The Role of Alfven Wave Energy Transport in Geospace Dynamics

阿尔文波能量传输在地球空间动力学中的作用

• 批准号: RGPIN-2018-06006
• 负责人: Mann, Ian
• 金额: $ 4.44万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=714029
• 关键词: Role; Alfven; Wave; Energy; Transport

Space plasma physics in the solar system is a major focus for current and future national and international space agency missions. This research focuses on the fundamental processes active in solar and planetary plasma environments, a plasma being a hot ionised gas, strongly influenced by magnetic fields. The same processes are active in high energy plasma astrophysical systems, in magnetic fusion reactors, and their affects are felt on Earth and by human explorers in the solar system through the impacts of space weather. At the core of this research is are numerous important outstanding questions: whether this be the how energy is extracted from magnetic fields through a fundamental process known as magnetic reconnection, why the outer atmosphere of the sun (the solar coronal) is millions of degrees hotter than the 6000 degrees at the surface, how the solar wind is accelerated, or how magnetic storms affect our planet and result in the acceleration of particles to relativistic speeds! Such processes are important throughout the astrophysical universe, but only in the solar system can spacecraft collect the data needed to advance scientific understanding. The operation of a fleet international satellites around the Earth and in the solar system presents a unique opportunity for discovery. This is heralding a golden age for space research, and exploiting this opportunity is the focus of the Discovery Grant research and training proposed here. Our proposed research focuses on the impacts of Alfven waves in controlling geospace dynamics. Alfven waves are low-frequency waves whose energy transport and signals are guided by the magnetic field. Despite an increasing recognition that they are pervasive in these plasma systems, the potential that Alfven waves may control a number of energetically significant processes is only now beginning to be explored in detail. This is especially true at Earth in relation to radiation belt dynamics, and perhaps also to the dynamics of electrical current systems, and coupling between the ionised and neutral atmosphere, and perhaps even to climate. Addressing the role of Alfven waves in these processes are the specific research topics to be addressed in this proposal. Significantly, and according to a US National Academies report in 2008, space weather also represents a potential $2 Trillion USD threat to 21st century technological infrastructure in the US alone, including impacts on the electrical power grid, satellite systems, and communications networks. As a result, the research and training proposed here is also very timely since it aligns perfectly with an increasingly important need to understand, forecast, and mitigate the impacts arising from space weather. This ensures that the fundamental science discoveries arising from the proposed research will additionally have high profile applications, with national and indeed international importance.

太阳系中的空间等离子体物理学是国家和国际空间局当前和未来飞行任务的一个主要重点。这项研究的重点是太阳和行星等离子体环境中活跃的基本过程，等离子体是一种热电离气体，受磁场的强烈影响。高能等离子体天体物理系统和磁聚变反应堆中也活跃着同样的过程，地球和太阳系中的人类探索者通过空间天气的影响感受到了这些过程的影响。这项研究的核心是许多重要的悬而未决的问题：无论这是如何从磁场中提取能量通过一个基本的过程称为磁重联，为什么太阳的外层大气（太阳日冕）比表面的6000度要热数百万度，太阳风是如何加速的，或者磁暴如何影响我们的星球，导致粒子加速到相对论速度！这些过程在整个天体物理学宇宙中都很重要，但只有在太阳系中，航天器才能收集推进科学认识所需的数据。围绕地球和太阳系运行的一系列国际卫星提供了一个独特的发现机会。这预示着太空研究的黄金时代，利用这一机会是这里提出的发现补助金研究和培训的重点。 我们建议的研究重点是阿尔芬波在控制地球空间动力学的影响。阿尔芬波是低频波，其能量传输和信号由磁场引导。尽管越来越多的认识到，他们是普遍存在于这些等离子体系统中，阿尔芬波可能会控制一些积极的重大进程的潜力，现在才开始详细探讨。在地球上，辐射带的动力学、电流系统的动力学、电离和中性大气之间的耦合，甚至气候，都是如此。解决阿尔芬波在这些过程中的作用是本提案中要解决的具体研究课题。 值得注意的是，根据美国国家科学院2008年的一份报告，太空天气也代表着仅在美国就对21世纪的技术基础设施造成20亿美元的潜在威胁，包括对电网，卫星系统和通信网络的影响。因此，这里提议的研究和培训也非常及时，因为它完全符合了解、预测和减轻空间气象影响这一日益重要的需要。这确保了从拟议的研究中产生的基础科学发现将另外具有高知名度的应用，具有国家和国际重要性。