Positive Ion Acceleration in the 1 RE Altitude Range

  1. S.-I. Akasofu and
  2. J.R. Kan
  1. R. D. Sharp

Published Online: 26 MAR 2013

DOI: 10.1029/GM025p0112

Physics of Auroral Arc Formation

Physics of Auroral Arc Formation

How to Cite

Sharp, R. D. (1981) Positive Ion Acceleration in the 1 RE Altitude Range, in Physics of Auroral Arc Formation (eds S.-I. Akasofu and J.R. Kan), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM025p0112

Author Information

  1. Lockheed Palo Alto Research Laboratory, 3251 Hanover Street, Palo Alto, California 94304

Publication History

  1. Published Online: 26 MAR 2013
  2. Published Print: 1 JAN 1981

ISBN Information

Print ISBN: 9780875900506

Online ISBN: 9781118664360

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Keywords:

  • Auroras—Addresses, essays, lectures

Summary

The signatures of ionospheric acceleration mechanisms operating on auroral field lines at altitudes of about ∼1 RE have been observed with instruments on the S3–3 satellite. The mechanisms accelerate the ambient thermal plasma ions to keV energies and inject them upward into the trapped magnetospheric plasma population. Examples of ions accelerated by quasistatic parallel electric fields and by a primarily transverse acceleration mechanism are presented. The results of a statistical study are used to infer that the upflowing H+ ions observed with energies >500 eV in the evening local time sector are primarily energized electrostatically, while the O+ ions in these same ranges receive about half of their energy from electrostatic acceleration and about half from some mass dependent transverse acceleration mechanism.