Concentrations of Chlorophyll a and phaeopigments from CTD-rosette casts during the MOSAiC (PS122) drift expedition in the central Arctic Ocean. 2-4L of water were filtered onto precombusted GF/F filters (nominal pore size 0.7µm) and frozen at -80°C. Samples were subsequently extracted in 90°C acetone,homogenized using a cell mill, and meaured on the following day using a Turner flourometer, followed by an acidification step to determine pheopigments (see Knap et al. 1994 for details and calculations). Samples were collected roughly once per week from end of October 2019 to beginning of October 2020.