A 12‐hour case study of auroral phenomena in the midnight sector: Electrojet and precipitating particle characteristics

摘要: Airborne observations of auroral activity at midnight were conducted for a period 9 hours by employing an ionospheric sounder and all-sky cameras. During the observation period, two substorms occurred. The first substorm was associated with compression magnetosphere (as measured Dst) oscillations earth's bow shock. At this time, characterized series poleward equatorward motions absence breakup phase. Magnetic disturbances confined to small region in sector. second displayed many features large-scale polar magnetic substorm. For selected times locations eastward westward electrojets inferred from number high-latitude records. All-sky photographs ionosonde data indicate that edge electrojet bounded moving surge accompanied strong sporadic E ionization. boundary less well defined visual forms. Soft particle spectrometer measurements Isis 2 satellite made conjunction aircraft large fluxes field-aligned electrons gave rise bright surge, more isotropic energetic contributing layer.