Beauty is in the eye of the observatory system, or is it?

With continuously improving capabilities of ocean color remotes sensors, and especially now at the dawn of NASA’s Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) ocean color mission, the ocean science community’s focus toward development of remote sensing algorithms to detect phytoplankton diversity (for example, phytoplankton functional type) from space has intensified. These new algorithms, thanks to the multiple approaches, offer insights into different levels of complexity of phytoplankton community structure; by either focusing on absorption, scattering or ecological properties of single species or communities as whole. Over the past several years, we have conducted size fractionated in situ measurements of inherent optical properties (IOPs) and biogeochemical properties across World’s oceans, with concurrent measurements of hyperspectral radiometry, with the objective of (1) understanding contribution of different size classes to the IOPs , and (2) relationships between IOPs and biogeochemical parameters. In the context of this comprehensive dataset, we evaluate several contemporary phytoplankton diversity algorithms, in order to understand the advantages and limitations of each approach.