## 3 Assessment of the Developed Algorithm Efficiency in Some Case Studies
### Lake Huron  
Lake Huron is oligotrophic in its most areas, except for Saginaw Bay and the southern Georgian Bay where eutrophic conditions prevail [33]. The Saginaw Bay water quality is largely controlled by run-off, tributary discharge, as well as by anthropogenic effluents coming from Bay City and the city of Saginaw. The phytoplankton species for the Huron Lake _open_ area are typical of oligotrophic water bodies. In contrast, the phytoplankton community in Saginaw Bay is representative of typical eutrophic conditions [33]. The above indicates that there should be two distinctly different water masses residing in the outer and inner parts of the Bay which is conducive to a substantial difference in the optical characteristics of both parts of the Bay due to differences in the phytoplankton abundance and taxonomic composition, mineralogical and microphysical characteristics of suspended minerals. The suspended matter in the inner part should be directly provided by nearby tributaries, run-off and wind/water dynamics-driven resuspension whereas in the outer part it is largely the result of filtering due to gravitational settling of the particulate matter generated by _distant_ sources). Similar considerations could be suggested with regard to the dissolved organics (_doc_): the autochthonous component in the outer part of the bay could be predominant, whereas in the inner part the allochthonous component should most certainly prevail. Evidently, under appropriate conditions, due to wind and current impacts, both types of water masses can invade the counterparts of the bay and mix up with the ambient waters. \begin{table}
\begin{tabular}{|c|c|c|c|c|c|} \hline \multicolumn{3}{|c|}{_In situ_ measurements} & \multicolumn{3}{|c|}{**Remote sensing data**} \\ \hline _chl_, \(\underline{\upmu}\)g/L & _tsm_, mg/L & _toc_, mgC/L & _chl_, \(\underline{\upmu}\)g/L & _sm_, mg/L & _doc_, mgC/L \\ \hline
0.72 & 2.42 & 24.63 & 1.11 & 10.17 & 23.86 \\
1.2 & 1.34 & 22.19 & 1.85 & 9.81 & 24.37 \\
0.5 & 4.38 & 15.96 & 0.46 & 2.58 & 10.12 \\
0.46 & 1.65 & 37.73 & 0.44 & 3.91 & 24.37 \\
0.53 & 9.38 & 4.98 & 0.5 & 4.43 & 7.32 \\
0.63 & 1.36 & 8.45 & 0.57 & 2.76 & 7.89 \\
0.55 & 2.68 & 18.63 & 0.42 & 2.55 & 11.14 \\
0.54 & 1.45 & 7 & 0.2 & 1.3 & 4.8 \\
0.63 & 5.33 & 9.55 & 0.08 & 1.53 & 5.71 \\
0.71 & 3.95 & 7.71 & 0.12 & 1.19 & 4.51 \\
0.51 & 0.72 & 24.07 & 0.21 & 1.36 & 15.08 \\ \hline \multicolumn{3}{|c|}{**r**} & 0.82 & -0.09 & 0.88 \\ \hline \multicolumn{3}{|c|}{**RMSE**} & 0.36 & 4.1 & 5.9 \\ \hline \end{tabular}
\end{table} 
Table 7: Comparison of CPA concentrations measured _in situ_ and retrieved from SeaWiFS data from the eastern coast of Lake Michigan, July 2003; _tsm_– total (i.e. organic and inorganic) suspended matter, _toc_– total (i.e. suspended and dissolved) organic carbon. Field studies on the Great Laurentian Lakes were performed by ERIM in June and July 1998 at 13 stations in the inner and outer parts of Saginaw Bay. Conducted from board a small research vessel, spectrometric measurements and CPA sampling for _chl_, and _doc_ were performed. The spectrometric measurements (at the SeaWiFS wavelengths) allowed retrieving spectral volume reflectance, \(R(\lambda,\,\Theta_{0})\). The LM algorithm was applied for retrieval of WQP concentrations from spectra of \(R(\lambda,\,\Theta_{0})\) several times with different hydro-optical models. The test showed that for the inner and outer parts of the bay the most suitable hydro-optical models are that of Lake Ladoga and slightly modified [34] Ontario model [33], respectively (Table 8). The retrieved _sm_ values appear as quite plausible in view of the typical Secchi disc depths (averaging 1-3 m, [33]).