select the couple of variables available. The flags which can be used are:
flag = 1 pH and CO2 given
flag = 2 CO2 and HCO3 given
flag = 3 CO2 and CO3 given
flag = 4 CO2 and ALK given
flag = 5 CO2 and DIC given
f
var1
enter value of the first variable in mol/kg, except for pH and for pCO2 in $\mu$atm
var2
enter value of the second variable in mol/kg, except for pH
S
Salinity
T
Temperature in degrees Celsius
P
Hydrostatic pressure in bar (surface = 0)
Pt
Concentration of total phosphate in mol/kg
Sit
Concentration of total silicate in mol/kg
pHscale
choice of pH scale: "T" for the total scale, "F" for the free scale and "SWS" for using the seawater scale, default is "T" (total scale)
kf
"pf" for using Kf from Perez and Fraga (1987) and "dg" for using Kf from Dickson and Riley (1979), default is "pf"
k1k2
"l" for using K1 and K2 from Lueker et al. and "r" for using K1 and K2 from Roy et al. , default is "l"
Value
The function returns a data frame containing the following columns:
psiratio of CO2 released vs CaCO3 precipitated (mol/mol)
encoding
latin1
Details
The arguments can be given as a unique number or as vectors. If the lengths of the vectors are different, the longer vector is retained and only the first value of the other vectors is used. It is recommended to use either vectors with the same dimension or one vector for one argument and numbers for the other arguments.
References
Frankignoulle, M. 1994 A complete set of buffer factors for acid/base CO2 system in seawater. Journal of Marine Systems5, 111-118.
Frankignoulle, M., Canon, C. & Gattuso, J.-P., 1994. Marine calcification as a source of carbon dioxide- Positive feedback of increasing atmospheric CO2. Limnology and Oceanography2, 458-462.
## Calculation using the numerical example given in Frankignoulle et al. (1994)psi(flag=24, var1=350, var2=2400e-6, S=35, T=25, P=0, Pt=0,
Sit=0, pHscale="T", kf="pf", k1k2="l")