标题： 三维不均匀低太阳风模拟 显示英文标题

标题： Three-dimensional simulations of the inhomogeneous Low Solar Wind

摘要： 在不久的将来，帕克太阳探测器将对日冕和太阳风之间过渡的动力学和性质的理论进行严格的测试。 解释新生太阳风动力学，包括其加热和加速的最流行机制是磁流体动力学（MHD）湍流。 大多数先前的模型关注由向外传播的阿尔芬波及其反射之间的相互作用引起的非线性级联，而忽略了可能与日冕等离子体的横向结构有关的影响，尽管有大量证据表明存在这种影响。 在本文中，我们首次通过三维MHD数值模拟分析了从低日冕到15 R_Sun的横向结构化日冕和太阳风的动力学。 我们发现背景结构对MHD湍流的演化有显著影响，其时间尺度比横向均匀情况下的时间尺度快得多。 在小于非线性时间的时间尺度上，与相位混合相关的线性效应导致了1/f横向能量谱。 随着湍流级联的发展，我们观察到横向（平行）能量谱，其幂律指数为-3/2或-5/3（-2），横向磁场谱比速度谱更陡峭，并且负剩余能量显著增加。 我们得出结论，湍流很可能是由驱动的横向扭振波的自级联产生的，之前被称为“uniturbulence”，这可能代表了原始太阳风中主要的非线性能量级联通道。 显示英文摘要

摘要： In the near future, Parker Solar Probe will put theories about the dynamics and nature of the transition between the solar corona and the solar wind to stringent tests. The most popular mechanism aimed to explain the dynamics of the nascent solar wind, including its heating and acceleration is magnetohydrodynamic (MHD) turbulence. Most of the previous models focus on nonlinear cascade induced by interactions of outgoing Alfv\'en waves and their reflections, ignoring effects that might be related to perpendicular structuring of the solar coronal plasma, despite overwhelming evidence for it. In this paper, for the first time, we analyse through 3D MHD numerical simulations the dynamics of the perpendicularly structured solar corona and solar wind, from the low corona to 15 R_Sun. We find that background structuring has a strong effect on the evolution of MHD turbulence, on much faster time scales than in the perpendicularly homogeneous case. On time scales shorter than nonlinear times, linear effects related to phase mixing result in a 1/f perpendicular energy spectrum. As the turbulent cascade develops, we observe a perpendicular (parallel) energy spectrum with the power law index of -3/2 or -5/3 (-2), a steeper perpendicular magnetic field than velocity spectrum, and a strong build-up of negative residual energy. We conclude that the turbulence is most probably generated by the self-cascade of the driven transverse kink waves, referred to previously as `uniturbulence', which might represent the dominant nonlinear energy cascade channel in the pristine solar wind.