The atmospheric trajectory is calculated of a particularly well studied fir
eball and train during the 1999 Leonid Multi-Instrument Aircraft Campaign.
Less than a minute after the meteor's first appearance, the train curves in
to a "2"-shape, which persisted until at least 13 minutes after the firebal
l. We conclude that the shape results because of horizontal winds from grav
ity waves with a scale height of 8.3 km at 79-91 km altitude, as well as a
westerly wind gradient with altitude. In addition, there is downward drift
that affects the formation of loops in the train early on.