The nonlinear force-free field (NLFFF) modeling has been extensively used as a tool to infer three-dimensional (3D) magnetic field structure. In this study, the dependency of the NLFFF calculation with respect to the initial guess of the 3D magnetic field is investigated. While major part of the previous studies used potential field as the initial guess in the NLFFF modeling, we adopt the linear force-free fields with different constant force-free alpha as the initial guesses. This method enables us to investigate how unique the magnetic field obtained by the NLFFF extrapolation with respect to the initial guess is. The dependence of the initial condition of the NLFFF extrapolation is smaller in the strong magnetic field region. Therefore, the magnetic field at the lower height ($ 0.9 with different initial condition), although the Lorentz force is concentrated at the lower height.

中文翻译：

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不同初始条件下火炬产生活动区三维磁场结构的外推

非线性无力场 (NLFFF) 建模已被广泛用作推断三维 (3D) 磁场结构的工具。在这项研究中，研究了 NLFFF 计算与 3D 磁场初始猜测的相关性。虽然以前研究的主要部分在 NLFFF 建模中使用势场作为初始猜测，但我们采用具有不同恒定无力 alpha 的线性无力场作为初始猜测。这种方法使我们能够研究通过 NLFFF 外推获得的磁场相对于初始猜测的唯一性。NLFFF 外推的初始条件的依赖性在强磁场区域较小。因此，较低高度处的磁场（不同初始条件下的$ 0.9），