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oai:www.ideals.illinois.edu:2142/20558 2023-07-10 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Kudeki, Erhan Chapin, Elaine 2011-05-07T12:42:42Z 2011-05-07T12:42:42Z 10000-01-01 1996 Observations of meteor echoes at Jicamarca in August of 1990, 1991, and 1992 reveal some unusual properties. The echo durations are very long ($\sim$2 s to 3 minutes), radio wave scattering is non-specular (echoes are detected simultaneously over an $\sim$10 to 15 km altitude range centered about 97 km), and the Doppler spectra of the scattered signals contain components shifted by as much as $\sim$400 ms$\sp{{-}1}$ immediately after the onset of the echoes. These unusual properties are attributed to the growth and propagation of plasma irregularities along meteor trails deposited within the equatorial electrojet. It is suggested that trails at electrojet heights must carry intense transient currents that excite two-stream and/or gradient drift instabilities for irregularity growth. The direction of electron motion responsible for the transient current agrees with the Doppler shift of the high-frequency components in meteor echo signals. Nighttime Jicamarca electrojet data with simultaneous meteor observations are studied in detail and compared with the plasma irregularity explanation. Made available in DSpace on 2011-05-07T12:42:42Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9625120.pdf: 4181354 bytes, checksum: 763f67978dc362e8a762f8904ca91d64 (MD5) Previous issue date: 1996 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:44:42Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:19:42-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission ETDs are only available to UIUC Users without author permission U of I Only AAI9625120 (UMI)AAI9625120 http://hdl.handle.net/2142/20558 eng Copyright 1996 Chapin, Elaine Geophysics Engineering, Electronics and Electrical Simultaneous observations of meteors and the equatorial electrojet at Jicamarca text Electrical and Computer Engineering Electrical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.