Throughout the MOSAiC drift expedition on the RV POLARSTERN (Oct 2019 – Oct 2020), we used membrane-inlet mass spectrometry (MIMS) to continuously measure abundances of oxygen (represented by m/z 32) and argon (represented by m/z 40) in underway sampled surface waters (11m depth) of the Arctic Ocean. The instrument was regularly calibrated (i.e., measuring water equilibrated with pure nitrogen and reference air, respectively), enabling baseline corrections of obtained raw signals as well as the calculation of the gasses' individual concentrations. These data allow to distinguish the physical and biological contribution to oxygen supersaturation (O2phys, O2bio; Eveleth et al. 2014), and to reconstruct net community productivity of the transected waters (e.g., Ulfsbo et al. 2015). Alongside our data, we re-publish interpolated underway data from the ship's thermosalinograph and other sensors which we required in order to calculate theoretical saturation concentrations in the environment. Timespans in which bottle experiments were conducted with the instrument are presented as raw reads without calculated concentration and ratio data: Due to the pump-supported sample intake, these assessments required different calibrations and will be separately published in high resolution elsewhere.