1000;]
p_deep    =  [    110;     150;     225;     350;     700;    1100;]
enthalpy_diff = gsw_enthalpy_diff(SA,CT,p_shallow,p_deep)
enthalpy_diff = 
1.0e+002 *
   9.784180644568052
   9.780195056105020
   9.759587700515114
   9.727552719534447
   9.708223170174454
   9.687871289079633

AUTHOR:

Trevor McDougall and Paul Barker               [ 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. (3.32.2) and (A.30.6) 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