| Autor: |
Ryuho Kataoka, Kanako Seki, Yusuke Ebihara, Naomoto Iwagami, Yoshizumi Miyoshi, Kazuo Shiokawa, Yoko Fukuda, Herbert Akihito Uchida, Donald Hampton, Daniel Whiter |
| Rok vydání: |
2017 |
| Předmět: |
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| Zdroj: |
Geophysical Research Letters. 44:3963-3970 |
| ISSN: |
0094-8276 |
| Popis: |
Electromagnetic ion cyclotron (EMIC) waves, one of the possible origins of flickering aurora, have been thought to modulate the electron flux at a few thousand kilometers. In fact, flickering aurora with a frequency range of 3–15 Hz has often been identified by ground-based optical observations and has been interpreted to be caused by O+-band EMIC waves. However, extant research to date has not identified possible signatures of H+-band EMIC waves due to technical limitations of ground-based high-speed imagers. The present study shows the first evidence that patchy flickering aurora could be modulated by H+-band EMIC waves, based on the data obtained from imaging observations at 160 frames per second. The sporadic appearance of the flickering aurora in the frequency range of 50–80 Hz coexisted with typical flickering auroras of approximately 10 Hz. These results are consistent with the hypothesis that flickering auroras are generated by multi-ion EMIC waves. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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