51. Estimation of phytoplankton concentration from downwelling irradiance measurements in water
- Author
-
Peter Gege
- Subjects
Downwelling irradiance ,Ecology ,Underwater light field ,Plant Science ,inverse modeling ,Atmospheric sciences ,Reflectivity ,WASI ,Phytoplankton ,phytoplankton ,Spectroscopy ,Experimentelle Verfahren ,Agronomy and Crop Science ,Ecology, Evolution, Behavior and Systematics - Abstract
The downwelling irradiance spectrum is so far not used directly for the determination of water constituents, mainly due to the large and unpredictable fluctuations of the underwater light field induced by the water surface. The potential of a new analytical model, which can cope with such environmental influences, was analyzed for the estimation of phytoplankton concentration using data from two German lakes. It turned out that the model is able to determine in these lakes phytoplankton concentration above a threshold between 0.4 and 0.9 µg/l, depending on the phytoplankton class, and total pigment concentration (sum of chlorophyll-a and phaeophytin-a) with an uncertainty of 0.7 µg/l. This new in situ spectroscopy method is particularily of interest for shallow waters, where it is difficult to apply the usual reflectance-based algorithms due to bottom influences.
- Published
- 2012