论文标题
太阳能和恒星磁场的潜在场源表面外推的测试问题
Test Problems for Potential Field Source Surface Extrapolations of Solar and Stellar Magnetic Fields
论文作者
论文摘要
潜在的场源表面（PFSS）方程通常用于对太阳和其他恒星的冠状磁场进行建模。与任何计算模型一样，使用数值方案求解方程将由于离散化引起的错误。当输入场与单个球形谐音成正比时，我们提出了一组测试，通过利用PFSS方程的分析解决方案来量化这些误差。从球形谐波溶液中，我们得出了通过三维磁场溶液追踪的磁场线的分析方程。我们将这些建议作为一组标准分析解决方案，应对所有PFSS求解器进行测试以量化其固有错误。我们将这些测试应用于PFSSPY软件包，表明它可以很好地重现球形谐波解决方案，并略微高估未签名的开放磁通通量。它在复制分析场线方程方面也成功，场line脚步的错误通常远小于一个度。
The potential field source surface (PFSS) equations are commonly used to model the coronal magnetic field of the Sun and other stars. As with any computational model, solving equations using a numerical scheme introduces errors due to discretisation. We present a set of tests for quantifying these errors by taking advantage of analytic solutions to the PFSS equations when the input field is proportional to a single spherical harmonic. From the spherical harmonic solutions we derive analytic equations for magnetic field lines traced through the three dimensional magnetic field solution. We propose these as a set of standard analytic solutions that all PFSS solvers should be tested against to quantify their inherent errors. We apply these tests to the pfsspy software package, showing that it reproduces spherical harmonic solutions well with a slight overestimation of the unsigned open magnetic flux. It is also successful at reproducing analytic field line equations, with errors in field line footpoints typically much less than one degree.
