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Titel |
Role of the magnetospheric and ionospheric currents in the generation of the equatorial scintillations during geomagnetic storms |
VerfasserIn |
L. Z. Biktash |
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. 9 ; Nr. 22, no. 9 (2004-09-23), S.3195-3202 |
Datensatznummer |
250014999
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Publikation (Nr.) |
copernicus.org/angeo-22-3195-2004.pdf |
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Zusammenfassung |
The equatorial ionosphere parameters, Kp, Dst, AU and AL
indices characterized contribution of different magnetospheric and
ionospheric currents to the H-component of geomagnetic field are examined to
test the geomagnetic activity effect on the generation of ionospheric irregularities
producing VLF scintillations. According to the results of the current statistical
studies, one can predict near 70% of scintillations from Aarons' criteria
using the Dst index, which mainly depicts the magnetospheric ring current field.
To amplify Aarons' criteria or to propose new criteria for predicting
scintillation characteristics is the question. In the present phase
of the experimental investigations of electron density irregularities in the
ionosphere new ways are opened up because observations in the interaction between the solar wind -
magnetosphere - ionosphere during magnetic storms have progressed greatly.
According to present view, the intensity of the electric fields and currents at the
polar regions, as well as the magnetospheric ring current intensity, are
strongly dependent on the variations of the interplanetary magnetic field. The
magnetospheric ring current cannot directly penetrate the equatorial
ionosphere and because of this difficulties emerge in explaining its relation to
scintillation activity. On the other hand, the equatorial scintillations can
be observed in the absence of the magnetospheric ring current. It is shown
that in addition to Aarons' criteria for the prediction of the ionospheric
scintillations, models can be used to explain the relationship between the equatorial
ionospheric parameters, h'F, foF2, and the equatorial geomagnetic variations
with the polar ionosphere currents and the solar wind. |
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