UV stimulus at noon heats the atmosphere, causing a meridonal bulge at 2PM (30 degrees eastward of the direction of the sun).
The mean free path at the exobase (500 to 1000 km ) equals the scale height, much longer than scale height at M288. This suggests that atoms at M288 are thermally excited at the exobase, and move in ballistic orbits from the exobase to some maximum altitude and back.
UW Book Notes:
- Theory of Satellite Orbits in an Atmosphere, King-Hele 1964 - no mention of the bulge.