If alkalinity is added the ocean directly (e.g. via aqueous NaOH), the total alkalinity released it can be directly measured. Environmental conditions and alkalinity addition dynamics may result in different fractions of carbonate (CO₃⁻²) versus bicarbonate (HCO₃⁻). This fractionation impacts the total uptake of atmospheric CO₂. Overall CO₂ uptake efficiency can be estimated using seawater chemistry modeling software and the equation presented in Renforth & Henderson (2017)
. These estimates could also be validated by measurements of bicarbonate concentrations or total alkalinity in the water column. The conversion of alkalinity to CO₂ removal is estimated to be 70-95% on a mol to mol basis.