Modelling the effect of iron fertilization on dimethylsulphide emissions in the Southern Ocean

In this study, we use a 3D ocean biogeochemical model to explore the relationship between iron fertilization and dimethylsulphide (DMS) production in the Southern Ocean. The model is able to reproduce the observed decoupling between high productivity and DMS-rich waters because the main processes (variable sulphur-to-carbon ratio in phytoplankton, variable transfer efficiency from DMS precursor to DMS, and variable bacterial DMS-consumption rate) are taken into account. Moreover, the model predicts that a 20-yr iron fertilization of the entire Southern Ocean would actually reduce the emissions of DMS to the atmosphere.