AI 中文总结
本研究针对太阳大气中磁螺度和能量随高度变化的未知性，通过分析150个活动区数据与NLFFF外推，确定最优外推高度，为太阳活动区磁螺度统计研究提供参数约束。
AI 中文摘要
磁螺度和磁能是理解太阳发电机与太阳爆发的关键，它们的三维分布具有重要意义，但这些量如何随高度变化仍知之甚少。此外，由于三维分布依赖于磁场外推，如何从物理而非经验标准确定最优外推高度仍是一个未解决的问题。为解决该问题，本研究调查了活动区日冕中磁螺度和磁能的垂直分布。我们分析了1988年至2019年间太阳磁场望远镜（SMFT）观测的150个活动区，按绝对磁通量分组，进行非线性无力场（NLFFF）外推，并采用有限体积法计算相对磁螺度。研究发现，在所采用的配置下，外推高度至少为81 Mm时，可保留97%的总磁螺度和磁能，同时降低约38%的计算成本。本研究为太阳活动区磁螺度的长期统计研究提供了重要的参数约束。
英文摘要
Magnetic helicity and magnetic energy are key to understanding the solar dynamo and eruptions, and their three-dimensional distributions are of great significance. However, how these quantities vary with height remains poorly understood. Moreover, because the three-dimensional distribution depends on magnetic field extrapolation, determining the optimal extrapolation height from physical rather than empirical criteria remains an open problem. To address this issue, this work investigates the vertical distributions of magnetic helicity and magnetic energy in the solar corona within active regions. We analyze 150 active regions observed by the Solar Magnetic Field Telescope (SMFT) from 1988 to 2019, grouped by absolute magnetic flux, perform nonlinear force-free field (NLFFF) extrapolations, and compute the relative magnetic helicity with a finite volume method. It is found that an extrapolation height of at least 81 Mm retains 97% of the total magnetic helicity and energy while reducing computational costs by approximately 38% under the adopted configuration. This work provides important parameter constraints for the long-term statistical study of magnetic helicity in solar active regions.
Comments17 pages, 7 figures. To be accepted in Solar Physics
