The Physics of Quiet Sun Magnetic Fields

首席研究员（PI）计划通过对联合对流区-日冕系统进行三维磁流体动力学模拟，研究安静太阳磁场和大气的起源和演变。计算域将包括上层对流区、光球、色球、过渡区和低日冕（从可见表面以下约3毫米，到低密度、磁主导的日冕）的高度分层层。提议的团队将开发一种新的数字代码，能够同时发展这些空间和时间上不同的制度，以解决由对流表面发电机产生的磁场是否可以解释观测到的安静太阳磁场和大气的特性。新的代码还将模拟地下磁性结构和充满日冕的磁场之间的磁连通性。研究人员将研究联合系统中磁性元素的大小和空间分布、磁化日冕的拓扑演变、能量和磁螺旋度在太阳大气中的传输、日冕中能量的耗散以及来自日冕和大气其他层的辐射能量和诊断。这项研究将产生的模拟数据集可用于直接测试日震反演技术、用于获取地表流动的常用速度反演技术，以及用于表征日冕磁结构的许多外推技术。此外，本提案中概述的研究将极大地有助于Hinode、SDO、SOLIS和ATST等仪器获得的高分辨率观测结果的分析和解释。

The Principal Investigator (PI) plans to study the origin and evolution of the Quiet Sun magnetic field and atmosphere by performing 3D magnetohydrodynamic simulations of the combined convection zone-to-corona system. The computational domain will include the highly stratified layers of the upper convection zone, photosphere, chromosphere, transition region, and low-corona (from approximately 3 Mm below the visible surface, out to the low-density, magnetically-dominated corona). The proposing team will develop a new numerical code, capable of simultaneously evolving these spatially and temporally disparate regimes, to address whether the magnetic field generated by a convective surface dynamo can account for the observed properties of the Quiet Sun magnetic field and atmosphere. The new code would also model the magnetic connectivity between sub-surface magnetic structures and the magnetic field that fills the solar corona. The investigators will study the sizes and spatial distribution of magnetic elements in the combined system, the topological evolution of the magnetized corona, the energy and magnetic helicity transport through the solar atmosphere, the dissipation of energy in the corona, and the radiative energies and diagnostics from the corona and other layers of the atmosphere. The simulated datasets that will result from this study can be used to directly test helioseismic inversion techniques, commonly-used velocity inversion techniques designed to obtain surface flows, and the many extrapolation techniques used to characterize the magnetic structure of the solar corona. In addition, the studies outlined in this proposal will greatly aid in the analysis and interpretation of high-resolution observations obtained by instruments such as Hinode, SDO, SOLIS, and ATST.