Direct observation of the oceanic CO₂ increase

Abstract

The increase in atmospheric CO 2 of approximately 50 ppm from the mid‐nineteenth century to 1972 has led to a corresponding increase in the pCO 2 of sea water. The record of this increase is present in the oceanic water masses, though the signal is obscured. By observing the alkalinity and total CO 2 concentration within a water mass, and stripping off the perturbations of the CO 2 system due to respiration, carbonate dissolution and nitrate addition, the original atmospheric equilibration signal may be recovered. The application of these calculations to GEOSECS (1972) data from the core of the Antarctic Intermediate water reveals propagation of the atmospheric CO 2 signal northwards.