High Latitude Electromagnetic Plasma Wave Emissions.

• Main Author: Gurnett,Donald A
• Other Authors: IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY
• Format: Text
• Language: English
• Published: 1982
• Subjects: Atomic and Molecular Physics and Spectroscopy; Plasma Physics and Magnetohydrodynamics; Radiofrequency Wave Propagation; *Plasma waves; *Electromagnetic radiation; *Emission spectra; High latitudes; Radiation; Aurorae; Electrons; Magnetic fields; Broadband; Low energy; Intensity; Electromagnetic plasma wave emissions; Kiruna
• Online Access: http://www.dtic.mil/docs/citations/ADA115788; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA115788

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. Presented at the Nobel Symposium on High Latitude Space Plasma Physics, 22-25 Mar 82, Kiruna (Sweden). Sponsored in part by Contracts NAS5-25690, NGL-16-001-002 and NGL-16-001-043.