Global Transport of Magnetic Energy in Active Regions on the Sun

太阳大气层中不稳定的磁结构是太阳爆发事件的根源，这些事件可能对近地空间环境和高层大气造成严重扰动。我们的社会越来越依赖易受这些所谓空间气象事件影响的技术资产。 因此，预测这类事件的发生和详细性质对于尽量减少其损害至关重要。 了解太阳大气层中大规模磁活动区的产生和动态发展是目前太阳物理学研究的一个热门课题。 该项目将进行一系列高度复杂和计算要求高的数值模拟，以阐明基本的物理过程和相互作用。 这项调查是第一次描述太阳内部和大气层之间的耦合在整个范围内的物理条件和不同的空间和时间尺度的特点大活动区。它将通过利用新开发的先进计算技术和超级计算机资源来这样做。 进一步开发和测试这一活动区模型是建立太阳活动预测能力的关键一步。 在这项研究中进行的数值实验将产生数据集，是有用的其他正在进行的努力，模拟太阳磁活动和数值技术有许多额外的应用，特别是在天体物理学领域。 最后，工作成果将在开源许可下公开提供，允许其他研究人员或教育工作者使用，他们有兴趣使用三维、笛卡尔或球形、辐射磁流体动力学模型来描述物理系统。主要的科学目标是更好地理解太阳内部和大气之间的耦合，因为活动区域的出现和演变，以及在物理条件范围内的磁能传输，以及对流带-日冕系统的不同空间和时间尺度。为了实现这一目标，新开发的球形版本的辐射磁流体动力学代码RADMHD将被用来进行数值模拟的活动区磁通量出现通过上层对流进入日冕。模拟是独一无二的，因为它们将首次产生自洽和独立的模型，用于研究球形几何中跨越上部对流带至日冕的大规模活动区磁场的出现和演变。磁通量将被引入到域从下面，使用数据从现有的计算磁通量出现通过内部深处，和整个域的电磁能量的传输将被研究作为活动区磁场与对流湍流相互作用，使其径向向外进入模型大气。将在三个不同的空间尺度上进行三组通量出现的数值模拟：（1）单个活动区，（2）两个非常接近的活动区，（3）全球磁环境中两个相距很远的活动区。

Unstable magnetic structures in the atmosphere of the Sun are the root source of eruptive events at the Sun that can cause severe perturbations in the near-Earth space environment and upper atmosphere. Our society is becoming increasingly dependent on technological assets that are vulnerable to these, so-called, space weather events. Consequently, predicting the occurrence and detailed nature of such events is of critical importance to minimizing their damage. Understanding the creation and dynamic development of large-scale magnetically active regions in the solar atmosphere is currently a topic of intense research in solar physics. This project will perform a series of highly complex and computationally demanding numerical simulations to illuminate the basic physical processes and interactions at play. The investigation is the first to describe the coupling between the solar interior and atmosphere over the entire range of physical conditions and disparate spatial and temporal scales characteristic of large active regions. It will do so by utilizing newly developed advanced computational techniques and access to supercomputer resources. The further development and test of this active region model constitute a critical step towards establishing a predictive capability for solar events. The numerical experiments performed in this study will generate data sets that are useful to other ongoing efforts to model solar magnetic activity and the numerical techniques have many additional applications, particularly in the field of astrophysics. Finally, the work product will be made publicly available under an OpenSource license allowing it to be used by other researchers or educators with an interest in describing physical systems using a three-dimensional, Cartesian or spherical, radiative magneto-hydro-dynamic model.The principal scientific objective is to better understand both the coupling between the solar interior and atmosphere as active regions emerge and evolve, and the transport of magnetic energy over the range of physical conditions, and the disparate spatial and temporal scales of the convection zone-to-corona system. To address this objective, the newly developed spherical version of the radiative-magneto-hydro-dynamic code RADMHD will be used to perform numerical simulations of active region magnetic flux emergence through the upper convection into the corona. The simulations are unique in that they will, for the first time, produce self-consistent and self-contained models of the emergence and evolution of large-scale active region magnetic fields spanning the upper convection zone-to-corona in spherical geometry. Magnetic flux will be introduced into the domain from below, using data from existing calculations of magnetic flux emergence through the deep interior, and the transport of electromagnetic energy throughout the domain will be studied as active region magnetic fields interact with convective turbulence and make their way radially outward into the model atmosphere. Three sets of numerical simulations of flux emergence on three distinct spatial scales will be performed: (1) a single active region, (2) two active regions in close proximity, and (3) two widely separated active regions in a global magnetic environment.