Evaluation of fluorometrically-derived chlorophyll a as a satellite ocean color validation product using statistical...

The fluorescence of chlorophyll a (Chla) has long been considered a reliable estimate of phytoplankton biomass in aquatic environments. The in vitro fluorometric method for measuring Chla is a simple, fast, and cost-effective way to estimate phytoplankton biomass. High performance liquid chromatography measurements (HPLC) of Chla (HChla) have been used historically for ocean color validation. The applicability of fluorometrically-derived Chla (FChla) to satellite ocean color validation has not been fully evaluated. To this end, we developed statistical metrics to evaluate the uncertainty of fluorometric measurements of Chla by comparing them to coincident measurements made by HPLC. The distribution of uncertainties demonstrates occasional trends in the discrepancies between FChla and HChla, from which we developed a set of recommendations for future collection and validation efforts.