Energetic electron precipitation associated with pulsating aurora: EISCAT and Van Allen Probe observations

• Published in: Journal of Geophysical Research: Space Physics
• Main Authors: Miyoshi, Y., Oyama, S., Saito, S., Kurita, S., Fujiwara, H., Kataoka, R., Ebihara, Y., Kletzing, C., Reeves, G., Santolík, O. (Ondřej), Clilverd, M., Rodger, C. J., Turunen, E., Tsuchiya, F.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2015
• Subjects: pulsating aurora; EISCAT; Van Allen Probes; pitch angle scattering; Tromsø
• Online Access: https://doi.org/10.1002/2014JA020690; http://hdl.handle.net/11104/0247040

Pulsating auroras show quasi-periodic intensity modulations caused by the precipitation of energetic electrons of the order of tens of keV. It is expected theoretically that not only these electrons but also subrelativistic/relativistic electrons precipitate simultaneously into the ionosphere owing to whistler mode wave-particle interactions. The height-resolved electron density profile was observed with the European Incoherent Scatter (EISCAT) Tromsø VHF radar on 17 November 2012. Electron density enhancements were clearly identified at altitudes >68 km in association with the pulsating aurora, suggesting precipitation of electrons with a broadband energy range from ~10 keV up to at least 200 keV. The riometer and network of subionospheric radio wave observations also showed the energetic electron precipitations during this period. During this period, the footprint of the Van Allen Probe-A satellite was very close to Tromsø and the satellite observed rising tone emissions of the lower band chorus (LBC) waves near the equatorial plane. Considering the observed LBC waves and electrons, we conducted a computer simulation of the wave-particle interactions.