Evaluation of fluorometrically-derived Chlorophyll a as a satellite ocean color validation product using statistical metrics

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 (HPLC) measurements of Chla 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 estimates of Chla by comparing to coincident measurements made by HPLC. Further analyses on the distribution of uncertainties demonstrates occasional trends in the discrepancies between FChla and HChla, enabled the development of a set of recommendations for future collection and validation efforts.