Multi-ion Dynamics of the Slow Solar Wind in Coronal Streamers

日冕流中缓慢太阳风的多离子动力学

• 批准号: 1059838
• 负责人: Leon Ofman
• 金额: $ 32.1万
• 依托单位: Catholic University of America
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-15 至 2015-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1059838&HistoricalAwards=false
• 关键词: Multi; ion; Dynamics; Slow; Solar

The Principal Investigator (PI) will perform a computational study of the formation and acceleration of the multi-ion solar wind in coronal streamers. He is motivated by the fact that previous MHD studies that have attempted to describe the solar wind plasma as a single fluid did not reproduce the observed properties of solar wind ions. In this effort, the PI will investigate the solar wind's multi-ion dynamics and compositional variations by developing comprehensive multidimensional and multi-fluid models of coronal streamers that incorporate heavy ions along with protons and electrons as separate but coupled fluids. He will study the effects of preferential heavy-ion heating and ion temperature anisotropies by including empirical heating terms, as well as wave heating and acceleration terms, in his new models. The PI will perform detailed comparisons between his models and available spectroscopic observations by calculating the ultraviolet (UV) emissivity expected from his multi-fluid model output. The computation of coronal emission based on the PI's models will allow him to estimate the expected intensity of UV spectral lines that will be detected using future coronagraphic instruments. This research will lead to a better understanding of the slow solar wind's composition and structure, as well as of the acceleration and heating processes that affect its plasma components. This project will promote research and education by involving a graduate student who belongs to an underrepresented minority group, as well as by training a postdoctoral scholar. The numerical codes developed in this project will strengthen the nation's computational infrastructure by providing massively parallel multi-fluid models for use by other researchers. The PI's multidimensional, multi-fluid numerical modeling codes will be made available to the broader scientific community for ongoing solar wind research, as well as for other applications where multi-ion plasmas are present, such as in laboratory and astrophysical plasmas.

首席研究员（PI）将对日冕流中多离子太阳风的形成和加速进行计算研究。他的动机是，之前的 MHD 研究试图将太阳风等离子体描述为单一流体，但没有重现所观察到的太阳风离子的特性。在这项工作中，PI将通过开发日冕流的综合多维和多流体模型来研究太阳风的多离子动力学和成分变化，该模型将重离子以及质子和电子作为独立但耦合的流体结合在一起。他将通过在新模型中纳入经验加热项以及波加热和加速项来研究优先重离子加热和离子温度各向异性的影响。 PI 将通过计算多流体模型输出预期的紫外线 (UV) 发射率，对其模型和可用的光谱观测结果进行详细比较。基于 PI 模型的日冕发射计算将使他能够估计未来日冕仪器将检测到的紫外光谱线的预期强度。这项研究将有助于更好地了解慢速太阳风的成分和结构，以及影响其等离子体成分的加速和加热过程。该项目将通过让属于代表性不足的少数群体的研究生参与以及培训博士后学者来促进研究和教育。该项目开发的数字代码将通过提供大规模并行多流体模型供其他研究人员使用来加强国家的计算基础设施。 PI 的多维、多流体数值建模代码将提供给更广泛的科学界，用于正在进行的太阳风研究，以及存在多离子等离子体的其他应用，例如实验室和天体物理等离子体。