Detecting-storm-generated suspended materials in Lake Michigan using ADCP echo intensities

摘要

Data from Acoustic Doppler Current Profilers deployed in the nearshore region of southeastern Lake Michigan provide evidence of sediment resuspension episodes and cross-shelf flux of materials during strong winter storms. Significant increases(+20dB) in echo intensity and current velocities correlate well with satellite imagery of a sediment-laden plume transporting material in a cyclonic flow around the lake basinis perimeter. A decrease in echo intensity to near-background levels followingresuspension events suggests that the larger particles settle out, leaving the very fine material that remains visible in satellite imagery for many days. Although there were no concurrent Total Suspended Material measurements during the event, the ADCPresults suggest that resuspension events and plume movements can be detected.