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| Titel |
Proton precipitation at Mars: statistical study and comparison with modelling studies. |
| VerfasserIn |
C. Dieval, G. Stenberg, S. Barabash, H. Nilsson, A. Fedorov |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250058843
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| Zusammenfassung |
| Hybrid models of the solar wind interaction with Mars predict solar wind ions precipitation
onto the Martian atmosphere. The reason is that, at Mars, the gyroradius of heated protons
and alpha particles can have a size comparable to the subsolar magnetic pile-region. This
allows some of these particles to go through the magnetic pile-up region without being
deflected away by the strong magnetic field strength there.
We have made an observational statistical study of proton fluxes at low altitudes around
Mars to check this prediction. We have used ion and electron data from the Mars Express
spacecraft and magnetic field data from the Mars Global Surveyor spacecraft. The data
coverage is from February 2004 to April 2011.
We found that the proton precipitation indeed occurs at Mars. We have investigated the
dependence of the precipitation on the solar wind convection electric field, upstream solar
wind conditions and planetary crustal magnetic anomalies. The measured precipitating
energy flux varies in the range 107-1010 eV/cm2/s on average, being larger on the dayside
than on the nightside. We will present some results from this study and compare with
modelling studies. |
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