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

A steady-state sediment carbon mass balance has been performed using d ata from the Green Bay Mass Balance Study. This analysis aided the cal ibration of sediment organic carbon resuspension for use in the time-v ariable PCB mass balance model of the bay. The steady-state analysis i ndicated that the spatial range of open water resuspension rates was 3 2 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 resuspen sion fluxes were by far the largest particulate carbon fluxes in the s ystems, with their difference leading to net deposition velocities tha t 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.