Modeling oxygen depletion within stratified bottom boundary layers of lakes

Aidin Jabbari, Leon Boegman, Murray Mackay, Nader Nakhaei
Int. Symp. on Stratified Flows   unpublished
We have implemented two bottom boundary layer mixing sub-models in a one-dimensional bulk mixed-layer thermodynamic and dissolved oxygen model to diffuse the effects of the sediment oxygen demand from the bottom boundary condition in small lakes. In the first sub-model, bottom mixing is calculated following a mixed layer approach, whereas in the second sub-model the dissolved oxygen flux is computed from Fick's Law. The second sub-model results in better prediction of dissolved oxygen in two
more » ... ll Canadian Shield lakes, compared to the mixed-layer approach. While appropriate for the upper mixed layer, the bottom mixed-layer model produced excessive near-bed mixing. Bottom mixed layer approaches have been successful in large lakes, suggesting a Reynolds number dependence for mixed-layer development.