Statistical study of auroral electron precipitation structures detected by the aureol-3 satellite

We present a detailed statistical study of the distribution of the inverted-V electron precipitation commonly detected in the 500 - 2000 km altitude range aboard the AUREOL-3 satellite. These structured precipitations are statistically observed inside the auroral oval with a maximum occurrence in the evening-midnight sector. They correspond to primary electron fluxes peaked at energies generally below 10 keV and precipitating in large-scale structures (50-100 km in latitudinal width). It is shown that, as predicted by collision-less kinetic theories, most inverted-V structures present a clear relationship between the field-aligned current density carried by the 1 - 20 keV primary electrons and the potential drop inferred from particle distribution functions. Furthermore the study demonstrates the existence of strong electron heating, inside the acceleration region