Oh, Dave. You are Lu in disguise. What does that site you posted have to do with the question of how ground effect works?
I feel like those who debated with the Flat Earth Society back in the 1800's. The Flat Earthers were a group who argued that the earh is really flat. No matter what evidence was presented, they simply ignored it and went on with their assertions.
I guess Dave you are President of the Ground Pressure Society.
http://www.alaska.net/~clund/e_djubl...rthsociety.htm