Substorm associated micropulsations at synchronous orbitThe state of the art of observations of substorm associated waves in GEO is reviewed and research directions are indicated. Data were taken from fluxgate magnetometers on board the ATS 1 and 6 spacecraft in GEO. Mixed mode Pc 4 and 5 waves, with the largest amplitude of magnetic pulsations observed at GEO, have been found to display a quasi-sinusoidal waveform with amplitudes from 10-30 gamma and a period of 50-200 sec. The wave spectra confined the excited frequencies to a narrow band, and possible generating mechanisms for the Pc 4 and 5 waves are discussed. Pc 1 and 2 magnetic pulsations are the most common in GEO, with Pc 1 occurring every third day, particularly in the afternoon to dusk sector and during major substorm expansion onset. Pi 2 outbursts are observed in the majority of substorms passing through the midnight sector and have been correlated with changes in field aligned currents.
Document ID
19820053895
Acquisition Source
Legacy CDMS
Document Type
Other - Collected Works
Authors
Mcpherron, R. L. (California, University Los Angeles, CA, United States)