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首页> 外文期刊>Journal of Geophysical Research, A. Space Physics: JGR >Flickering Low Frequency Auroral Hiss
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Flickering Low Frequency Auroral Hiss

机译：闪烁的低频极光嘶嘶声

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摘要

A low- and medium-frequency (LF/MF) receiving system at South Pole Station, using a wide-beam dipole antenna, measured continuous fully sampled waveforms of more than 100 LF auroral hiss events between June and October 2019. Spectra of fluctuations of LF auroral hiss intensity at selected frequencies between 110 and 530 kHz showed these are broadband, with spectral power monotonically decreasing to an upper bound typically 20-60 Hz, comparable to frequencies reported for optical flickering aurora. Occasionally intervals of periodic fluctuations in auroral hiss intensity occurred, in most cases lasting only tens of cycles. On September 1, 2019, periodic fluctuations lasted thousands of cycles during two 30-s intervals, at frequencies 125-145 Hz. Close examination showed these to be dispersed with low frequencies arriving before high frequencies by approximately 4.5 ms per 100 kHz. Ray-tracing calculations and consideration of the Temerin et al. (1986, 1993) mechanisms of flickering aurora shows that the September 1 flickering auroral hiss observations are consistent with resonant amplification of whistler mode noise by an electron beam accelerated and modulated by electromagnetic proton cyclotron waves originating near 4,500 km, with the wave excitation taking place at 2,000-3,000 km.
机译：一个低收入和中频(低频/ MF)接收在南极站系统,使用宽束偶极子天线,连续测量完全采样波形的低频极光嘘事件超过1002019年6月至10月间。低频极光嘶嘶声强度的波动选择的频率在110和530千赫显示,这些都是宽带,光谱的力量单调递减的一个上界通常20 - 60 Hz,与频率报告光闪烁的极光。偶尔的间隔周期波动极光嘶嘶声强度发生的原因,在大多数情况下持续的周期。2019年,持续了数千周期性波动周期在两个30多岁的间隔,在频率125 - 145赫兹。分散与低频之前到达高频率大约每100人4.5毫秒kHz。Temerin et al。(1986、1993)的机制闪烁的极光显示,9月1日闪烁的极光嘶嘶声的观察与谐振放大的一致惠斯勒模式噪声的电子束电磁加速和调制质子回旋波原始近4500公里,与波励磁发生2000 - 3000公里。

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