太阳大气中等离子体电流的形成机制和不稳定性

Solar eruptive activity is a driven source of space weather phenomena. The present-day high-resolution observations show that the solar atmosphere, especially the coronal plasmas are in a highly magnetized, non-uniform as well as non-equilibrium state in dynamics, and solar activity phenomenon is a result of magnetic energy rapid release due to magnetic-plasma interactions in solar atmospheres. Therefore, formation mechanisms and dynamical evolution behaviors of the local plasma currents system in the solar atmosphere play a key role for us to further understand the solar activity phenomena, especially the microphysical mechanism of their energy transformation and release process. In this project, based on the microphysical process of magnetic-plasma interactions and by use of the solar magneto-plasma parameters from high-resolution solar observations, we plan to study possible formation mechanisms of local plasma currents, their dynamical evolution behaviors, and instabilities driven by these plasma currents in the solar atmosphere. The aim of this project is to establish corresponding physical models for the produce, instability, and evolution of plasma currents in the solar corona. This project can provide necessary theory model for us to further investigate whole physical model of the formation and evolution process of solar plasma currents system, the role of plasma currents in the energy storage, transformation and release processes of solar activities phenomena, and to reveal the microphysical mechanisms of solar eruptive phenomena.

太阳爆发活动是空间天气现象的驱动源头。现代高分辨观测显示太阳大气、特别是日冕等离子体处于高度磁化的、非均匀和非平衡的动力学状态，而太阳活动现象正是太阳大气中磁场－等离子体相互作用导致磁能快速释放的结果。因此，太阳大气中局部等离子体电流系统的形成机制及其电动力学演化行为是我们进一步深入了解太阳活动现象、特别是其中能量转换与释放过程微观物理机制的关键因素。本项目计划从磁场－等离子体相互作用的微观物理过程出发，结合太阳高分辨观测有关太阳大气磁等离子体环境参数的分析，对太阳大气中局部等离子体电流的形成机制、电动力学演化行为、及其不稳定爆发特性等方面的问题进行深入研究，并提出相应的物理模型。这将为进一步开展建立太阳大气等离子体电流系统形成和演化过程完整物理模型的研究，深入系统地了解它们在太阳活动现象能量储存、转化和释放过程中的作用，揭示驱动太阳爆发现象的微观物理机制提供必要的理论模型。

诸如太阳耀斑、日冕物质抛射等许多太阳活动爆发现象是空间天气的主要扰动源。这类爆发活动被认为是由磁能释放所致。关于磁能释放的物理机制问题迄今仍然没有一个能自洽地说明其微观物理机制的理论模型。本项目从太阳大气等离子体电流体系的形成和不稳定耗散角度来审视磁能释放问题。研究工作采用等离子体多流体模型或者等离子体动力论方法，主要研究了具有电流系统的密度非均匀丝化精细结构的形成机制、能化电子束建立的束流-回流系统的耗散机制、束流-回流系统下太阳射电爆发现象的自洽辐射机制模型。本项目研究成果为进一步深入、系统地研究太阳大气等离子体电流系统在太阳爆发活动能量转换过程中的作用、揭示太阳爆发现象的微观物理机制奠定必要的物理理论基础。