SHINE: Numerical Modeling of SHINE Campaign Events by Means of Coupled MagnetoHydroDynamics-Solar Energetic Particle (MHD-SEP) Simulations

这项提议寻求资金，通过耦合MHD-SEP数值模拟，改善我们对太阳喷发和相关的太阳高能粒子(SEP)事件的理解(重点放在闪耀运动事件上)。利用最先进的3D磁流体力学(MHD)代码BATS-R-US，再加上密歇根大学最近开发的新粒子代码FLAMPA(用于粒子加速的场-线-平流模型)，提出者计划对选定的SEP事件进行详细研究，以解决以下基本问题：(1)太阳喷发是如何开始的，它们是如何演化的？(2)太阳粒子是如何加速和运输的？虽然人们普遍认为最大的SEP事件是由CME驱动的行星际空间激波造成的，但CME驱动的冲击与耀斑相关的太阳粒子加速的相对重要性是一个活跃的研究和辩论领域。这场争论的部分原因是我们对内日冕中的激波演化，以及在那里遇到的条件如何可能导致SEP变异性，特别是在与空间天气相关的高能情况下的认识不完全。只有对日冕中日冕物质抛射的详细模拟才能阐明这些问题。PI将开发这些事件的三维数值模型，以研究相关喷发的动力学。特别是，这项工作将研究由太阳CME驱动的冲击波形成的距离有多近；这些冲击波的强度和几何形状如何随时间变化；以及冲击波性质随时间的变化如何解释观察到的渐变SEP事件的特征。BATS-R-US代码的自适应网格能力将使PI在太阳附近获得足够高的数值分辨率，以跟踪CME和激波演变。另一方面，FLAMPA程序将使PI能够检查太阳粒子(从质子到重离子铁离子)在CME驱动的激波中随时间变化的输运和扩散加速。这些数值研究的结果将与SOHO、Wind、ACE和GOES卫星的现有数据进行比较，以验证和改进模型。这将是第一个三维的、耦合的MHD-SEP研究，重点是了解日冕内由CME驱动的激波的形成和演化，以及它们在造成观测到的SEP变化中的作用。

This proposal seeks funds to improve our understanding of solar eruptions and related solar energetic particle (SEP) events (with a focus on SHINE Campaign Events), by means of coupled MHD-SEP numerical simulations. Using the state-of-the-art 3D MagnetoHydroDynamic (MHD) code BATS-R-US, coupled with a new particle code called FLAMPA (Field-Line-Advection Model for Particle Acceleration) recently developed at the University of Michigan, the proposers plan to perform detailed studies of selected SEP events in order to address the following fundamental questions: (1) How are solar eruptions initiated and how do they evolve? (2) How are solar particles accelerated and transported? While it is generally accepted that the largest SEP events result from CME-driven shocks in interplanetary space, the relative importance of CME-driven shocks versus flare-associated acceleration of solar particles is an area of active research and debate. Part of this debate arises from our incomplete understanding of shock evolution in the inner corona, and how the conditions encountered there may contribute to SEP variability, especially at high energies relevant for space weather. Only detailed modeling of CMEs throughout the corona can clarify these issues.The PI will develop three-dimensional numerical models of these events to investigate the dynamics of associated eruptions. In particular, this effort will study how close to the Sun CME-driven shocks form; how the strengths and geometries of these shock waves vary in time; and how the time-dependent changes in shock properties explain the observed signatures of gradual SEP events. The BATS-R-US code's adaptive grid capability will allow the PI to achieve sufficiently high numerical resolution near the Sun to follow CME and shock evolution. The FLAMPA code, on the other hand, will enable the PI to examine the time-dependent transport and diffusive acceleration of solar particles (from protons to the heavy ions of iron) at the CME-driven shocks.The results of these numerical investigations will be compared with the available data from SoHO, Wind, ACE, and GOES satellites in order to validate and improve the models. These will be the first three-dimensional, coupled MHD-SEP studies focused on understanding the formation and evolution of CME-driven shocks in the inner corona and their role in causing the observed SEP variability.