A magnetic flux rope configuration derived by optimization of two-spacecraft In-situ measurements
A magnetic flux rope configuration derived by optimization of two-spacecraft In-situ measurements
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DOI：
10.3389/fphy.2022.960315
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发表时间：
2022-06
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影响因子：
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通讯作者：
Q. Hu;W. He;Yu Chen
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作者：
Q. Hu;W. He;Yu Chen
越来越多的一种行星际日冕物质抛射（ICME）结构可以在太阳风中传播到不止一艘航天器上。当两个或多个航天器以相对较小的纵向分离角几乎径向对齐时，通常会发生这种情况。这提供了同一结构的多点测量，并能够更好地表征和验证这些 ICME 中嵌入的结构的建模结果。我们报告了 2019 年 10 月 13 日至 14 日发生的这一事件，当时太阳地球关系观测站 (STA) 航天器和帕克太阳探测器 (PSP) 在两个不同位置穿过一个 ICME 结构，日心距离和纵向角度均具有标称间隔。我们首先基于分析准三维 (3D) 模型对 STA 现场测量进行最佳拟合，得到最小减小的 χ 2 = 0.468。然后，我们进一步应用优化方法，将两个航天器沿着 ICME 结构的单独路径进行的磁场测量相结合。我们发现，鉴于模型输出与 PSP 数据的一致性大大提高，基于组合两航天器数据集优化（最小减少 χ 2 = 3.15）的输出产生了更一致的结果。结果展示了具有清晰 3D 空间变化的磁通绳配置。
Increasingly one interplanetary coronal mass ejection (ICME) structure can propagate across more than one spacecraft in the solar wind. This usually happens when two or more spacecraft are nearly radially aligned with a relatively small longitudinal separation angle from one another. This provides multi-point measurements of the same structure and enables better characterization and validation of modeling results of the structures embedded in these ICMEs. We report such an event during October 13-14, 2019 when the Solar TErrestrial RElations Observatory Ahead (STA) spacecraft and the Parker Solar Probe (PSP) crossed one ICME structure at two different locations with nominal separations in both heliocentric distances and the longitudinal angles. We first perform an optimal fitting to the STA in-situ measurements, based on an analytic quasi-three dimensional (3D) model, yielding a minimum reduced χ 2 = 0.468. Then we further apply the optimization approach by combining the magnetic field measurements from both spacecraft along their separate paths across the ICME structure. We find that the output based on the optimization (with the minimum reduced χ 2 = 3.15) of the combined two-spacecraft dataset yields a more consistent result, given the much improved agreement of the model output with PSP data. The result demonstrates a magnetic flux rope configuration with clear 3D spatial variations.