This dataset was collected during the cruise HE545 (10.11.2019 - 12.11.2019) with RV HEINCKE from Cuxhaven, Germany to Bremerhaven, Germany. It contains absorption coefficients [m-1] from water constituents in a range of 400 to 710 nm (2 nm resolution). In total, 31 samples have been taken in approx. 5 m depth. At some occasions, also other depths were sampled. The water samples were analyzed for the total absorption coefficients of water constituents (a_tot). The absorption coefficient measurements were performed with a point-source integrating-cavity absorption meter (PSICAM) with a sample volume of approx. 400 ml. The specifications of the PSICAM, relevant publications, information regarding the measurements, calibration of the instrument, and data correction are provided in a separate document. Raw data are available on request from the authors. Supplementary Information attached.Chief Scientist of HE545: Dr. Thomas Badewien / Dr. Jochen Wollschläger, Institute for Chemistry and Biology of the Marine Environment (ICBM).Work related to Coastal ocean darkening - Light availability in the past and future marine environment (COD).

Data binned at 2 nm intervals