CAREER: Observational and Modeling Investigations of Pulsating Aurora Electrodynamics

职业：脉动极光电动力学的观测和建模研究

• 批准号: 2339961
• 负责人: Stephen Kaeppler
• 金额: $ 72.16万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-05-01 至 2029-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2339961&HistoricalAwards=false
• 关键词: CAREER; Observational; Modeling; Investigations; Pulsating

Aurora is a high latitude phenomenon and is visible as arcs, sheets, curtains, etc. One common variety is referred to as pulsating aurora that includes on-and-off modulations. This spectacular feature results from the natural occurring emissions, and their intensity depends on precipitating electrons at high latitudes, which in turn can influence energy deposition. Deposited energy can be propagated away in the form of gravity waves and can affect other latitudinal regions. Energetic particle precipitation associated with different aurora, and in particular pulsating aurora, can cause enhancements in the upper regions of the ionosphere, which absorbs high-frequency radio wave propagation. This impacts communication systems that are important for transpolar flights requiring continuous communication links to be open to the ground. The focus of this investigation is specifically to understand pulsating aurora, which is one of the most observed auroral types. Despite its ubiquitous occurrence, the electrodynamics of pulsating aurora have not been investigated in detail as other kinds of aurora. This investigation intends to address fundamental problems associated with the electrodynamics of a time changing system, driven by the on-and-off modulations occurring during pulsating auroral events. Educational efforts include a space science summer research experience for underrepresented minority (URM) middle school students and establishment of a NASA Rocksat-X program for undergraduate students at Clemson University. The activities will promote collaboration between academic (Clemson University) and non-academic, non-profit organization (Pisgah Astronomical Research Institute) and community partner (Littlejohn Community Center). Enhanced electron precipitation during auroral events modifies ionospheric conductivity, and thus investigation of pulsating aurora offers an excellent opportunity to expand knowledge about electrodynamics of the high latitude regions. Two scientific questions that will be addressed as a part of this effort are (a) What is the electric field, current, and conductivity structure of pulsating aurora? and (b) How do temporal changes in the average energy and energy flux of the pulsating aurora precipitation affect the conductivity? To address the first objective, the methodology will utilize Poker Flat incoherent scatter radar data and perform modeling investigations of pulsating aurora electrodynamics using the 3-D Geospace Environment Model of Ion-Neutral Interactions (GEMINI) ionosphere model. The GEMINI modeling simulations will be conducted on idealized pulsating aurora and actual events in which all-sky imager and PFISR data will be used to drive the model. To achieve the second goal, utilization of the Poker Flat DPS-4D Digisonde, all-sky imager observations, and deployment of high frequency (HF) radio receivers and transmitters at Poker Flat Research Range are suggested. Additionally, a new technique will be developed that will leverage HF radio wave observations at high temporal resolution to capture fast ionospheric and associated electrodynamical changes occurring during the pulsating aurora. This project is jointly funded by Aeronomy program, in the AGS Division of the GEO directorate and the Established Program to Stimulate Competitive Research (EPSCoR) at the NSF.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.

Aurora是一种高纬度现象，可见为弧，床单，窗帘等。一种常见品种被称为脉动极光，其中包括在开机调制中。 这种壮观的特征是由于自然发生的排放而产生的，它们的强度取决于高纬度的沉淀电子，这又会影响能量沉积。沉积的能量可以以重力波的形式传播，并可能影响其他纬度区域。与不同的极光相关的能量颗粒沉淀，尤其是脉动极光，可能会在电离层的上部区域引起增强，从而吸收高频无线电波传播。这会影响通信系统，这对于需要连续通信链接开放的跨极航班很重要。 这项研究的重点是专门理解脉动极光，这是最观察到的极光类型之一。 尽管出现无处不在，但脉动极光的电动力学尚未像其他类型的极光一样详细研究。这项调查旨在解决与随时间变化系统的电动力学相关的基本问题，这是由于在脉动极光事件期间发生的开关调节驱动。教育工作包括为代表性不足的少数民族（URM）中学生的太空科学研究经验以及在克莱姆森大学（Clemson University）为本科生的NASA Rocksat-X计划。这些活动将促进学术（克莱姆森大学）与非学术，非营利组织（Pisgah天文学研究所）和社区合作伙伴（Littlejohn社区中心）之间的合作。 在极光事件中增强的电子沉淀可修饰电离层的电导率，因此对脉动极光的研究为扩展有关高纬度区域的电动力学知识提供了绝佳的机会。这项工作的一部分将被解决的两个科学问题是（a）脉动极光的电场，电流和电导率结构是什么？ （b）脉动极光沉淀的平均能量和能量通量的时间变化如何影响电导率？为了解决第一个目标，该方法将利用扑克平坦的散射雷达数据，并使用离子中性相互作用（Gemini）电离层模型的3-D地球上环境模型对脉动极光电动力学进行建模研究。 GEMINI建模模拟将以理想化的脉动极光和实际事件进行，其中所有天空成像器和PFISR数据将用于驱动模型。为了实现第二个目标，建议在扑克扁平研究范围内使用扑克扁平DPS-4D Digisonde，全天空成像仪观察以及高频（HF）无线电接收器和发射机的部署。此外，将开发一种新技术，该技术将利用高时间分辨率的HF无线电波观测来捕获脉动极光期间发生的快速电离层和相关的电动力学变化。 该项目由空气计划，GEO局的AGS部门共同资助，并在NSF上刺激竞争研究（EPSCOR）的既定计划。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知识分子优点和更广泛影响的审查标准来通过评估来通过评估来支持的。