Quasilinear Dissipation of Turbulently-Generated Kinetic Alfven Waves: Kinetics of Ion Heating and Solar Wind Acceleration in Coronal Holes

湍流产生的动能阿尔芬波的拟线性耗散：冕洞中离子加热和太阳风加速的动力学

• 批准号: 2005982
• 负责人: Philip Isenberg
• 金额: $ 55.3万
• 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: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2005982&HistoricalAwards=false
• 关键词: Quasilinear; Dissipation; Turbulently; Generated; Kinetic

The solar wind defines the Earth's plasma environment, mediating all solar disturbances and space weather effects. A full microscale understanding of the processes that operate in the flow will aid investigations in these areas. This 3-year research study of ion heating by turbulently generated kinetic Alfven waves (KAWs) will address the long-standing puzzle of how the solar wind is heated and accelerated through the dissipation of Alfvenic plasma turbulence. The ion energization expected from this mechanism should finally provide a kinetic basis for detailed solar wind models that require accurate, physically motivated heating rates. It will also provide a physical explanation for the preferential heating of heavy ions in the solar wind. Ultimately, this 3-year project will yield a quantitative kinetic model of the multi-ion accelerated and heated solar wind as it emerges from a coronal hole. Furthermore, it will provide valuable insight on the many other phenomena in the plasma universe that involve turbulence, such as solar and stellar flares, supernova remnants, accretion discs of compact objects, as well as interstellar, intergalactic and intra-cluster flows. Additionally, the project team members are active participants in the educational efforts at the UNH, and the support provided by this grant will enable continuation of their productive research interactions with graduate and undergraduate students.It is widely accepted that the solar wind is driven by ion heating due to the dissipation of plasma turbulence in the solar corona. The kinetic details of this heating process determine the microscale properties of the resulting wind, but such details are not presently known. Observationally, the heating must act preferentially on the perpendicular ion motion, and act more strongly on heavy ions than on protons. Simulations of plasma turbulence can produce these results but do not clearly pinpoint the kinetic mechanism. Recently, a picture of collisionless turbulence has emerged that describes the small-scale fluctuations in terms of KAWs. These fluctuations are highly oblique, compressive, and elliptically polarized. Although these turbulent fluctuations are not waves in the standard sense, their polarization and propagation properties may still be obtained from a plasma dispersion relation. In the past, the project team has shown that a plausible turbulent spectrum of KAWs will heat ions in the perpendicular direction through the quasilinear (QL) cyclotron resonance, and that this heating can dominate the effect of the seemingly stronger Landau resonance in circumstances relevant to the solar wind. During this 3-year project, the team will carry out a thorough investigation of this QL interaction in the corona and solar wind, adding more physical details to their initial example and investigating the effects of different plasma and turbulent properties. In each case, the team will follow the self-consistent evolution of the ion distributions and fluctuation dispersion relations obtained from our Arbitrary Linear Plasma Solver (ALPS). The investigators will explore the effects of different plasma beta: different assumptions on the turbulent spectral shape; imbalanced turbulent spectra; intermittency; and, resonance broadening. They will study the preferential effects on heavy ions throughout these explorations. The results of spatially homogeneous studies will be incorporated into their inhomogeneous kinetic guiding-center coronal hole model, which derives radially dependent ion distributions when the turbulent heating is coupled with global coronal forces. The research and EPO agenda of this project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research.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.

