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| Titel |
Super Dual Auroral Radar Network observations of fluctuations in the spectral distribution of near range meteor echoes in the upper mesosphere and lower thermosphere |
| VerfasserIn |
N. F. Arnold, T. R. Robinson, Mark Lester, P. B. Byrne, P. J. Chapman |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 19, no. 4 ; Nr. 19, no. 4, S.425-434 |
| Datensatznummer |
250014236
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| Publikation (Nr.) |
 copernicus.org/angeo-19-425-2001.pdf |
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| Zusammenfassung |
The Doppler shifts of
meteor echoes measured by the SuperDARN HF radar network have been used in
several studies to observe neutral winds in the upper mesosphere and lower
thermosphere region. In the absence of accurate height information for
individual meteors, it has been necessary to assume a statistical mean meteor
layer where the variations in altitude were not correlated to changes in the
horizontal winds. Observations of spectral width distribution variations made by
the radars allow an independent determination of the systematic error in the
height. We have investigated the dependence of this distribution on a number of
factors including the radar geometry, diurnal and seasonal cycles, variations in
solar UV irradiance and geomagnetic activity. Changes in the altitude of the
mean meteor layer observed at different radar ranges provide us with some
insight into the structure of the upper mesosphere and the lower thermosphere
within which the meteors are being ablated. An examination of the spectral
widths, as measured by the CUT-LASS Finland radar, in the days preceding and
following a Storm Sudden Commencement in April 1997, illustrates how the
spectral properties of the observed region can be affected. The variations in
the widths were consistent with model calculations of the changes to the
temperature profile over this interval. Further refinements in the determination
of the spectral width are outlined for future experiments.
Key words. Meterology and
atmospheric dynamics (middle atmosphere dynamics; thermospheric dynamics;
instruments and techniques) |
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