Complexity Induced Bimodal Anisotropic Intermittent Turbulence in Geospace

地球空间中复杂性引起的双峰各向异性间歇湍流

• 批准号: 0355463
• 负责人: Tom Chang
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0355463&HistoricalAwards=false
• 关键词: Complexity; Induced; Bimodal; Anisotropic; Intermittent

Considerable observational and theoretical attention has been devoted towards the understanding of local, point observations of geospace plasma phenomena observed by research satellites. However, it is clear that there are important questions that involve global and multiscale issues: questions of energy and momentum transport within the magnetosphere, ionosphere and the Sun-Earth connection region, and of the nature of the particle populations, their source, entry, energization, diffusion, and ultimate loss from the systems. Theoretical models are being forced to confront issues of non-locality and "complexity". For systems involving non-locality and complexity effects connected with the fluctuations of the electric and magnetic fields, the in homogeneities, and anomalous anisotropic transport and energization processes are important. This project will quantitatively examine the plasma turbulence and the intermittent fluctuations in the geospace region. Detailed spectra and other stochastic properties of both the non-propagating and propagating portions of the turbulence will be determined and compared with experimental observations. The goal is to produce a self-consistent picture of the complexity-generated, intermittent turbulence and the evolutionary processes of space plasmas. The mode of approach for the first part of the research is based on the method of path integrals and the theory of the dynamic renormalization group along with direct numerical simulations. Realistic models characterizing the anisotropic intermittency and anomalous transport of the auroral zone will be developed. The second part of the research program is based on the interaction of the particle distributions with both the intermittent propagating and non-propagating fluctuations. A global hybrid simulation model developed for the evolution of the polar wind, solar wind, and auroral ions will be enhanced and applied to determine the interactions. The project will also contribute to symposia and workshops on the physics of space plasmas, which will be hosted at MIT in cooperation with the MIT Graduate School and the MIT Minority Summer Research Program (MSRP). In addition there will be collaborations with the Washington-based Center of Excellence in Education (CEE) to sponsor the education of genius-level high school students. By intermingling with the scientists at MIT, these young interns will obtain first hand experience in scientific research in geoplasma physics.

对研究卫星观测到的地球空间等离子体现象的局部点观测的理解，在观测和理论上都给予了相当大的关注。然而，很明显，有一些重要的问题涉及全球和多尺度问题：磁层、电离层和日地连接区域内的能量和动量传输问题，以及粒子群的性质、它们的来源、进入、扩散、扩散和最终从系统中消失的问题。理论模型正被迫面对非定域性和“复杂性”的问题。对于涉及非局域性和复杂性的影响与波动的电场和磁场，在均匀性，和异常各向异性运输和湍流过程的系统是重要的。该项目将定量研究地球空间区域的等离子体湍流和间歇性波动。湍流的非传播和传播部分的详细光谱和其他随机特性将被确定，并与实验观测结果进行比较。我们的目标是产生一个自洽的图片的复杂性产生的，间歇性的湍流和空间等离子体的演化过程。第一部分的研究方法是基于路径积分方法和动力学重整化群理论沿着与直接数值模拟。将开发描述极光带各向异性折射率和异常传输的实际模型。研究计划的第二部分是基于粒子分布与间歇性传播和非传播波动的相互作用。将加强为极风、太阳风和极光离子演变而开发的全球混合模拟模型，并将其用于确定相互作用。该项目还将为空间等离子体物理学专题讨论会和讲习班作出贡献，这些专题讨论会和讲习班将与麻省理工学院研究生院和麻省理工学院少数民族暑期研究方案合作在麻省理工学院主办。此外，还将与总部位于华盛顿的卓越教育中心（CEE）合作，赞助天才级高中生的教育。通过与麻省理工学院的科学家们的交流，这些年轻的实习生将获得第一手的地质等离子体物理学科学研究经验。