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| Titel |
The Role of Plasmas on Enhanced O2+ Loss at Mars |
| VerfasserIn |
Robert Ergun, Laila Andersson, Adam Woodson, Chris Fowler, Tristan Weber, Greg Delory, David Andrews, Anders Eriksson, Mitchico Mooroka, Ian Stweart, Paul Mahaffy, Bruce Jakosky |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250130643
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| Publikation (Nr.) |
 EGU/EGU2016-10929.pdf |
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| Zusammenfassung |
| Recent results from the MAVEN Langmuir Probe and Waves instrument suggest higher than predicted electron temperatures in Mars’ day side ionosphere above ~180 km in altitude. Correspondingly, measurements from Neutral Gas and Ion Mass Spectrometer indicate significant abundances of O2+ up to ~500 km in altitude, suggesting that O2+ may be a principal ion loss mechanism of oxygen. In this article, we investigate the effects of the higher electron temperature (which results from electron heating) and ion heating on ion outflow and loss. Numerical solutions show that plasma processes including ion heating and higher electron temperature may greatly increase O2+ loss at Mars. In particular, enhanced Te in Mars’ ionosphere just above the exobase creates a substantial ambipolar electric field, which draws ions out of the region allowing for enhanced escape. With active solar wind, electron and ion heating, direct O2+ loss could match or exceed loss via dissociative recombination of O2+. These results suggest that direct loss of O2+ may have played a significant role in the loss of oxygen at Mars. |
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