R: Ratio of vert. gradient of pot. density to vert grad of...

gsw_IPV_vs_fNsquared_ratio {gsw} | R Documentation

## Ratio of vert. gradient of pot. density to vert grad of locally-referenced pot density

### Description

Note that the C library had to be patched to get this working; a new version of the library will address the bug directly.

### Usage

    gsw_IPV_vs_fNsquared_ratio(SA, CT, p, p_ref = 0)

### Arguments

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

list containing IPV_vs_fNsquared_ratio [ unitless ] and mid-point pressure p_mid [ dbar ]

### References

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

### 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)
    p_ref <- 0
    r <- gsw_IPV_vs_fNsquared_ratio(SA, CT, p, p_ref)
    expect_equal(r$IPV_vs_fNsquared_ratio, c(0.999742244888022, 0.996939883468178, 0.986141997098021,
                                             0.931595598713477, 0.861224354872028))
    expect_equal(r$p_mid, c(30, 87.5, 187.5, 425, 800))

[Package gsw version 1.0-5 Index]