论文标题
来自加权边界条件的自洽的非线力场重建
Self-consistent Nonlinear Force-free Field Reconstruction from Weighted Boundary Conditions
论文作者
论文摘要
矢量磁图数据通常用作无力冠状磁场外推的光晶边界条件。但是，通常，矢量磁图数据与无力的假设不一致。在本文中，我们通过概括了Wheatland＆Regnier（2009）的“自矛盾程序”，展示了一种处理不一致的边界数据的方法。在该过程中，通过迭代过程解决了基于在边界中该田间的两个极性（P和N极性）上构建两种溶液的迭代过程，并以P和N解决方案中边界Alpha值的不确定性加权平均值来解决。当p和n区域中的α值大不相同时，自洽的解决方案可能会因边界条件而失去高α值。我们展示了如何通过改变P或N边界条件下不确定性的加权，我们可以在自洽解决方案中保留高α值。加权自一致的外推法在分析两极场上进行了证明，并应用于NOAA活动区域AR 12017的Helioseissic和Magical Imager（HMI）仪器在2014年3月29日获取的矢量磁图数据。
Vector magnetogram data are often used as photospheric boundary conditions for force-free coronal magnetic field extrapolations. In general, however, vector magnetogram data are not consistent with the force-free assumption. In this article, we demonstrate a way to deal with inconsistent boundary data, by generalizing the "self-consistency procedure" of Wheatland & Regnier (2009). In that procedure, the inconsistency is resolved by an iterative process of constructing two solutions based on the values of the force-free parameter alpha on the two polarities of the field in the boundary (the P and N polarities), and taking uncertainty-weighted averages of the boundary alpha values in the P and N solutions. When the alpha values in the P and N regions are very different, the self-consistent solution may lose high alpha values from the boundary conditions. We show how, by altering the weighting of the uncertainties in the P or N boundary conditions, we can preserve high alpha values in the self-consistent solution. The weighted self-consistent extrapolation method is demonstrated on an analytic bipole field and applied to vector magnetogram data taken by the Helioseismic and Magnetic Imager (HMI) instrument for NOAA active region AR 12017 on 2014 March 29.
