Density First Derivatives wrt SA, CT and p (75-term equation)

Usage

gsw_rho_first_derivatives(SA, CT, p)

Arguments

SA: Absolute Salinity [ g/kg ]. The valid range for most `gsw` functions is 0 to 42 g/kg.
CT: Conservative Temperature [ degC ].
p: sea pressure [dbar], i.e. absolute pressure [dbar] minus 10.1325 dbar

Value

list containing drho_dSA [ kg^2/(g m^3) ], drho_dCT [ kg/(K m^3) ] and drho_dp [ kg/(Pa m^3) ]

Implementation Note

This R function uses a wrapper to a C function contained within the GSW-C system as updated 2022-10-11 at https://github.com/TEOS-10/GSW-C with git commit `657216dd4f5ea079b5f0e021a4163e2d26893371`.

The C function uses data from the library/gsw_data_v3_0.mat file provided in the GSW-Matlab source code, version 3.06-11. Unfortunately, this version of the mat file is no longer displayed on the TEOS-10.org website. Therefore, in the interests of making GSW-R be self-contained, a copy was downloaded from http://www.teos-10.org/software/gsw_matlab_v3_06_11.zip on 2022-05-25, the .mat file was stored in the developer/create_data directory of https://github.com/TEOS-10/GSW-R, and then the dataset used in GSW-R was created based on that .mat file.

Please consult http://www.teos-10.org to learn more about the various TEOS-10 software systems.

References

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

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

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_first_derivatives(SA, CT, p)
stopifnot(all.equal(r$drho_dSA, c(0.733153791778356, 0.733624109867480, 0.743950957375504,
                                  0.771357282286743, 0.777581141431288, 0.781278296628328)))
stopifnot(all.equal(r$drho_dCT, c(-0.331729027977015, -0.329838643311336, -0.288013324730644,
                                  -0.178012962919839, -0.150654632545556, -0.133556437868984)))
stopifnot(all.equal(r$drho_dp, 1e-6*c(0.420302360738476, 0.420251070273888, 0.426773054953941,
                                      0.447763615252861, 0.452011501791479, 0.454118117103094)))