IAOOS winter hydrographic data during N-ICE 2015 North of Svalbard

We gathered ocean profiles during the first two floes of the N-ICE2015 ice camp north of Svalbard with IAOOS ocean profilers. Between January and March 2015, four ocean profilers were deployed: two below a full IAOOS platform (500 m long cable) during floe 1, two on an 800 m long instrumented line in a tent‐covered testing‐hole during floe1 and floe 2. The ocean profilers, from French manufacturer NKE (PROVOR SPI), carried a Seabird SBE41CP CTD (Conductivity, Temperature, Depth) with an Aanderaa 4330 optode for dissolved oxygen (DO). The profilers were set to perform two profiles a day from 500 m upward (800 m from testing hole) starting at 6 am and 6 pm. They provided the first winter data in the region with a total of 138 profiles during floe 1 (January 15- February 21) with 62, 50, and 26 profiles for IAOOS7, IAOOS8, and IAOOS 9, respectively and 16 profiles during floe 2 (February 24 - March 19- IAOOS 11 from testing hole). Following quality control, we retain all the temperature profiles and remove 1% of the salinity profiles. Finally, the accuracy is estimated to be 0.002°C in temperature, and 0.02 g/kg in salinity. Several profiles are missing or incomplete because of high drift speeds (> 0.4 m s−1) impeding the ascent of the profiler. There are no bottle DO measurements during Floe 1 to calibrate the DO data. DO accuracy is estimated comparing the deep values of DO concentration (rather stable at 500m) between the three profilers. A difference of 3 μmol L−1 is observed between IAOOS 8 and 9, and IAOOS 7. An offset of 3 μmol L−1 is then applied to the oxygen data from IAOOS7 and the accuracy of the data is estimated to be at ±3 μmol L−1. The vertical resolution of the processed CTD data is 1 dbar in the upper 400 dbars, 5 dbars from 400 to 550 dbars and 10 dbars from 550 to 850 dbars. The vertical resolution in dissolved oxygen is 2 dbars over all depths.