Contents
USAGE:
[ntp_pt_vs_CT_ratio_CT25, in_funnel] = gsw_ntp_pt_vs_CT_ratio_CT25(SA,CT,p)
DESCRIPTION:
Calculates the ratio of the two-dimensional gradient of potential
temperature versus that of Conservative Temperature, CT, along the
neutral tangent plane. The potential temperature is the regular one
which has a reference sea pressure of 0 dbar. Part of the calculation
uses the 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:
ntp_pt_vs_CT_ratio_CT25 = The ratio of the spatial gradient of
potential temperature versus that of
Conservative Temperature in the
neutral tangent plane (ntp). [ unitless ]
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;]
[ntp_pt_vs_CT_ratio_CT25, in_funnel] = ...
gsw_ntp_pt_vs_CT_ratio_CT25(SA,CT,p)
ntp_pt_vs_CT25_ratio = in_funnel =
1.016122079370071 1
1.016078060102738 1
1.011790779852534 1
1.004313933279649 1
1.003007924869312 1
1.002330826430900 1
AUTHOR:
Trevor McDougall and Paul Barker [ gsw_help@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 Eqn. (A.14.5) 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.
This software is available from http://www.TEOS-10.org