# gsw_specvol_alpha_beta

```specific volume, thermal expansion & saline
contraction coefficient (75-term equation)```

## USAGE:

`[specvol, alpha, beta] = gsw_specvol_alpha_beta(SA,CT,p)`

## DESCRIPTION:

```Calculates specific volume, the appropiate thermal expansion coefficient
and the appropriate saline contraction coefficient of seawater from
Absolute Salinity and Conservative Temperature.  This function uses the
computationally-efficient 75-term expression for specific volume in terms
of SA, CT and p (Roquet et al., 2015).```
```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 ]
(ie. absolute pressure - 10.1325 dbar)```
```SA & CT need to have the same dimensions.
p may have dimensions 1x1 or Mx1 or 1xN or MxN, where SA & CT are MxN.```

## OUTPUT:

```specvol =  specific volume                                    [ m^3/kg ]
alpha  =  thermal expansion coefficient                          [ 1/K ]
with respect to Conservative Temperature
beta   =  saline contraction coefficient                        [ kg/g ]
at constant Conservative Temperature```

## 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;]```
`[specvol, alpha, beta] = gsw_specvol_alpha_beta(SA,CT,p)`
`specvol =`
`1.0e-003 *`
```    0.978626852431313
0.978222365701325
0.976155264597929
0.972961258011157
0.971026719344908
0.968989944622149```
`alpha =`
`1.0e-003 *`
```   0.324638934509245
0.322655537959731
0.281145723210171
0.173199716344780
0.146289673594824
0.129414845334599```
`beta =`
`1.0e-003 *`
```   0.717483987596135
0.717647512290095
0.726211643644768
0.750500751749777
0.755052064788492
0.757050813384370```

## 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 appendix A.20 and appendix K 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`