Exploiting solar visible-range observations by inversion techniques: from flows in the solar subsurface to a flaring atmosphere
Michal Švanda, Jan Jurčák, David Korda, Jana Kašparová
备注：
29 pages, 15 figures. Accepted for publication in the book "Reviews in Frontiers of Modern Astrophysics: From Space Debris to Cosmology" (eds Kabath, Jones and Skarka; publisher Springer Nature) funded by the European Union Erasmus+ Strategic Partnership grant "Per Aspera Ad Astra Simul" 2017-1-CZ01-KA203-035562
发表信息：
In: Kabáth P., Jones D., Skarka M. (eds) Reviews in Frontiers of Modern Astrophysics. 2020, p. 349-378. Springer, Cham
Observations of the Sun in the visible spectral range belong to standard measurements obtained by instruments both on the ground and in the space. Nowadays, both nearly continuous full-disc observations with medium resolution and dedicated campaigns of high spatial, spectral and/or temporal resolution constitute a holy grail for studies that can capture (both) the long- and short-term changes in the dynamics and energetics of the solar atmosphere. Observations of photospheric spectral lines allow us to estimate not only the intensity at small regions, but also various derived data products, such as the Doppler velocity and/or the components of the magnetic field vector. We show that these measurements contain not only direct information about the dynamics of solar plasmas at the surface of the Sun but also imprints of regions below and above it. Here, we discuss two examples: First, the local time-distance helioseismology as a tool for plasma dynamic diagnostics in the near subsurface and second, the determination of the solar atmosphere structure during flares. The methodology in both cases involves the technique of inverse modelling.
Improving the Understanding of Subsurface Structure and Dynamics of Solar Active Regions (A white paper submitted to the decadal survey for solar and space Physics (Heliophysics) -- SSPH 2024-2033)
Solar fine-scale structures. I. Spicules and other small-scale, jet-like events at the chromospheric level: observations and physical parameters
在过去20年中，从许多航天器上的优秀望远镜进行的不间断的高分辨率太阳观测，再加上从先进的地面望远镜进行的观测，开辟了一个新的世界，产生了比以往更加完整的关于太阳大气层物理条件的信息。太阳低层大气中的能量是由次表层对流产生的，而日冕与低层大气之间的界面构成了色球层，色球层主要由喷流状的动态结构所控制，在安静区域被称为斑点，在活跃区域被称为原纤维，在太阳边缘被称为针状物。最近，Hinode的空间观测表明应该存在两种不同类型的针状体，称为I型和II型，它们具有不同的性质。Ca II H和K滤波图的地面观测揭示了在靠近边缘的观测中存在长而薄的发射特征，称为吸管，以及一类被称为快速蓝移偏移的短命事件，其特征是仅出现在Ca II红外线的蓝翼中的大多普勒频移。有人认为，理解太阳等离子体如何被加速和加热的关键可能会在这些类似喷流的动态事件的研究中找到。然而，尽管这些结构在可见光区以及紫外和极紫外发射线和连续谱中被观察和研究了130多年，但仍有许多问题需要回答。在这篇评论中，我们提出的意见和物理性质的小规模的喷色球活动和安静的地区，在磁盘上，并在肢体观察到，并讨论它们之间的相互关系。
