Shovon gave an invited talk at the Challenger Society in Plymouth University, on “Cell size, size spectrum and size classes of phytoplankton from ocean colour by a single bio-optical algorithm based on absorption spectra” at the Challenger Society for Marine Science Conference. This talk was attended by scientists from PML, NOC and other institutes.

Over the recent years, various methods have been developed to compute phytoplankton functional types from remote sensing of ocean colour. One class of those methods deals with phytoplankton size structure, and can provide estimates of phytoplankton biomass at 2-3 size classes. However, the estimates of phytoplankton size classes are known to vary significantly among models suggesting that further investigations are needed along this line of study. The presentation dealt with a new method, developed for computing phytoplankton size structure from ocean colour based on their absorption spectra in the visible domain. It was demonstrated how this method would be useful in computing quantitative information on phytoplankton size structure, in particular, the size of phytoplankton cells, the exponent of phytoplankton size spectrum, and the fractions of chlorophyll in pico-, nano- and micro-phytoplankton in mixed samples. Further, how the uncertainties in the input variables retrieved by ocean colour could affect the estimates of cell size and size classes was presented. Finally, the applicability of this approach in understanding the spatial distribution and biogeography of phytoplankton size structure in the global oceans was discussed.