# gsw_SA_CT_from_sigma1_spiciness1

SA and CT from sigma and spiciness at p = 1000 dbar (75-term equation)

## USAGE:

[SA,CT] = gsw_SA_CT_from_sigma1_spiciness1(sigma1,spiciness1)

## DESCRIPTION:

Calculates the Absolute Salinity and the Conservative Temperature of a
seawater sample at given values of potential density referenced to
1000 dbar and spiciness1.  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:

sigma1    =  density anomaly of a seawater sample (e.g 26 kg/m^3)
referenced to 1000 dbar                         [ kg/m^3 ]
Note. This input has had 1000 kg/m^3 subtracted from it.  That is,
it is 'density anomaly', not 'density'.

spiciness1 = spiciness appropriate to 1000 dbar, as given by the paper of
McDougall and Krzysik (2015), and the GSW algorithm
gsw_spiciness1(SA,CT)                           [ kg/m^3 ]
sigma1 and spiciness1 need to have the same dimensions.

## OUTPUT:

SA  =  Absolute Salinity.                                       [ g/kg ]
CT  =  Conservative Temperature (ITS-90)                       [ deg C ]

## EXAMPLE:

sigma1   =   [25.9556; 26.2131; 28.1254; 31.1204; 31.6377; 32.0025;]
spiciness1 = [ 6.3110;  6.3264;  4.6672;  1.3517;  0.6285;  0.2248;]
[SA,CT] = gsw_SA_CT_from_sigma1_spiciness1(sigma1,spiciness1)
SA =
34.711761274805134
34.891471674852035
35.025571500983958
34.847212933737914
34.736586922069982
34.732445807599724
CT =
28.809872867656239
28.439231699034760
22.786209105041554
10.226045025810093
6.827288021081957
4.323517735371240

## 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