Imagine if you build a "parking lot" square of asphalt and paint it the deepest black possible to absorb maximum heat...would that spot essentially be a thermal generator that you could fly over with a glider and reasonably expect good thermals? Assume it's summer and no other obvious obstructions to solar radiation on the day. 

Even on a day when there's a relatively low altitude temperature inversion, could this make the air so hot that it would take a good vertical distance for the thermal generator's "parcel" of air to cool to the ambient temperature (and still make a flyable thermal on a mediocre soaring day)? Or, do thermodynamics not really allow you to get very far with this...assume usual 5.4 degrees Fahrenheit of cooling per thousand feet.