re: Sounds logical to me.
The laws of physics work with the atmosphere, so it is possible to cool the air by expanding it.
Adiabatic cooling also occurs in the Earth's atmosphere with orographic lifting and lee waves, and this can form pileus or lenticular clouds if the air is cooled below the dew point.
http://en.wikipedia.org/wiki/Adiabatic_process
If the air is heated it will expand, if after heating most of the hot molecules are removed from the system, then the colder and denser air is left behind.
This process sounds reasonable to me.