Indicates that the presumption is of constant energy, towhit there can be no addition or subtraction of mass/energy, i.e. a closed system.
No, a closed
fluid element, not a closed
system. There's a significant difference when the
element is moving around the
system!
Accepting that there is a decrease in pressure over the wing I have difficulty in accepting the hydraulic explanation of an increase in ground level pressure under a wing that is producing lift. There are notable exceptions, Wing In Ground Effect (WIGE) springs to mind.
The WIGE concentrates the force in a smaller area. If you imagine moving the wing continuously to a greater height, the pressure on the ground becomes less, but it acts over a much greater area. It doesn't have to be over very much area before the pressure gets lost in the noise -- but the integral, the force, is the same.
By Newton's 3rd Law, the wing applies a force to the atmosphere. If an opposing force on the atmosphere is not provided by something, the entire atmosphere would accelerate downwards. Given that the global atmosphere is not a still fishtank but a turmoil of large scale motions in which a few million tons is neither here nor there, that's not an unreasonable model. But what happens at the boundaries of the model, whether it be miles away from the aircraft or hundreds of feet away, makes little difference to the pressures at the wing surface.