# gsw_geo_strf_dyn_height

    dynamic height anomaly

## Contents

- USAGE:
- DESCRIPTION:
- INPUT:
- OUTPUT:
- EXAMPLE:
- AUTHOR:
- VERSION NUMBER:
- REFERENCES:

## 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 48-term
    expression for specific volume of McDougall et al. (2011).

    This function evaluates the pressure integral of specific volume using
    SA and CT "interpolated" with respect to pressure using a scheme based
    on the method of Reiniger and Ross (1968).  Our method uses a weighted
    mean of (i) values obtained from linear interpolation of the two nearest
    data points, and (ii) a linear extrapolation of the pairs of data above
    and below.  This "curve fitting" method resembles the use of cubic
    splines.

    Note that the 48-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. (2011).  For dynamical oceanography we may
    take the 48-term rational function expression for density as essentially
    reflecting the full accuracy of TEOS-10.  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".

    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 =

              17.292238085013480
      14.933132053101872
      11.187848272884139
       7.901116636076495
       3.607208810117299
                       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 =

      12.591685524603520
      10.232579492691912
       6.487295712474179
       3.200564075666534
      -1.093343750292661
      -4.700552560409960

## AUTHOR:

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

## VERSION NUMBER:

    3.01 (18th 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 Eqn. (3.7.3) and section 3.27 of this TEOS-10 Manual.

    McDougall T.J., P.M. Barker, R. Feistel and D.R. Jackett, 2011:  A
     computationally efficient 48-term expression for the density of
     seawater in terms of Conservative Temperature, and related properties
     of seawater.  To be submitted to Ocean Science Discussions.

    Reiniger, R. F. and C. K. Ross, 1968: A method of interpolation with
     application to oceanographic data. Deep-Sea Res. 15, 185-193.

    The software is available from http://www.TEOS-10.org