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| Titel |
Outflow of Low-Energy Ions and the Solar Cycle |
| VerfasserIn |
Mats André, Kun Li, Anders Eriksson |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250092341
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| Publikation (Nr.) |
 EGU/EGU2014-6676.pdf |
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| Zusammenfassung |
| Non-thermal escape of ions from the upper Terrestrial atmosphere has been observed by
spacecraft and radars for decades. Typical total upflow rates are 1025 to 1026 ions/s, mainly
H+ and O+varying with solar and magnetospheric magnetic activity. Recent findings show
that the escape, and the plasma in the magnetosphere, often is dominated by low-energy
(below about 10 eV) ions. These ions often cannot be detected onboard sunlit spacecraft,
which often become positively charged to tens of volts. We discuss how a supersonic flow of
low-energy ions cause a wake behind a charged spacecraft and how this can be used to detect
the ions.
We use the wake method and observations by two Cluster spacecraft, covering most of a
solar cycle (2001 to 2010). We find that often (more than 50% of the time) low-energy ions
dominate the magnetosphere. We also find a clear variation of the outflow of low-energy ions
with the solar EUV flux. |
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