The data set includes the light absorption coefficient of colored dissolved organic matter (CDOM) from 200 nm to 700 nm wavelength and dissolved organic carbon (DOC) together with physical oceanographic observations (temperature and salinity) from the Laptev Sea and East Siberian Sea. Sampling was carried out September and October 2019. During the ship-based expedition, we operated a CTD profiler (conductivity temperature-depth; Seabird 911+) to sample the basic hydrographic parameters. The CTD is operated on a carousel water sampler (SBE 32), which can take water samples at the selected depths.The dataset is part of a multi-year study (different seasons over a period of 9 years: 2010-2019) of the dissolved organic matter (CDOM), which includes observations in marine waters from the coastal zone to the shelf edge of the Laptev Sea and East Siberian Sea, the river Lena and ice and water samples from the land-fast in the south-eastern Laptev Sea.