gsw_isopycnal_slope_ratio

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

Contents

USAGE:

isopycnal_slope_ratio = gsw_isopycnal_slope_ratio(SA,CT,p,p_ref)

DESCRIPTION:

Calculates the ratio of alpha_CT/beta_CT at pressure p to that at
pressure p_ref.  This function uses the computationally-efficient 75-term
expression for specific volume in terms of SA, CT and p (Roquet et al.,
2015).
Note that the 75-term equation has been fitted in a restricted range of 
parameter space, and is most accurate inside the "oceanographic funnel" 
described in McDougall et al. (2003).  The GSW library function 
"gsw_infunnel(SA,CT,p)" is avaialble to be used if one wants to test if 
some of one's data lies outside this "funnel".
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 ]
         ( i.e. absolute pressure - 10.1325 dbar )
p_ref =  reference pressure                                    [ dbar ]
         ( i.e. absolute reference pressure - 10.1325 dbar )
SA & CT need to have the same dimensions.
p & p_ref may have dimensions 1x1 or Mx1 or 1xN or MxN, where SA & CT
are MxN

OUTPUT:

isopycnal_slope_ratio  =  The ratio of alpha_CT/beta_CT evaluated at
                          pressure p to that at pressure p_ref.  
                                                            [ unitless ]

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;]
p_ref = 0
isopycnal_slope_ratio = gsw_isopycnal_slope_ratio(SA,CT,p,p_ref)
isopycnal_slope_ratio = 
   1.000435598406882
   1.002211450149232
   1.007313601141281
   1.033747554906412
   1.112513649348894
   1.254180124792826

AUTHOR:

Trevor McDougall, Paul Barker & David Jackett   [ help@teos-10.org ]

VERSION NUMBER:

3.05 (16th February, 2015)

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, D.G. Wright and R. Feistel, 2003: 
 Accurate and computationally efficient algorithms for potential 
 temperature and density of seawater.  J. Atmosph. Ocean. Tech., 20,
 pp. 730-741.
Roquet, F., G. Madec, T.J. McDougall, P.M. Barker, 2015: Accurate
 polynomial expressions for the density and specifc volume of seawater
 using the TEOS-10 standard. Ocean Modelling.
This software is available from http://www.TEOS-10.org