Results elucidate a biochemical mechanism for large-scale transfer of organic matter from sinking particles to the dissolved phase. Calculations with the University of Melbourne GCM are used to deduce sources and sinks of atmospheric CO 2 . Net sources are found in the Northern Hemisphere and equatorial regions, and net sinks in the Southern Hemisphere. The latter result is of interest in view of the uncertainty of CO 2 uptake by Southern Hemisphere oceans. Calculations show that the magnitude and direction of CO 2 flux are strongly dependent on the temperature of the surface layer of liquid, and that existing measurements of CO 2 fluxes have probably erred on the low side, in the right direction to account for the current imbalance in the global CO 2 budget.
Performance is compared to that of other, more complicated models.
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