Fate of Artificially Injected Oxygen in the Hypolimnion of a Two‐Basin Lake: Amisk Lake, Revisited

Bubble-plume diffusers are increasingly used to add dissolved oxygen (DO) the hypolimnion of lakes and reservoirs. Bubble plumes successful at replenishing hypolimnetic DO, but they also introduce mixing energy that induces subtle changes in thermal structure reservoir, driving plume behavior. To account for this complex plume-reservoir interaction, a double bubble-plume model is coupled with three-dimensional hydrodynamic model. The reassess field-scale analysis diffuser two-basin Amisk Lake, aiming evaluating relative role bubble-induced circulation internal-seiching inter-basin transport under stratified conditions. A large-scale plume-induced was previously thought be main driver transport. This interpretation based on attribution time-averaged channel due operation. However, intrinsic complexity hydraulic system sparseness field data introduced large uncertainties previous analysis. Here, we demonstrate primarily result wind-driven internal seiches. Oxygen exchange shown controlled by interaction between seiche-driven horizontal along channel, and, rate which added reaches layers above sill, mainly circulation. Internal-seiche driven through basin constrictions will vary depending magnitude wind forcing, depth thermocline geometry. These results highlight importance understanding water movement prior introducing restoration actions lakes.