Scex 3 Observations of Hf Z-Mode Emissions from the Aurora

  1. Robert L. Lysak
  1. R.T. Goerke1,
  2. P.J. Kellogg1,
  3. S.D. Bale1,
  4. S.J. Monson1,
  5. H.R. Anderson2,
  6. D.W. Potter2,
  7. E.P. Szuszczewicz3 and
  8. G.D. Earle3

Published Online: 18 MAR 2013

DOI: 10.1029/GM080p0275

Auroral Plasma Dynamics

Auroral Plasma Dynamics

How to Cite

Goerke, R.T., Kellogg, P.J., Bale, S.D., Monson, S.J., Anderson, H.R., Potter, D.W., Szuszczewicz, E.P. and Earle, G.D. (1993) Scex 3 Observations of Hf Z-Mode Emissions from the Aurora, in Auroral Plasma Dynamics (ed R. L. Lysak), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM080p0275

Author Information

  1. 1

    School of Physics and Astronomy, University Of Minnesota, Minneapolis

  2. 2

    Science Applications International Corporation, Bellevue, Wa

  3. 3

    Science Applications International Corporation, Mclean, Va

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1993

ISBN Information

Print ISBN: 9780875900391

Online ISBN: 9781118664001



  • Auroras;
  • Space plasmas—Plasma dynamics


We have observed moderately strong HF (high frequency ≈4 MHz) plasma waves with amplitudes in excess of .1 mV/m(Hz)1/2 at frequencies slightly less than the ambient plasma frequency and about 2 to 3 times the electron cyclotron frequency. These observations coincide with in situ measurements of broad band low energy (10 eV to 600 eV) auroral electrons and ground-based observations of auroral luminosity. These results were obtained from the rocket-borne experiment SCEX 3 (Several Compatible Experiments Using a Rocket-Borne Accelerator), NASA Flight 39.002 UE, launched February 1, 1990 from Poker Flat Research Range.

The frequency and intensity of the HF emissions are modulated at the spin period of the spacecraft in such a way that they appear like saucers on frequency-time spectrogram. This indicates that the source of these observations is a directional wave. If these waves are transverse (electromagnetic), then the k vector points in the north/south direction, which is consistent with an auroral source. Due to the lack of an observable interference pattern, we assume the waves have a wavelength that is much larger than the antenna length (2 m). These waves are seen consistently above the Z cutoff and persist over a region of ˜100 km which is suggestive of transverse electromagnetic waves. Other features of the aurora which produced these emissions will be presented and discussed.