 |
| Titel |
Evidence of a noon-to-midnight electric field in Saturn's inner magnetosphere, using microsignatures |
| VerfasserIn |
M. Andriopoulou, E. Roussos, N. Krupp, C. Paranicas, M. Thomsen, S. Krimigis, M. K. Dougherty, K.-H. Glassmeier |
| Konferenz |
EGU General Assembly 2012
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250058331
|
|
|
|
|
|
| Zusammenfassung |
| Using electron data of the MIMI-LEMMS detector that is onboard the Cassini spacecraft, we
have created new, updated catalogues of energetic electron microsignature events caused by
the Kronian moons Tethys and Dione. We studied the deviations of the moon’s wake from the
nearly circular path of the orbit of the moon-absorber and observed significant radial
displacements that exhibit systematic asymmetries with respect to the local time, following a
systematic trend: inward in the nightside and outward in the dayside of the inner
magnetosphere. We show that these asymmetries cannot be explained by asymmetries of
the magnetic field in the inner magnetosphere. We developed several methods to
associate the properties of the displacements to magnetospheric electric fields. Our
results are consistent with an electric field that has a noon-to-midnight orientation
and amplitudes that do not exceed 1 mV/m. Such an electric field is not predicted
by any theoretical model and its origin is still unknown. While several ongoing
studies are in agreement with our result, the radial displacement of microsignatures
is the most sensitive tracer of this electric field so we will also discuss how the
microsignature dataset can be used to put tighter constraints on its properties and origin. |
|
|
|
|
|
|