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Titel |
Energetic protons at Mars: interpretation of SLED/Phobos-2 observations by a kinetic model |
VerfasserIn |
E. Kallio, S. McKenna-Lawlor, M. Alho, R. Jarvinen, S. Dyadechkin, V. V. Afonin |
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 ; 30, no. 11 ; Nr. 30, no. 11 (2012-11-27), S.1595-1609 |
Datensatznummer |
250017287
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Publikation (Nr.) |
copernicus.org/angeo-30-1595-2012.pdf |
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Zusammenfassung |
Mars has neither a significant global intrinsic magnetic field nor a dense
atmosphere. Therefore, solar energetic particles (SEPs) from the Sun can
penetrate close to the planet (under some circumstances reaching the
surface). On 13 March 1989 the SLED instrument aboard the Phobos-2
spacecraft recorded the presence of SEPs near Mars while traversing a
circular orbit (at 2.8 RM). In the present study the response of the
Martian plasma environment to SEP impingement on 13 March was simulated
using a kinetic model. The electric and magnetic fields were derived using a
3-D self-consistent hybrid model (HYB-Mars) where ions are modelled as
particles while electrons form a massless charge neutralizing fluid. The
case study shows that the model successfully reproduced several of the
observed features of the in situ observations: (1) a flux
enhancement near the inbound bow shock, (2) the formation of a magnetic
shadow where the energetic particle flux was decreased relative to its solar
wind values, (3) the energy dependency of the flux enhancement near the bow
shock and (4) how the size of the magnetic shadow depends on the incident
particle energy. Overall, it is demonstrated that the Martian magnetic field
environment resulting from the Mars–solar wind interaction significantly
modulated the Martian energetic particle environment. |
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