[P-EM09] Dynamics of Magnetosphere and Ionosphere

[PEM09-P17] Amplitude modulations of the flickering aurora

*野村 佳槻¹、三好 由純¹、栗田 怜²、遠山 航平¹、片岡 龍峰³ (1.名古屋大学宇宙地球環境研究所、2.京都大学生存圏研究所、3.国立極地研究所)

キーワード：フリッカリングオーロラ、高速撮像カメラ観測、波動粒子相互作用

The flickering aurora appears during aurora breakup, and the average frequency is ~3-15 Hz. One of the possible origins of flickering aurora is that electromagnetic ion cyclotron (EMIC) waves that cause electron flux modulations at a few thousand kilometers. The flickering aurora has the amplitude modulations, and 10-20 % modulations to the background aurora intensity have been reported. In order to understand detail characteristics of the amplitude modulations of the flickering aurora, we analyze the s-CMOS camera at Poker Flat Research Range, Alaska and investigate distributions of the amplitude of the flickering aurora at different background aurora intensity. We analyzed the intense flickering aurora event at 06:40 UTC on February 8^th, 2016. The frequency range of the observed flickering aurora was a few Hz. We derived the relative amplitudes to the background aurora arc. The average ratio was ~13 % and its standard deviation was ~10 % while the background aurora intensities are different. We suggest that the amplitudes and distribution to the background aurora arc do not depend on the background aurora arc. In this presentation, we will show the spatial and time variations of relative amplitude within the flickering aurora arcs.