Retrospective Analysis: Measuring the Historical Magnitude of Turbidity Plumes
Using Archived Remote Sensing Imagery

C. Kerfoot, J. Budd, and R. Stumpf

We propose a ten-year retrospective study (1987-1996) of the southern Lake Michigan spring coastal plume using remotely sensed data. Advanced Very High Resolution Radiometer (AVHRR) visible and thermal infrared data will form the basis of the retrospective study, whereas higher resolution imagery (e.g., Landsat MSS and Landsat TM images, CZCS images, and available aircraft data) will monitor specific events of short duration. The objectives are:
  1. to assess the relationship of winter ice formation, coastal plume development, and thermal bar movement to cross-margin transport phenomena in southern Lake Michigan;
  2. to determine the timing, duration and extent of river plumes on a seasonal and interannual basis;
  3. to use higher resolution satellite data (e.g., Landsat and Landsat TM imagery) to separate total solids, chlorophyll (as chlorophyll and phaeophytin), and DOC signals (where possible); and
  4. to utilize historical surface water quality data (e.g., NOAA/GLERL Mass Balance monitoring data, EPA Storet data, NOAA meteorological buoys) for empirical comparisons with the remotely sensed data.
Recently launched and proposed ocean color missions (i.e., ADEOS-OCTS and SeaWiFS), in conjunction with shipboard sampling data (e.g., temperature, suspended solids, Chl, DOC, kPAR), will provide additional information on surface water features and opportunities for cross comparison with the AVHRR imagery. Resting stages of organisms previously buried several centimeters deep in pelagic and transitional sediments may be resuspended and redistributed by plume formation. These wind-driven episodic events could alter seasonal plankton biomass or even change community composition, as resuspended zooplankton resting eggs establish certain copepod (Diaptomus minutus) populations and set the stage for later cladoceran recruitment. Our efforts cross-connect with the mesozooplankton trophic dynamics group.