Diffusion and Structure of Meteor Trails in the E-Region Ionosphere

Details Diffusion and Structure of Meteor Trails in the E-Region Ionosphere Diffusion and Structure of Meteor Trails in the E-Region Ionosphere

May 2004

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004agusm.p33c..03d&link_type=abstract

American Geophysical Union, Spring Meeting 2004, abstract #P33C-03

Statistics

Computation

0654 Plasmas, 2411 Electric Fields (2712), 2435 Ionospheric Disturbances, 2439 Ionospheric Irregularities, 6245 Meteors

Scientific paper

A meteoroid penetrating the Earth's ionosphere leaves behind a trail of dense plasma which disperses with time. For micrometeoroids, which comprise the majority of all meteoroids bombarding the Earth, the only practical way to observe the trail is using radars. An important feature of radar images from large-aperature radars is the non-specular echoes, which show strong aspect sensitivity and remain visible for a relatively long time in a broad altitude range within the E-region ionosphere. We have argued that non-specular echoes result from radar signals scattered from turbulent electron density irregularities generated by plasma instabilities. Strong electrostatic electric fields and diamagnetic drifts developing during the plasma trail diffusion drive these instabilities. In order to draw quantitative conclusions about the meteoroids based on radar measurements, we need to model this instability process. This modeling in turn requires knowledge of spatial/temporal distribution of the driving polarization electric field and plasma density. Previously, we performed such modeling in the simplest case for a trail aligned strictly along the geomagnetic field [1]. However, the majority of routinely observed meteoroids have a significant angle between these two directions. The dynamical theory and simulations of meteor trail diffusion were developed starting in the 1960s (e.g., [2-5]). While these earlier papers caught some aspects of the plasma trail dynamics, they did not provide accurate predictions for the polarization electric field because they did not properly treat interaction between the trail and background ionospheric plasma. In this paper, we present results of our recent 2-D analytical theory and numerical computations, which for an arbitrary angle between the magnetic field and the trail axis take into account the current closure in the background plasma. This study provides us with quantitative knowledge of the electric field spatial distribution and dynamics. We show that the non-specular echo should disappear well before the true dispersion of the meteor trail itself. Using our theory and observations of non-specular meteors should yield information about meteor trails and the surrounding atmosphere.
\ [1] M. Oppenheim et al., J. Geophys. Res., 108, SIA 8-1, ID 1064 (2003). [2] T. R. Kaiser et al., Planet. Space Sci., 17, 519 (1969); [3] W. M. Pickering and D. W. Windle, Planet. Space Sci., 18, 1153 (1970); [4] W. Jones, Planet. Space Sci., 39, 1283 (1991); [5] R. E. Robson, Phys. Rev. E, 63, 026404 (2001)

Affiliated with

Also associated with

No associations

Rating

Diffusion and Structure of Meteor Trails in the E-Region Ionosphere does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Diffusion and Structure of Meteor Trails in the E-Region Ionosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Diffusion and Structure of Meteor Trails in the E-Region Ionosphere will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1177736