Multi-point observations of modulated whistler-mode waves and energetic electron precipitation

Both long period modulation at periods of several to tens of minutes and short period modulation at about tens of seconds are observed in X-ray measurements. Similar periodicities are also observed for whistler-mode wave amplitude.

We show that the correlation coefficient between whistler-mode waves and electron precipitation is high in several regions, including plumes and plasma trough. Ultra-low-frequency waves (8-30 mHz), which have been suggested to play a potential role in precipitating electrons by modulating whistler-mode wave intensity or loss cone size, show a weak correlation with whistler-mode wave amplitudes and the X-ray counts during the conjunction.