gsw (version 1.0-5)

gsw_CT_freezing_first_derivatives: First Derivatives of Conservative Temperature for Freezing Water

Description

First Derivatives of Conservative Temperature for Freezing Water

Usage

gsw_CT_freezing_first_derivatives(SA, p, saturation_fraction = 1)

Arguments

SA

Absolute Salinity [ g/kg ]

p

sea pressure [dbar], i.e. absolute pressure [dbar] minus 10.1325 dbar

saturation_fraction

fraction of air in water [unitless]

Value

A list containing CTfreezing_SA [ K/(g/kg) ], the derivative of Conservative Temperature with respect to Absolute Salinity at constant potential temperature, and CTfreezing_p [ unitless], the derivative of Conservative Temperature with respect to pressure at constant Absolute Salinity.

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.

References

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

Examples

# NOT RUN {
SA <- c(                 34.7118, 34.8915, 35.0256, 34.8472, 34.7366, 34.7324)
p <- c(                       10,      50,     125,     250,     600,    1000)
saturation_fraction <- c(      1,     0.8,     0.6,     0.5,     0.4,       0)
r <- gsw_CT_freezing_first_derivatives(SA, p, saturation_fraction)
expect_equal(r$CTfreezing_SA, c(-0.058193253897272, -0.058265158334170, -0.058345661671901,
                              -0.058373842446463, -0.058534544740846, -0.058730846361252))
expect_equal(r$CTfreezing_p/1e-7, c(-0.765300390432684, -0.766942996466485, -0.769892679988284,
                                  -0.774561011527902, -0.787769143040504, -0.802771548245855))
# }