冕羽形成与演化过程的SDO多波段成像观测研究
发布时间：2018-07-29 06:48
【摘要】：冕羽是日冕中出现的明亮细长的喷射结构,其足点扎根于色球层,向上延伸到高日冕-行星际太阳风区域。有观测表明,冕羽可能与太阳风的形成有密切的联系,因此对冕羽形成与演化过程的深入研究有助于我们理解初始太阳风的形成机制。冕羽足点在光球、色球以及日冕上对应的活动现象是了解冕羽形成和演化背后物理机制的重要载体。已有的研究证实,冕羽的足点都对应着光球上单极性主导的混合极性磁结构,且其中存在磁对消现象。在色球上,冕羽被发现与色球网络结构有关,最近的一些研究还发现冕羽根部存在很多小喷流和冕羽瞬时增亮事件。另一方面,冕羽与日冕亮点间的联系也是人们关心的另外一个问题,相关研究发现并不是所有的冕羽都有日冕亮点对应。已有的研究工作主要关心冕羽与光球、色球和日冕内特定的活动现象之间对应关系的存在性,对两者间动态演化过程的对应性还没有较明确的结论。我们的工作瞄准相关研究中尚未完备的地方,着重研究冕羽的动态演化过程及其与其它太阳大气层次上发生的动态等离子体现象之间的关联。利用SDO观测的连续性优点,结合其色球和日冕波段的成像以及光球纵向磁场数据,我们分析了 15个冕羽的形成和动态演化过程与动态的光球磁活动、色球活动以及日冕亮点之间的关联。首先,通过对AIA图像分析,我们发现在冕洞内几乎所有单极磁场聚集区域都会存在冕羽,只是这些冕羽出现的亮度有所不同,这和以往EIT观测有所不同,其原因主要是AIA仪器具有更高的观测灵敏度。进一步通过跟踪冕羽及其对应的光球磁场的动态演化过程,发现冕羽形成过程对应着根部主极性磁场与周围同极性磁场汇聚的过程。我们还发现冕羽辐射强度最大时刻与汇聚的磁通量最大时刻有时间延迟,而冕羽辐射最强时刻往往与磁对消过程相对应。其次,利用SDO/AIA 304 A的观测,我们发现冕羽根部与扎根于色球网络场中的针状体位置一致,且巨型针状体可以引起冕羽的显著增亮。这些巨型针状体结构同时对应着主极场与周围浮现的相反极性磁结构的对消过程。这些磁对消活动对应的巨型针状体虽然只持续几分钟到十几分钟,但却可以维持冕羽数小时的增亮,与预计的辐射冷却时标相符。基于上述观测事实,我们认为冕羽的形成与开放磁结构的汇聚过程有关,而小尺度的磁对消活动(很可能对应着磁重联)关联的巨型针状体活动是导致并维持冕羽持续增亮的原因之一。最后,我们研究了日冕亮点与冕羽之间的关系,发现日冕亮点与冕羽的形成与演化有密切的关系,但不是一一对应关系。在冕羽根部存在日冕亮点的情况下,日冕亮点存在时间内伴随的小尺度爆发现象可以引起冕羽的显著增亮。然而并不是所有的冕羽根部都存在日冕亮点。综上,我们的数据分析结论表明,开放磁结构的汇聚是形成冕羽主体的基本物理过程,而影响冕羽演化的等离子体活动都与冕羽主极场和相反极性磁结构的对消过程有关。这些等离子体活动可能是发生在色球层的巨型针状体喷流,也可能是发生在日冕中与日冕亮点有关的等离子体喷流。
[Abstract]:The coronal plume is a bright and elongated spray structure appearing in the corona. Its foot points are rooted in the chromosphere and extending upward to the high coronal interplanetary solar wind region. Observations show that the coronal plume may be closely related to the formation of the solar wind, so the deep study of the formation and evolution of the coronal plume will help us to understand the formation of the initial solar wind. Mechanism. The activity of the coronal plume at the photosphere, the chromosphere and the corona is an important carrier for understanding the physical mechanism behind the formation and evolution of the coronal plumes. The existing studies have confirmed that the feet of the coronal plumes are all corresponding to the unipolar mixed polar magnetic structure on the photosphere, and there is a magnetic cancellation phenomenon. The structure of the ball network is related. Some recent studies have found that there are many small jet and instantaneous brightening events in the coronal roots. On the other hand, the relationship between the coronal feather and the coronal highlights is another concern. The related research finds that not all coronal feathers have coronal highlights. The main concern of the existing research work is of concern. The correspondence between the coronal feathers and the photosphere, the chromosphere and the specific activity in the corona has no definite conclusion on the correspondence of the dynamic evolution processes between the two. Our work aims to focus on the dynamic evolution process of the coronal plumes and the occurrence of the evolution of the coronal feathers and the other solar atmosphere levels. Dynamic plasma shows the correlation between images. Using the continuity advantage of SDO observation, combining with the imaging of the chromosphere and coronal band and the longitudinal magnetic field data of the photosphere, we analyze the formation and dynamic evolution of the 15 coronal feathers, the dynamic photomagnetic activity, the correlation between the chromosphere activity and the coronal highlights. First, the AIA diagram is passed. Like analysis, we found that almost all the monopole magnetic field aggregation regions in the coronal cavity have coronal plumes, but the luminance of these coronal feathers is different, which is different from the previous EIT observations. The main reason is that the AIA instrument has higher observational sensitivity. The dynamic evolution of the coronal plume and its corresponding optical sphere magnetic field is further developed. It is found that the formation process of the coronal plume corresponds to the process of convergence between the main polar magnetic field of the root and the surrounding magnetic field. We also found that the maximum time for the maximum radiation intensity of the coronal plume and the maximum flux of the converged flux has time delay, and the strongest time of the coronal plume is often corresponding to the magnetic cancellation process. Secondly, we use the observation of SDO/AIA 304 A. The coronal root is in accordance with the position of the acicular body that is rooted in the chromosphere network field, and the giant needles can cause a significant brightening of the coronal plumes. These Mega acicular structures simultaneously correspond to the opposite polarity magnetic structure of the main pole field and the surrounding floating polarity. On the basis of the above observations, we believe that the formation of coronal feathers is related to the converging process of the open magnetic structure, and the mega acicular activity associated with the small scale magnetic cancellation activity (probably corresponding to the magnetic Reunion) leads to and maintains the crown based on the above observations. In the end, we have studied the relationship between the coronal highlights and the coronal plumes, and found that the coronal highlights are closely related to the formation and evolution of the coronal feathers, but not a one-to-one correspondence. In the case of coronal highlights in the coronal roots, the small scale eruptions associated with the time of the coronal highlights can be caused. However, the coronal highlights are not present in all the coronal plumes. To sum up, our data analysis shows that the convergence of the open magnetic structure is the basic physical process to form the main body of the coronal plume, and the plasma activity affecting the evolution of the coronal feathers is related to the elimination process of the main pole field of the coronal plume and the opposite polarity magnetic structure. These plasma activities may be large needle like exhales occurring in the chromosphere, or the plasma jet related to the coronal highlights in the corona.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P182
