ORIGINAL: av8tr7
according to the dictionary of aeronautical terms 2nd edition, published by asa in the late 80's early 90's. ground effect is an increase in lift of an aerodynamic flying machine (airplane or helicopter) flying very near the ground. this additional lift is caused by a distortion of the airflow that produces an increased angle of attack. grond effect disappears when the flying machine is about a half a wingspan or half rotor span above the ground.
This is a pretty darn good explanation of ground effect.
The bouyancy I mentioned is simply any increase in pressure caused by a large body passing by and "gathering up" air as it goes
If the air is disturbed -it HAS to go someplace and if it can't equalize before the "body" passes by - there is a pressure build up .
We call that condition,
ground effect.
Not really much different than watching a large piece of plywood fall to the ground - the final part of the fall is cushioned by the air which simply can"t equalize pressure with the surrounding air.