Contents
USAGE:
[Tu, Rsubrho, p_mid, in_funnel] = gsw_Turner_Rsubrho_CT25(SA,CT,p)
DESCRIPTION:
Calculates the Turner angle and the Rsubrho as a function of pressure
down a vertical water column. These quantities express the relative
contributions of the vertical gradients of Conservative Temperature and
Absolute Salinity to the vertical stability (the square of the
Brunt-Vaisala Frequency squared, N^2). Tu and Rsubrho are evaluated at
the mid pressure between the individual data points in the vertical.
This function uses computationally-efficient 25-term expression for
density in terms of SA, CT and p (McDougall et al., 2010).
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:
Tu = Turner angle, on the same (M-1)xN grid as p_mid.
Turner angle has units of: [ degrees of rotation ]
Rsubrho = Stability Ratio, on the same (M-1)xN grid as p_mid.
Rsubrho is dimensionless. [ unitless ]
p_mid = mid pressure between the indivual points of the p grid.
That is, p_mid is on a (M-1)xN grid in the vertical.
p_mid has units of: [ dbar ]
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;]
[Tu, Rsubrho, p_mid, in_funnel] = gsw_Turner_Rsubrho_CT25(SA,CT,p)
Tu =
-2.081599636326501
41.758226366707646
47.604100420927587
53.716687678781497
45.527957856195947
Rsubrho =
1.0e+002 *
-0.009298559867815
-0.176553434913642
0.219869869025208
0.065223236816021
1.085203244744855
p_mid =
1.0e+002 *
0.300000000000000
0.875000000000000
1.875000000000000
4.250000000000000
8.000000000000000
in_funnel =
1
1
1
1
1
1
AUTHOR:
Trevor McDougall & Paul Barker [ help_gsw@csiro.au ]
VERSION NUMBER:
2.0 (26th August, 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 Eqns. (3.15.1) and (3.16.1) 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