Global Transport of Magnetic Energy in Active Regions on the Sun

太阳活跃区域的磁能全球传输

• 批准号: 1455492
• 负责人: William Abbett
• 金额: $ 43.08万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-12-15 至 2018-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1455492&HistoricalAwards=false
• 关键词: Global; Transport; Magnetic; Energy; Active

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.

太阳大气中的不稳定的磁性结构是太阳喷发事件的根源，在近地太空环境和上层大气中可能会引起严重的扰动。我们的社会越来越依赖于容易受到这些所谓的太空天气事件的技术资产。 因此，预测此类事件的发生和详细性质对于最大程度地减少其损害至关重要。 当前，在太阳能物理学中，了解太阳大气中的大型磁性区域的创造和动态发展是一个强烈研究的话题。 该项目将执行一系列高度复杂和计算要求的数值模拟，以阐明起作用的基本物理过程和相互作用。 该研究是第一个描述整个物理条件范围内太阳能内部与大气之间的耦合，以及大型活性区域的不同空间和时间尺度的耦合。它将通过利用新开发的高级计算技术和对超级计算机资源的访问来做到这一点。 该活动区域模型的进一步发展和测试构成了建立太阳事件的预测能力的关键步骤。 在这项研究中执行的数值实验将生成数据集，这些数据集可用于对太阳能磁性活动进行建模的其他努力，并且数值技术具有许多其他应用，尤其是在天体物理学领域。 最后，该工作产品将在Opensource许可下公开提供，允许其他研究人员或教育工作者使用三维，笛卡尔或球形，辐射性的磁性磁性动力模型来描述物理系统的兴趣。条件，以及对流区与库纳系统的不同空间和时间尺度。为了解决这一目标，新开发的球形版本的辐射磁力 - 动力代码RADMHD将用于通过上层对流进行活性区域磁通量出现进行数值模拟。这些模拟是独一无二的，因为它们首次产生了跨越球形几何形状的上层对流区域到科罗纳的大规模活性区域磁场的出现和演变的自洽和自包式模型。磁通量将从下方引入域，使用来自深层内部磁通量出现的现有计算的数据，并且随着活动区域磁场与对流湍流相互作用，并将电磁能在整个结构域中进​​行研究，并将其径向向外移动到模型大气中。将执行三组在三个不同的空间尺度上出现的通量出现的数值模拟：（1）一个有效区域，（2）两个处于近距离的活动区域，（3）两个在全球磁性环境中广泛分离的活动区域。