Local time distributions of repetition periods for rising tone lower band chorus waves in the magnetosphere

Whistler mode chorus waves generally occur outside the plasmapause in the magnetosphere. The most striking feature of the waves is their occurrence in discrete elements. One of the parameters that describe the discrete elements is the repetition period (T_rp), the time between consecutive elements. The T_rp has not been studied statistically before. We use high-resolution waveform data to derive distributions of T_rp for different local times. We find that the average T_rp for the nightside (0.56 s) and dawnside (0.53 s) are smaller than those for the dayside (0.81 s) and duskside (0.97 s). Through a comparison with the background plasma and magnetic fields, we also find that the total magnetic field and temperature are the main controlling factors that affect the variability of T_rp. These results are important for understanding the generation mechanism of chorus and choosing parameters in simulations that model the acceleration and loss of electrons by wave-particle interactions.