Dipolarization of geomagnetic fields had been found to occur at Earth’s tailside during geomagnetic activities associated with decreasing in AL index and substorms [1]. Recently, the dipolarization phenomena were also reported to be observed in the inner magnetosphere [2]. Therefore, it would be essential to investigate properties of waves and particles associated with the dipolarization events. Based on our preliminary analysis from observations of THEMIS mission, both whistler-mode waves and variations in pitch angle distributions of electrons were found at a dipolarization site near the magnetic equator around 10 RE (Earth radii), and changes in energies and pitch angles of electrons according to observed wave parameters were simulated [3]. We found that the observed changes in pitch angles of electrons may ralate to their interaction with the observed waves. To substantiate the findings mentioned above, in this study, we aim to analyze observed wave parameters in more detail in terms of frequency ranges as well as amplitudes, wave angles, and polarities versus frequencies, to improve the input wave parameters of the simulation for their effects on electrons. Changes in the background magnetic field would also be taken into account. We anticipate the results will be beneficial to understand the properties of waves and electrons of dipolarization sites in the transition region from inner plasma sheet to the inner magnetosphere.
