Aurora and Energetic Particle Signatures During a Substorm with Multiple Expansions

  1. Joseph R. Kan,
  2. Thomas A. Potemra,
  3. Susumu Kokubun and
  4. Takesi Iijima
  1. Rumi Nakamura1,
  2. Takasi Oguti2,
  3. Tatsundo Yamamoto3,
  4. Susumu Kokubun3,
  5. Daniel N. Baker4 and
  6. Richard D. Belian5

Published Online: 19 MAR 2013

DOI: 10.1029/GM064p0285

Magnetospheric Substorms

Magnetospheric Substorms

How to Cite

Nakamura, R., Oguti, T., Yamamoto, T., Kokubun, S., Baker, D. N. and Belian, R. D. (1991) Aurora and Energetic Particle Signatures During a Substorm with Multiple Expansions, in Magnetospheric Substorms (eds J. R. Kan, T. A. Potemra, S. Kokubun and T. Iijima), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM064p0285

Author Information

  1. 1

    National Institute of Polar Research, Kaga 1-9-10, Itabashiku, Tokyo, 173 Japan

  2. 2

    Solar Terrestrial Environment Laboratory, Nagoya University, Honohara 3-13, Toyokawa, Aichi, 442 Japan

  3. 3

    Department of Earth and Planetary Physics, University of Tokyo, Bunkyoku, Tokyo 113 Japan

  4. 4

    NASA / Goddard Space Flight Center, Laboratory for Extraterrestrial Physics, Greenbelt, Maryland 20771

  5. 5

    Los Alamos National Laboratory, Los Alamos, New Mexico 87545

Publication History

  1. Published Online: 19 MAR 2013
  2. Published Print: 1 JAN 1991

ISBN Information

Print ISBN: 9780875900308

Online ISBN: 9781118663981



  • Magnetospheric substorms—Congresses


We compare geosynchronous particle signatures with aurora and geomagnetic disturbances during a substorm with multiple expansions, which began at 0852 UT on January 18, 1986. There were three localized expansions whose onset region moved successively westward. Energetic particle signatures observed from the geosynchronous satellite 1984–129 at the premidnight sector differed significantly for these three expansions in accordance with the transition of the onset region from the east to the west of the satellite foot-point. The results suggest that the source region of the energetic particle injection is confined within the local time sector of the expansion aurora. It was estimated that during this event an injection associated with an expansion started from a localized region with less than 28° in longitudinal width and was still confined within a region of about 40° even at the maximum of the expansion. This study also confirms that an injection boundary, if it ever exists, would be produced due to multiple localized injections, rather than due to a continuous expansion of a source region.