Statistical Study on the Azimuthal Mode Number of Pc5 ULF Wave in the Inner Magnetosphere
- 1School of Space and Environment, Beihang University, Beijing, China
- 2Key Laboratory of Space Environment Monitoring and Information Processing of MIIT, Beihang University, Beijing, China
- 3Department of Electrical Engineering, Democritus University of Thrace, Xanthi, Greece
- 4Laboratory for Atmospheric & Space Physics, University of Colorado Boulder, Boulder, CO, USA
The azimuthal mode number, m, of ULF waves is a significant contributing factor for radiation belt electron energization, because it determines the conditions for resonant interaction between waves and particles. Based on multi-point magnetic field measurements of GOES satellites from January to September of 2011, we statistically analyze the distributions of the characteristics of m of Pc5 ULF waves. In the dayside, the local peaks in the distributions of wave power spectra density locate at ~10 and ~13 MLT for m < 0 (westward propagation) and m > 0 (eastward propagation) waves respectively, suggesting the waves generally propagate anti-sunward. In the nightside, the local peaks are at 22~23 MLT for both m < 0 and m > 0 waves, suggesting possible relation to substorm activities. Further investigation shows that, with increasing solar wind activities, the enhancements of dayside peaks are primarily contributed by m ≤ 3 waves, whereas the enhancements of nightside peak are contributed by both m ≤ 3 and m > 3 waves. With increasing AE index, the enhancements are more significant for the nightside peaks comparing to dayside peaks, and for m > 3 waves comparing to m ≤ 3 waves. The results of this study provide inputs for further investigation on the radial diffusion coefficient of radiation belt electrons with considering mode number information.
How to cite: Tong, X., Liu, W., Zhang, D., Sarris, T., Li, X., Zhang, Z., and Yan, L.: Statistical Study on the Azimuthal Mode Number of Pc5 ULF Wave in the Inner Magnetosphere, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5036, https://doi.org/10.5194/egusphere-egu24-5036, 2024.