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Titel |
The sporadic radiant and distribution of meteors in the atmosphere as observed by VHF radar at Arctic, Antarctic and equatorial latitudes |
VerfasserIn |
P. T. Younger, I. Astin, D. J. Sandford, N. J. Mitchell |
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 ; 27, no. 7 ; Nr. 27, no. 7 (2009-07-15), S.2831-2841 |
Datensatznummer |
250016592
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Publikation (Nr.) |
copernicus.org/angeo-27-2831-2009.pdf |
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Zusammenfassung |
Results are presented of a study of the temporal and spatial variability in
meteor count rate observations from three VHF meteor radars. These radar are
located in the Arctic (at Esrange, 68° N), in the Antarctic (at Rothera,
68° S) and near the Equator (on Ascension Island, 8° S). It is found
that for all three locations there is a strong diurnal cycle in observed
hourly meteor counts and the time of maxima and minima in these counts
depends on the month of the year. In addition, at high latitude there is a
strong annual cycle in observed monthly-mean meteor counts, whereas for the
radar at low latitude there is a semi-annual cycle. At high latitude there
is also an annual cycle in the mean height at which meteors are observed.
However, no such annual cycle is found in observed meteor count rates from
the low latitude radar. The meteor count data from all the radars are
combined to investigate the sporadic radiant distribution (i.e. the
distribution of direction of arrival on the celestial sphere of sporadic
meteors). This combined radiant distribution shows that there are six main
source regions for meteors. The latitudinal and temporal dependence in
observed meteor count rates appears to result from a combination of the
sporadic radiant distribution, annual fluctuations in atmospheric
density, the sensitivity of the radar to meteors from different
source directions and the temporal and spatial variability in meteor
fluxes. |
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