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

首席研究人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，因为粘性可以强烈影响日冕中磁场的动力学和能量学。他的团队将采用解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一个稳定的Sweet-Parker重联模型中；将预测的标度与观测到的耀斑功率输出和重联喷流的速度进行比较；获得描述日冕磁零区附近磁场扰动粘性衰减的新的瞬变解；并评估这些过程对日冕加热的贡献。这位首席研究员打算将他的粘阻解与基于Hall MHD方程的无碰撞磁重联模拟的数值结果进行比较，以确定这种分析何时有效，何时需要更严格(但更复杂的动力学)处理。预期的结果将有助于解释SOHO、Yohkoh、TRACE和Hinode等航天器的可用数据。更广泛地说，这项研究将有助于开发基于物理的空间天气模型，并伴随着对社会的好处。这些活动将有助于研究和教育的结合，以及促进教学、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参与，提名者本人(作为研究助理教授)将与新汉普郡大学(UNH)的本科生和研究生互动，担任论文委员会成员，并丰富新汉普郡大学学生的课堂教育和研究经验。

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.