当前位置: X-MOL 学术J. Geophys. Res. Space Phys. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Inner Magnetospheric ULF Waves: The Occurrence and Distribution of Broadband and Discrete Wave Activity
Journal of Geophysical Research: Space Physics ( IF 2.8 ) Pub Date : 2020-08-10 , DOI: 10.1029/2020ja027887
K. R. Murphy 1, 2 , A. R. Inglis 2, 3 , D. G. Sibeck 2 , C. E. J. Watt 4 , I. J. Rae 5
Affiliation  

Ultralow frequency (ULF) waves are electromagnetic pulsations observed throughout the magnetosphere driven by processes both external and internal to the magnetosphere. Within the magnetosphere, discrete and broadband ULF wave activity can couple to the local plasma via coherent or stochastic wave‐particle interactions. These wave‐particle interactions can lead to dynamic changes in local plasma including rapid acceleration and transport of radiation belt electrons. Using observations from GOES‐15 and the Automated Flare Inference of Oscillations algorithm we investigate the distribution and occurrence of broadband and discrete ULF waves to help understand the relative importance of coherent and stochastic wave‐particle interactions. We find that intervals of discrete ULF waves are more commonly identified during slow and low‐density solar wind and when Bz is near zero. Broadband waves are more commonly identified during periods of active solar wind, including periods of high solar wind speeds and large density perturbations, and large negative Bz. We also find that under all solar wind conditions the number of intervals of broadband ULF wave power exceeds that of discrete wave power; for example, ULF wave activity is more likely to be broadband. These results suggest that radial diffusion due to incoherent broadband waves is an important driver of wave‐particle interactions, especially during active solar wind conditions. However, the presence of discrete waves during both active and quiet solar wind conditions suggests that these waves and the corresponding wave‐particle interactions cannot be ignored, especially since discrete wave‐particle interactions tend to be more efficient than radial diffusion.

中文翻译:

内磁层ULF波:宽带和离散波活动的发生和分布

超低频(ULF)波是在整个磁层中观察到的电磁脉冲,由磁层的内部和外部过程驱动。在磁层内,离散的和宽带的ULF波活动可以通过相干或随机的波粒子相互作用耦合到局部等离子体。这些波粒相互作用会导致局部等离子体发生动态变化,包括辐射带电子的快速加速和传输。使用来自GOES-15的观测结果和“振荡的自动火炬推断”算法,我们研究了宽带和离散ULF波的分布和发生,以帮助理解相干波和随机波-粒子相互作用的相对重要性。B z接近零。在活跃的太阳风期间,通常会识别宽带波,包括太阳风速高,密度扰动大和负B z大时。。我们还发现,在所有太阳风条件下,宽带ULF波功率的间隔数都超过了离散波功率的间隔数。例如,ULF波活动更可能是宽带。这些结果表明,宽带非相干波引起的径向扩散是波粒相互作用的重要驱动力,特别是在活跃的太阳风条件下。但是,在活跃和安静的太阳风条件下都存在离散波,这表明这些波和相应的波粒相互作用不容忽视,尤其是因为离散波粒相互作用往往比径向扩散更有效。
更新日期:2020-09-20
down
wechat
bug