Sabri S, Farahani S Vasheghani, Ebadi H, Poedts S
Department of Theoretical Physics and Astrophysics, Faculty of Physics, University of Tabriz, P.O.Box 51666-16471, Tabriz, Iran.
Department of Mathematics, Center for mathematical Plasma Astrophysics, KU Leuven, Celestijnenlaan 200B, 3001, Leuven, Belgium.
Sci Rep. 2020 Sep 24;10(1):15603. doi: 10.1038/s41598-020-70995-y.
The aim of the present study is to provide insight on the induced compressive perturbations together with the modifications of the environmental parameters in the course of Alfvén wave interaction with a solar magnetic null-point. The shock-capturing Godunov-type code PLUTO is used to solve the set of ideal magnetohydrodynamic equations. The nonlinear effects connected with an initial Alfvén pulse nearing a magnetic null point induces fast and slow magnetoacoustic waves with anti phase conduct. The induced current density and flows are independent of the local plasma-[Formula: see text] at the reconnection site. The induced inflows and outflows highly depend on the polarization. The inflows have a stronger effect compared to the outflows in both the x and y directions showing its peak in the x-direction. The dominant wave that couples to flows is the fast wave due to the in-phase harmony between perturbations of the compressive parameters and the fast wave. The induced current density possesses a steady orientation at the reconnection site which governs the diffusion or propagation of the waves. Induced perturbations by the nonlinear forces together with their back reaction on the Alfvén wave have a significant role in the current density excitation being responsible for the creation of inflows and outflows that are possible candidates for the creation of solar jets which has a significant contribution towards coronal seismology.
本研究的目的是深入了解阿尔文波与太阳磁中性点相互作用过程中产生的压缩扰动以及环境参数的变化。采用捕捉激波的戈东诺夫型代码PLUTO来求解理想磁流体动力学方程组。与接近磁中性点的初始阿尔文脉冲相关的非线性效应会诱导出具有反相位传导的快磁声波和慢磁声波。感应电流密度和流场与重联点处的局部等离子体 - [公式：见原文]无关。感应的流入和流出高度依赖于极化。在x和y方向上，流入的影响都比流出更强，且在x方向上达到峰值。由于压缩参数的扰动与快波之间的同相协调，与流场耦合的主导波是快波。感应电流密度在重联点处具有稳定的方向，它控制着波的扩散或传播。非线性力引起的感应扰动及其对阿尔文波的反作用在电流密度激发中起着重要作用，电流密度激发导致了流入和流出的产生，而流入和流出可能是太阳喷流形成的候选因素，这对日冕地震学有重要贡献。
