The two platforms IAOOS 23 and IAOOS 24 were deployed within 600 m from each other at the North Pole from the Russia-operated Barneo ice camp on April 12, 2017. They followed a meandering trajectory, reaching as far as 30°E in the Nansen Basin, before turning back to the western Fram Strait. On both IAOOS 23 and 24, the ocean profiler was a PROVOR SPI (from French manufacturer NKE) equipped with a Seabird SBE41 CTD (Conductivity, Temperature, Depth) and a dissolved oxygen (DO) Aandera 4330 optode. For the first time, the profiler on IAOOS 23 also carried biogeochemical sensors. It featured a bio-optics sensor suite and a submersible ultraviolet nitrate analyzer (SUNA, Satlantic-Seabird Inc.). The bio-optics sensor suite (called Pack Rem A) combines a three-optical-sensor instrument (ECO Triplet, WET Labs Inc.) and a multispectral radiometer (OCR-504, Satlantic Inc.). The present dataset is composed of CTD-DO data from IAOOS 23 and 24, corrected from the thermal lag and the sensor lag, despiked and interpolated vertically every 0.5 m. It also comprises nitrate concentrations from the SUNA and CDOM fluorescence from the WETLabs ECO sensor on IAOOS 23. Other biogeochemical data will be added to this dataset. The profilers were set to perform two upward profiles a day from 250 m (IAOOS 23) and 350 m (IAOOS 24) upward starting at approximately 6 am and 6 pm. They provided a unique 8-month long dataset, gathering a total of 793 profiles of the temperature, salinity and oxygen (upper 350m) and 427 profiles of CDOM and nitrates concentrations (upper 250m).   Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

A mooring, equipped with a CTD sensor (SBE37) at 350 m depth, was deployed in the Yermak Pass on the 24 September 2017 from the R/V Lance. The mooring was recovered in summer 2020 from K/V Svalbard. The present dataset provides 10-day smoothed time series of daily conservative temperature (CT, °C), absolute salinity (SA, g/kg) and pressure (db) recorded by the SBE37 sensor, from the 24 September 2017 to the 31 May 2020. The mooring was located at 80.63°N, 6.88°E. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

The fugacity of CO2 is measured underway with an autonomous system on board a merchant ship sailing from France to Brazil. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

In April 2017, two Ice Atmosphere Arctic Ocean Observing System platforms (IAOOS 23 and IAOOS 24) were deployed near the North Pole. Over the next 8 months, they meandered southwards with the ice in the Transpolar Drift, collecting measurements in the upper 250 m of Amundsen Basin, Nansen Basin and Fram Strait. The ocean profilers are PROVOR SPI (from French manufacturer NKE), which includes a Seabird SBE41 CTD (Conductivity, Temperature, Depth) and a dissolved oxygen (DO) Aandera 4330 optode. IAOOS 23 also featured a bio-optics sensor suite and a submersible ultraviolet nitrate analyzer (SUNA, Satlantic-Seabird Inc.). The bio-optics sensor suite (called Pack Rem A) combines a three-optical-sensor instrument (ECO Triplet, WET Labs Inc.) and a multispectral radiometer (OCR-504, Satlantic Inc.). The present dataset is composed of chlorophyll-a fluorescence, backscatter, irradiances (at 412, 490 and 555 nm), photosynthetically active radiation (PAR), nitrate and colored-dissolved organic matter data from the IAOOS 23 platform, as well as composites of absolute salinity, conservative temperature and apparent oxygen utilization data from both profilers. The profilers were set to perform two upward profiles a day from 250 m starting at approximately 6 am and 6 pm. In this dataset, chlorophyll-a, PAR and irradiances were corrected with a shift to set dark values to zero. Nitrate was interpolated vertically every 5 m, and all other parameters were interpolated vertically every 0.5 m. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

This data set includes CTD-O2 and LADCP data from the 46 stations occupied in Storfjorden and Storfjordrenna during the STEP cruise in July 2016 onboard R/V l'Atalante. Hydrographic data are provided in the form of Seabird ascii format (cnv), with two files per station (up and down). The data set also includes  underway S-ADCP data provided in netcdf format. Sensor metadata: CTD data were collected with a Seabird SBE 911+ probe. Dissolved oxygen data were collected with a Seabird SBE43 probe attached to the rosette. Additional data include fluorescence (Chelsea Aqua3) and transmission (WET labs C-Star).LADCP data were collected with a pair of  300 kHz Workhorse Sentinel from RD Instruments mounted on the rosette. Shipborne-ADCP data were collected with the  150 kHz Ocean Surveyor (RD Instruments)  mounted on the hull of R/V L'Atalante. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

Seawater samples (500 mL) were taken during the (PIRATA FR-32)-[https://doi.org/10.17600/18001832] cruise to measure surface inorganic carbon and alkalinity. The analyses were realised by potentiometric titration using a closed-cell at the SNAPO-CO2, LOCEAN in Paris. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

Surface alkalinity and total inorganic carbon (in µmol/kg) were measured by closed-cell potentiometric titration during PIRATA Brazilian cruises. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.