Solar wind and kinetic heliophysics
Solar wind and kinetic heliophysics
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DOI：
10.5194/angeo-36-1607-2018
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发表时间：
2018-09
影响因子：
1.9
通讯作者：
E. Marsch
中科院分区：
文献类型：
--
作者：
E. Marsch
抽象的。本文综述了太阳风物理的最新进展，并阐明了阿尔芬波在太阳风加速和湍流中的作用，这种加速和湍流普遍存在于低日冕和内日光层。基于遥感、现场测量、动力学模拟和流体模拟，我们对太阳风的理解已经取得了相当大的进展。预计帕克太阳探测器和太阳轨道器等任务将提供进一步的见解。太阳风的来源已经在太阳的色球网络、过渡区和日冕中被确定。由网络中的重联激发的Alfvén波有助于推动漏斗和日冕洞中的湍流和等离子体流动。动态的太阳磁场导致太阳风在太阳周期内发生变化。太阳的磁场活动产生了快速和缓慢的太阳风流，以及瞬变的日冕物质抛射。磁流体湍流起源于太阳，并演化到行星际空间。主要的Alfvén波和次要的磁声波，在不同的尺度上混合了压力平衡结构，构成了太阳物理湍流。它的光谱沿径向演化，并形成各向异性。湍流谱的数值模拟再现了主要的观测特征。波动的无碰撞消散仍然是一个密集研究的主题。对粒子速度分布的详细测量揭示了非麦克斯韦电子、强各向异性质子和重离子束。除了日球层中的宏观作用力外，局域波-粒子相互作用也影响着分布函数。它们可以用包含碰撞和波的Boltzmann-Vlasov方程来描述。动力学模拟使我们能够更好地理解日光层中粒子和波的组合演化。
Abstract. This paper reviews recent aspects of solar wind physics and elucidates the role Alfvén waves play in solar wind acceleration and turbulence, which prevail in the low corona and inner heliosphere. Our understanding of the solar wind has made considerable progress based on remote sensing, in situ measurements, kinetic simulation and fluid modeling. Further insights are expected from such missions as the Parker Solar Probe and Solar Orbiter. The sources of the solar wind have been identified in the chromospheric network, transition region and corona of the Sun. Alfvén waves excited by reconnection in the network contribute to the driving of turbulence and plasma flows in funnels and coronal holes. The dynamic solar magnetic field causes solar wind variations over the solar cycle. Fast and slow solar wind streams, as well as transient coronal mass ejections, are generated by the Sun's magnetic activity. Magnetohydrodynamic turbulence originates at the Sun and evolves into interplanetary space. The major Alfvén waves and minor magnetosonic waves, with an admixture of pressure-balanced structures at various scales, constitute heliophysical turbulence. Its spectra evolve radially and develop anisotropies. Numerical simulations of turbulence spectra have reproduced key observational features. Collisionless dissipation of fluctuations remains a subject of intense research. Detailed measurements of particle velocity distributions have revealed non-Maxwellian electrons, strongly anisotropic protons and heavy ion beams. Besides macroscopic forces in the heliosphere, local wave–particle interactions shape the distribution functions. They can be described by the Boltzmann–Vlasov equation including collisions and waves. Kinetic simulations permit us to better understand the combined evolution of particles and waves in the heliosphere.