Raw physical oceanography data was acquired by a ship-based Seabird SBE911plus CTD-Rosette system onboard RV POLARSTERN during research cruise PS134. The CTD was equipped with duplicate sensors for temperature (SBE3plus) and conductivity (SBE4). Additional sensors such as an oxygen sensor (SBE43), 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.