IAOOS14, IAOOS15 and IAOOS25 were deployed from the Korean Icebreaker R/V Araon during cruises in the northern Chukchi Sea. IAOOS14 and IAOOS15 were deployed 300 m apart on the same floe on 12 August 2015 in the Makarov Basin (80.8°N;173°E) and they drifted together remaining always less than 6 km apart. IAOOS25 was deployed on 15 August 2017 south-west Mendeleev Ridge (77.7°N;180°E) and drifted westward to the continental slope of the East Siberian Sea. IAOOS14 and IAOOS25 stopped transmitting on 9 October 2015 and 19 November 2017 respectively, likely due to the loss of their profilers while crossing relatively shallow bathymetry. IAOOS15 dataset ends in 15 October 2015. Ocean profilers were PROVOR SPI (from French manufacturer NKE) equipped with a Seabird SBE41 CTD (Conductivity, Temperature, Depth) and a dissolved oxygen (DO) Aandera 4330 optode. The profilers were set to perform two upward profiles a day from 800 m (IAOOS 14), 300 m (IAOOS 15) and 420 m (IAOOS 25), upward starting at approximately 6 am and 6 pm. The present dataset is composed of CTD-DO data from IAOOS 14 and 15, and CTD data from IAOOS 25 in the Makarov Basin, corrected from salinity errors and interpolated vertically every 0.5 m.

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