This dataset contains hydrographic data collected with a small hand-held conductivity, temperature, depth sensor (CTD, a Sea&Sun CTD48M) – mostly operated from the ice – during Leg 4 and Leg 5 of the Multidisciplinary drifting observatory for the study of Arctic climate (MOSAiC). In total, 24 profiles were obtained, 12 from each leg. The data collected was processed manually. Conductivity readings below 0.5 mS/cm and temperature readings below the surface freezing temperature were removed. A pressure offset was then subtracted to start the profile at 0 dbar. The data was then binned in steps of 0.1 dbar from the surface to 5 dbar, in steps of 0.25 dbar to 20 dbar, and in steps of 0.5 dbar below. Large density inversions were manually removed and linearly interpolated over. Absolute Salinity (SA) and Conservative Temperature (CT) were derived using the TEOS-10 GSW toolbox (McDougall & Barker, 2011).This work was carried out as part of the international Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC) with the tag MOSAiC20192020. We thank all persons involved in the expedition of the Research Vessel Polarstern during MOSAiC in 2019-2020 (AWI_PS122_00) as listed in Nixdorf et al. (2021).