Contents
USAGE:
[SA,CT] = gsw_SA_CT_from_sigma2_spiciness2(sigma2,spiciness2)
DESCRIPTION:
Calculates the Absolute Salinity and the Conservative Temperature of a
seawater sample at given values of potential density referenced to
2000 dbar and spiciness2. 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 this 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:
sigma2 = density anomaly of a seawater sample (e.g 26 kg/m^3)
referenced to 2000 dbar [ kg/m^3 ]
Note. This input has had 1000 kg/m^3 subtracted from it. That is,
it is 'density anomaly', not 'density'.
spiciness2 = spiciness appropriate to 2000 dbar, as given by the paper of
McDougall and Krzysik (2015), and the GSW algorithm
gsw_spiciness0(SA,CT) [ kg/m^3 ]
sigma2 and spiciness2 need to have the same dimensions.
OUTPUT:
SA = Absolute Salinity. [ g/kg ]
CT = Conservative Temperature (ITS-90) [ deg C ]
EXAMPLE:
sigma2 = [30.0232; 30.2838; 32.2656; 35.4746; 36.0673; 36.4926;]
spiciness2 = [ 6.8747; 6.8846; 5.1545; 1.6243; 0.8235; 0.3551;]
[SA,CT] = gsw_SA_CT_from_sigma2_spiciness2(sigma2,spiciness2)
SA =
34.711851242409708
34.891499698032746
35.025657128992080
34.847215869981895
34.736613425608752
34.732415247259667
CT =
28.809869483639652
28.439152063398041
22.786195745017753
10.226027250979216
6.827198537163698
4.323715171988169
AUTHOR:
Trevor McDougall and Paul Barker [ help@teos-10.org ]
VERSION NUMBER:
3.06.12 (2nd July, 2020)
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.
McDougall, T.J., and O.A. Krzysik, 2015: Spiciness. Journal of
Marine Research, 73, 141-152.
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