The Generation of Banded Chorus Waves in the Earth's Radiation Belt

地球辐射带中带状合唱波的产生

• 批准号: 1923126
• 负责人: Jinxing Li
• 金额: $ 35.23万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1923126&HistoricalAwards=false
• 关键词: Generation; Banded; Chorus; Waves; Earth

Radio waves are naturally produced in the near-Earth space environment. Chorus waves are a type of such radio waves that interact with relativistic particles in the radiation belts. Understanding the interactions between these waves and particles is important for predicting the changing space environment and its societal impacts. In particular, this allows us to predict space weather and prepare for impacts to national commercial and defense satellites and communications - a priority set out in the National Space Weather Action Plan. This project aims to explore the origin of banded chorus waves in Earth's radiation belt by analyzing data from the Van Allen Probes and performing particle-in-cell simulations to aid in interpretation. Naturally occurring chorus waves are believed to play a key role in accelerating relativistic electrons in the Earth's outer radiation belt, and in precipitating ~keV (and higher) electrons to the upper atmosphere, causing diffuse aurorae and pulsating aurorae. Chorus typically occurs in two distinct frequency bands separated by a gap at half of the electron gyro-frequency. The origin of this two-band structure has been a half-century-long open scientific question. This project, by systematically surveying the chorus waves and their properties right in the source region, will explore whether the spectral gap at half the electron gyro-frequency is generated at the magnetic equator, or is formed by damping as the waves propagate to higher latitudes. The electron distributions that accompany banded chorus waves will be statistically investigated and linear growth calculations made to investigate the direct energy source of banded chorus waves. Based on typical observations of waves and particle distribution, 1-Dimensional and 2-Dimensional particle-in-cell simulations will be performed to explore the multi-stage interaction processes that could account for the banded chorus waves.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

无线电波是在近地空间环境中自然产生的。合唱波是一种与辐射带中的相对论性粒子相互作用的无线电波。了解这些波和粒子之间的相互作用对于预测不断变化的空间环境及其社会影响非常重要。特别是，这使我们能够预测空间天气并为国家商业和国防卫星和通信的影响做好准备——这是国家空间天气行动计划中规定的优先事项。该项目旨在通过分析范艾伦探测器的数据并进行细胞内粒子模拟以帮助解释，探索地球辐射带中带状合唱波的起源。人们认为，自然发生的合唱波在加速地球外辐射带中的相对论电子以及将~keV（和更高）电子沉淀到高层大气中发挥着关键作用，从而导致弥漫极光和脉动极光。合唱通常发生在由电子陀螺频率一半的间隙隔开的两个不同频带中。这种双能带结构的起源一直是一个长达半个世纪的开放科学问题。该项目通过系统地调查源区的合唱波及其特性，将探讨电子陀螺频率一半的谱隙是在磁赤道处产生的，还是在波传播到更高纬度时通过阻尼形成的。将统计研究伴随带状合唱波的电子分布，并进行线性增长计算以研究带状合唱波的直接能量来源。基于对波和粒子分布的典型观察，将进行一维和二维细胞内粒子模拟，以探索可以解释带状合唱波的多阶段相互作用过程。该奖项反映了 NSF 的法定使命和通过使用基金会的智力优点和更广泛的影响审查标准进行评估，该项目被认为值得支持。

项目成果

Unraveling the Formation Region and Frequency of Chorus Spectral Gaps

• DOI: 10.1029/2022gl100385
• 发表时间: 2022-09
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Jinxing Li;J. Bortnik;Wen Li;X. An;L. Lyons;W. Kurth;G. Hospodarsky;D. Hartley;G. Reeves

Multipoint Observations of Quasiperiodic Emission Intensification and Effects on Energetic Electron Precipitation

• DOI: 10.1029/2020ja028484
• 发表时间: 2021-01
• 期刊: Journal of Geophysical Research: Space Physics
• 作者: Jinxing Li;J. Bortnik;Q. Ma;Wen Li;X. Shen;Y. Nishimura;X. An;S. Thaller;A. Breneman;J. Wygant;W. Kurth;G. Hospodarsky;D. Hartley;G. Reeves;H. Funsten;J. Blake;H. Spence;D. Baker

Parallel Acceleration of Suprathermal Electrons Caused by Whistler‐Mode Hiss Waves

• DOI: 10.1029/2019gl085562
• 发表时间: 2019-11
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Jinxing Li;Q. Ma;J. Bortnik;Wen Li;X. An;G. Reeves;H. Funsten;H. Spence;D. Baker;W. Kurth;G. Hospodarsky;D. Hartley

Origin of two-band chorus in the radiation belt of Earth

• DOI: 10.1038/s41467-019-12561-3
• 发表时间: 2019-10
• 期刊: Nature Communications
• 影响因子: 16.6
• 作者: Jinxing Li;J. Bortnik;X. An;Wen Li;V. Angelopoulos;R. Thorne;C. Russell;B. Ni;X. Shen