球面几何中磁流体静力日冕平衡计算的最优化方法
Optimization approach for the computation of magnetohydrostatic coronal equilibria in spherical geometry
摘要：
背景：本文提出了一种可用于根据观测数据计算全球日冕模型的方法。目的：本文提出了一种计算球面几何中非线性磁流体静力平衡的优化方法，目的是利用观测数据得到日冕磁场、日冕等离子体密度和等离子体压力的自洽解。研究方法：我们的代码的自洽计算的日冕磁场和日冕等离子体解决了非力自由磁流体静力平衡使用的优化方法。以前版本的代码已被用来计算非线性无力日冕磁场从光球测量笛卡尔和球面几何，和静磁平衡笛卡尔几何。我们测试我们的代码的帮助下，一个已知的分析三维平衡解的磁流体静力学方程。通过使用磁场线图、密度和压力图以及一些常用的定量数值比较措施，对数值计算和精确平衡解进行了详细的比较。结果如下：我们发现，该方法准确地重建平衡，与残余力的顺序的离散化误差的解析解。与参考溶液的相关性好于99.9%，磁能计算准确，误差小于0.1%。结论：到目前为止，我们将该方法应用于分析测试案例。我们正计划尽快将这种方法与实际观测数据一起使用。
英文摘要：
Context: This paper presents a method which can be used to calculate models of the global solar corona from observational data. Aims: We present an optimization method for computing nonlinear magnetohydrostatic equilibria in spherical geometry with the aim to obtain self-consistent solutions for the coronal magnetic field, the coronal plasma density and plasma pressure using observational data as input. Methods: Our code for the self-consistent computation of the coronal magnetic fields and the coronal plasma solves the non-force-free magnetohydrostatic equilibria using an optimization method. Previous versions of the code have been used to compute non-linear force-free coronal magnetic fields from photospheric measurements in Cartesian and spherical geometry, and magnetostatic-equilibria in Cartesian geometry. We test our code with the help of a known analytic 3D equilibrium solution of the magnetohydrostatic equations. The detailed comparison between the numerical calculations and the exact equilibrium solutions is made by using magnetic field line plots, plots of density and pressure and some of the usual quantitative numerical comparison measures. Results: We find that the method reconstructs the equilibrium accurately, with residual forces of the order of the discretisation error of the analytic solution. The correlation with the reference solution is better than 99.9% and the magnetic energy is computed accurately with an error of <0.1%. Conclusions: We applied the method so far to an analytic test case. We are planning to use this method with real observational data as input as soon as possible.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
