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Ion composition of the topside equatorial ionosphere during solar minimum
Journal of Geophysical Research (1992)
  • S. A. Gonzales
  • Bela G. Fejer, Utah State University
  • R. A. Heelis
  • W. B. Hanson
We have used observations from both the Bennett ion mass spectrometer and the retarding potential analyzer on board the Atmosphere Explorer E satellite to study the longitudinally averaged O+, H+, and He+ concentrations from 150 to 1100 km in the equatorial ionosphere during the 1975–1976 solar minimum. Our results suggest that the ion mass spectrometer measurements need to be increased by a factor of 2.15 to agree with the densities from the retarding potential analyzer and with ground-based measurements. The peak H+ concentrations are about 2.5×104 cm−3 during the day and 104 cm−3 at night and vary little with season. The O+/H+ transition altitude lies between 750 and 825 km during the day and between 550 and 600 km at night. He+ is a minor species at all altitudes; its concentration is highly variable with a maximum value of about 103 cm−3 during equinox daytime.
  • Ion,
  • composition,
  • topside,
  • equator,
  • ionosphere,
  • solar,
  • minimum
Publication Date
April 1, 1992
Publisher Statement
Copyright 1992 by the American Geophysical Union. DOI: 10.1029/91JA03111
Citation Information
González, S. A., B. G. Fejer, R. A. Heelis and W. B. Hanson, Ion composition of the topside equatorial ionosphere during solar minimum, J. Geophys. Res., 97, 4299, 1992.