MOSAiC1 resulted in an unprecedented amount and diversity of observation data over the central Arctic sea ice (Fig. 1): over 660 unique sensors or measurement devices with >8200 registered events, resulting in more than 90000 managed parameters in 73 endorsed sub-projects have been recorded (see https://mosaic-expedition.org/). 122 PIs are registered to work on the data. The year-round experiment started in September 2019 -and ended in October 2020 after a long-lasting preparation phase. The Implementation planning meeting in November 2017 in St. Petersburg was the starting point of its data logistics and data management concepts, with its core organizational component being the MOSAiC Data Policy2, described further below. As technical core component the MOSAiC Central Storage (MCS) was drafted, to be operated on board of the research icebreaker Polarstern3 and mirrored on land, leg by leg, allowing for data sharing and collaboration amongst researchers of the MOSAiC consortium.