gsw_ntp_pt_vs_CT_ratio_CT25

ratio of gradients of potential temperature
and Conservative Temperature in a neutral 
tangent plane (in a locally-referenced 
potential density surface) (25-term equation)

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).
TEOS-10
Click for a more detailed description of the ratio of
gradients of potential temperature and Conservative
Temperature in a neutral tangent plane.

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