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Titel |
Persistence of the planetary wave type oscillations in foF2 over Europe |
VerfasserIn |
J. Laštovička, P. Križan, P. Šauli, D. Novotná |
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 ; 21, no. 7 ; Nr. 21, no. 7, S.1543-1552 |
Datensatznummer |
250014661
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Publikation (Nr.) |
copernicus.org/angeo-21-1543-2003.pdf |
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Zusammenfassung |
Planetary waves are
oscillations of very predominantly tropospheric origin with typical periods of
about 2–30 days. Their dominant zonal wave numbers are 1, 2 and 3, i.e. the
waves are of large-scale (global) character. The planetary wave type
oscillations have been observed in the lower and middle atmosphere but also in
the ionosphere, including the ionospheric F2-layer. Here, we deal only with the
oscillations analyzed for four European stations over a solar cycle with the
use of the Meyer and Morlet wavelet transforms. Waves with periods near 5, 10
and 16 days are studied. Only events with a duration of three wave-cycles and
more are considered. The 5-day period wave events display a typical duration of
4 cycles, while 10- and 16-day wave events are less persistent, with a typical
duration of about 3.5 cycles and 3 cycles, respectively. The persistence
pattern in terms of number of cycles and in terms of number of days is
different. In terms of number of cycles, the typical persistence of
oscillations decreases with increasing period. On the other hand, in terms of
number of days the typical persistence evidently increases with increasing
period. The spectral distribution of event duration is too broad to allow for a
reasonable prediction of event duration. Thus, the predictability of the
planetary wave type oscillations in foF2 seems to be very questionable.
Key words. Ionosphere
(ionosphere-atmosphere interaction, mid-latitude ionosphere, ionospheric
disturbances) – Meteorology and atmospheric dynamics (waves and tides) |
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