Debye-Hückel limiting slopes

The casual user has no need to explicitly call this module.

.debyehueckel contains functions to evaluate the Debye-Hückel limiting slope for the osmotic coefficient (i.e. $A_\phi$).

The syntax for the functions is similar to that for the interaction coefficients: inputs are tempK and pres, in K and dbar respectively; outputs are the $A_\phi$ value Aosm and a logical validity indicator valid.

Several different calculation approaches are possible. As a function of temperature only, at a pressure of c. 1 atm:

• .Aosm_CRP94 - following Clegg et al. (1994);
• .Aosm_MarChemSpec - following Clegg et al. (1994), with a constant correction to agree better with Archer and Wang (1990);
• .Aosm_M88 - following Møller (1988).

As a function of temperature and pressure:

• Aosm_AW90 - following Archer and Wang (1990), but with pure water density evaluated using the functions in the TEOS-10 module.