Siegenthaler & Sarmiento (1993)
Also: Siegenthaler & Sarmiento 1993
Siegenthaler, U., Sarmiento, J.L. (1993). Atmospheric carbon dioxide and the ocean. Nature, 365, 119. Link to paper
https://doi.org/10.1038/365119a0
References
All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.