Short Chorus Wave Packets: Generation Within Chorus Elements, Statistics, and Consequences on Energetic Electron Precipitation.
Short Chorus Wave Packets: Generation Within Chorus Elements, Statistics, and Consequences on Energetic Electron Precipitation.
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DOI：
10.1029/2022ja030310
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发表时间：
2022-05
影响因子：
2.8
通讯作者：
Wilkins, C.
中科院分区：
文献类型：
--
作者：
Mourenas, D.;Zhang, X. -J;Nunn, D.;Artemyev, A., V;Angelopoulos, V;Tsai, E.;Wilkins, C.
关键词：
短而强烈的低波段合唱波包在地球的外辐射带中无处不在。在这篇文章中，我们进行各种Vlasov混合模拟，与一个或两个触发波，研究生成短合唱包/子包内长升调元素。我们表明，所产生的短波包的长度是一致的两个独立的叠加波的共振不重叠的标准，这些合唱包具有类似的特点，在货车艾伦探测器的观测。我们发现，短波包主要形成在中等线性增长率的长升调的中/端附近，而在更强的线性增长率的任何地方。最后，我们分析了一个事件，其特征在于在亚暴航天器测量的合唱上升音附近的赤道和同时测量低海拔ELFIN立方体卫星的沉淀和捕获的电子通量在同一部门的时间历史事件和大尺度相互作用。测得的沉淀电子通量很好地恢复测试粒子模拟使用测得的等离子体和波的属性。我们发现，中等振幅（160-250 pT）的短合唱波包基本上导致50-200 keV电子比长包更像扩散的输运。与此相反，长合唱包被发现产生重要的非线性效应，通过异常捕获，显着减少电子沉淀低于150千电子伏，特别是对于较高的波振幅。Vlasov混合模拟通过波叠加一致地产生短合唱波包，具有与观测中类似的特征。对于低线性增长率，在上升音调的中间/末端发现短合唱波包，但对于高增长率，在任何地方都可以发现短中等振幅合唱波包的电子沉淀发生在近准线性状态
Short and intense lower‐band chorus wave packets are ubiquitous in the Earth's outer radiation belt. In this article, we perform various Vlasov hybrid simulations, with one or two triggering waves, to study the generation of short chorus packets/subpackets inside long rising tone elements. We show that the length of the generated short wave packets is consistent with a criterion of resonance non‐overlap for two independent superposed waves, and that these chorus packets have similar characteristics as in Van Allen Probes observations. We find that short wave packets are mainly formed near the middle/end of long rising tones for moderate linear growth rates, and everywhere for stronger linear growth rates. Finally, we analyze an event characterized by Time History of Events and Macroscale Interactions during Substorms spacecraft measurements of chorus rising tones near the equator and simultaneous measurements by low altitude ELFIN CubeSats of precipitating and trapped electron fluxes in the same sector. The measured precipitating electron fluxes are well recovered by test particle simulations performed using measured plasma and wave properties. We show that short chorus wave packets of moderate amplitudes (160–250 pT) essentially lead to a more diffusive‐like transport of 50–200 keV electrons toward the loss cone than long packets. In contrast, long chorus packets are found to produce important nonlinear effects via anomalous trapping, which significantly reduces electron precipitation below 150 keV, especially for higher wave amplitudes. Vlasov hybrid simulations consistently produce short chorus packets by wave superposition, with similar characteristics as in observations Short chorus wave packets are found in the middle/end of rising tones for low linear growth rates but everywhere for high growth rates Electron precipitation by short moderate amplitude chorus wave packets occurs in a nearly quasi‐linear regime