I am interested in the interactions between marine plankton ecosystems, biogeochemistry, the carbon cycle and climate. I primarily develop and use numerical models ocean biogeochemistry and the Earth system. Current research areas: Implications of processes affecting organic carbon fluxes in the twilight zone (mesopelagic) for future changes in carbon fluxes and NPP (funded by AXA Research Fund) Developing and using the EcoGEnIE model, a trait-based ecosystem model coupled with an Earth system model. Dynamics of plankton ecosystems, biogeochemistry and climate in past climates, e.g., impact of mass extinction events on biogeochemistry, plankton ecosystems in warm climates, evolution of plankton through time. Developing and using biogeochemical models based on the Transport Matrix Method (a method of diagnosing steady-state ocean transport). The role of dissolved organic carbon (DOC) in marine biogeochemistry and the carbon cycle.