Microbial particles and oceanic optics: Where do we go next?

Achieving a detailed understanding of the roles played by various types of microbial particles in oceanic optics is a prerequisite to advancing remote sensing of water component concentrations and improving bio-optical models beyond their present one-parameter, chlorophyll-based description of very complicated and variable situations. There is now information available on the single-particle optical properties of various microbial species and a numerical radiative transfer model that is computationally efficient and accurate enough to permit extensive studies of light fields within and leaving the water as particle types, concentrations, and optical properties are systematically varied. A new approach combining a database of single-particle optical properties and radiative transfer modeling is very promising because it identifies bio-optical relationships and details which are not resolved by common correlational models parameterized in terms of chlorophyll concentration alone.