Accession Number : ADA115788

Title :   High Latitude Electromagnetic Plasma Wave Emissions.

Descriptive Note : Progress rept.,


Personal Author(s) : Gurnett,Donald A

PDF Url : ADA115788

Report Date : May 1982

Pagination or Media Count : 50

Abstract : This paper reviews the principal types of electromagnetic plasma wave emissions produced in the high latitude auroral regions. Three types of radiation are described: auroral kilometric radiation, auroral hiss, and Z-mode radiation. Auroral kilometric radiation is a very intense radio emission generated in the free space R-X mode by electrons associated with the formation of discrete auroral arcs in the local evening. Current theories suggest that this radiation is an electron cyclotron resonance instability driven by an enhanced loss cone in the auroral acceleration region at altitudes of about 1 to 2 RE. Auroral hiss is a somewhat weaker whistler-mode emission generated by low energy (100 eV to 10 keV) auroral electrons. The auroral hiss usually has a V-shaped frequency-time spectrum caused by a frequency dependent beaming of the whistler mode into a conical beam directed upward or downward along the magnetic field. Z-mode radiation is a recently discovered broadband emission similar in some respects to auroral hiss, except that this radiation is propagating in the Z-mode.

Descriptors :   *Plasma waves, *Electromagnetic radiation, *Emission spectra, High latitudes, Radiation, Aurorae, Electrons, Magnetic fields, Broadband, Low energy, Intensity

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Plasma Physics and Magnetohydrodynamics
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE