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| Titel |
Solar-wind control of plasma sheet dynamics |
| VerfasserIn |
M. Myllys, E. Kilpua, T. Pulkkinen |
| 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 ; 33, no. 7 ; Nr. 33, no. 7 (2015-07-21), S.845-855 |
| Datensatznummer |
250121220
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| Publikation (Nr.) |
 copernicus.org/angeo-33-845-2015.pdf |
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| Zusammenfassung |
| The purpose of this study is to quantify how solar-wind conditions affect the
energy and plasma transport in the geomagnetic tail and its large-scale
configuration. To identify the role of various effects, the magnetospheric
data were sorted according to different solar-wind plasma and interplanetary
magnetic field (IMF) parameters: speed, dynamic pressure, IMF north–south
component, epsilon parameter, Auroral Electrojet (AE) index and IMF ultra low-frequency (ULF) fluctuation power. We
study variations in the average flow speed pattern and the occurrence rate of
fast flow bursts in the magnetotail during different solar-wind conditions
using magnetospheric data from five Time
History of Events and Macroscale Interactions during Substorms
(THEMIS) mission spacecraft and solar-wind data from
NASA's OMNIWeb. The time interval covers the years from 2008 to 2011 during
the deep solar minimum between cycles 23 and 24 and the relatively quiet
rising phase of cycle 24. Hence, we investigate magnetospheric
processes and solar-wind–magnetospheric coupling during a relatively quiet state of the magnetosphere. We show that the occurrence rate of the
fast (|Vtail| > 100 km s−1) sunward flows varies under different solar-wind
conditions more than the occurrence of the fast tailward flows. The occurrence
frequency of the fast tailward flows does not change much with the solar-wind conditions.
We also note that the sign of the IMF BZ has the most visible effect on the occurrence
rate and pattern of the fast sunward flows. High-speed flow bursts are more common during
the slow than fast solar-wind conditions. |
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