calc_K: Calculate a single equilibrium constant

In kgen: A Tool for Calculating Stoichiometric Equilibrium Constants (Ks) for Seawater

Calculate a single equilibrium constant

Description

Calculate a single specified stoichiometric equilibrium constant at given temperature, salinity, pressure and the concentration of magnesium, calcium, sulphate, and fluorine.

Usage

calc_K(
  k,
  temp_c = 25,
  sal = 35,
  p_bar = NULL,
  magnesium = 0.0528171,
  calcium = 0.0102821,
  sulphate = NULL,
  fluorine = NULL,
  method = "r_polynomial"
)

calc_Ks(
  ks = NULL,
  temp_c = 25,
  sal = 35,
  p_bar = NULL,
  magnesium = 0.0528171,
  calcium = 0.0102821,
  sulphate = calc_sulphate(sal = sal),
  fluorine = calc_fluorine(sal = sal),
  method = "r_polynomial"
)

Arguments

k	K to be calculated
temp_c	Temperature (Celcius)
sal	Salinity
p_bar	Pressure (Bar) (optional)
magnesium	Magnesium concentration in mol/kgsw. Default is modern seawater (0.0528171). Should be the average magnesium concentration in seawater - a salinity correction is then applied to calculate the magnesium concentration in the sample.
calcium	Calcium concentration in mol/kgsw. Default is modern seawater (0.0102821). Should be the average calcium concentration in seawater - a salinity correction is then applied to calculate the calcium concentration in the sample.
sulphate	Sulphate concentration in mol/kgsw. Calculated from salinity if not given.
fluorine	Fluorine concentration in mol/kgsw. Calculated from salinity if not given.
method	string describing method which should be either 'myami', 'myami_polynomial', or 'r_polynomial' (Default: 'r_polynomial').
ks	character vectors of Ks to be calculated e.g., c("K0", "K1") (Default: NULL, calculate all Ks)

Value

A single K at given conditions

Data.table of multiple Ks at given conditions

Functions

• calc_Ks(): Wrapper to calculate multiple stoichiometric equilibrium constants at given temperature, salinity, pressure and the concentration of magnesium, calcium, sulphate, and fluorine.

Author(s)

Dennis Mayk

Examples

# Calculate K1 at default conditions
calc_K("K1", temp_c = 25, sal = 35)

# Calculate K1 with pressure correction
calc_K("K1", temp_c = 25, sal = 35, p_bar = 100)
# Calculate all Ks at default conditions
calc_Ks(temp_c = 25, sal = 35)

# Calculate specific Ks
calc_Ks(ks = c("K1", "K2"), temp_c = 25, sal = 35)


# Parallel execution (requires future + future.apply packages)
if (requireNamespace("future", quietly = TRUE)) {
  future::plan(future::multisession,
    workers = future::availableCores() - 1
  )

  dt_list <- as.list(data.table::CJ(
    temp_c = seq_len(40),
    sal = 30:40,
    p_bar = 0:100,
    magnesium = seq(0, 0.06, by = 0.01),
    calcium = seq(0, 0.06, by = 0.01)
  ))

  res <- do.call(what = calc_Ks, args = dt_list)
  future::plan(future::sequential)
}

kgen documentation built on March 28, 2026, 9:08 a.m.