Small-scale magnetic flux ropes (SMFRs) fill much of the solar wind, but their origin and evolution are debated. We apply our recently developed, improved Grad–Shafranov algorithm for the detection and reconstruction of SMFRs to data from Parker Solar Probe, Solar Orbiter, Wind, and Voyager 1 and 2 to detect events from 0.06 to 10 au. We observe that the axial flux density is the same for SMFRs of all sizes at a fixed heliocentric distance but decreases with distance owing to solar wind expansion. Additionally, using the difference in speed between SMFRs, we find that the vast majority of SMFRs will make contact with others at least once during the 100 hr transit to 1 au. Such contact would allow SMFRs to undergo magnetic reconnection, allowing for processes such as merging via the coalescence instability. Furthermore, we observe that the number of SMFRs with higher axial flux increases significantly with distance from the Sun. Axial flux is conserved under solar wind expansion, but the observation can be explained by a model in which SMFRs undergo turbulent evolution by stochastically merging to produce larger SMFRs. This is supported by the observed log-normal axial flux distribution. Lastly, we derive the global number of SMFRs above 10¹⁵ Mx near the Sun to investigate whether SMFRs begin their journey as small-scale solar ejections or are continuously generated within the outer corona and solar wind.

中文翻译：

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0.06 至 10 au 的小型磁通绳的轴向通量演变

小尺度磁通绳（SMFR）充满了太阳风的大部分，但它们的起源和演变仍存在争议。我们将最近开发的改进的 Grad-Shafranov 算法应用于帕克太阳探测器、太阳轨道飞行器、风以及旅行者 1 号和 2 号的数据来检测和重建 SMFR，以检测 0.06 到 10 个天文单位的事件。我们观察到，在固定的日心距离下，所有尺寸的 SMFR 的轴向通量密度都是相同的，但由于太阳风膨胀，轴向通量密度随着距离的增加而减小。此外，利用 SMFR 之间的速度差异，我们发现绝大多数 SMFR 在到达 1 天文单位的 100 小时内至少会与其他人接触一次。这种接触将使 SMFR 发生磁重联，从而允许通过聚结不稳定性进行合并等过程。此外，我们观察到具有较高轴向通量的 SMFR 的数量随着距太阳的距离而显着增加。轴向通量在太阳风膨胀下守恒，但这一观察结果可以用一个模型来解释，在该模型中，SMFR 通过随机合并产生更大的 SMFR 来经历湍流演化。观察到的对数正态轴向磁通分布支持了这一点。最后，我们得出了太阳附近超过 10 ¹⁵ Mx的全球 SMFR 数量，以研究 SMFR 是否以小规模太阳抛射的形式开始其旅程，或者在外日冕和太阳风内持续产生。