Tracking of Plasma Motions and the Global Plasma Distribution Using ENA Imaging
Abstract
The distribution and dynamics of plasma in the inner magnetosphere have long been studied with the help of in situ satellite measurements. These studies provide good knowledge of the local particle as well as the magnetic and electric field environment. Correlating simultaneous satellite measurements also gives some indication of the spatial characteristics of the plasma and its large scale movement. However, the inference of global plasma dynamics can, depending on the particle energy, be rather uncertain or incomplete. We have developed methods to characterize and track large-scale plasma motions using global energetic neutral atom (ENA) imaging from the IMAGE spacecraft. Global ENA imaging provides a powerful tool to observe the spatial development and distribution of plasma in the inner magnetosphere as long as care is taken in understanding the inherent limitations of ENA imaging. We are applying our methods to the tracking of medium energy (1.0-15 keV) and high energy (10's of keV and up) plasma movements during substorm events as well as the morphology of the storm time ring current decay. Events were chosen such that IMAGE was located close to the magnetic pole, providing a good view of the inner magnetosphere while minimizing adverse viewing effects. In general, ENA tracking from near the pole provides more reliable results along the longitudinal direction compared to the radial direction due to line-of-sight viewing considerations.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AGUFMSM11A0777J
- Keywords:
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- 2720 Energetic particles;
- trapped;
- 2730 Magnetosphere: inner;
- 2740 Magnetospheric configuration and dynamics;
- 2778 Ring current;
- 2788 Storms and substorms