Particle Size and Composition from Flow Cytometry
Size and composition of the particle population play an important role in determining the inherent optical properties of natural waters. We are exploring the potential for using flow cytometry to determine particle size distributions (PSD) down to sub-micron scales. In addition, we are attempting to resolve the composition of particle sub-populations through retrieval of refractive index. Our CytoSense flow cytometer (CytoBuoy, Woerden, Netherlands) provides additional information on fluorescence, pulse profiling and particle imaging, all of which can be used to provide higher levels of particle discrimination.
The ultimate aim of this research is to use the retrieved information on particle PSD, shape and composition to provide inputs to optical models (Mie, T-matrix, DDA, geometric optics) that will allow us to investigate relationships with scattering and backscattering properties that contribute to remote sensing signals. This work is therefore closely linked to our efforts elsewhere to refine IOP measurement methodologies and to develop radiative transfer models for ocean colour applications.