gsw_entropy_second_derivatives

second derivatives of entropy

Contents

USAGE:

[eta_SA_SA, eta_SA_CT, eta_CT_CT] = gsw_entropy_second_derivatives(SA,CT)

DESCRIPTION:

Calculates the following three second-order partial derivatives of
specific entropy (eta)
 (1) eta_SA_SA, the second derivative with respect to Absolute
     Salinity at constant Conservative Temperature, and
 (2) eta_SA_CT, the derivative with respect to Absolute Salinity and
     Conservative Temperature.
 (3) eta_CT_CT, the second derivative with respect to Conservative
     Temperature at constant Absolute Salinity.
TEOS-10 
Click for a more detailed description of the second
derivatives of entropy.

INPUT:

SA   =   Absolute Salinity                                      [ g/kg ]
CT   =   Conservative Temperature                              [ deg C ]
SA & CT need to have the same dimensions.

OUTPUT:

eta_SA_SA =  The second derivative of specific entropy with respect
             to Absolute Salinity (in units of g/kg) at constant
             Conservative Temperature.  eta_SA_SA has units of:
                                                     [ J/(kg K(g/kg)^2)]
eta_SA_CT =  The second derivative of specific entropy with respect
             to Conservative Temperature at constant Absolute
             Salinity. eta_SA_CT has units of:     [ J/(kg (g/kg) K^2) ]
eta_CT_CT =  The second derivative of specific entropy with respect
             to Conservative Temperature at constant Absolute
             Salinity.  eta_CT_CT has units of:           [ J/(kg K^3) ]

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;]
[eta_SA_SA, eta_SA_CT, eta_CT_CT] = gsw_entropy_second_derivatives(SA,CT)
eta_SA_SA =
  -0.007627718929669
  -0.007591969960708
  -0.007528186784540
  -0.007455177590576
  -0.007441108287466
  -0.007414368396280
eta_SA_CT =
  -0.001833104216751
  -0.001819473824306
  -0.001580843823414
  -0.000930111408561
  -0.000717011215195
  -0.000548410546830
eta_CT_CT =
  -0.043665023731109
  -0.043781336189326
  -0.045506114440888
  -0.049708939454018
  -0.050938690879443
  -0.051875017843472

AUTHOR:

Trevor McDougall and Paul Barker       [ help@teos-10.org ]

VERSION NUMBER:

3.01 (17th May, 2011)

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. (P.14b) and (P.15a,b) of this TEOS-10 Manual.
This software is available from http://www.TEOS-10.org