This dataset contains spectral reflectances, measured at the top-of-atmosphere in the solar spectral range, by the three different sensors GOME, SCIAMACHY and GOME-2A respectively on board the ERS-2, ENVISAT and MetOpA satellites. The time interval covered is January 1996 up to and including December 2017. The temporal granularity is monthly. The geographic extent is from parallel 60 N to 85 N. The dataset is functional to inspect long-term changes in Arctic reflectivity and to analyze the relative contribution of mainly sea ice, snow and clouds. Data in this version has already been harmonized for the spatial footprint at the ground of the respective sensors and for subsequent analysis with complementary and independent datasets of cloud properties and radiative fluxes. As such, they are not suitable for in-situ validation of ground, air- or ship-borne reflectances. The underlying original reflectances at native resolution are available upon request.

The file is a multi-dimensional, multi-level NetCDF following COARDS-CF 1.5 convention.