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| Titel |
Venus Express observations of magnetic field fluctuations in the magnetosheath: A case study and a statistical study |
| VerfasserIn |
J. Du, T. L. Zhang, C. Wang, M. Volwerk, M. Delva, W. Baumjohann |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250024879
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| Zusammenfassung |
| Using magnetosheath crossings of Venus Express on two consecutive days, we investigate
magnetic fluctuations in the same locations for two extreme interplanetary magnetic field
orientations, i.e. nearly along and nearly perpendicular to the solar wind flow. The strength
and properties of the fluctuations are strongly controlled by the types of the upstream bow
shock. The magnetic fluctuations behind a quasi-parallel bow shock are quite strong and
turbulent, having a strongly varying angle αeB between maximum variance direction of the
fluctuations and the direction of the magnetic field, and may be convected from the upstream
wave region in the foreshock. The magnetic fluctuations behind a quasi-perpendicular bow
shock are less intensive and wave-like, showing a less perturbed angle αeB, and are probably
generated locally by some instability. Based on the Venus Express observations
in 2006 and 2007, we also investigate the spatial distributions of magnetic field
fluctuations in the Venus magnetosheath statistically. Both the compressional and
transverse components of the field fluctuations decrease as the θBn angle (the angle
between the interplanetary magnetic field and the bow shock normal) increases. |
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