Contents
USAGE:
[rho, alpha_CT, beta_CT, in_funnel] = gsw_rho_alpha_beta_CT25(SA,CT,p)
DESCRIPTION:
Calculates in-situ density, the appropiate thermal expansion coefficient
and the appropriate saline contraction coefficient of seawater from
Absolute Salinity and Conservative Temperature. This function uses the
computationally-efficient 25-term expression for density in terms of
SA, CT and p (McDougall et al., 2010).
Note that potential density (pot_rho) with respect to reference pressure
pr is obtained by calling this function with the pressure argument being
pr as in [pot_rho, ~, ~, in_funnel] = gsw_rho_alpha_beta_CT25(SA,CT,pr).
INPUT:
SA = Absolute Salinity [ g/kg ]
CT = Conservative Temperature [ deg C ]
p = sea pressure [ dbar ]
(ie. absolute pressure - 10.1325 dbar)
SA & CT need to have the same dimensions.
p may have dimensions 1x1 or Mx1 or 1xN or MxN, where SA & CT are MxN.
OUTPUT:
rho = in-situ density [ kg m^-3 ]
alpha_CT = thermal expansion coefficient [ 1/K ]
with respect to Conservative Temperature
beta_CT = saline contraction coefficient [ kg/g ]
at constant Conservative Temperature
in_funnel = 0, if SA, CT and p are outside the "funnel"
= 1, if SA, CT and p are inside the "funnel"
Note. The term "funnel" describes the range of SA, CT and p over which
the error in the fit of the computationally-efficient 25-term
expression for density was calculated (McDougall et al., 2010).
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 = [ 10; 50; 125; 250; 600; 1000;]
[rho, alpha_CT, beta_CT, in_funnel] = gsw_rho_alpha_beta_CT25(SA,CT,p)
rho =
1.0e+003 *
1.021839541498949
1.022261845123599
1.024426245497197
1.027792152543827
1.029838876568916
1.032002445797635
alpha_CT =
1.0e-003 *
0.324356899200044
0.322411511462120
0.281313314947018
0.173211327216534
0.146078398825498
0.129148950914940
beta_CT =
1.0e-003 *
0.717340839421976
0.717514858800028
0.726299524800543
0.750622769257820
0.755000880950473
0.756865290355974
in_funnel =
1
1
1
1
1
1
AUTHOR:
David Jackett, Trevor McDougall and Paul Barker [ help_gsw@csiro.au ]
VERSION NUMBER:
2.0 (23rd July, 2010)
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 appendix A.20 and appendix K of this TEOS-10 Manual.
McDougall T. J., D. R. Jackett, P. M. Barker, C. Roberts-Thomson, R.
Feistel and R. W. Hallberg, 2010: A computationally efficient 25-term
expression for the density of seawater in terms of Conservative
Temperature, and related properties of seawater. To be submitted
to Ocean Science Discussions.
The software is available from http://www.TEOS-10.org