Earthdata Forum

Hello everyone,

Usually PIC algorithms are related with coccolitophores. However, some species of zooplankton also incorporate CaCO3 in their skeleton so how can we be sure that the concentrations and/or variability of PIC that we observe in the satellite imagery (MODIS) reflect only phytoplankton (coccoliths) and not other zoo species?

Thank you :-)

The PIC algorithms are based on the light scattering properties of coccolithophorids, primarily Emiliania huxleyi. Because of their larger size and generally lower population density in the water column, calcareous zooplankton are unlikely to significantly influence the ocean optical characteristics of surface waters. The PIC algorithm was refined by experiments in which an overpass coincided with the release of chalk from a ship, in experiments called "Chalk-Ex", so the algorithm is specifically attuned to the light scattering and reflective properties of coccolithophorids and coccoliths.