Auroral Radio Emissions: A Window Into Electron Acceleration Processes

极光无线电发射：了解电子加速过程的窗口

• 批准号: 1915058
• 负责人: James LaBelle
• 金额: $ 19.9万
• 依托单位: Dartmouth College
• 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: 2019-05-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1915058&HistoricalAwards=false
• 关键词: Auroral; Radio; Emissions; Window; Into

The Northern Lights or aurorae result when energetic particles interact with the atmosphere ? producing a colorful sight in the night sky. The Arctic region near the North Pole is a prime location for viewing aurorae. This project is a follow-on to an NSF funded program that deployed and calibrated a receiver array in Toolik Lake, Alaska. This instrumentation will be used to view the aurorae and make new discoveries about how they are created. Graduate and undergraduate students will be trained and the scientific datasets will be shared with the public.A significant manifestation of high-latitude electromagnetic energy and particle flows is the terrestrial aurora which involves many acceleration processes affecting electrons and ions. These processes occur in both the magnetosphere and the ionosphere and are a key component of magnetosphere-ionosphere (M-I) coupling. Radio emissions from the accelerated auroral electron beams, with their complicated temporal and spatial variations, provide a window into the accelerated electron distributions and the processes that produce them. Auroral Medium Frequency Burst (MFB) emissions are especially promising in this regard because they are associated with substorm expansion arcs and exhibit structure on a range of time scales overlapping with those of Alfvenically accelerated suprathermal electron bursts and other phenomena such as flickering aurora. MFB is, however, relatively poorly understood: its source altitudes is not known, and although a mechanism has been proposed that suggests a connection to Alfvenic aurora, it has not been conclusively confirmed by observations. The proposed experiments, which will answer these and other outstanding questions about MFB and auroral radio emissions, are critical steps toward using MFB and its time and frequency structure as a diagnostic of auroral acceleration and nonlinear wave processes, to answer key questions about the temporal and spatial dynamics of these processes in the ionospheric context as well as their relation to larger dynamical processes such as storms and substorms.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.

当能量颗粒与大气相互作用时，北极光或极光会产生？在夜空中产生丰富多彩的景象。北极附近的北极地区是观看Aurorae的主要位置。该项目是NSF资助的计划的后续项目，该计划在阿拉斯加的Toolik Lake部署和校准了接收器阵列。该仪器将用于查看Aurorae，并就其创建方式进行新发现。将培训毕业生和本科生，并将与公众共享科学数据集。高纬度电磁能和粒子流的显着表现是地面极光，它涉及许多影响电子和离子的加速过程。这些过程都发生在磁层和电离层中，并且是磁层层（M-I）耦合的关键组成部分。来自加速的极光电子梁的无线电排放及其复杂的时间和空间变化为加速电子分布及其产生它们的过程提供了一个窗口。在这方面，极光中频率爆发（MFB）的排放尤其有希望，因为它们与近时间尺度上的近代膨胀弧和展示结构相关，并与Alfgenther上加速的超颗粒上电子爆发和其他现象（例如闪烁Aurora）重叠。但是，MFB的理解相对较少：尚不清楚其源高度，尽管提出了一种机制，提出了与Alfgenic Aurora有联系的机制，但尚未通过观察结果确认它。提出的实验将回答有关MFB和Auroral无线电排放的这些和其他杰出问题，是使用MFB及其时间和频率结构作为极光加速度和非线性波过程的关键步骤，以回答有关时间和时间和时间的关键问题这些过程在电离层环境中的空间动态及其与更大的动态过程（例如风暴和实体）的关系。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力优点和更广泛的影响来通过评估来支持的。

项目成果

A Statistical Study of Auroral Medium Frequency Bursts and Anomalous Incoherent Scatter Radar Echoes

极光中频爆发和异常非相干散射雷达回波的统计研究

• DOI: 10.1029/2021rs007353
• 发表时间: 2022
• 期刊: Radio Science
• 影响因子: 1.6
• 作者: Hudson, Emily;LaBelle, James;Reimer, Ashton;Akbari, Hassanali
• 通讯作者: Akbari, Hassanali

Langmuir Turbulence in the Auroral Ionosphere: Origins and Effects

极光电离层中的朗缪尔湍流：起源和影响

• DOI: 10.3389/fspas.2020.617792
• 发表时间: 2021
• 期刊: Frontiers in Astronomy and Space Sciences
• 影响因子: 3
• 作者: Akbari, Hassanali;LaBelle, James W.;Newman, David L.
• 通讯作者: Newman, David L.

Estimating Polar Cap Density and Medium‐Frequency Burst Source Heights Using 2 f ce Roar Radio Emissions

使用 2 f ce 咆哮无线电发射估算极盖密度和中频爆发源高度

• DOI: 10.1029/2020ja028166
• 发表时间: 2020
• 期刊: Journal of Geophysical Research: Space Physics
• 作者: Burnett, Adam C.;LaBelle, James
• 通讯作者: LaBelle, James

Properties of the Stimulated Electromagnetic Emissions During the Inclined High‐Frequency Pumping of the Ionosphere Near the Fourth Electron Gyroharmonic at the High‐Frequency Active Auroral Research Program Facility

高频主动极光研究计划设施第四电子陀螺谐波附近电离层倾斜高频泵浦过程中受激电磁发射的特性

• DOI: 10.1029/2019gl082890
• 发表时间: 2019
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Shindin, A. V.;Grach, S. M.;Sergeev, E. N.;Smolina, V. P.;Pogorelko, N. A.;Bernhardt, P. A.;Briczinski, S. J.;Broughton, M.;LaBelle, J.;McCarrick, M. J.
• 通讯作者: McCarrick, M. J.