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| Titel |
Magnetic configurations of the tilted current sheets in magnetotail |
| VerfasserIn |
C. Shen, Z. J. Rong, X. Li, M. Dunlop, Z. X. Liu, H. V. Malova, E. Lucek, C. Carr |
| 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 ; 26, no. 11 ; Nr. 26, no. 11 (2008-11-17), S.3525-3543 |
| Datensatznummer |
250016291
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| Publikation (Nr.) |
 copernicus.org/angeo-26-3525-2008.pdf |
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| Zusammenfassung |
| In this research, the geometrical structures of tilted current sheet and
tail flapping waves have been analysed based on multiple spacecraft
measurements and some features of the tilted current sheets have been made
clear for the first time. The geometrical features of the tilted current
sheet revealed in this investigation are as follows: (1) The magnetic field
lines (MFLs) in the tilted current sheet are generally plane curves and the
osculating planes in which the MFLs lie are about vertical to the equatorial
plane, while the normal of the tilted current sheet leans severely to the
dawn or dusk side. (2) The tilted current sheet may become very thin, the
half thickness of its neutral sheet is generally much less than the minimum
radius of the curvature of the MFLs. (3) In the neutral sheet, the
field-aligned current density becomes very large and has a maximum value at
the center of the current sheet. (4) In some cases, the current density is a
bifurcated one, and the two humps of the current density often superpose two
peaks in the gradient of magnetic strength, indicating that the magnetic
gradient drift current is possibly responsible for the formation of the two
humps of the current density in some tilted current sheets. Tilted current
sheets often appear along with tail current sheet flapping waves. It is
found that, in the tail flapping current sheets, the minimum curvature
radius of the MFLs in the current sheet is rather large with values around
1 RE, while the neutral sheet may be very thin, with its half thickness
being several tenths of RE. During the flapping waves, the current sheet
is tilted substantially, and the maximum tilt angle is generally larger than
45°. The phase velocities of these flapping waves are several tens
km/s, while their periods and wavelengths are several tens of minutes, and
several earth radii, respectively. These tail flapping events generally last
several hours and occur during quiet periods or periods of weak
magnetospheric activity. |
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