gsw (version 1.0-5)

gsw_enthalpy_second_derivatives: Second Derivatives of Enthalpy

Description

Second Derivatives of Enthalpy

Usage

gsw_enthalpy_second_derivatives(SA, CT, p)

Arguments

SA

Absolute Salinity [ g/kg ]

CT

Conservative Temperature [ degC ]

p

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

Value

A list containing h_SA_SA [ (J/kg)/(g/kg)^2 ], the second derivative of enthalpy with respect to Absolute Salinity, h_SA_CT [ (J/kg)/(K*g/kg) ], the derivative of enthalpy with respect to Absolute Salinity and Conservative Temperature, and h_CT_CT [ (J/kg)/degC^2 ], the second derivative of enthalpy with respect to Conservative Temperature.

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_enthalpy_second_derivatives.html

Examples

# NOT RUN {
SA <- c(34.7118, 34.8915, 35.0256, 34.8472, 34.7366, 34.7324)
CT <- c(28.7856, 28.4329, 22.8103, 10.2600,  6.8863,  4.4036)
p <- c(      10,      50,     125,     250,     600,    1000)
r <- gsw_enthalpy_second_derivatives(SA, CT, p)
expect_equal(r$h_SA_SA, c(0.000080922482023, 0.000404963500641, 0.001059800046742,
                        0.002431088963823, 0.006019611828423, 0.010225411250217))
expect_equal(r$h_SA_CT, c(0.000130004715129, 0.000653614489248, 0.001877220817849,
                        0.005470392103793, 0.014314756132297, 0.025195603327700))
expect_equal(r$h_CT_CT, c(0.000714303909834, 0.003584401249266, 0.009718730753139,
                        0.024064471995224, 0.061547884081343, 0.107493969308119))
# }