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| Titel |
Auroral electrojet dynamics during magnetic storms, connection with plasma precipitation and large-scale structure of the magnetospheric magnetic field |
| VerfasserIn |
Y. I. Feldstein, L. I. Gromova, A. Grafe, C.-I. Meng, V. V. Kalegaev, I. I. Alexeev, Y. P. Sumaruk |
| 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. 4 ; Nr. 17, no. 4, S.497-507 |
| Datensatznummer |
250013711
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| Publikation (Nr.) |
 copernicus.org/angeo-17-497-1999.pdf |
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| Zusammenfassung |
Effect of the equatorward shift of the
eastward and westward electrojets during magnetic storms main phase is analyzed
based on the meridional chains of magnetic observatories EISCAT and IMAGE and
several Russian observatories (geomagnetic longitude ~110°,
corrected geomagnetic latitudes 74°F 51°.)
Magnetic storms of various Dst index intensity where the main phase falls
on 1000 UT - 2400 UT interval were selected so that one of the observatory
chains was located in the afternoon - near midnight sector of MLT. The eastward
electrojet center shifts equatorward with Dst intensity increase: when Dst
~ - 50 nT the electrojet center is located at F ~ 62°,
when Dst ~ -300 nT it is placed at F ~54°.
The westward electrojet center during magnetic storms main phase for intervals
between substorms shifts equatorward with Dst increase: at F~
62° when Dst ~ -100 nT and at F ~
55° when Dst ~ -300 nT. During substorms within the magnetic
storms intervals the westward electrojet widens poleward covering latitudes F~
64°- 65°. DMSP (F08, F10 and F11) satellite
observations of auroral energy plasma precipitations at upper atmosphere
altitudes were used to determine precipitation region structure and location of
boundaries of various plasma domains during magnetic storms on May 10-11, 1992,
February 5-7 and February 21-22, 1994. Interrelationships between center
location, poleward and equatorward boundaries of electrojets and characteristic
plasma regions are discussed. The electrojet center, poleward and equatorward
boundaries along the magnetic observatories meridional chain were mapped to the
magnetosphere using the geomagnetic field paraboloid model. The location of
auroral energy oxygen ion regions in the night and evening magnetosphere is
determined. Considerations are presented on the mechanism causing the appearance
in the inner magnetosphere during active intervals of magnetic storms of ions
with energy of tens KeV. In the framework of the magnetospheric magnetic field
paraboloid model the influence of the ring current and magnetospheric tail
plasma sheet currents on large-scale magnetosphere structure is considered.
Key words. Ionosphere (particle precipitation) ·
Magnetospheric physics (current systems; magnetospheric configuration and
dynamics). |
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