2 - 12 Minute Quasi-Periodic Variations of 50 - 1,000 keV Trapped Electron Fluxes Detected in the Afternoon Magnetosphere. 1. Physical Characteristics

摘要

Physical properties of electron variations of period in the range 2 - 12 minutes detected in the afternoon magnetosphere at synchronous altitudes by the University of Minnesota electron spectrometer on the ATS-1 are presented. We find that in the energy interval 50 keV to 1 meV, most of the electron variations are correlated with the intensity of the local magnetic field. This correlation exists down to a few minutes time scale. The pitch-angle analysis shows that the enhancement of fluxes occur primarily at large pitch-angles. We show in Part 2 of this series of papers that the electron variations can be accounted for by adiabatic causes. (Author)