On the Exchange of Carbon Dioxide between the Atmosphere and the Sea

The physical and chemical processes responsible for exchange of carbon dioxide between the atmosphere and the sea are analyzed. It is shown that the rate of transfer is considerably decreased due to the finite rate of hydration of CO₂ in water. This is the case both for a smooth water surface where molecular diffusion plays a rôle in the first few hundredths of a millimeter as well as for a rough sea where turbulence extends all the way to the surface. A general agreement is found between the transfer rate deduced in this way and the rate of exchange estimated on the basis of the C¹⁴/C¹² ratio in the atmosphere and the sea.