ANALYSIS OF ORGANIC-CARBON SEDIMENT-WATER EXCHANGE IN GREEN BAY, LAKE-MICHIGAN, USA

A steady-state sediment carbon mass balance has been performed using data from the Green Bay Mass Balance Study. This analysis aided the calibration of sediment organic carbon resuspension for use in the time-variable PCB mass balance model of the bay. The steady-state analysis indicated that the spatial range of open water resuspension rates was 32 to 195 mm/y, with larger values in shallow, high energy areas of die bay. Under ice, resuspension rates ranged spatially from 15 to 63 mm/y. Gross water column to sediment deposition fluxes and gross resuspension fluxes were by far the largest particulate carbon fluxes in the systems, with their difference leading to net deposition velocities that ranged spatially from 0.02 to 0.27 m/d during the open water period and from 0.09 to 0.64 m/d under ice.