太阳风定义了地球的等离子体环境，介导了所有太阳干扰和空间天气影响。 对流动中运作的过程的全面了解将有助于在这些领域进行调查。 这项为期三年的研究研究了通过湍流产生的动力学阿尔文波（KAWS）加热离子加热的研究，将解决长期存在的难题，即如何通过耗散阿尔法维克血浆湍流来加热太阳风和加速。 这种机制预期的离子能量最终应为需要准确，物理动机的加热率的详细太阳风模型提供动力学基础。 它还将为在太阳风中优先加热重离子提供物理解释。 最终，这个3年的项目将产生从冠状孔出现的多离子加速和加热太阳风的定量动力学模型。 此外，它将对涉及湍流的许多其他现象，例如太阳和恒星耀斑，超新星残留物，紧凑型物体的积聚盘以及星际，间层间和群集内流动。 此外，项目团队成员是UNH的教育工作的积极参与者，这笔赠款提供的支持将使他们与研究生和本科生的生产研究互动继续进行。它已广泛接受，太阳能是由于Solar Corarona等血浆湍流的耗散而导致离子加热驱动的。这种加热过程的动力学细节决定了所得风的微观特性，但目前尚不清楚这些细节。 从观察上讲，加热必须优先在垂直离子运动上起作用，并且比质子更强烈地对重离子作用。 血浆湍流的模拟可以产生这些结果，但不能清楚地指出动力学机制。 最近，出现了一幅无碰撞湍流的图片，描述了KAWS的小规模波动。 这些波动高度倾斜，压缩和椭圆极化。 尽管这些湍流波动不是标准意义上的波，但它们的极化和传播特性仍然可以从血浆分散关系中获得。 过去，项目团队表明，kaw的合理湍流光谱将通过icarinear（QL）循环转基因共振朝着垂直方向加热离子，并且这种加热可以主导与Solar Wind相关的情况下，看似强的Landau共振的效果。 在这个为期三年的项目中，该团队将对电晕和太阳风中的这种QL相互作用进行彻底的调查，从而为他们的初始示例增加了更多的物理细节，并研究了不同等离子体和动荡特性的影响。 在每种情况下，团队都将遵循从我们任意的线性等离子体求解器（ALP）获得的离子分布和波动分散关系的自洽演变。 研究人员将探讨不同等离子体β的影响：不同的假设对湍流形状；不平衡的动荡光谱；间歇性；以及共鸣的扩展。 他们将在这些探索过程中研究对重离子的优惠影响。 空间均匀研究的结果将纳入其不均匀的动力学指导中心冠状孔模型，当湍流加热与全球冠状动力耦合时，该模型衍生出径向依赖的离子分布。 该项目的研究和EPO议程支持了AGS部门在发现，学习，多样性和跨学科研究方面的战略目标。该奖项反映了NSF的法定任务，并认为值得通过基金会的知识分子优点和更广泛影响的评估标准通过评估来获得支持。

项目成果

Observational Analysis and Numerical Modeling of the Solar Wind Fluctuation Spectra during Intervals of Plasma Instability

等离子体不稳定期间太阳风脉动光谱的观测分析和数值模拟

• DOI: 10.3847/1538-4357/ac9f42
• 发表时间: 2022
• 期刊: The Astrophysical Journal
• 作者: Markovskii, S. A.;Vasquez, Bernard J.
• 通讯作者: Vasquez, Bernard J.

Three-dimensional Hybrid Simulation Results of a Variable Magnetic Helicity Signature at Proton Kinetic Scales

• DOI: 10.3847/1538-4357/ac3bbc
• 发表时间: 2022-01
• 期刊: The Astrophysical Journal
• 作者: B. Vasquez;S. Markovskii;Charles W. Smith

Turbulence Driving by Interstellar Pickup Ions in the Outer Solar Wind

• DOI: 10.3847/1538-4357/acb337
• 发表时间: 2023-01
• 期刊: The Astrophysical Journal
• 作者: P. Isenberg;B. Vasquez;Charles W. Smith

Four-dimensional Frequency–Wavenumber Power Spectrum of a Strong Turbulence Obtained from Hybrid Kinetic Simulations

• DOI: 10.3847/1538-4357/abb99f
• 发表时间: 2020-11
• 期刊: The Astrophysical Journal
• 作者: S. Markovskii;B. Vasquez

The effect of variations in the magnetic field direction from turbulence on kinetic-scale instabilities

湍流引起的磁场方向变化对动力学尺度不稳定性的影响

• DOI: 10.1051/0004-6361/202345965
• 发表时间: 2023
• 期刊: Astronomy & Astrophysics
• 影响因子: 6.5
• 作者: Opie, Simon;Verscharen, Daniel;Chen, Christopher H.;Owen, Christopher J.;Isenberg, Philip A.
• 通讯作者: Isenberg, Philip A.