This dataset collection contains data collected from the Microbiology-Ocean-Cloud Coupling in the High Arctic (MOCCHA) project. MOCCHA aimed to study aerosol processes, the contribution of marine microbiology to their formation and properties, and their impact on the life cycle of low-lewel clouds in the central Arctic as part of the Arctic Ocean 2018 (AO2018) expedition. AO2018 took place between 1 August and 21 September 2018, departing from and returning to Longyearbyen. The expedition was centered around a 4-week long intensive observation period, where e icebreaker Oden was moored to an ice flow and drifted passively with the ice.