Accession Number : AD0646234

Title :   A SYSTEMATIC STUDY OF STRUCTURED MICROPULSATIONS,

Corporate Author : BOEING SCIENTIFIC RESEARCH LABS SEATTLE WASH GEO-ASTRO PHYSICS LAB

Personal Author(s) : Kenney,J. J. ; Knaflich,H. B.

Report Date : NOV 1966

Pagination or Media Count : 32

Abstract : A pair of three-component micropulsation detectors are in operation near Seattle, Washington to investigate the cause and behavior of pc 1 micropulsations. The mid-frequency and bandwidth of pearls show very strong diurnal variations, but any seasonal changes which may exist are smaller than changes du to other factors, such as compression of the magnetosphere during disturbed times. Seasonal variations in the diurnal occurrence of pearls at middle latitudes are, however, large. The observations imply the existence of a pearl oval that responds to changes in the magnetosphere with solar activity. The majority of the pearls showed the characteristics of wave propagation through a dispersive magnetosphere and subsequent ducting through a nondispersive ionosphere. A particle-wave interaction is consistent with the experimental data if the basic interaction is due to a resonance between the wave and a Doppler-shifted ion gyrofrequency of extra-thermal protons flowing through the background dispersive medium. Grouping of the protons into bunches is not consistent with most of the events which have been analyzed. (Author)

Descriptors :   (*ELECTROMAGNETIC PULSES, *GEOMAGNETISM), PROTONS, MAGNETOSPHERE, PERIODIC VARIATIONS, SOLAR DISTURBANCES, PROPAGATION, INTERACTIONS

Subject Categories : Geomagnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE