Value of the constant at P=0 (hydrostatic pressure in bar, surface = 0)
Ktype
Name of the constant,
K1 First dissociation constant of carbonic acid (mol/kg)
K2 Second dissociation constant of carbonic acid (mol/kg)
Kb Dissociation constant of boric acid (mol/kg)
Kw Ion product of water (mol2/kg2)
T
Temperature in degrees Celsius, default is 25oC
S
Salinity, default is 35
P
Hydrostatic pressure in bar (surface = 0), default is 0
pHscale
pHscale of the constant given in Kvalue
kconv2ScaleP0
Conversion factor from the pH scale selected to the SWS (or free for Kf) scale at pressure zero. It is computed if it is not given, which significantly slows down the computation
kconv2Scale
Conversion factor from the pH scale selected to the SWS (or free for Kf) scale at the hydrostatic pressure value indicated. It is computed if it is not given, which significantly slows down the computation
Value
The equilibrium constant given in argument but after pressure correction
encoding
latin1
Details
The pressure correction is applied on the seawater scale for K1, K2, K1p, K2p, K3p, Kb, Khs, Kn, Ksi and Kw. Hence the K value is first converted on the seawater scale if needed. After pressure correction, the constant is converted back to the initial pH scale.
The pressure correction is applied on the free scale for Kf.
There is no issue of pH scale for Ks, Kspa and Kspc.
References
Millero F. J., 1995 Thermodynamics of the carbon dioxide system in the oceans. Geochimica et Cosmochimica Acta59 661-677.