# gsw_alpha_on_beta

```thermal expansion divided by the saline
contraction coefficient (75-term equation)```

## USAGE:

`alpha_on_beta = gsw_alpha_on_beta(SA,CT,p)`

## DESCRIPTION:

```Calculates alpha divided by beta, where alpha is the thermal expansion
coefficient and beta is the 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". ```
 ```Click for a more detailed description of alpha on beta.```

## 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:

```alpha_on_beta  =  thermal expansion coefficient with respect to
Conservative Temperature divided by the saline
contraction coefficient at constant Conservative
Temperature.                           [ g kg^-1 K^-1 ]```

## 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;]```
`alpha_on_beta = gsw_alpha_on_beta(SA,CT,p)`
`alpha_on_beta =`
```   0.452468543022009
0.449601695030057
0.387140203094424
0.230778871228268
0.193747796234162
0.170946048860385```

## AUTHOR:

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

## VERSION NUMBER:

`3.06.15 (1st June, 2022)`

## 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, 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`