The Kilometric Radio Emission Spectrum: Relationship to Auroral Acceleration Processes

  1. S.-I. Akasofu and
  2. J.R. Kan
  1. D. A. Gurnett and
  2. R. R. Anderson

Published Online: 26 MAR 2013

DOI: 10.1029/GM025p0341

Physics of Auroral Arc Formation

Physics of Auroral Arc Formation

How to Cite

Gurnett, D. A. and Anderson, R. R. (1981) The Kilometric Radio Emission Spectrum: Relationship to Auroral Acceleration Processes, in Physics of Auroral Arc Formation (eds S.-I. Akasofu and J.R. Kan), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM025p0341

Author Information

  1. Department of Physics & Astronomy, the University of Iowa, Iowa City, IA 52242

Publication History

  1. Published Online: 26 MAR 2013
  2. Published Print: 1 JAN 1981

ISBN Information

Print ISBN: 9780875900506

Online ISBN: 9781118664360

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Keywords:

  • Auroras—Addresses, essays, lectures

Summary

Satellite measurements have now confirmed that intense radio emissions called auroral kilometric radiation are generated at altitudes of 2 to 3 RE over the auroral regions. These radio emissions are believed to be generated by Doppler-shifted cyclotron radiation from the electrons involved in the auroral acceleration process. Using current theories for the generation of this radiation we discuss the possibilities for obtaining information on the auroral acceleration processes from the spectrum of this radiation. For example, under certain conditions it is shown that the low frequency cutoff provides a direct indication of the upper altitude limit of the acceleration region. Also, certain discrete features in the kilometric radiation spectrum show a very close similarity to whistler-mode emissions, thereby suggesting that the basic instability mechanisms are quite similar. Some of these discrete features have frequency drifts which can be interpreted in terms of the propagation of shock-like disturbances along the auroral field lines at velocities near the ion-acoustic speed.