# gsw_z_from_p

    height from pressure (25-term equation)

## Contents

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

## USAGE:

    z = gsw_z_from_p(p,lat)

## DESCRIPTION:

    Calculates height from sea pressure using the computationally-efficient
    25-term expression for density in terms of SA, CT and p. (McDougall et
    al., 2010).
    Note. Height z is NEGATIVE in the ocean. ie. Depth is -z.
     Depth is not used in the GSW computer software library.

    Click for a more detailed description of calculating
    height from pressure.

## INPUT:

    p    =  sea pressure                                            [ dbar ]
           ( ie. absolute pressure - 10.1325 dbar )
    lat  =  latitude in decimal degrees north                [ -90 ... +90 ]

    lat may have dimensions 1x1 or Mx1 or 1xN or MxN, where p is MxN.

## OUTPUT:

    z  =  height                                                       [ m ]
    Note. At sea level z = 0, and since z (HEIGHT) is defined to be
      positive upwards, it follows that while z is positive in the
      atmosphere, it is NEGATIVE in the ocean.

## EXAMPLE:

    z =  [   10;   50;  125;  250;  600; 1000;]
    lat = 4;

    z = gsw_z_from_p(p,lat)

    z =
       -9.9446
      -49.7182
     -124.2728
     -248.4704
     -595.8262
     -992.0932

## AUTHOR:

    Trevor McDougall, Claire Roberts-Thomson & Paul Barker.
                                                      [ help_gsw@csiro.au ]

## VERSION NUMBER:

    2.0 (26th August, 2010)

## 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.

    McDougall T. J., D. R. Jackett, P. M. Barker, C. Roberts-Thomson, R.
     Feistel and R. W. Hallberg, 2010:  A computationally efficient 25-term
     expression for the density of seawater in terms of Conservative
     Temperature, and related properties of seawater.  To be submitted
     to Ocean Science Discussions.

    Moritz (2000) Goedetic reference system 1980. J. Geodesy, 74, 128-133.

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