Viscous Effects in Magnetic Reconnection and Energy Dissipation in the Solar Corona

日冕中磁重联的粘性效应和能量耗散

• 批准号: 0734032
• 负责人: Terry Forbes
• 金额: $ 29.41万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-11-01 至 2011-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0734032&HistoricalAwards=false
• 关键词: Viscous; Effects; Magnetic; Reconnection; Energy

The principal investigator plans to analyze the role of viscous stresses and viscous energy dissipation in the magnetized plasma of the solar corona, since viscosity can strongly influence the dynamics and energetics of the magnetic field in the corona. His team will study the contribution of viscous dissipation to coronal heating and flare energy release by employing a combination of analytical arguments and magnetohydrodynamic (MHD) simulations. The team will incorporate the effects of viscosity, compressibility, and flux pile-up into a steady Sweet-Parker reconnection model; compare the predicted scalings with the observed flare power output and the speeds of reconnection jets; obtain new transient solutions describing the viscous decay of field disturbances in the vicinity of magnetic nulls in the solar corona; and evaluate the contribution of these processes to coronal heating. The principal investigator intends to compare his visco-resistive solutions with numerical results of modeling collisionless magnetic reconnection, based on Hall MHD equations, in order to determine when this analysis is valid and when a more rigorous (but more complicated kinetic) treatment is necessary.The expected results will help in interpreting the available data from spacecraft such as SOHO, Yohkoh, TRACE, and Hinode. More generally, the research will contribute to the development of physics-based models for space weather, with concomitant benefits to society. The activities will contribute to the integration of research and education, as well as promote teaching, training, and learning. The project involves the participation of a postdoctoral research scientist as collaborator, and the proposer himself (as a research assistant professor) will interact with University of New Hampshire (UNH) undergraduate and graduate students, serve on thesis committees, and enrich the classroom education and research experience of UNH students.

首席研究员计划分析粘性应力和粘性能量耗散在日冕磁化等离子体中的作用，因为粘性会强烈影响日冕磁场的动力学和能量学。 他的团队将通过采用分析论证和磁流体动力学（MHD）模拟相结合的方法，研究粘性耗散对日冕加热和耀斑能量释放的贡献。 该团队将把粘性，可压缩性和通量堆积的影响纳入稳定的Sweet-Parker重联模型;将预测的缩放与观察到的耀斑功率输出和重联射流的速度进行比较;获得新的瞬态解，描述太阳日冕中磁零附近场扰动的粘性衰减;并评估这些过程对日冕加热的贡献。 主要研究者打算将他的粘阻解与基于Hall MHD方程的无碰撞磁重联模型的数值结果进行比较，以确定这种分析何时有效以及何时需要更严格（但更复杂的动力学）的处理。预期结果将有助于解释SOHO，Yohkoh，TRACE和Hinode等航天器的可用数据。 更一般地说，这项研究将有助于开发基于物理学的空间气象模型，同时给社会带来惠益。 这些活动将有助于研究与教育的结合，并促进教学、培训和学习。 该项目涉及一名博士后研究科学家作为合作者的参与，而提议者本人（作为研究助理教授）将与新罕布什尔州大学（UNH）的本科生和研究生互动，担任论文委员会成员，并丰富UNH学生的课堂教育和研究经验。