SATELLITE MONITORING OF OPTICALLY-ACTIVE COMPONENTS OF INLAND WATERS - AN ESSENTIAL INPUT TO REGIONAL CLIMATE CHANGE IMPACT STUDIES

Consistent with the climate change objectives of the IGBP is the need to remotely monitor and map both global and regional biological productivity over lands, oceans, and inland waters. Models and algorithms are currently being developed to infer aquatic primary production from near-surface chlorophyll concentration values determined from satellite sensors. Data from Lake Ladoga are utilized to illustrate that the algorithms currently being used to monitor near-surface chlorophyll concentrations in oceanic waters are inadequate when applied to water masses optically complicated by their proximity to land masses. Methodologies originally developed for retrieving simultaneous concentrations of chlorophyll, suspended minerals, and dissolved organic carbon from volume reflectance measurements of Lake Ontario are shown to display success in Lake Ladoga that could not be duplicated by six different oceanic chlorophyll retrieval algorithms. The principal requirements for water quality satellite monitoring are the cross sections of the optically-active components of the water body being remotely monitored. It is argued that, despite the spatial and temporal variability of such cross sections, their determination for principal water bodies should comprise both global and regional climate change studies.