Using Fundamental Optical Property Sensors for Characterization of Biogeochemical Materials and Processes in Marine Waters

Optical properties of the earth's natural waters characterization efforts have largely merged, over the past ten years, with the need for better understanding of underlying chemical and biological processes. Light level, absorption, scattering and fluorescence are among the fundamental optical properties being utilized now with increasingly effective particulate and dissolved in-water components' specification in a wide application range, including harmful algal bloom detection, ecosystem dynamics study, industrial and agricultural pollutant effect monitoring, and carbon sequestration processes understanding in the oceans. A diverse commercial optical sensing product offering is now available capable for research, routine measurements, and, in some cases, operational monitoring. The scientific community has been provided with a toolset for analytical and semi-analytical method development, testing, and implementation for specific biogeochemical parameters and processes to be inferred. New, more specialized sensors are now beginning to emerge as a result. Basic optical property measurements and processing algorithms are coupled in the new sensors for specific harmful algal bloom, identification and particle size, nutrients, and carbon product distribution indicators. The author describes basic measurement methods and gives examples of devices which incorporate them for illustration of their modern oceanographic research and monitoring use.