Methodology:

The dataset was collected during a cruise to the Chukchi Sea onboard the Korean ice breaking research vessel Araon from August 3 to 27 2019. During the cruise, three ice floes were visited and the light measurements were collected on each floe. The sites visited are ordered alphabetically: A-E sites correspond to the first floe, F-I sites correspond to the second floe and J-M sites correspond to the third floe. For each site, 3 locations separated by 90 degrees were taken with 6 measurements per location and, except for the ponded sites, under ice irradiance measurements were taken with snow on and without snow, by removing a square of around 1x1m on top of each measurement location. Each measurement was repeated until obtention of a tilt less than 10 degrees was obtained for 6 spectra. Only 6 spectra with proper tilt per core have been kept in the dataset. For the incoming irradiance, several measurements were taken at intervals for each site in order to insure a coverage of the varying sky conditions following the same method.

Data collection:

All irradiances were collected using TriOS RAMSES ACC-Vis-NIR hyperspectral radiometers. The wavelength range was 305.6 to 1145.4 nm with a resolution of 3.3 nm. The TriOS software MSDA_XE was used to collected and pre-process the data into the files given.

Data quality:

We ensured that the tilt of the radiometers was always below 10 degrees to validate a spectrum. 6 spectra were collected for each core (3) within a site.