Auroral mechanisms and morphology

摘要: This past quadrennium has witnessed a considerable expansion of our knowledge and understanding processes responsible for the aurora. Because number diversity contributions, complete description is difficult, many topics are presented here in summary form only. Instead, this review will emphasize major accomplishments outline problems that should be addressed during next quadrennium. The scope includes observations, analysis observations theoretical work which likely to relevant Ground-based reviewed include (l) auroral imagery, both by television all-sky camera, (2) gross magnetic variations indicative ionospheric currents, (3) VLF hiss (4) effects high-energy electron impact measured through cosmic radio noise absorption bremsStrahlung x-rays from balloons. Not included spectroscopic observation micropulsation activity radar as these seem provide less direct diagnostic information on basic mechanism. However, incoherent scatter utilized extent they currents electric fields.