Buoyancy of the "Y2K" persistent train and the trajectory of the 04 : 00 :29 UT Leonid fireball

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.