On the Loss of Oions (< 17 KEV/e) in the Ring Current During the Recovery Phase of a Storm

  1. Tom Chang,
  2. M. K. Hudson,
  3. J. R. Jasperse,
  4. R. G. Johnson,
  5. P. M. Kintner and
  6. M. Schulz
  1. J. B. Cladis and
  2. O. W. Lennartsson

Published Online: 21 MAR 2013

DOI: 10.1029/GM038p0153

Ion Acceleration in the Magnetosphere and Ionosphere

Ion Acceleration in the Magnetosphere and Ionosphere

How to Cite

Cladis, J. B. and Lennartsson, O. W. (1986) On the Loss of Oions (< 17 KEV/e) in the Ring Current During the Recovery Phase of a Storm, 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/GM038p0153

Author Information

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

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

Under favorable circumstances some trapped ions that drift toward the west may be observed twice along their drift paths by the ISEE-1 satellite; once while the satellite is inbound and again while it is outbound. Since, in the absence of diffusion and loss, the phase space densities of the ions at the two observation points should be the same, the drift paths may be identified by comparing the measured phase space densities along the outbound and inbound legs. The H+ and O+ measurements made on the satellite during the recovery phase of the storm of December 11, 1977, were examined in this manner. Using the inbound measurements as initial conditions, ion drift paths were calculated for a dipole magnetic field containing a corotation electric field and a convection field. It was found that for a convection electric field appropriate for Kp = 2. the phase space densities of H+ at the two measurement points along the drift paths were approximately the same. However, the phase space densities of O+ ions, which should have followed the same adiabatic drift paths, were much lower along the outbound leg. The implied loss of O+ ions along these westward drift paths is attributed to a bounce-resonance interaction of the ions with standing Alfvén waves that were simultaneously observed with five satellites. The observations also revealed that the phase space densities of the eastward drifting H+ ions (energies at which the corotation drift exceeds the curvature-gradient drift) were about the same in the L shells at the two measurement points. Again, however, the corresponding O+ phase space densities were lower along the outbound leg. These low-energy ion observations are attributed to a decrease with time of the phase space density of the O ions (but not the H+ ions) in the magnetotail during the convection process.