I am interested in marine biogeochemistry and ocean biosphere-atmosphere interactions. For over 25 years I have investigated the biological and environmental actors that govern the production and emission of volatile sulfur from the ocean, which I have now extended to other volatile compounds and their biochemical precursors. Besides their role in the atmosphere, I am interested in their involvement in chemical communication between marine organisms. On the upper side of the ocean-atmosphere interface, I am interested in the production of primary and secondary aerosols and their effects on clouds and climate. For my research I make use of a broad array of methodologies, from “single-cell biogeochemistry” and omics, through experimental plankton ecology and physiology, including photobiology, all the way up to satellite analyses of the global ocean and atmosphere. I have conducted fieldwork in the Mediterranean, the North Atlantic, the tropical Pacific, the Southern Indian, the Arctic and Antarctica.