近地磁尾不稳定性及亚暴触发机制的综合研究

Dr. Ping Zhu is a professor of physics at the Unversity of Science and Technology of China. He is specialized in theoretical and computational plasma physics, as well as their application in the fields of fusion and space plasma physics. He has theoretically and systematically studied the ballooning instability in the Earth's magnetotail and the trigger mechanism for substorm onset. Based on his research results, Dr. Zhu has developed a promising new model for the onset trigger which invokes the coupling of the ballooning instability and the magnetic reconnection in the magnetotail. This project proposes to further examine the model through a combined approach of theory, simulation, and analysis of satellite observation data. The project plans to focus on investigating the relations between the instabilities of the near-Earth magnetotail and the onset trigger process, particularly the mechanism and role of the coupling between the ballooning instability and the reconection process. The proposed tasks will include: (1) Reconstruction of the magnetotail configuration in the substorm growth phase based on observation data and global MHD simulations; (2) Theoretically and numerically evalute the linear and nonlinear instabilities (ballooning and tearing modes) of magnetotail configuration during the substorm growth phase; (3) Select typical substorm events for comparisons between the theory/simulation analyses and the corresponding observation data. This project intends to take advantage of the unprecedented opportunity provided by the multiple-point in-situ satellite observations in recent years, in order to enhance the understanding of the substorm onset trigger mechanism, and improve the physics base of space weather models.

朱平博士是中国科学技术大学近代物理系教授，长期从事等离子体理论计算及其在聚变和空间物理领域的应用研究。他在地球磁尾气球模不稳定性与亚暴触发机制领域进行了系统深入的理论工作，并提出了磁尾气球模与重联相耦合的物理模型。为了进一步确定亚暴触发机制，检验现有物理模型，本项目计划通过理论、模拟、以及多点卫星观测数据分析，综合研究近地磁尾不稳定性与亚暴触发机制的关系，重点考察气球模与磁重联在近地磁尾的耦合方式及其在亚暴触发过程中的作用。具体研究内容包括：（1）依据多点观测数据和磁层全局数值模拟，进行亚暴增长期近地磁尾的平衡位形重建；（2）通过理论和模拟计算，分析亚暴增长期近地磁尾位形的线性和非线性宏观不稳定性(气球模,撕裂模等）；（3）选择典型亚暴事件，比较数值计算结果和卫星观测数据。本研究项目致力于充分利用近年来多点卫星观测所呈现的良好契机，推动对亚暴触发机制的理解，完善空间天气模型。

近地磁尾的稳定性问题是理解磁层亚暴触发机制的基础和关键。为了进一步确定亚暴触发机制，检验项目负责人之前所提出的磁尾气球模与重联相耦合触发亚暴的物理模型，本项目计划通过理论、模拟、以及多点卫星观测数据分析，综合研究近地磁尾不稳定性与亚暴触发机制的关系，重点考察气球模与磁重联在近地磁尾的耦合方式及其在亚暴触发过程中的作用。具体研究内容包括：（1）依据多点观测数据和磁层全局数值模拟，进行亚暴增长期近地磁尾的平衡位形重建；（2）通过理论和模拟计算，分析亚暴增长期近地磁尾位形的线性和非线性宏观不稳定性(气球模,撕裂模等）；（3）选择典型亚暴事件，比较数值计算结果和卫星观测数据。本项目按计划系统开展了近地磁尾不稳定性及亚暴触发机制的综合研究，包括1. 三维磁重联过程的几何与动力学结构；2. 磁尾双流体气球模非线性不稳定性诱发等离子体团及磁重联过程模拟；3. 磁尾位形的动理学气球模线性不稳定性分析；4. 剪切流对磁尾位形气球模不稳定性的影响；5. 理论模拟与卫星观测数据分析的比较研究等。通过本项目研究计划执行，验证和探索了双流体模型和动理学模型框架下，近地磁尾气球模不稳定性发生发展的可能性和位形参数条件；同时，发展了新的方法工具，首次将准分界线层(quasi-separatrix layer or QSL)的概念和方法推广到磁层磁场结构研究, 得到了磁尾位形非线性气球模不稳定性所引发准分界层QSL结构的三维分布, 进一步证明这种磁场重联是一种内禀的三维过程, 演示了近地磁尾气球模不稳定性所引起的三维磁重联过程的几何与动力学结构。这一成果对于理解重联过程的物理本质, 确定重联过程的几何特征,在观测数据中检测重联信号和地点, 有基础和实际意义。本研究项目致力于充分利用近年来多点卫星观测所呈现的良好契机，推动对亚暴触发机制的理解，完善空间天气模型。