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| Titel |
High resolution observations of spectral width features associatedwith ULF wave signatures in artificial HF radar backscatter |
| VerfasserIn |
D. M. Wright, T. K. Yeoman, L. J. Baddeley, J. A. Davies, R. S. Dhillon, Mark Lester, S. E. Milan, E. E. Woodfield |
| 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 ; 22, no. 1 ; Nr. 22, no. 1 (2004-01-01), S.169-182 |
| Datensatznummer |
250014758
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| Publikation (Nr.) |
 copernicus.org/angeo-22-169-2004.pdf |
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| Zusammenfassung |
The EISCAT high power heating facility at Tromsø, northern Norway, has been
utilised to generate artificial radar backscatter in the fields of view of the CUTLASS
HF radars. It has been demonstrated that this technique offers a means of making
very accurate and high resolution observations of naturally occurring ULF waves.
During such experiments, the usually narrow radar spectral widths associated with
artificial irregularities increase at times when small scale-sized (high m-number)
ULF waves are observed. Possible mechanisms by which these particle-driven high-m waves
may modify the observed spectral widths have been investigated. The
results are found to be consistent with Pc1 (ion-cyclotron) wave activity, causing
aliasing of the radar spectra, in agreement with previous modelling work. The
observations also support recent suggestions that Pc1 waves may be modulated by
the action of longer period ULF standing waves, which are simultaneously detected
on the magnetospheric field lines. Drifting ring current protons with energies of
∼ 10keV are indicated as a common plasma source population for both wave types.
Key words. Magnetospheric physics (MHD waves and instabilities)
– Space plasma physics (wave-particle interactions)
– Ionosphere (active experiments) |
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