Statistical Study of Enhanced Ion Fluxes in the Outer Plasmasphere

  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. D. Menietti1,
  2. J. L. Burch1,
  3. R. L. Williams1,
  4. D. L. Gallagher2 and
  5. J. H. Waite Jr.2

Published Online: 21 MAR 2013

DOI: 10.1029/GM038p0172

Ion Acceleration in the Magnetosphere and Ionosphere

Ion Acceleration in the Magnetosphere and Ionosphere

How to Cite

Menietti, J. D., Burch, J. L., Williams, R. L., Gallagher, D. L. and Waite, J. H. (1986) Statistical Study of Enhanced Ion Fluxes in the Outer Plasmasphere, 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/GM038p0172

Author Information

  1. 1

    Department of Space Sciences, Southwest Research Institute, San Antonio, TX 78284

  2. 2

    Space Science Laboratory, NASA Marshall Space Flight Center, Huntsville, Al 35812

Publication History

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

ISBN Information

Print ISBN: 9780875900636

Online ISBN: 9781118664216



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


Statistical studies of outer plasmaspheric ions in the northern hemisphere have been made utilizing the High Altitude Plasma Instrument (HAPI) on board the Dynamics Explorer-1 satellite. The data were collected during equinox and winter seasons and during a period of solar maximum activity conditions. The data include approximately 40 dayside and over 50 nightside plasmaspheric passes covering a range of magnetic activities (0 < Kp < 7). A total of six magnetic storms and recovery periods and a number of quiet times are included in the sampling. The range of magnetic local times on the dayside is from about 6 hours to 12 hours, while the nightside range is from about 18 hours to 23 hours. Our results indicate a clear enhancement in the low energy (5 eV < E < 30 eV) number flux during periods of large magnetic activity in both the dayside and nightside outer plasmasphere (the inner plasmasphere was not observed). The dayside plasmaspheric fluxes were predominately upward (anti-parallel to ) while the nightside plasmaspheric fluxes were predominately downward (parallel to ). The net number fluxes sometimes reached a value of over 108cm sec−1 (assuming H+ as the predominate species). The largest flows up the field line occur in the outer plasmasphere and decrease in the plasma trough. The ion temperatures in the outer plasmasphere were typically lower than those in the plasma trough and auroral regions. Since the largest flows both parallel and anti-parallel to are observed at periods of high magnetic activity, enhanced outer plasmaspheric fluxes may be due to ionospheric ions expanding into depleted plasmaspheric flux tubes. The nightside fluxes may be due to expansion of the ionosphere in the magnetic conjugate hemisphere.