Total chlorophyll a and phytoplankton functional type chlorophyll a concentrations estimated from underway hyperspectral spectrophotometric measurements during the Atlantic Ocean transect of RV Polarstern cruise PS113

This dataset provides high-spatial-resolution (approximately 300 m) estimates of total chlorophyll a concentration and chlorophyll a concentrations of five phytoplankton functional types, including diatoms, dinoflagellates, haptophytes, green algae, and prokaryotic phytoplankton. The products were generated by applying an EOF–GLM model to particulate absorption spectra derived from continuous hyperspectral spectrophotometric measurements of absorption and beam attenuation acquired through the ship's underway seawater intake system during RV Polarstern cruise PS113 between 10 May and 9 June 2018. The model was trained using paired ACS-derived particulate absorption spectra and HPLC-derived pigment observations and subsequently applied to the complete particulate absorption dataset to generate continuous chlorophyll a concentrations. The final products were averaged into 1 min intervals and include the associated uncertainty estimates. Further details on the methodology are provided in Mehdipour et al. (2026a, 2026b) and Bracher et al. (2026).