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Titel |
Auroral pulsations and accompanying VLF emissions |
VerfasserIn |
V. R. Tagirov, V. S. Ismagilov, E. E. Titova, V. A. Arinin, A. M. Perlikov, J. Manninen, T. Turunen, K. Kaila |
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 ; 17, no. 1 ; Nr. 17, no. 1, S.66-78 |
Datensatznummer |
250013645
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Publikation (Nr.) |
copernicus.org/angeo-17-66-1999.pdf |
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Zusammenfassung |
Results of simultaneous TV observations of
pulsating auroral patches and ELF-VLF-emissions in the morning sector carried
out in Sodankylä (Finland) on February 15, 1991 are presented. Auroral
pulsating activity was typical having pulsating patches with characteristic
periods of about 7 s. Narrow-band hiss emissions and chorus elements at
intervals of 0.3–0.4 s formed the main ELF-VLF activity in the frequency range
1.0–2.5 kHz at the same time. The analysis of auroral images with time
resolution of 0.04 s allowed perfectly separate analysis of spatial and temporal
variations in the auroral luminosity. Mutual correspondence between the
behaviour of the luminous auroral patches and the appearance of ELF noise type
hiss emissions and VLF chorus trains was found in two intervals chosen for
analysis. While the hiss emissions were associated with the appearance of
luminosity inside a limited area close to the zenith, the structured VLF
emissions were accompanied by rapid motion of luminosity inside the area. The
spatial dimension of the pulsating area was about 45–50 km and luminosity
propagated inside it with velocity of about 10–12 kms. We discuss a new approach
to explain the 5–15 s auroral pulsation based on the theory of flowing cyclotron
maser and relaxation characteristics of ionosphere.
Key words. Magnetospheric physics (auroral phenomena;
magnetosphere-ionosphere interactions) · Space plasma physics (wave-particle
interactions) |
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