Explaining occurrences of auroral kilometric radiation in Van Allen radiation belts

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• 作者：Fuliang Xiao ; Qinghua Zhou ; Zhenpeng Su ; Zhaoguo He ; Chang Yang ; Si Liu ; Yihua He ; Zhonglei Gao
• 刊名：Geophysical Research Letters
• 出版年：2016
• 出版时间：16 December 2016
• 年：2016
• 卷：43
• 期：23
• 页码：11,971-11,978
• 全文大小：4.0MB
• ISSN：1944-8007

文摘

Auroral kilometric radiation (AKR) is a strong terrestrial radio emission and dominates at higher latitudes because of reflection in vicinities of the source cavity and plasmapause. Recently, Van Allen Probes have observed occurrences of AKR emission in the equatorial region of Earth's radiation belts but its origin still remains an open question. Equatorial AKR can produce efficient acceleration of radiation belt electrons and is a risk to space weather. Here we report high-resolution observations during two small storm periods 4–6 April and 18–20 May 2013 and show, using a 3-D ray tracing simulation, that AKR can propagate downward all the way into the equatorial plane in the radiation belts under appropriate conditions. The simulated results can successfully explain the observed AKR's spatial distribution and frequency range, and the current results have a wide application to all other magnetized astrophysical objects in the universe.