Lake Superior is the least productive and most pristine lake of Great Lakes. The typical ranges of chlorophyll concentration are 0.1 to 1.2 ug/L. This might indicate case 1 open ocean optical classification. But the influence of the other major absorbing species, i.e., chromophoric dissolved organic matter of terrigenous origin and suspended materials, makes the system very complex optically. This influence necessitates a case 2 optical classification.

Evaluation of the Published Empirical and Semi-analytical chlorophyll Algorithms:

The initial evaluation results indicate that none of the published chlorophyll algorithm designed for ocean water can be applied to Lake Superior directly. Although those empirical algorithms simulated the variation of chlorophyll concentration from near shore to off shore, all of them overestimated the chlorophyll concentration, with overestimates as high as ~45:1 for the OC2 algorithm. Compare to the empirical algorithms, semi-analytical algorithm is more optimal to be used on Lake Superior. The on going work is to calculate the value of those parameters for Lake Superior using the in situ bio-optical data.