Contents
USAGE:
specvol_diff = gsw_specvol_diff(SA,CT,p_shallow,p_deep)
DESCRIPTION:
Calculates the difference of the specific volume 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 expression for specific
volume in terms of SA, CT and p (Roquet et al., 2015). The output
(specvol_diff) is the specific volume evaluated at (SA,CT,p_deep)
minus the specific volume 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".
INPUT:
SA = Absolute Salinity [ g/kg ]
CT = Conservative Temperature [ deg C ]
p_shallow = upper sea pressure [ dbar ]
( i.e. shallower absolute pressure - 10.1325 dbar )
p_deep = lower sea pressure [ dbar ]
( i.e. deeper absolute pressure - 10.1325 dbar )
SA & CT need to have the same dimensions.
p_shallow and p_deep may have dimensions 1x1 or Mx1 or 1xN or MxN, where
SA and CT are MxN.
OUTPUT:
specvol_diff = difference of specific volume [ m^3/kg ]
(deep minus shallow)
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_shallow = [ 10; 50; 125; 250; 600; 1000;]
p_deep = [ 60; 110; 200; 450; 900; 1400;]
specvol_diff = gsw_specvol_diff(SA,CT,p_shallow,p_deep)
specvol_diff =
1.0e-05 *
-0.020111062863217
-0.024106728658928
-0.030464766950093
-0.084512585565385
-0.127262626083441
-0.169490226833100
AUTHOR:
Trevor McDougall and Paul Barker [ help@teos-10.org ]
VERSION NUMBER:
3.06.13 (30th July, 2021)
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 and P.M. Barker, 2015: Accurate
polynomial expressions for the density and specific volume of seawater
using the TEOS-10 standard. Ocean Modelling, 90, pp. 29-43.
http://dx.doi.org/10.1016/j.ocemod.2015.04.002
The software is available from http://www.TEOS-10.org