Hydrographic (CTD) profiles of Temperature, Salinity, Dissolved Oxygen, Chlorophyll A fluorescence and Coloured Dissolved Organic Matter (CDOM) collected in the Arctic Ocean, over the western Eurasian Basin and Lomonosov Ridge, between 2 August and 11 September 2021, from I/B Oden. This is the Swedish contribution to the international Synoptic Arctic Survey. This dataset merges the full-depth physical CTD and the shallow biological CTD profiles. Both systems had the standard SeaBird SBE911 plus system with dual sensors to measure in-situ temperature and conductivity and single sensors measuring pressure and oxygen. The physical CTD also had a CDOM sensor (Turner Cyclops fluorometer), while the Chl-A fluorometer (WET Labs, ECO-AFL/FL) was moved throughout the expedition between the two systems. Salinity, Oxygen, Chl-A fluorescence and CDOM were calibrated against sample data collected and analysed by the co-authors: - Salinity samples from the deep stations were analysed post-cruise using a salinometer (Guildline Autosal) and IAPSO standard seawater at the GEOMAR, Germany. - Dissolved oxygen was determined onboard using an automatic Winkler titration setup with UV detection (Scripps Institute of Oceanography Oxygen Titration System version 2.35m). - Chl-A concentration was determined post-cruise from flow cytometry (FCM) at Linnaeus University, Sweden. The samples consisted of 4 mL cryovials, of which 3.8 mL was sample water and 76 μL 25% EM grade glutaraldehyde solution (Glu stock). The samples incubated at room temperature for 5 minutes before flash freezing in liquid nitrogen and then placing in the -80 °C freezer in cryoboxes. - CDOM was determined post-cruise at the National Institute of Aquatic Resources - DTU Aqua, Denmark, following the method of Lawaetz and Stedmon (2009) This dataset contains the 1-m bin-averaged profiles. For more information about each sensor and their calibration, the reader is invited to check the cruise report (final version submitted on 20 September; shareable version with DOI coming soon)