Access count of this item: 52
|Title:||Discovery of 1 Hz Range Modulation of Isolated Proton Aurora at Subauroral Latitudes|
Uchida, H. A.
Danskin, D. W.
|Author's alias:||海老原, 祐輔|
|Keywords:||isolated proton aurora|
Pc1 geomagnetic pulsations
|Publisher:||American Geophysical Union (AGU)|
|Journal title:||Geophysical Research Letters|
|Abstract:||Isolated proton aurora (IPA) is a manifestation of the wave‐particle interaction visible at subauroral latitudes, with activity on many timescales. We herein present the first observational evidence of rapid luminous modulation of IPA correlated with simultaneously observed Pc1 waves observed on the ground, which are equivalent to the electromagnetic ion cyclotron (EMIC) waves in the magnetosphere. The fastest luminous modulation of IPA was observed in the 1 Hz frequency range, which was twice the frequency of the related Pc1 waves. The time lag between variations of Pc1 wave power and the IPA luminosity suggests that the source regions of IPA are distributed near the magnetic equator, suggesting an EMIC wave‐energetic (a few tens of keV) proton or relativistic (MeV or sub‐MeV) electron interaction. The generation mechanism of this 1 Hz luminous modulation remains an open issue, but this study supports the importance of nonlinear pitch angle scattering via wave‐particle interactions.|
|Rights:||©2018. The Authors. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.|
|Appears in Collections:||Journal Articles|
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