Plasma heating of small-scale loops in the solar atmosphere

太阳大气中小规模环路的等离子体加热

• 批准号: 452856778
• 负责人: Dr. Thomas Wiegelmann
• 金额: --
• 依托单位: Max-Planck-Institut für Sonnensystemforschung (MPS)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/452856778?language=en
• 关键词: Plasma; heating; small; scale; loops

Loops are the fundamental structures that shape the magnetic skeleton of the solar atmosphere. The extreme-ultra-violet emission from plasma at a temperature of a million degrees in the quiet Sun is mostly confined to small-scale magnetic loops. Therefore, it is imperatively important to understand the physical mechanisms that heat the plasma in these loops. The main objective of the project is to further advance our understanding of the mechanisms of plasma heating in small-scale loops. Clusters of these small-scale loops are as coronal bright points (CBPs) known. We will investigate what is the role of eruptions in CBPs in the mass and energy transfer in the solar atmosphere and the solar wind. Although the past several years steps forward in this research domain were made, numerous fundamental open questions remain that require further comprehensive observational and theoretical modelling. Some of the open questions are: Which plasma-heating models of small-scale loop systems match best the observed morphology, evolution of plasma and magnetic field properties of small-scale loops? What is the possible interplay of magnetic reconnection and magneto-acoustic wave propagation in the heating of plasma confined in small-scale coronal magnetic loop structures? Are intensity variations in individual small-scale loops related to micro- or nanoflare heating, or are other physical mechanisms at play? In phase one of this project, we will derive the observational constraints of plasma-heating models of small-scale magnetic loops. The model constraints will be obtained through the comparison of model-predicted scaling of heating rates with loop lengths and magnetic fluxes with those determined observationally. Model constraints will also be obtained from the morphology and evolution of magnetic loops and their plasma properties. This will be done in emerging CBPs, which are formed from many loops as recorded in spectroscopic and imaging data, but also from the evolution and lifetime of the loops. In phase 2, we will conduct a statistical investigation of microflares and loop brightenings and their link to various heating processes. In phase 3, we will investigate CBP evolution and eruptions and their possible link to plumes and magnetic switchbacks both statistically and through case studies. To achieve the goals of the new project we will use state-of-the-art observations from space (IRIS, Hinode, Solar Orbiter, and Parker Solar Probe) and ground-based observatories (Fast Imaging Solar Spectrograph, Solar Swedish Telescope, and Daniel K. Inouye Solar Telescope). A state-of-the-art modelling including linear magneto-hydrostatic and non-linear force-free field extrapolations, magneto-frictional, and 3D radiative MHD will also be employed or compared with observations. The project will provide benchmarking knowledge on plasma heating of small-scale loops.

环是塑造太阳大气磁骨架的基本结构。 在安静的太阳中，温度为一百万度的等离子体发出的极紫外辐射大部分局限于小规模的磁环。因此，了解在这些回路中加热等离子体的物理机制至关重要。该项目的主要目标是进一步加深我们对小规模回路中等离子体加热机制的理解。这些小规模环的簇被称为日冕亮点（CBP）。我们将研究 CBP 喷发在太阳大气和太阳风的质量和能量转移中的作用。尽管过去几年该研究领域取得了进步，但仍然存在许多基本的悬而未决的问题，需要进一步全面的观察和理论建模。一些悬而未决的问题是：哪些小规模环路系统的等离子体加热模型最适合观察到的小规模环路的形态、等离子体演化和磁场特性？在加热小尺度日冕磁环结构中限制的等离子体时，磁重联和磁声波传播可能存在什么相互作用？单个小规模环路的强度变化是否与微或纳耀斑加热有关，或者是否有其他物理机制在起作用？在该项目的第一阶段，我们将推导出小规模磁环等离子体加热模型的观测约束。模型约束将通过将模型预测的加热速率与环路长度和磁通量的缩放比例与观测确定的缩放比例进行比较来获得。模型约束也将从磁环的形态和演化及其等离子体特性中获得。这将在新兴的 CBP 中完成，这些 CBP 由光谱和成像数据中记录的许多环形成，但也由环的演化和寿命形成。在第二阶段，我们将对微耀斑和环路增亮及其与各种加热过程的联系进行统计调查。在第三阶段，我们将通过统计和案例研究来研究 CBP 的演化和喷发，以及它们与羽流和磁之字形的可能联系。为了实现新项目的目标，我们将使用最先进的太空观测（IRIS、Hinode、太阳轨道飞行器和帕克太阳探测器）和地面观测站（快速成像太阳摄谱仪、瑞典太阳望远镜和 Daniel K. Inouye 太阳望远镜）。还将采用最先进的建模，包括线性磁流体静力和非线性无力场外推、磁摩擦和 3D 辐射 MHD，或与观测结果进行比较。该项目将提供小规模回路等离子加热的基准测试知识。