GALCIT Colloquium

Considerable advances have been made in the understanding of most of the fluid processes in a lake and it will shortly be possible to to manipulate the thermal stratification in a lake, using impellers,  with the objective of avoiding undesirable water quality episodes such a toxic algal blooms and or hypolimnetic anoxia. I shall present a review of the important physical processes and the non dimensional numbers that govern each of these process; surface layers, inflows, outflows, differential mixing, differential heating and cooling, differential absorption, benthic boundary fluxes, shear instabilities and internal mixing. From this it will be shown that solar powered impellers, have sufficient momentum flux to be to compete with above natural processes, determining the stratification of a lake, that in turn determines the ecology of the lake.