 |
| Titel |
Three-dimensional multispecies hybrid simulation of Titan's highly variable plasma environment |
| VerfasserIn |
S. Simon, A. Boesswetter, T. Bagdonat, U. Motschmann, J. Schuele |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 25, no. 1 ; Nr. 25, no. 1 (2007-02-01), S.117-144 |
| Datensatznummer |
250015767
|
| Publikation (Nr.) |
 copernicus.org/angeo-25-117-2007.pdf |
|
|
|
|
|
| Zusammenfassung |
| The interaction between Titan's ionosphere and the Saturnian magnetospheric
plasma flow has been studied by means of a three-dimensional (3-D) hybrid simulation
code. In the hybrid model, the electrons form a mass-less, charge-neutralizing
fluid, whereas a completely kinetic approach is retained to describe ion dynamics.
The model includes up to three ionospheric and two magnetospheric
ion species. The interaction gives rise to a pronounced magnetic draping
pattern and an ionospheric tail that is highly asymmetric with respect to the
direction of the convective electric field. Due to the dependence of the ion
gyroradii on the ion mass, ions of different masses become spatially dispersed
in the tail region.
Therefore, Titan's
ionospheric tail may be considered a mass-spectrometer, allowing to distinguish
between ion species of different masses. The kinetic nature of this effect is
emphasized by comparing the simulation with the results obtained from a simple
analytical test-particle model of the pick-up process. Besides, the results
clearly illustrate the necessity of taking into account the multi-species
nature of the magnetospheric plasma flow
in the vicinity of Titan. On the one hand, heavy magnetospheric particles,
such as atomic Nitrogen or Oxygen, experience only a slight modification of
their flow pattern. On the other hand, light ionospheric ions, e.g. atomic
Hydrogen, are clearly deflected around the obstacle, yielding a widening of
the magnetic draping pattern perpendicular to the flow direction.
The simulation results
clearly indicate that the nature of this interaction process, especially the
formation of sharply pronounced plasma boundaries in the vicinity of Titan, is
extremely sensitive to both the temperature of the magnetospheric ions and the
orientation of Titan's dayside ionosphere with respect to the corotating
magnetospheric plasma flow. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|