R: In-situ density, thermal expansion coefficient and haline...

gsw_rho_alpha_beta {gsw} | R Documentation

## In-situ density, thermal expansion coefficient and haline contraction coefficient (75-term equation)

### Description

Calculate the in-situ density, the expansion coefficient (with respect to Conservative Temperature) and the haline contraction coefficient (with respect to Absolute Salinity), using the 75-term equation.

### Usage

    gsw_rho_alpha_beta(SA, CT, p)

### Arguments

`SA` | Absolute Salinity [ g/kg ]
`CT` | Conservative Temperature [ degC ]
`p` | sea pressure [dbar], i.e. absolute pressure [dbar] minus 10.1325 dbar

### Details

The present R function works with a wrapper to a C function contained within the GSW-C system (Version 3.05-4 dated 2017-08-07, available at https://github.com/TEOS-10/GSW-C, as git commit '5b4d959e54031f9e972f3e863f63e67fa4f5bfec'), which stems from the GSW-Fortran system (https://github.com/TEOS-10/GSW-Fortran) which in turn stems from the GSW-Matlab system (https://github.com/TEOS-10/GSW-Matlab). Consult http://www.teos-10.org to learn more about these software systems, their authorships, and the science behind it all.

### Value

A list containing in-situ density `rho` [ kg/m^3 ], thermal expansion coefficient `alpha` [ 1/degC ], and haline contraction coefficient `beta` [ kg/g ].

### References

http://www.teos-10.org/pubs/gsw/html/gsw_rho_alpha_beta.html

### See Also

Other things related to density: `gsw_CT_from_rho`, `gsw_CT_maxdensity`, `gsw_SA_from_rho`, `gsw_alpha_on_beta`, `gsw_alpha_wrt_t_exact`, `gsw_alpha_wrt_t_ice`, `gsw_alpha`, `gsw_beta_const_t_exact`, `gsw_beta`, `gsw_pot_rho_t_exact`, `gsw_rho_first_derivatives_wrt_enthalpy`, `gsw_rho_first_derivatives`, `gsw_rho_ice`, `gsw_rho_t_exact`, `gsw_rho`, `gsw_sigma0`, `gsw_sigma1`, `gsw_sigma2`, `gsw_sigma3`, `gsw_sigma4`, `gsw_specvol_alpha_beta`, `gsw_specvol_anom_standard`, `gsw_specvol_ice`, `gsw_specvol_t_exact`, `gsw_specvol`

### Examples

    SA <- c(34.7118, 34.8915, 35.0256, 34.8472, 34.7366, 34.7324)
    CT <- c(28.8099, 28.4392, 22.7862, 10.2262,  6.8272,  4.3236)
    p <-  c(     10,      50,     125,     250,     600,    1000)
    r <- gsw_rho_alpha_beta(SA, CT, p)
    expect_equal(r$rho/1000, c(1.021839935738108, 1.022262457966867, 1.024427195413316,
                             1.027790152759127, 1.029837779000189, 1.032002453224572))
    expect_equal(r$alpha*1000, c(0.324638934509245, 0.322655537959731, 0.281145723210171,
                               0.173199716344780, 0.146289673594824, 0.129414845334599))
    expect_equal(r$beta*1000, c(0.717483987596135, 0.717647512290095, 0.726211643644768,
                              0.750500751749777, 0.755052064788492, 0.757050813384370))

[Package gsw version 1.0-5 Index]