Ocean microstructure profiles were collected using an MSS (Microstructure Sensor Profiler, Sea&Sun Technology, Germany) profiler during the Polarstern PS131 cruise, ATWAICE (28 June – 17 August 2022), from ice floes and from the ship. This dataset includes 1) the raw binary data in the instrument-specific MRD files and 2) the full-resolution time series from each channel converted into physical units with no further data processing applied (NetCDF, NC files). A set of two files (MRD and NC) is supplied per profile. The converted data are prepared following the SCOR Working Group ATOMIX guidelines and convention, corresponding to their Level 1. In total, 196 raw data files (cast004 to 199) are submitted. Casts 1 to 3 were from another profiler which flooded and the data are not useful. Out of 196 profiles, 16 were collected from the ship and 180 from sea ice. Of the 196 profile attempts, 10 were aborted, but all files are delivered for completeness. Please see the detailed log spreadsheet for stations and comments in the NC files. Throughout the cruise, the instrument functioned well, except the vibration sensor did not work and the fast thermistor channel produced a cut-off at low end, probably for output that exceeded the range of the A/D converter of the probe. In the later part of the cruise, episodic data transmission errors were encountered. The profiler used was MSS90L (SN 097), a loosely-tethered free-fall instrument equipped with two airfoil probes aligned parallel to each other, a fast-tip thermistor (FP07), an acceleration sensor (for body vibration measurements), conventional CTD sensors for precision measurements, a Turner Design Cyclops-7 in Vivo Chlorophyll/Blue sensor for ChlA fluorescence and a SST-DO, fast optical dissolved oxygen sensor. All channels were sampled at 512 Hz. The instrument was ballasted for a typical fall speed of 0.5 m s-1. The shear probes used were type PNS6, serial numbers C6258 (sensitivity 3.54e-04 at 21C, SHE1) and C6259 (sensitivity 3.99e-4 at 21C, SHE2). A temperature correction for the sensitivity was applied using the average in situ temperature, TM, as (1-0.011*(TC-TM)), where TC=21C. The same sensors were used throughout the cruise and the sensors point downward when the instrument profiles vertically. The deployment of the MSS from the ship was done from the starboard side. Because of the keel of the ship, the upper 15 m of dissipation rate profiles from the ship should be excluded in post-processing. The deployment from sea ice was typically by using a Nansen sled, through a hole, located approximately 100 -250 m away from the ship. The upper 2 m of the dissipation profiles from ice should be excluded in post-processing.