By itself, the heating and cooling of the ocean surface would only be capable of driving a significant flow in a thin surface layer ("Sandstrom's theorem"). The flow below this layer must be mechanically driven, and the two possible sources of mechanical energy are the winds and the tides [1]. In the main thermocline, the winds play a dominating role, mainly via Ekman pumping, but in the abyss below, the tides are probably more important. When tidal currents encounter rough topography on the bottom of the ocean, internal waves are created, and when these waves steepen and break through nonlinear interactions, they cause vertical mixing. This mixing is what drives the deep circulation. It is therefore of great interest to calculate the energy flux from the tides to the internal wave field.
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