Figure 3.

Specimen calculation of a vertical profile of the partial pressure of CO₂ at WOCE P17N Station 13, corrected for the effects of oxidative organic matter decomposition and carbonate dissolution so as to reveal an approximation to the original water mass surface conditions. The corrections resulting from the use of the original (1934) Redfield ratios (17, 18) and the more recent coefficients (1994) of Anderson and Sarmiento (25) are shown: both profiles are computed utilizing the thermodynamic constants of Goyet and Poisson (30). The deep water value of 280 ± 6 ppm given by the Anderson and Sarmiento coefficients is close to the established preindustrial atmospheric level.