The position is part of the BASS research group funded by the German Research Foundation. The overall goal is to investigate the importance of sea-surface microlayer (SML) as a biogeo- and photochemical reactor and how its reactivity affects ocean-atmosphere interactions. BASS will provide new insights into the accumulation of organic material in the SML and how well-adapted microbes and (photo)chemistry transform organic material. BASS will investigate the extent to which photochemical production of trace gases and the presence of natural surfactants in the SML influence ocean-atmosphere exchange processes. BASS will also investigate the coupling between the SML and bulk water, as this coupling determines the distribution of the unique products of biogeo- and photochemical processes in the SML to the upper ocean. Eight subprojects will collaborate in joint field campaigns in the open North Sea, a joint mesocosm study at the Sea-Surface Facility at ICBM, and a joint experiment at the University of Hamburg Wind Wave tank. BASS will combine interdisciplinary expertise, advanced technologies for millimeter-scale observations, core infrastructures for controlled experiments, and state-of-the-art analytical facilities at the molecular and cellular levels. Remotely operated and autonomous catamarans, drifter buoys, and measuring buoys are used for field work.