This is the third and final volume of manuscripts comprising the results from a series of process studies conducted as part of the US Joint Global Ocean Flux Study. The objectives of this study were to provide insights into the quantities and controls of fluxes in the Southern Ocean, to elucidate the processes that control primary production in both space and time, and to use these results to model the processes that were dominant in past environments. The results demonstrate the importance of the Southern Ocean with regard to both the present and past productivity patterns and vertical fluxes from the surface layer.