Observation of ionospheric source cone enhancements at the substorm injection boundary

摘要: A large number of time-varying electron and ion features, such as those observed in energy-time spectrograms data obtained near geosynchronous orbit, have been previously explained through the use an injection boundary model. This model describes features terms dispersion signatures fresh, hot plasma which is “injected” into extended region tailward at time substorm onset. Using from Lockheed composition instrument University California, San Diego, analyzers on SCATHA, we present two events indicating that innermost edge especially important location for input ionospheric ions. The are identified by comparison with predicted various electric magnetic field models. In both show intense, narrow-energy, field-aligned O+ fluxes limiting dispersing feature corresponds to ions can be backtracked localized positions vicinity onset time. We conclude boundary, statistically equatorward auroral oval, times direct trapped, energetic particle population.