Observation of a persistent Leonid meteor train with an all-sky camera

Abstract

We observed an unusually persistent meteor train with an all-sky camera at Mt. Bohyun in Korea on November 17, 2001. The meteor was first detected at 19:18 UT, and evolution of its train was clearly recorded in 6 subsequent all-sky images until it faded below the detection limit at 19:41 UT. The train appeared first as an arc shape near the eastern horizon that subsequently expanded toward zenith in the all-sky images. We interpret the arc shape train as a consequence of wind profile whose direction revolves with altitude in the mesosphere due to inertio gravity waves. We fit the train loci in the 6 subsequent images with a wind profile model that can be decomposed with two periodic components over the altitude. The two periodic components were interpreted as two inertio gravity waves that were propagating nearly horizontally over the observing site with intrinsic periods of 15 and 17h in the azimuthal directions of 80° and 45°, respectively. If we assume the base altitude of 80km for the train, the vertical and horizontal wavelengths of the two waves are 10 and 2500km, and 40 and 3200km, respectively. The periods and propagating directions of the wave are not affected by the assumed base altitude, and thus gravity waves can readily be studied by sequential all-sky observation of meteor trains even in case of no altitude information.