Title: Satellite observations of impulsive Bremsstrahlung X ray events associated with substorms
Abstract: With bremsstrahlung X ray data taken on a polar‐orbiting satellite a study has been made of impulsive electron (>50 keV) precipitation events at high latitudes, many of which occurred in the vicinity of local midnight near the beginning of a magnetic substorm. The impulsive events were truly temporal in character and lasted for times of the order of 5 min or less. The angular distributions of the X rays measured at the satellite indicated that the electron precipitation occurred generally near the energetic electron (>155 keV) trapping boundary with a tendency often to be somewhat poleward of that boundary. Just prior to the onset of several of the events there was a significant decrease in X ray flux. The energy spectra often softened during the pronounced increases in X ray flux. For some of the events the maximum total rate of precipitation of electrons of >50 keV into the atmosphere was ∼10 23 particles/s over the broad region of observation spanning a MLT range of about 6 hours near the midnight sector. The total energy dissipation rates by electrons of >50 keV over the same MLT interval were found to be in the range from 2.5 × 10 14 to 2.8 × 10 16 ergs/s.
Publication Year: 1978
Publication Date: 1978-09-01
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 16
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot