太阳耀斑导致的光球扰动

The abrupt motions of the magnetic structures on the photosphere during a solar flare could be a result of the energy release in the solar corona. Here, we will survey what percentage of the flares can produce obvious motions of the photospheric structures and whether the motions on the photosphere can occur in flares with various energy ranges. To study how the energy release in the corona produces the abrupt photospheric motions, we will investigate the changes in the transportations of the magnetic helicity across the photosphere accompanying with the abrupt photospheric motions, the changes in the Lorentz force acted on the photospheric structures, and the changes in the coronal magnetic systems connecting the photospheric structures disturbed by the flares.. The data used here mainly includes the first uninterrupted time series of space-based, full-disk, vector magnetic field observations of the Sun with a at least 12-minute cadence from SDO/HMI, as well as the vector magnetic data and the photospheric images with high-resolution from NVST. The HMI data enables us to detect the motions of the photospheric structures during a host of flares, while NVST data allows a detailed examination of the smaller displacement of the structures on the photosphere during the flare.

太阳耀斑期间光球磁场结构的突然运动意味着发生在日冕中的剧烈能量释放过程可能足以扰动光球层。本项目拟了解有多大比例的耀斑会产生光球的扰动，以及是不是所有能级的耀斑都会产生光球扰动。本项目拟分析光球扰动伴随的磁场螺度输运模式、被扰动的光球磁场结构对应的光球磁场变化和光球洛伦兹力的变化、对应的日冕磁场结构的变化，从而探讨耀斑扰动光球层的物理机制。. 本项目主要采用NASA/SDO卫星的HMI光球矢量场数据以及云南天文台NVST的矢量场数据和高时空分辨率的光球像数据。其中SDO提供了大量的耀斑事件的矢量场数据；NVST的高分辨数据有利于探测耀斑期间光球特征的更细微的水平运动。

利用国内地面望远镜和国外卫星观测数据，我们研究了耀斑期间的光球扰动以及日冕中的能量释放。（1）本项目研究了小级别耀斑导致的螺度输运率的突变。发现耀斑带扫过的光球区域易于探测到反符号的磁场螺度注入率，支持我们提出的耀斑导致部分日冕磁场螺度落回到太阳内部的物理图像；利用NVST的高分辨光球图像详细研究了一个耀斑期间光球层黑子的本影-半影的转化现象，进一步丰富了耀斑如何扰动光球层的观测特征和唯像理论 。（2）通过对NVST高分辨日珥图像的观测分析，我们提出日珥内大量的匀速下落等离子体团对局地宁静区日冕加热有不可忽略的贡献。（3）本项目结合机器学习方法实现了不同观测波段数据的迁移以及对图像中精细结构的探测 。这些方法可进一步运用于探测耀斑期间光球层更微小的异常扰动。（4）本项目也开展了一系列耀斑事件的分析，包括暗条的爆发和形成，日冕电流片的观测，Fan-spine磁场位型下的耀斑过程，进一步扩展了本项目的后续研究思路。