A complete set of buffer factors for acid/base CO2 system in seawater

A set of buffer factors is proposed which allows to compute changes of pH and pCO2 resulting from an input or an output of bicarbonate, carbonate and proton ions in seawater. Results are compared to the well-known buffer factors that describe a dissolved CO2 change (among which the Revelle factor β =dln(pCO2)/dln|ΣCO2|). It is pointed out that the actual β value can be quite different from the usual one (about 10) when other processes than air-sea exchanges are involved. Two examples of application are discussed: (1) A relationship is proposed to estimate β = dln(pCO2)/dln|ΣCO2| by taking into account simultaneous organic and inorganic carbon metabolism: β = -7.02 + 0.186%Corg (r2 = 0.9994), where %Corg is the percentage of carbon uptake for organic metabolism, (2) A relationship is proposed to calculate the amount of CO2 that has to be exchanged with the atmosphere when adding strong acid to an equilibrated open seawater system.