HR: 1340h
AN: AE23A-0913    [Abstracts]
TI: Very Small Meteors -- A comparison of ablation, deceleration and detection theory with observations
AU: * Zinn, J
EM: jzinn@lanl.gov
AF: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, United States
AU: Colestock, P L
EM: colestoc@lanl.gov
AF: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, United States
AU: Close, S
EM: sigrid@lanl.gov
AF: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, United States
AU: Janches, d
EM: diego@cora.nwra.com
AF: NorthWest Research Associates, Inc, 3380 Mitchell Lane, Boulder, CO 80301, United States
AB: In order to determine the mass and velocity distributions of the large flux of very small meteors (< 10 microns) from radar scattering data, it is necessary to model the plasma that is created as these meteors burn up in the upper atmosphere. Although an extensive body of large-aperture radar scattering data has been accumulated in recent years, the essential physics that relates the measured radar cross-section to meteor mass and velocity has only been partially formulated in the limit of long-wavelength scattering from nominally spherical plasmas. In this work we present a comprehensive model of meteor ablation and plasma formation around the meteor head in order to better understand the radar scattering cross-sections. Plasma profiles are determined from first- principle fluid or Monte-Carlo simulations including collisions and collective fields. The results indicate that the plasma parameters vary widely with altitude, as expected, and hence with the initial meteor mass. Collective effects can play an important role in determining the plasma properties. The implications of this plasma model on radar scattering will be discussed and the results compared with existing data.
DE: 6245 Meteors
DE: 6969 Remote sensing
DE: 7849 Plasma interactions with dust and aerosols (2461)
SC: Atmospheric and Space Electricity [AE]
MN: 2007 Fall Meeting