Ion specific differences in energetic field aligned upflowing ions at 1 RE

  1. Tom Chang,
  2. M. K. Hudson,
  3. J. R. Jasperse,
  4. R. G. Johnson,
  5. P. M. Kintner and
  6. M. Schulz
  1. A. G. Ghielmetti,
  2. E. G. Shelley,
  3. H. L. Collin and
  4. R. D. Sharp

Published Online: 21 MAR 2013

DOI: 10.1029/GM038p0077

Ion Acceleration in the Magnetosphere and Ionosphere

Ion Acceleration in the Magnetosphere and Ionosphere

How to Cite

Ghielmetti, A. G., Shelley, E. G., Collin, H. L. and Sharp, R. D. (1986) Ion specific differences in energetic field aligned upflowing ions at 1 RE , in Ion Acceleration in the Magnetosphere and Ionosphere (eds T. Chang, M. K. Hudson, J. R. Jasperse, R. G. Johnson, P. M. Kintner and M. Schulz), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM038p0077

Author Information

  1. Lockheed Palo Alto Research Laboratory, Palo Alto, California 94304

Publication History

  1. Published Online: 21 MAR 2013
  2. Published Print: 1 JAN 1986

ISBN Information

Print ISBN: 9780875900636

Online ISBN: 9781118664216

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Keywords:

  • Magnetosphere—Congresses;
  • Ionosphere—Congresses;
  • Ion flow dynamics—Congresses;
  • Space plasmas—Congresses

Summary

Measurements of energetic (0.5 to 16 keV) upward flowing ion distributions above the auroral regions within broad structures associated with parallel electric fields below the satellite are presented. The pitch angle distributions of the two major ion species (H+ and O+) were both field aligned as expected. However, the angular widths of the distributions and their dependence on energy were inconsistent with purely parallel acceleration: The H+ distributions became more strongly field aligned with increasing energy, while the O+ distributions became broader. The H+ ion distributions were characterized by a high parallel (∼0.6 keV) and low perpendicular (∼0.1 keV) temperature. In contrast, the O+ transverse and parallel temperatures were comparable (∼1 keV). Within these acceleration regions, the O+ ions were on the average a factor of 2 to 3 more energetic than H+. The mean energies of the H+ ions were substantially less than the potential drops below the satellite, while the O+ ion energy corresponded more closely to the potential. Candidate interpretations include preferential perpendicular heating of the O+ component coupled with an H+ sourceand electric field region extended in altitude, and/or parallel energy loss processes acting primarily on the H+ beam.