Raw physical oceanography data was acquired by a ship-based Seabird SBE911plus CTD-Rosette system onboard RV POLARSTERN during research cruises PS133/1 and PS133/2. The CTD was equipped with duplicate sensors for temperature (SBE3plus), conductivity (SBE4) and oxygen (SBE43). Additional sensors such as a WET Labs C-Star transmissometer, a WET Labs ECO-AFL fluorometer (FLRTD) and an altimeter (Teledyne Benthos PSA-916) were mounted to the CTD. The data was recorded using pre-cruise calibration coefficients. No correction, post-cruise calibration or quality control was applied. Processed data will be linked to this dataset once they are available. During this cruise an ultra clean CTD for trace metal analysis was operated in parallel. Data of this CTD will be published separately and linked below.