# 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. (2013).

    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. (2013).  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:

    3.02 (17th November, 2012)

## 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, 2013:  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 J. Atm. Ocean. Technol., xx, yyy-zzz.

    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