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| Titel |
Turbulence characteristics inside ionospheric small-scale expanding structures observed with SuperDARN HF radars |
| VerfasserIn |
R. André, C. Hanuise, J.-P. Villain, V. Krasnoselskikh |
| 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. 8 ; Nr. 21, no. 8, S.1839-1845 |
| Datensatznummer |
250014681
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| Publikation (Nr.) |
 copernicus.org/angeo-21-1839-2003.pdf |
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| Zusammenfassung |
Unusual structures
characterized by a very high-velocity divergence have been observed in the
high-latitude F-region with SuperDARN radars (André et al., 2000). These
structures have been interpreted as due to local demagnetization of the plasma
in the ionospheric F-region, during very specific geophysical conditions. In
this study, the collective wave scattering theory is used to characterize the
decameter-scale turbulence (l approx 15 m) inside
the structures. The distribution function of the diffusion coefficient is
modified when the structures are generated, suggesting that two regimes of
turbulence coexist. A temporal analysis decorrelates the two regimes and gives
access to the dynamics associated with the structures. It is shown that a high
turbulent regime precedes the plasma demagnetization and should be related to
an energy deposition. Then a second regime appears when the plasma is
demagnetized and disappears simultaneously with the structures. This study is
the first application of the collective wave scattering theory to a specific
geophysical event.
Key words. Ionosphere (auroral
ionosphere; ionospheric irregularities) – Space plasma physics (turbulence) |
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