Collaborative Research: Characterizing High-latitude Ionospheric Fluid Turbulence and Radio Scintillation with New Observations and Data-Driven Modeling

合作研究：通过新的观测和数据驱动的建模来表征高纬度电离层流体湍流和射电闪烁

• 批准号: 2027308
• 负责人: Matthew Zettergren
• 金额: $ 30.39万
• 依托单位: Embry-Riddle Aeronautical University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2027308&HistoricalAwards=false
• 关键词: Collaborative; Research; Characterizing; latitude; Ionospheric

This collaborative award is for a study of the complex spatial structure exhibited by ionosphere plasma in Earth's polar regions. Small-scale plasma structuring modifies the phase and amplitude of trans-ionospheric radio signals, producing significant scintillation activity. These effects are detrimental to communication and navigation systems but can be used as a remote-sensing diagnostic to help discern the characteristics of fundamental small-scale plasma processes that result in ionospheric structure. This research will improve understanding of the two major processes contributing to ionospheric scintillation: gradient drift and Kelvin Helmholz instabilities. The research plan directly relate to goals of NSF Aeronomy and CEDAR programs to investigate cross-scale coupling in the ionosphere-thermosphere-magnetosphere system, and would be applicable to other disciplines within plasma physics. The team will develop and apply rarely utilized capabilities of the Resolute Bay incoherent scatter radar (RISR), expanding the range of measurements the community can easily request from this facility while also advancing modeling capabilities. The project is co-led by two early-career scientists including a first-time NSF PI. The award enhances the space physics program at ERAU with support provided for one undergraduate student and one graduate student. Spatial irregularities within ionospheric plasma undergo dynamical evolution under the influence of magnetospheric forcing and internal ionospheric processes, producing a cascade of energy moving generally from large scales into intermediate and small scale structures. These scales are believed to be generated by a variety of instability mechanisms and structuring processes, but the details of the evolution of this plasma structuring over time are poorly constrained, especially for the non-linear aspects. The research plan will focus upon detailed data-model synthesis to characterize physical parameters expected to contribute to irregularity evolution in the ionosphere (i.e., large-scale density structures, background velocity fields, gradients and shears, and precipitation regions). The approach include modeling of radio wave propagation (using SIGMA) and polar cap ionosphere based upon the ingestion of existing and new observations from RISR, characterizing large-to-medium scales and scintillation activity using GPS (L-band) and UHF/VHF radio beacons. Results will be interpreted through comparisons with the predictions of a physics-based instability model as represented by the GEMINI model to characterize observable effects of ionospheric instability in many idealized situations and for select case studies based on data-driven model inputs.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.

这个合作奖是为了研究地球极地电离层等离子体所展示的复杂空间结构。小规模的等离子体结构改变了电离层无线电信号的相位和振幅，产生了显著的闪烁活动。这些影响对通信和导航系统是有害的，但可以用作遥感诊断，以帮助辨别导致电离层结构的基本小规模等离子体过程的特征。这项研究将提高对导致电离层闪烁的两个主要过程的理解：梯度漂移和开尔文亥姆霍兹不稳定性。该研究计划与美国国家科学基金会航空学和雪松计划的目标直接相关，旨在研究电离层-热层-磁层系统的跨尺度耦合，并将适用于等离子体物理学的其他学科。该团队将开发和应用Resolute Bay非相干散射雷达（RISR）很少使用的功能，扩大社区可以轻松地从该设施请求的测量范围，同时也提高建模能力。该项目由两名早期职业科学家共同领导，其中包括一名首次获得NSF PI的科学家。该奖项为一名本科生和一名研究生提供支持，以加强ERAU的空间物理项目。电离层等离子体内部的空间不规则性在磁层强迫和电离层内部过程的影响下发生动力学演化，产生从大尺度向中、小尺度结构运动的能量级联。这些尺度被认为是由各种不稳定机制和结构过程产生的，但是这种等离子体结构随时间演变的细节很少受到限制，特别是非线性方面。研究计划将侧重于详细的数据模型综合，以表征预计有助于电离层不规则演变的物理参数（即大尺度密度结构、背景速度场、梯度和剪切以及降水区域）。该方法包括无线电波传播（使用SIGMA）和基于RISR现有和新观测数据的极帽电离层建模，利用GPS （l波段）和UHF/VHF无线电信标表征大中型尺度和闪烁活动。结果将通过与以GEMINI模型为代表的基于物理的不稳定性模型的预测进行比较来解释，以表征在许多理想情况下电离层不稳定性的可观测影响，以及基于数据驱动模型输入的精选案例研究。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。