gsw_isopycnal_slope_ratio_CT25

ratio of the slopes of isopycnals on the 
SA-CT diagram for p and pr
(25-term equation)

Contents

USAGE:

[isopycnal_slope_ratio_CT25, in_funnel] = gsw_isopycnal_slope_ratio_CT25(SA,CT,p,pr)

DESCRIPTION:

Calculates the ratio of alpha_CT/beta_CT at pressure p to that at
pressure pr.  This function uses the computationally-efficient 25-term
expression for density in terms of SA, CT & p (McDougall et al., 2010).
TEOS-10
Click for a more detailed description of the isopycnal
slope ratio.

INPUT:

SA  =  Absolute Salinity                                        [ g/kg ]
CT  =  Conservative Temperature                                [ deg C ]
p   =  sea pressure                                             [ dbar ]
       (ie. absolute pressure - 10.1325 dbar)
pr  =  reference pressure                                       [ dbar ]
       (ie. absolute reference pressure - 10.1325 dbar)
SA & CT need to have the same dimensions.
p & pr may have dimensions 1x1 or Mx1 or 1xN or MxN, where SA & CT
are MxN

OUTPUT:

isopycnal_slope_ratio_CT25
                     =  The ratio of alpha_CT/beta_CT evaluated at
                        pressure p to that at pressure pr.  [ 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;]
pr = 0;
[isopycnal_slope_ratio_CT25, in_funnel] = ...
                gsw_isopycnal_slope_ratio_CT25(SA,CT,p,pr)
isopycnal_slope_ratio_CT25 =         in_funnel =
 1.000443300473299                    1
 1.002247196919216                    1
 1.007323843523325                    1
 1.033841543679809                    1
 1.113488165501534                    1
 1.257603349708546                    1

AUTHOR:

Trevor McDougall, Paul Barker & David Jackett [ 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. (3.17.2) 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