Discoveries and testable hypotheses arising from Coastal Zone Color Scanner imagery of southern Lake Michigan 1

CZCS (Coastal Zone Color Scanner) images, confined mainly to the southern basin of Lake Michigan during the warm‐up phases of 1979, 1980, and 1981, have furnished tools for synoptic reconnaissance of the wind‐perturbed transition of the thermal regime in large basins from the winter to summer condition (including front formation and upwelling events), the coupling of phytoplankton growth with that transition, the intermittent mobilization and surface transport of sediment resuspended by storms, and the extensive temporary trapping of river‐derived dissolved organic matter (gelbstoff) between the shoreline and the offshore‐migrating thermal front. Intermittent resuspension of particles and variable inputs of gelbstoff, which occur in many coastal waters, render inapplicable the CZCS algorithms successfully used in ocean studies for atmospheric correction and for quantification of phytoplankton chlorophyll. That disappointment notwithstanding, there is a favorable match of the coverage and scene‐revisit frequency of the CZCS and the space and time scales of significant features of the above‐listed processes. The observed pattern changes shed new light on the above processes and generate several testable conjectures. These relate to whole‐basin sediment transport, coastal upwelling of near‐bottom sediment suspensions, and frontal hydrodynamics and its coupling with phytoplankton distributions.