Turbulent microstructure profile (MSS) measurements from the MOSAiC drift, Arctic Ocean, version 2

During the year-long drift expedition MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) from September 2019 to September 2020, we obtained an unprecedented data set of vertical turbulent dissipation rate profiles and high resolved hydrodynamic properties, including oxygen concentration and fluorescence, also covering the winter season. Nearly 1,700 individual profiles, covering the upper ocean down to approximately 400~m, were collected on a near-daily base and complemented with several periods of intensified continuous sampling.
Version 2: To ensure the quality of the dataset, we compared the MSS data to the Polarstern and Ocean City CTD data, which provide the only in-situ calibrated measurements of salinity. As casts of two different instruments were rarely co-located, this comparison was done statistically, i.e., by comparing as many as possible pairs of casts closest in time. Most data channels are found to agree well, with the exception of the casts performed with the profiler MSS055, which was mostly used during leg 3 and was equipped with a substitute conductivity sensor. For this probe, a calibration cast was performed with the MSS attached to the Ocean City CTD on February 2, 2020, which showed a constant offset in conductivity of 0.11 mS/cm. After reprocessing the affected data with this offset correction, values were in good agreement with the CTD data. In addition, we calibrated the dissolved oxygen readings from MSS091 (used during legs 4 and 5) with the CTD data.