gsw_geo_strf_dyn_height

dynamic height anomaly (75-term equation)

Contents

USAGE:

geo_strf_dyn_height = gsw_geo_strf_dyn_height(SA,CT,p,p_ref)

DESCRIPTION:

Calculates dynamic height anomaly as the integral of specific volume
anomaly from the pressure p of the "bottle" to the reference pressure
p_ref.
Hence, geo_strf_dyn_height is the dynamic height anomaly with respect
to a given reference pressure.  This is the geostrophic streamfunction 
for the difference between the horizontal velocity at the pressure 
concerned, p, and the horizontal velocity at p_ref.  Dynamic height 
anomaly is the geostrophic streamfunction in an isobaric surface.  The 
reference values used for the specific volume anomaly are 
SSO = 35.16504 g/kg and CT = 0 deg C.  This function calculates 
specific volume anomaly using the computationally efficient 75-term
expression for specific volume (Roquet et al., 2015). 
This function evaluates the pressure integral of specific volume using 
SA and CT interpolated with respect to the intergral of bouyancy 
frequency N2 using the method of Barker et al. (2017).  This "curve 
fitting" method uses a Piecewise Cubic Hermite Interpolating Polynomial 
to produce a smooth curve with minimal artificial watermasses  between
the observed data points.
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 dynamic
height anomaly.

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. reference absolute pressure - 10.1325 dbar )
SA & CT need to have the same dimensions.
p may have dimensions Mx1 or 1xN or MxN, where SA & CT are MxN.
p_ref needs to be a single value, it can have dimensions 1x1 or Mx1 or  
1xN or MxN.

OUTPUT:

geo_strf_dyn_height = dynamic height anomaly                 [ m^2/s^2 ]

EXAMPLE 1:

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 = 1000
geo_strf_dyn_height = gsw_geo_strf_dyn_height(SA,CT,p,p_ref)
geo_strf_dyn_height =
  17.434370534476397
  15.077272863514917
  11.353433025780669
   7.942688032614864
   3.608928554434066
                   0

EXAMPLE 2:

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 = 500
geo_strf_dyn_height = gsw_geo_strf_dyn_height(SA,CT,p,p_ref)
geo_strf_dyn_height =
  12.723940504666212
  10.366842833704730
   6.643002995970482
   3.232258002804677
  -1.101501475376121
  -4.710430029810187

AUTHOR:

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

VERSION NUMBER:

3.06 (15th May, 2017)

REFERENCES:

Barker, P.M., T.J. McDougall and S.J. Wotherspoon, 2017: An 
 interpolation method for oceanographic data. J. Atmosph. Ocean. Tech.
  (To be submitted).
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. (3.7.3) and section 3.27 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 and P.M. Barker, 2015: Accurate
 polynomial expressions for the density and specific volume of seawater 
 using the TEOS-10 standard.  Ocean Modelling, 90, pp. 29-43. 
 http://dx.doi.org/10.1016/j.ocemod.2015.04.002
The software is available from http://www.TEOS-10.org