gsw_CT_freezing_first_derivatives {gsw} | R Documentation |
First Derivatives of Conservative Temperature for Freezing Water
gsw_CT_freezing_first_derivatives(SA, p, saturation_fraction = 1)
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] |
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.
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.
http://www.teos-10.org/pubs/gsw/html/gsw_CT_freezing_first_derivatives.html
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))