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Titel |
Low-latitude ionospheric turbulence observed by Aureol-3 satellite |
VerfasserIn |
Y. Hobara, F. Lefeuvre, M. Parrot, O. A. Molchanov |
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 ; 23, no. 4 ; Nr. 23, no. 4 (2005-06-03), S.1259-1270 |
Datensatznummer |
250015221
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Publikation (Nr.) |
copernicus.org/angeo-23-1259-2005.pdf |
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Zusammenfassung |
Using PSD (Power Spectral Density) data on electron density and electric
field variations observed on board Aureol-3 satellite at low-to-mid-latitude
ionosphere we analyze a scale distribution of the ionospheric turbulence in
a form k-α, where k is the wave number and α is the spectral index.
At first, high-resolution data in the near-equator region for several orbits
have been processed. In this case the frequency range is from 6Hz to 100Hz
(corresponding spatial scales from 80m to 1.3km), each power spectrum
obeys a single power law fairly well, and the mean spectral indices are
rather stable with αN=2.2±0.3 and αE=1.8±0.2, for the
density and electric field, respectively. Then we produce a statistical study
of 96 electric field bursts in the frequency range 10-100Hz from low-time
resolution data (filter bank envelope). These bursts concentrate on the side of
the Equatorial Anomaly crest (geomagnetic latitude 30-40°). Spectral indices
of the bursts vary in the interval αE=2.0-2.5 but are fairly stable
in seasons and local times. The electric field power of the burst has rather
a large variability but has a relative increase in mean values for the summer
and winter, as well as the daytime. The effect of major seismic activities toward the
ionospheric turbulence is not conclusive either for the refractive index or
for the electric field power. However, the mean value for the electric field power of
bursts during seismic periods is larger than that for non seismic periods,
and the statistical difference of the mean values is rather significant. |
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