Intermittency and Ion Heating in Reduced Magnetohydrodynamic Turbulence

减少磁流体动力湍流中的间歇和离子加热

• 批准号: 1500041
• 负责人: Benjamin Chandran
• 金额: $ 28万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1500041&HistoricalAwards=false
• 关键词: Intermittency; Ion; Heating; Reduced; Magnetohydrodynamic

This project will advance the scientific community's understanding of turbulence in the solar wind, which is the quasi-steady outflow of high-temperature, ionized gas (plasma) from the Sun. Turbulence plays a key role in heating and accelerating the solar wind, which in turn mediates the interactions between the Sun and Earth's near-space environment. This project will thus ultimately contribute to the scientific community's ability to understand and model space weather, which includes disturbances in the Earth's magnetic field that have the potential to damage power grids. In addition, this project will contribute to the training of future scientists by supporting the research team's involvement in, and organization of, the annual Solar Heliospheric and INterplanetary Environment (SHINE) Workshop. This Workshop attracts roughly 200 attendees, of whom approximately 60 are students. The Workshop provides students with specialized training in space science and helps integrate students into the community of space-science researchers. The principal investigator of the project will teach in summer schools for undergraduate students, graduate students, and postdoctoral researchers in the fields of plasma physics and space physics. The principal investigator will also incorporate research findings from this project into his teaching of physics and astronomy at the University of New Hampshire. These activities will contribute to the development of a strong science-technology-engineering-mathematics (STEM) workforce, which will benefit society at large.The particular scientific focus of the project's turbulence research is on the phenomenon of intermittency and its effects upon solar-wind turbulence. Intermittency is a property of turbulent flows in which random fluctuations in, for example, the velocity of the medium (``eddies'') become concentrated into a decreasing fraction of the volume as the size of the eddies decreases. Intermittency profoundly impacts almost every aspect of solar-wind turbulence, from the rate at which it heats the interplanetary medium to the mechanisms by which turbulent energy is transferred to the different types of charged particles contained in the solar wind. To tackle this problem, the research team will employ a range of methodologies, including mathematical modeling and computer simulations, and they will test their theoretical predictions using spacecraft measurements.

该项目将增进科学界对太阳风湍流的理解，太阳风是来自太阳的高温电离气体（等离子体）的准稳定流出。湍流在加热和加速太阳风方面发挥着关键作用，而太阳风反过来又调节了太阳与地球近太空环境之间的相互作用。因此，该项目最终将有助于科学界理解和模拟空间天气的能力，其中包括可能损坏电网的地球磁场扰动。此外，该项目将通过支持研究团队参与和组织年度太阳日光层和行星际环境（SHINE）研讨会，为未来科学家的培训做出贡献。本次研讨会吸引了大约 200 名与会者，其中大约 60 名是学生。该讲习班为学生提供空间科学方面的专门培训，并帮助学生融入空间科学研究人员群体。该项目的主要研究者将在暑期学校为等离子体物理和空间物理领域的本科生、研究生和博士后研究人员授课。首席研究员还将将该项目的研究成果纳入他在新罕布什尔大学的物理和天文学教学中。这些活动将有助于培养一支强大的科学技术工程数学（STEM）劳动力队伍，这将使整个社会受益。该项目的湍流研究的特别科学重点是间歇性现象及其对太阳风湍流的影响。 间歇性是湍流的一种特性，其中介质（“涡流”）速度的随机波动随着涡流尺寸的减小而集中到体积的减小部分中。间歇性对太阳风湍流的几乎各个方面都有深远的影响，从加热行星际介质的速率到湍流能量转移到太阳风中包含的不同类型带电粒子的机制。为了解决这个问题，研究小组将采用一系列方法，包括数学建模和计算机模拟，并且他们将使用航天器测量来测试他们的理论预测。