specific volume anomaly (75-term equation)



specvol_anom = gsw_specvol_anom(SA,CT,p,SA_ref,CT_ref)


Calculates specific volume anomaly from Absolute Salinity,
Conservative Temperature and pressure.  It uses the computationally 
efficient 75-term expression for specific volume in terms of SA, CT
and p (Roquet et al., 2015).  If the Absolute Salinity and Conservative
Temperature reference value (SA_ref and CT_ref) are not defined then a
default reference value of Absolute Salinity is SSO and the reference 
value of Conservative Temperature is equal to 0 degress C.
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". 


SA  =  Absolute Salinity                                        [ g/kg ]
CT  =  Conservative Temperature                                [ deg C ]
p   =  sea pressure                                             [ dbar ]
       ( i.e. absolute pressure - 10.1325 dbar )
SA_ref =  reference Absolute Salinity                           [ g/kg ]
CT_ref =  reference Conservative Temperature (ITS-90)          [ deg C ]
SA & CT need to have the same dimensions.
SA_ref & CT_ref must be scalars and have dimensions 1x1.
p may have dimensions 1x1 or Mx1 or 1xN or MxN, where SA & CT are MxN.


specvol_anom  =  specific volume anomaly                      [ m^3/kg ]


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;]
SA_ref = 30
CT_ref = 4
specvol_anom = gsw_specvol_anom(SA,CT,p,SA_ref,CT_ref)
specvol_anom = 
 1.0e-005 *


Paul Barker and Trevor McDougall                        [ ]


3.05 (16th February, 2015)


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 Eqn. (3.7.3) 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