Dynamics and variability of the plasmasphere observed from synchronous orbit
The behavior of the cold ions in the outer plasmasphere is studied using data obtained with the magnetospheric plasma analyzers from multiple geosynchronous satellites. Dense (10-100 cm{sup {minus}3}), cold ({approx}1 eV) regions of plasma are often observed at geosynchronous orbit; in this study the authors refer to these as plasmaspheric intervals. The duration, local time of observation, density variability, and temperature behavior within these regions often depend in a systematic way on geomagnetic and substorm activity. With increasing geomagnetic activity (as indicated by Kp) the plasmaspheric regions are generally observed over shorter durations and at earlier local times. With increasing substorm activity (as indicated by geosynchronous energetic electron injections) the density becomes increasingly variable in these regions. Occasionally, up to order-of-magnitude density variations are observed over several minute timescales corresponding to regions with physical dimensions on the order of 1000 km or less. The appearance of these short-duration, cold-plasma intervals is strongly correlated with energetic ion and electron signatures both at the spacecraft making the plasmaspheric observations and at other spacecraft observing simultaneously in the midnight region. Such energetic particle signatures are indicative of the growth and expansive phase of geomagnetic substorms. The authors conclude that the appearance of these short-duration, plasmaspheric intervals is due to a reconfiguration of the duskside magnetosphere during geomagnetic substorms.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 10193764
- Report Number(s):
- LA-UR-94-3510; CONF-9408182-2; ON: DE95002733; TRN: 94:010457
- Resource Relation:
- Journal Volume: 383; Conference: 10. Taos workshop on the earth`s trapped particle environment,Taos, NM (United States),14-19 Aug 1994; Other Information: PBD: [1994]
- Country of Publication:
- United States
- Language:
- English
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