The simultaneous use of chemical tracers in oceanic studies: I. General theory of reservoir models1, 2

The reservoir, or “box”, model is a useful starting point for studies of chemical tracers. The model can be derived from the chemical transport equation for a continuous ocean and thus rests on a sound physical foundation. The assumption that the tracers are well-mixed inside each reservoir is discussed and found unnecessary. The model is well adapted for dealing with sets of chemical tracers which simultaneously undergo chemical reactions, isotopic fractionation, radioactive decay, and exchange with the atmosphere.

In this article we relate the transfer coefficients of the reservoir model to the advective and diffusive coefficients of the space-averaged chemical transport equation for a continuous ocean, and we develop general methods for applying the reservoir model to a large suite of nonconservative chemical tracers. In an article which follows we apply the concepts of this article to a study of eight chemical tracers in the Pacific Ocean.