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| Titel |
Anti-sunward high-speed jets in the subsolar magnetosheath |
| VerfasserIn |
F. Plaschke, H. Hietala, V. Angelopoulos |
| 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 ; 31, no. 10 ; Nr. 31, no. 10 (2013-10-31), S.1877-1889 |
| Datensatznummer |
250086137
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| Publikation (Nr.) |
 copernicus.org/angeo-31-1877-2013.pdf |
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| Zusammenfassung |
| Using 2008–2011 data from the five Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft in Earth's subsolar
magnetosheath, we study high-speed jets identified as intervals when the
anti-sunward component of the dynamic pressure in the subsolar magnetosheath exceeds half of its
upstream solar wind value. Based on our comprehensive data set of 2859
high-speed jets, we obtain the following statistical results on jet properties
and favorable conditions: high-speed jets occur predominantly downstream of
the quasi-parallel bow shock, i.e., when interplanetary magnetic field cone
angles are low. Apart from that, jet occurrence is only very weakly dependent
(if at all) on other upstream conditions or solar wind variability. Typical
durations and recurrence times of high-speed jets are on the order of tens of
seconds and a few minutes, respectively. Relative to the ambient
magnetosheath, high-speed jets exhibit higher speed, density and magnetic
field intensity, but lower and more isotropic temperatures. They are
almost always super-Alfvénic, often even super-magnetosonic, and
typically feature 6.5 times as much dynamic pressure and twice as much total
pressure in anti-sunward direction as the surrounding plasma does. Consequently,
they are likely to have significant effects on the magnetosphere and
ionosphere if they impinge on the magnetopause. |
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