Some Statistical Results about the Energetic Particle Pulses in the Magnetotail

This paper presents the results of correlation analysis between the data of energetic particle pulses obtained by IMP-Jspacecraft (P4: 230keV>E>160keV) and auroral electrojet index AE. The magnetotail is devided into three regions: neutral sheet region, low latitude region and high latitude region. It is found that: (1) In the neutral sheet region, the average energetic particle fluxes is the highest among all three regions. In the high latitude region the fluxes is the lowest. This indicates that the "source" of energetic particle pulses may be located in the neatral sheet region. (2) The correlation between energetic particle pulses and AEindex is most significant in the neutral sheet region, the correlation coefficient Ris 0.59. In low and high latitude region, Rdecreases sharply. It coincide with the idea that energetic particle pulses event is substorm relevant event, the particles are accelerated by induced electric field caused by magnetic field line reconnection near the neutral sheet region. (3) Accelerated area is limited to a thin layer around neutral sheet, it coincides with Hones results.