Research expedition MSM111 took place from September 9th, 2022 (Reykjavik, Iceland) to October 10th, 2022 (St. John's, Canada). CTD data for 8 stations with a total of 15 individual casts were recorded using a Sea & Sun Technology CTD90M (SN 979) down to depths of 700m. The CTD was mounted on a Hydro-BIOS MPS midi and equipped with the following sensors: Temperature sensor Pt100 model 1509 (Thermal Developments International), Conductivity sensor 7-pole platinum coated electrode cell in quartz glass (Sea & Sun Technology), Seapoint Chlorophyll Fluorometer (Seapoint) and dissolved oxygen sensor (DO522M18, Clark type, OxyGuard). The data files contain the data for temperature, salinity, density, chlorophyll a concentration and photosynthetically active radiation; as raw data and processed and flagged according to the recommendations for real-time data processing of EuroGOOS and GTSPP, as well as the outlier detection method CoTeDe (https://github.com/castelao/CoTeDe). TEOS-10 unit conversions have been performed with the GSW Oceanographic Toolbox (McDougall and Barker, 2011).