R: Specific Entropy i.t.o. Absolute Salinity, Temperature, and...

gsw_entropy_from_t {gsw} | R Documentation

## Specific Entropy i.t.o. Absolute Salinity, Temperature, and Pressure

### Description

Calculates specific entropy in terms of Absolute Salinity, in-situ temperature and pressure.

### Usage

    gsw_entropy_from_t(SA, t, p)

### Arguments

`SA` | Absolute Salinity [ g/kg ]
`t` | in-situ temperature (ITS-90) [ 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

specific entropy [ J/(kg*K) ]

### References

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

### See Also

Other things related to entropy: `gsw_CT_from_entropy`, `gsw_entropy_first_derivatives`, `gsw_entropy_from_pt`, `gsw_entropy_ice`, `gsw_pt_from_entropy`

### Examples

    SA <- c(34.7118, 34.8915, 35.0256, 34.8472, 34.7366, 34.7324)
    t <- c( 28.7856, 28.4329, 22.8103, 10.2600,  6.8863,  4.4036)
    p <- c(      10,      50,     125,     250,     600,    1000)
    e <- gsw_entropy_from_t(SA, t, p)
    expect_equal(e/1e2, c(4.003894252787245, 3.954381784340642, 3.198664981986740,
                        1.467908815899072, 0.986473408657975, 0.627915087346090))

[Package gsw version 1.0-5 Index]