本文编号：2151869
[Abstract]:The coronal plume is a bright and elongated spray structure appearing in the corona. Its foot points are rooted in the chromosphere and extending upward to the high coronal interplanetary solar wind region. Observations show that the coronal plume may be closely related to the formation of the solar wind, so the deep study of the formation and evolution of the coronal plume will help us to understand the formation of the initial solar wind. Mechanism. The activity of the coronal plume at the photosphere, the chromosphere and the corona is an important carrier for understanding the physical mechanism behind the formation and evolution of the coronal plumes. The existing studies have confirmed that the feet of the coronal plumes are all corresponding to the unipolar mixed polar magnetic structure on the photosphere, and there is a magnetic cancellation phenomenon. The structure of the ball network is related. Some recent studies have found that there are many small jet and instantaneous brightening events in the coronal roots. On the other hand, the relationship between the coronal feather and the coronal highlights is another concern. The related research finds that not all coronal feathers have coronal highlights. The main concern of the existing research work is of concern. The correspondence between the coronal feathers and the photosphere, the chromosphere and the specific activity in the corona has no definite conclusion on the correspondence of the dynamic evolution processes between the two. Our work aims to focus on the dynamic evolution process of the coronal plumes and the occurrence of the evolution of the coronal feathers and the other solar atmosphere levels. Dynamic plasma shows the correlation between images. Using the continuity advantage of SDO observation, combining with the imaging of the chromosphere and coronal band and the longitudinal magnetic field data of the photosphere, we analyze the formation and dynamic evolution of the 15 coronal feathers, the dynamic photomagnetic activity, the correlation between the chromosphere activity and the coronal highlights. First, the AIA diagram is passed. Like analysis, we found that almost all the monopole magnetic field aggregation regions in the coronal cavity have coronal plumes, but the luminance of these coronal feathers is different, which is different from the previous EIT observations. The main reason is that the AIA instrument has higher observational sensitivity. The dynamic evolution of the coronal plume and its corresponding optical sphere magnetic field is further developed. It is found that the formation process of the coronal plume corresponds to the process of convergence between the main polar magnetic field of the root and the surrounding magnetic field. We also found that the maximum time for the maximum radiation intensity of the coronal plume and the maximum flux of the converged flux has time delay, and the strongest time of the coronal plume is often corresponding to the magnetic cancellation process. Secondly, we use the observation of SDO/AIA 304 A. The coronal root is in accordance with the position of the acicular body that is rooted in the chromosphere network field, and the giant needles can cause a significant brightening of the coronal plumes. These Mega acicular structures simultaneously correspond to the opposite polarity magnetic structure of the main pole field and the surrounding floating polarity. On the basis of the above observations, we believe that the formation of coronal feathers is related to the converging process of the open magnetic structure, and the mega acicular activity associated with the small scale magnetic cancellation activity (probably corresponding to the magnetic Reunion) leads to and maintains the crown based on the above observations. In the end, we have studied the relationship between the coronal highlights and the coronal plumes, and found that the coronal highlights are closely related to the formation and evolution of the coronal feathers, but not a one-to-one correspondence. In the case of coronal highlights in the coronal roots, the small scale eruptions associated with the time of the coronal highlights can be caused. However, the coronal highlights are not present in all the coronal plumes. To sum up, our data analysis shows that the convergence of the open magnetic structure is the basic physical process to form the main body of the coronal plume, and the plasma activity affecting the evolution of the coronal feathers is related to the elimination process of the main pole field of the coronal plume and the opposite polarity magnetic structure. These plasma activities may be large needle like exhales occurring in the chromosphere, or the plasma jet related to the coronal highlights in the corona.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P182
【参考文献】
相关期刊论文 前1条
1 Fang-Ran Jiao;Li-Dong Xia;Zheng-Hua Huang;Bo Li;Hui Fu;Ding Yuan;Kalugodu Chandrashekhar;;Damping and power spectra of quasi-periodic intensity disturbances above a solar polar coronal hole[J];Research in Astronomy and Astrophysics;2016年06期
，本文编号：2151869
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