# gsw_specvol_anom

specific volume anomaly (75-term equation)

## Contents

## USAGE:

specvol_anom = gsw_specvol_anom(SA,CT,p,SA_ref,CT_ref)

## DESCRIPTION:

Calculates specific volume anomaly from Absolute Salinity, Conservative Temperature and pressure. It uses the computationally efficient 75-term expression for specific volume in terms of SA, CT and p (Roquet et al., 2015). If the Absolute Salinity and Conservative Temperature reference value (SA_ref and CT_ref) are not defined then a default reference value of Absolute Salinity is SSO and the reference value of Conservative Temperature is equal to 0 degress C.

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".

## INPUT:

SA = Absolute Salinity [ g/kg ] CT = Conservative Temperature [ deg C ] p = sea pressure [ dbar ] ( i.e. absolute pressure - 10.1325 dbar )

OPTIONAL: SA_ref = reference Absolute Salinity [ g/kg ] CT_ref = reference Conservative Temperature (ITS-90) [ deg C ]

SA & CT need to have the same dimensions. SA_ref & CT_ref must be scalars and have dimensions 1x1. p may have dimensions 1x1 or Mx1 or 1xN or MxN, where SA & CT are MxN.

## OUTPUT:

specvol_anom = specific volume anomaly [ m^3/kg ]

## 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;] p = [ 10; 50; 125; 250; 600; 1000;] SA_ref = 30 CT_ref = 4

specvol_anom = gsw_specvol_anom(SA,CT,p,SA_ref,CT_ref)

specvol_anom =

1.0e-005 *

0.182698820023788 0.160145418717917 -0.013071960825064 -0.276827482245674 -0.315639023928321 -0.344663237300281

## AUTHOR:

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

## VERSION NUMBER:

3.05 (16th February, 2015)

## 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) 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, P.M. Barker, 2015: Accurate polynomial expressions for the density and specifc volume of seawater using the TEOS-10 standard. Ocean Modelling.

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