Vertical distribution of dust particles in the Earth's atmosphere during the 1998 Leonids

Photometric observations of the twilight sky were carried out during Leonids 1998. The obtained vertical distributions of aerosol between 20 and 140 km demonstrate the processes of the intrusion of fine meteor dust and its subsequent intra-atmospheric dynamics. The characteristic radii of two fractions of the meteor dust particles were estimated by their sedimentation velocities. They varied within r(p) = 0.006-0.06 mu m and r(p) = 19-81 mu m limits depending on an assumed particle density within rho(p) = 0.4-4.0 g cm(-3). The assumption of rho(p) = 2.0 g cm(-3) gave radii of the two fractions to be 0.01 and 30 mu m, respectively.