Assessment of Magnetospheric Processes of Importance in HANE.
Abstract
Conditions in the unstable field-aligned current sheet above the auroral oval have been obtained from analyses of the electron and ion measurements on the S3-3 satellite. The measurements were obtained while the satellite was in and near the nominal region of the current sheet, remaining within a few degrees in invariant latitude, over a magnetic local-time interval of about 6 hours. Potential differences along the magnetic field, above and below the satellite, were inferred from the energy and pitch-angle distributions of the electrons. These potential differences, which exceeded 10 kV at times, were generally higher during the local evening than during the local afternoon, and were quite variable along the satellite trajectory, indicating latitudinal fluctuations of the current sheet with periods of 2-7 minutes. Upward flowing H+ and O+ ions were observed whenever the potential differences exceeded about .5 kV, which corresponds to the lowest energy threshold of the detectors. However, the pitch-angle distributions of the ions imply that the ions were accelerated not only along the magnetic field by the potential difference, but also perpendicularly to the field. The transverse acceleration of the ions most probably occurred through interactions with electrostatic ion cyclotron (EIC) waves, which are an expected product of the current-driven instability, and which have been observed in the current-sheet region.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 15, 1979
- Accession Number
- ADA086221
Entities
People
- G. T. Davidson
- J. B. Cladis
- L. L. Newkirk
- M. Walt
- W. E. Francis
Organizations
- Lockheed Martin Missiles and Space