开场环境下的太阳小尺度活动观测与研究

Small-scale solar activities have been hot spots on researches of solar physics, due to the appearance of huge amount of high resolution observations. A great of previous studies suggest that solar eruptive activity from small scale to large scale is self-similar in terms of properties and instability mechanisms. For example a lot of small-scale bipolar fields erupt in the manner similar to large coronal mass ejections (CMEs), showing miniature version of filament, flare ribbons, and coronal dimming on disk. Such micro eruptions are so-called mini-CMEs. However, little papers report that mass ejections produced by mini-CMEs are observed in white light coronagraph. On the other hand, lots of jet-like eruptions that occurring in open fields are actually observed to cause micro white-light CMEs. These studies together suggest that coronal open field configurations may play a key role in the form of small-scale eruptions and in producing micro white-light CMEs. Therefore, in this proposal we will focus on small-scale solar activities under open field configurations. By using high quality data from ground instruments (including NST and NVST) and spacecraft (such as SDO, STEREO, HINODE and IRIS) which take multi-viewpoints and multi-wavelengths observations, we try to find that which type of magnetic reconnection may occur between small eruptive structures and open fields and promote small-scale eruptions ejecting plasma into high corona.

当前高分辨观测资料大量涌现，已促使太阳小尺度活动成为太阳物理研究热点。众多研究表明，多尺度太阳爆发活动表现出自相似性。大量的小尺度偶极场爆发其表现形式往往类似于大尺度日冕物质抛射(CMEs)，这些微爆发被称之为微CME事件。然而大量的微CMEs并没有在高日冕中观测到相应的物质抛射，相关研究也十分稀少。另一方面，开场环境下的众多喷流状微爆发，确被如实观测到白光微CMEs。这些结果暗示着日冕开场结构对太阳小尺度爆发表现形式以及向高层日冕传输物质，可能有着重要影响。基于这一初始想法，本项目拟采用当前多视角、多波段、高时空分辨率的地基(NST和NVST)和空间(SDO、STEREO、HINODE以及IRIS)观测资料，重点研究开场位形下的太阳小尺度爆发。试图探寻小尺度磁结构在爆发中可能与开场发生哪些重联相互作用？这些相互作用是否能够促使低层大气的小尺度爆发向高层日冕抛射物质？

研究基于当前高分辨率太阳观测数据，包括我国自主研发的大口径太阳望远镜NVST以及国际空间望远镜SDO和IRIS，对发生在日冕开场环境下的众多太阳小尺度爆发现象作了深入研究。其主要内容包括：结合多波段观测，详细分析了小尺度爆发磁结构是如何与背景开场在低层太阳大气相互作用的； 结合日面观测与行星际空间观测，研究了太阳小尺度爆发对行星际空间的可能影响；剖析了特定磁拓扑位形即日冕零点位形下的小尺度爆发与零点磁重联的关系。项目旨在全面理解开场与太阳小尺度爆发之间的相互关联，为关于太阳小尺度磁活动在太阳大气中的能量建立、释放以及传播情况提供新的认识。