论文标题
径向距离对太阳风中小尺度磁通绳的影响
Effects of Radial Distances on Small-scale Magnetic Flux Ropes in the Solar Wind
论文作者
论文摘要
太阳风中的小规模磁通绳（SFR）已经研究了数十年。利用各种原位航天器测量的统计分析是主要的观察方法，可帮助研究这些小规模结构的产生和演变。基于Grad-Shafranov（GS）的重建技术，我们使用自动检测算法通过不同的以不同的中心距离的各种航天器测量来构建这些小规模结构的数据库。我们介绍了SFR性能，包括磁场和等离子参数，与靠近黄道平面附近的太阳不同。发现事件的发生率仍在每月数百个，持续时间和量表大小分布遵循功率定律，并且通量绳轴方向大约围绕当地的帕克螺旋方向。通常，大多数SFR性质都表现出径向衰变。此外，在建立了各种数据库的情况下，我们为径向距离提供了平均场幅度，事件计数和SFR尺寸的变化的缩放定律，从HELIOS的$ \ sim $ 0.3 au到Voyager spacecraft的$ \ sim $ 0.3 au到$ \ sim $ 7 au。讨论了我们结果对与相关理论工作以及对Parker太阳探针（PSP）任务的应用的比较的含义。
Small-scale magnetic flux ropes (SFRs), in the solar wind, have been studied for decades. Statistical analysis utilizing various in situ spacecraft measurements is the main observational approach which helps investigate the generation and evolution of these small-scale structures. Based on the Grad-Shafranov (GS) reconstruction technique, we use the automated detection algorithm to build the databases of these small-scale structures via various spacecraft measurements at different heliocentric distances. We present the SFR properties including the magnetic field and plasma parameters at different radial distances from the sun near the ecliptic plane. It is found that the event occurrence rate is still in the order of a few hundreds per month, the duration and scale size distributions follow power laws, and the flux rope axis orientations are approximately centered around the local Parker spiral directions. In general, most SFR properties exhibit radial decays. In addition, with various databases established, we derive scaling laws for the changes of average field magnitude, event counts, and SFR scale sizes, with respect to the radial distances, ranging from $\sim$ 0.3 au for Helios to $\sim$ 7 au for the Voyager spacecraft. The implications of our results for comparisons with the relevant theoretical works and for the application to the Parker Solar Probe (PSP) mission are discussed.
