CME驱动的运动激波对太阳高能粒子加速的研究

大型缓变型太阳高能粒子(SEPs)事件爆发可以产生数百 Mev/n甚至到10 GeV/n以上的高通量高能粒子，是极具灾害性的一类空间天气事件。本项目计划利用新发射的两颗内日球探测卫星（Parker Solar Probe，Solar Orbiter）在太阳附近的观测数据分析,以及基于各向异性激波加速模式的数值模拟，聚焦研究在近日冕加速区激波种子粒子注入和加速过程。分析不同类型缓变型SEP事件在日冕加速区的种子离子的来源与能谱直接观测特征；讨论影响种子粒子注入效率的主要因素；开展近日冕典型缓变型SEP事件数值模拟，定量研究伴随CME爆发的耀斑事件，以及同一活动区CME连续爆发等对太阳高能粒子加速的贡献与影响。本项目的研究将有助于我们更深层次理解粒子加速机制、湍动电磁场中波粒子相互作用等基础物理过程，并且为下一步开发SEP事件物理预报模式奠定理论基础。

Large gradual solar energetic particle (SEP) events associated with fast CME-driven shocks can produce particles with energy of many tens MeV/n and sometimes even up to 10 GeV/n, which could last for several days and are a great concern of near-Earth space weather environment. In this proposal, we will systematically investigate the injection and acceleration process of SEP seed particles accelerated by fast CME-driven shocks at the near-corona region, through data analysis of two newly-launched missions (Parker Solar Probe and Solar Orbiter) and numerical simulation based on the anisotropic shock acceleration model. The direct observational features of the source and energy spectrum of seed particles in different type SEP events, as well as the main factors that affect the shock injection efficiency, will be selectively analyzed. We will develop the numerical simulations on the SEP acceleration at the near-corona region for typical gradual SEP events to quantitatively study the contributions of CME-associated flares and successive CME eruptions in special active region to the SEP acceleration. With comprehensive studies of SEP pre-acceleration and injection, we hope to enhance our understanding to the fundamental physics of particle acceleration and wave-particle interaction in turbulent fields. This study is expected to lay a firm foundation for development of the physical SEP prediction model for space weather application in our near-future research.