Can someone explain how the coefficient of lift can be greater than one.
Megan provided the equation. It's really just a matter of when the particular section plus high lift bits and pieces lets go of the air and it all turns to turbulence. The numbers come from the measurements. No reason I can see why it ought not to be greater than one if that's what the section does ...
The reactive force to this acceleration of air downwards is additional lift.
It really is a matter of how you want to go about explaining stuff.
There is a pressure difference above and below - easy to show experimentally.
There is upwash and downwash - again, easy to show.
The two are not different/unrelated animals, though. To get the flow changes we need the pressure difference and the associated pressure gradients from the near-surface flow out to the free stream - one needs to recall that the only way to exert a force on a fluid flow is by the influence of pressure gradients - otherwise, the flow sort of just slips left, right, up, or down, as the case may be and continues to do its own thing. One needs the other and I don't think it is valid to try to separate them ?
only if the wing passes through the volume of air and leaves it undisturbed.
Now, that's an interesting concept. You don't happen to have a convenient video showing this happening in a tunnel, do you ?