# pgas

### Description

Calculates the carbonate chemistry after changes in pCO2 generated by gas bubbling

### Usage

1 | ```
pgas(flag, var1, var2, pCO2g, S=35, T=20, P=0, Pt=0, Sit=0, k1k2="l", kf="pf", pHscale="T")
``` |

### Arguments

`flag` |
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 flag = 6 pH and HCO3 given flag = 7 pH and CO3 given flag = 8 pH and ALK given flag = 9 pH and DIC given flag = 10 HCO3 and CO3 given flag = 11 HCO3 and ALK given flag = 12 HCO3 and DIC given flag = 13 CO3 and ALK given flag = 14 CO3 and DIC given flag = 15 ALK and DIC given flag = 21 pCO2 and pH given flag = 22 pCO2 and HCO3 given flag = 23 pCO2 and CO3 given flag = 24 pCO2 and ALK given flag = 25 pCO2 and DIC given |

`var1` |
Value of the first variable in mol/kg, except for pH and for pCO2 in |

`var2` |
Value of the second variable in mol/kg, except for pH |

`pCO2g` |
CO2 partial pressure of the gas used for bubbling in |

`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 |

`k1k2` |
"l" for using K1 and K2 from Lueker et al. and "r" for using K1 and K2 from Roy and al. , default is "l" |

`kf` |
"pf" for using Kf from Perez and Fraga (1987) and "dg" for using Kf from Dickson and Goyet (1979), default is "pf" |

`pHscale` |
choice of pH scale: "T" for using the total scale, "F" for using the free scale and "SWS" for using the seawater scale, default is total scale |

### Value

The function returns a data frame containing the following columns:

`comment` |
The initial or final state water |

`S` |
Salinity |

`T` |
Temperature in degrees Celsius |

`P` |
Pressure in bar |

`pH` |
pH |

`CO2` |
CO2 concentration (mol/kg) |

`pCO2` |
pCO2, CO2 partial pressure ( |

`fCO2` |
fCO2, CO2 fugacity ( |

`HCO3` |
HCO3 concentration (mol/kg) |

`CO3` |
CO3 concentration (mol/kg) |

`DIC` |
DIC concentration (mol/kg) |

`ALK` |
ALK, total alkalinity (mol/kg) |

`OmegaAragonite` |
Omega aragonite, aragonite saturation state |

`OmegaCalcite` |
Omega calcite, calcite saturation state |

### Author(s)

Jean-Pierre Gattuso gattuso@obs-vlfr.fr

### Examples

1 | ```
pgas(flag=15, var1=2302e-6, var2=2050e-6, pCO2g=750, S=35, T=20, P=0, Pt=0, Sit=0, pHscale="T", kf="pf", k1k2="l")
``` |