发表机构
School of Astronomy and Space Science and Key Laboratory of Modern Astronomy and Astrophysics, Nanjing University; National Key Laboratory of Deep Space Exploration/School of Earth and Space Sciences, University of Science and Technology of China; Institute for Space-Earth Environmental Research, Nagoya University; School of Earth and Space Sciences, Peking University（南京大学天文与空间科学学院与现代天文学和天体物理学重点实验室; 中国科学技术大学深空探测全国重点实验室/地球与空间科学学院; 名古屋大学宇宙地球环境研究所; 北京大学地球与空间科学学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对重复日冕喷流的三维磁流体模拟，发现电流螺旋度随喷流演化、自由磁能无明显积累，常用螺旋度比对积分体积敏感，而局部归一化量更稳定，表明归一化螺旋度可作为喷发条件的有效诊断量。
AI 中文摘要
重复太阳日冕喷流源自同一源区，为研究磁能与螺旋度的积累、再分布及释放提供了有利环境。然而，这些物理量如何表征磁演化及喷发的起始条件仍不清楚。我们对由底部边界汇聚运动驱动的重复喷流开展了完整的三维热力学磁流体模拟，该模拟自然产生了两次连续喷发。载流螺旋度$H_J$在第一次喷流期间减小，且在两次喷流之间逐渐恢复；相比之下，自由磁能$E_{\mathrm{free}}$在首次释放后无明显积累。这一差异表明，$H_J$提供了超出$E_{\mathrm{free}}$所给出的磁演化信息。此外，常用的螺旋度比$H_J/H_V$在两次喷流起始附近达到不同峰值，且对积分体积敏感；相比之下，局地归一化量$H_J/\Phi_{\mathrm{closed}}^2$在两次喷流起始附近达到相似峰值，且对所测试积分体积的选择相对不敏感，其中$\Phi_{\mathrm{closed}}$为闭合场区域的单极性磁通量。这些结果揭示了喷发的局地性质，并表明由闭合磁通量平方归一化的$H_J$可作为喷发条件的有效诊断量。
英文摘要
Recurrent solar coronal jets originate from the same source region, providing a useful setting for studying the buildup, redistribution, and release of magnetic energy and helicity. However, how these quantities can characterize magnetic evolution and the onset conditions of the eruptions remains unclear. We perform a full three-dimensional (3D) thermodynamic magnetohydrodynamic simulation of recurrent jets driven by converging motions imposed at the bottom boundary. The simulation naturally produces two successive eruptions. The current-carrying helicity $H_J$ decreases during the first jet and gradually recovers between the two jets. In contrast, the free magnetic energy $E_{\mathrm{free}}$ shows no clear accumulation after its first release. This difference indicates that $H_J$ provides information on magnetic evolution beyond that provided by $E_{\mathrm{free}}$. Furthermore, the commonly used helicity ratio $H_J/H_V$ reaches different peaks near the onset of the two jets and is sensitive to the integration volume. By comparison, the locally normalized quantity $H_J/Φ_{\mathrm{closed}}^2$ reaches similar peaks near the onset of both jets and is relatively insensitive to the choice among the tested integration volumes, where $Φ_{\mathrm{closed}}$ is the single-polarity magnetic flux of the closed-field domain. These results reveal the local nature of the eruptions and suggest that $H_J$ normalized by the square of the closed magnetic flux may be a useful diagnostic of eruptive conditions.
Comments9 pages, 5 figures. Accepted for publication in The Astrophysical Journal Letters
