Temporal variability of the ion abundance ratios in the Jovian magnetosphere
Abstract
Galileo as the first orbiting spacecraft around Jupiter provides the opportunity to study globally and in an extended energy range the energetic particle composition of the Jovian magnetosphere Analyzing data from the Energetic Particles Detector onboard Galileo we study the relative ion abundance ratios of S O S He O He and p He at various energy nucleon The global coverage of the Galileo trajectories enables a quantitative comparison with results of previous missions and especially Voyager 2 for the same radial distance and local time The large discrepancies found are attributed to a strong energy dependence but also to secular variations Ion intensities exhibit strong time variations between the two missions Temporal variations do exist also on times scales of several weeks as shown by the analysis of consecutive Galileo orbits Large and small scale variations of the ion abundance ratios are related to the temporal variability of the Io torus and to solar wind changes Additionally time varying particle acceleration processes are discussed
- Publication:
-
36th COSPAR Scientific Assembly
- Pub Date:
- 2006
- Bibcode:
- 2006cosp...36..661R