gsw (version 1.0-5)

gsw_entropy_first_derivatives: First Derivatives of Entropy

Description

First Derivatives of Entropy

Usage

gsw_entropy_first_derivatives(SA, CT)

Arguments

SA

Absolute Salinity [ g/kg ]

CT

Conservative Temperature [ degC ]

Value

a list containing eta_SA [ (J/(kg*degC) / (g/kg) ], the derivative of entropy wrt Absolute Salinity, and eta_CT [ (J/(kg*degC^2) ], the derivative of entropy wrt 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_entropy_first_derivatives.html

See Also

Other things related to entropy: gsw_CT_from_entropy, gsw_entropy_from_pt, gsw_entropy_from_t, gsw_entropy_ice, gsw_pt_from_entropy

Examples

# NOT RUN {
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)
d <- gsw_entropy_first_derivatives(SA, CT)
expect_equal(d$eta_SA, c(-0.263286800711655, -0.263977276574528, -0.255367497912925,
                       -0.238066586439561, -0.234438260606436, -0.232820684341694))
expect_equal(d$eta_CT, c(13.221031210083824, 13.236911191313675, 13.489004628681361,
                       14.086599016583795, 14.257729576432077, 14.386429945649411))
# }