Raw data acquired by two thermosalinographs (SBE21, SeaBird GmbH) on board RV POLARSTERN were processed to receive a calibrated and validated data set of temperature and salinity during expedition PS126. Data were downloaded from DAVIS SHIP data base (https://dship.awi.de) with a resolution of 1 sec. Both sensors were equipped with an additional external temperature sensor (SBE38, Sea-Bird GmbH). The raw data are converted to temperature and conductivity values using the calibration coefficients from the calibration before deployment. However, data can only be finally processed after replacement and renewed calibration because correction values for the sensor drift can only be obtained by the post cruise calibration. Thermosalinographs on board RV Polarstern are exchanged about once a year and calibration procedures are conducted after every exchange. Salinity was calculated according to the instructions from the Practical Salinity Scale PSS-78 using the obtained internal temperature and conductivity data. Processing and evaluation of the data is outlined in the data processing report found at EPIC repository https://hdl.handle.net/10013/epic.e9b67f8a-dc1e-4f43-b56d-cfddc20d3c63. Processed data are provided as 10min means of salinity and water temperature aligned with position data taken from master track of the respective cruise.