Fig. I: Map of the Pomeranian Bight in the southern

Variation of specific optical properties and their influence on measured andmodelled spectral reflectances in the Baltic SeaHerbert Siegel, Monika Gerth, Marko BeckertBaltic Sea Research Institute WarnemUndeSeestrasse 15, D-181 19 Rostock, GermanyABSTRACTSpatial and temporal variations due to seasonal and regional development of phytoplankton and the freshwater inflowin river mouth areas influencing the optical properties in the Baltic Sea. The phytoplankton blooms in different seasons aredominated by special taxonomical groupes. The variation intervals for the concentration of different optical activ waterconstituents are presented. Regional and seasonal variations in the absorption of phytoplankton, detritus and geibstoff arediscussed in relation to the sources. The specific absorptions of chlorophyll show more regional differences than temporal.Measured volume scattering functions from the open Baltic and Pomeranian Bight are compared with published data. Theb,/b- ratio deliver the known values for different dominating water constituents, which influences also the spectral shapethe backscattering coefficient. Derived spectral specific absorption and backscattering coefficients were used to control thereflectance model by comparison to measurements ofthe total internal reflectance. Selected inherent optical properties forthe spring bloom were included in the inverse procedure by Krawczyk et al. for the derivation of water constituents fromsimultaneous satellite data ofthe Modular Optical Scanner (MOS) at the Indian Satellite IRS- P3.2. INTRODUCTIONThe Baltic Sea is a tideless marginal sea with a limited water exchange to open ocean. In optical sense the Baltic is a