日冕物理的辐射磁流体数值模拟研究

Radiative magnetohydrodynamics simulations on solar corona

太阳的最外层大气日冕中发生着多种活动现象,如耀斑、日冕物质抛射、日珥、冕雨等.为了深入研究这些活动现象的非线性物理过程,通过辐射磁流体数值模拟,构建多维数值模型是主流的研究手段之一.数值模拟日冕等离子体的宏观行为需要求解磁流体力学、辐射、热传导和加热等物理过程.首先简要介绍了求解这些物理过程的主流数值算法.求解磁流体力学方程组的数值格式由网格界面值的重构方法、黎曼问题近似解法、磁场散度控制方法和时间积分方法等部分组成.之后,综述了辐射磁流体数值模拟对太阳活动区磁环、耀斑、日珥和冕雨等日冕中的活动现象的研究进展.

The outmost layer of solar atmosphere, corona, has many activities, such as flares, coronal mass ejections, solar prominences, and coronal rains. In order to fully understand the nonlinear physical process of these activities, one of the most popular approaches is to construct multidimensional numerical models via radiative magnetohydrodynamic numerical simulations. To simulate macroscopic coronal physics, we need to numerically solve magnetohydrodynamic equations coupled with radiative cooling, thermal conduction, and heating. The mainstream numerical methods to numerically solve these problems are introduced. The numerical scheme to solve the magnetohydrodynamic equations is composed of reconstruction to cell-interface values, approximate Riemann solver, methods to control divergence of magnetic field, and time integrator. We then review on the state of art in numerical studies on solar active region, flares,prominences, and coronal rains.