Measuring the global magnetic field of the solar corona remains exceptionally challenging. The fine-scale density structures observed in white light images taken during Total Solar Eclipses (TSEs) are currently the best proxy for inferring the magnetic field direction in the corona from the solar limb out to several solar radii (Rs). We present, for the first time, the topology of the coronal magnetic field continuously between 1 and 6 Rs, as quantitatively inferred with the Rolling Hough Transform (RHT) for 14 unique eclipse coronae that span almost two complete solar cycles. We find that the direction of the coronal magnetic field does not become radial until at least 3 Rs, with a high variance between 1.5 and 3 Rs at different latitudes and phases of the solar cycle. We find that the most non-radial coronal field topologies occur above regions with weaker magnetic field strengths in the photosphere, while stronger photospheric fields are associated with highly radial field lines in the corona. In addition, we find an abundance of field lines which extend continuously from the solar surface out to several solar radii at all latitudes, regardless of the presence of coronal holes. These results have implications for testing and constraining coronal magnetic field models, and for linking in situ solar wind measurements to their sources at the Sun.

中文翻译：

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来自日全食观测的日冕磁场拓扑

测量日冕的全球磁场仍然极具挑战性。在日全食 (TSE) 期间拍摄的白光图像中观察到的精细密度结构目前是推断日冕中从太阳边缘到几个太阳半径 (Rs) 的磁场方向的最佳代表。我们首次展示了日冕磁场的拓扑结构，连续在 1 到 6 Rs 之间，这是通过滚动霍夫变换 (RHT) 对跨越几乎两个完整太阳周期的 14 个独特日冕进行定量推断的。我们发现日冕磁场的方向直到至少 3 Rs 才会变为径向，在太阳周期的不同纬度和阶段，1.5 和 3 Rs 之间的差异很大。我们发现大多数非径向日冕场拓扑发生在光球中磁场强度较弱的区域上方，而较强的光球场与日冕中的高径向场线相关。此外，我们发现大量的场线从太阳表面连续延伸到所有纬度的几个太阳半径，无论是否存在日冕洞。这些结果对测试和约束日冕磁场模型，以及将原位太阳风测量与它们在太阳处的来源联系起来具有重要意义。我们发现大量的场线从太阳表面连续延伸到所有纬度的几个太阳半径，而不管是否存在日冕洞。这些结果对测试和约束日冕磁场模型，以及将原位太阳风测量与它们在太阳处的来源联系起来具有重要意义。我们发现大量的场线从太阳表面连续延伸到所有纬度的几个太阳半径，而不管是否存在日冕洞。这些结果对测试和约束日冕磁场模型，以及将原位太阳风测量与它们在太阳处的来源联系起来具有重要意义。