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| Titel |
Compressional wave events in the dawn plasma sheet observed by Interball-1 |
| VerfasserIn |
O. Verkhoglyadova, A. Agapitov, A. Andrushchenko, V. Ivchenko, S. Romanov, Yu. Yermolaev |
| 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. 9 ; Nr. 17, no. 9, S.1145-1154 |
| Datensatznummer |
250013807
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| Publikation (Nr.) |
 copernicus.org/angeo-17-1145-1999.pdf |
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| Zusammenfassung |
Compressional waves with periods greater than
2 min (about 10-30 min) at low geomagnetic latitudes, namely compressional Pc5
waves, are studied. The data set obtained with magnetometer MIF-M and plasma
analyzer instrument CORALL on board the Interball-1 are analyzed. Measurements
performed in October 1995 and October 1996 in the dawn plasma sheet at -30 RE ≤ XGSM
and |ZGSM| ≤ 10 RE are considered. Anti-phase
variations of magnetic field and ion plasma pressures are analyzed by searching
for morphological similarities in the two time series. It is found that
longitudinal and transverse magnetic field variations with respect to the
background magnetic field are of the same order of magnitude. Plasma velocities
are processed for each time period of the local dissimilarity in the pressure
time series. Velocity disturbances occur mainly transversely to the local field
line. The data reveal the rotation of the velocity vector. Because of the field
line curvature, there is no fixed position of the rotational plane in the space.
These vortices are localized in the regions of anti-phase variations of the
magnetic field and plasma pressures, and the vortical flows are associated with
the compressional Pc5 wave process. A theoretical model is proposed to explain
the main features of the nonlinear wave processes. Our main goal is to study
coupling of drift Alfven wave and magnetosonic wave in a warm inhomogeneous
plasma. A vortex is the partial solution of the set of the equations when the
compression is neglected. A compression effect gives rise to a nonlinear
soliton-like solution.
Key words. Magnetosphere physics (magnetotail) · Space
plasma physics (kinetic and MHD theory; non-linear phenomena) |
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