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Potential Enthalpy of Ice at Freezing Point

Source: R/gsw.R
gsw_pot_enthalpy_ice_freezing.Rd

Potential Enthalpy of Ice at Freezing Point

Usage

gsw_pot_enthalpy_ice_freezing(SA, p, saturation_fraction = 1)

Arguments

SA

Absolute Salinity [ g/kg ]. The valid range for most `gsw` functions is 0 to 42 g/kg.

p

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

saturation_fraction

fraction of air in water [unitless]

Value

potential enthalpy [ J/kg ]

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.

Bugs

1. The C source underlying this function lacks an argument, saturation_fraction, which is present in the Matlab source, and so that argument is ignored here.

2. The R code does not reproduce the check values stated at http://www.teos-10.org/pubs/gsw/html/gsw_pot_enthalpy_ice_freezing.html. Those values are incorporated in the test provided in ‘Examples’, so that test is not performed during build tests. See https://github.com/TEOS-10/GSW-R/issues/27.

References

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

See also

Other things related to enthalpy: gsw_CT_from_enthalpy(), gsw_dynamic_enthalpy(), gsw_enthalpy(), gsw_enthalpy_CT_exact(), gsw_enthalpy_diff(), gsw_enthalpy_first_derivatives(), gsw_enthalpy_first_derivatives_CT_exact(), gsw_enthalpy_ice(), gsw_enthalpy_t_exact(), gsw_frazil_properties_potential(), gsw_frazil_properties_potential_poly(), gsw_pot_enthalpy_from_pt_ice(), gsw_pot_enthalpy_from_pt_ice_poly(), gsw_pot_enthalpy_ice_freezing_poly(), gsw_pt_from_pot_enthalpy_ice(), gsw_pt_from_pot_enthalpy_ice_poly(), gsw_specvol_first_derivatives(), gsw_specvol_first_derivatives_wrt_enthalpy()

Examples

SA <- c(34.7118, 34.8915, 35.0256, 34.8472, 34.7366, 34.7324)
p <- c(      10,      50,     125,     250,     600,    1000)
saturation_fraction = 1
e <- gsw_pot_enthalpy_ice_freezing(SA, p, saturation_fraction)
if (FALSE) { # \dontrun{
stopifnot(all.equal(e/1e5, c(-3.373409558967978, -3.374434164002012, -3.376117536928847,
                             -3.378453698871986, -3.385497832886802, -3.393768587631489)))
} # }