Studies of Magnetohydrodynamic Turbulence and Turbulence in the Corona and Interplanetary Medium

磁流体动力湍流以及日冕和行星际介质中的湍流研究

• 批准号: 0105254
• 负责人: William Matthaeus
• 金额: $ 50.52万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-15 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0105254&HistoricalAwards=false
• 关键词: Studies; Magnetohydrodynamic; Turbulence; Corona; Interplanetary

The investigators will perform theoretical investigations of incompressible and nearly incompressible magnetohydrodynamic turbulence and anisotropic linear cascades in the corona and interplanetary medium. Complex nonlinear dynamical behavior, or turbulence, is observed in space plasmas over a wide range of scales that may be described by a magnetohydrodynamic (MHD) model. Many phenomena in the extended solar corona, including the solar wind, in the magnetosphere, and in the interstellar medium may involve turbulence. Turbulence is likely to have importance in coronal heating, the acceleration of solar wind, and the acceleration and diffusion of energetic particles. An integrated approach will be adopted using MHD and fluid simulation techniques, transport theory, analytic theory of turbulence and particle diffusion, and related analysis and interpretation of spacecraft observations. Work in basic MHD theory will include development and refinement of phenomenologies for MHD relaxation and decay processes, further characterization of the nature of MHD spectral anisotropy, and information theory-based attempts to advance a description of coherent structures in MHD turbulence. Advances in phenomenologies and transport models will be used to further develop scattering and transport theories of cosmic rays. Long-term goals are self-consistent models of coronal heating and the acceleration and evolution of the solar wind.

研究人员将对日冕和行星际介质中的不可压缩和几乎不可压缩的磁流体动力学湍流和各向异性线性级联进行理论研究。 空间等离子体中存在复杂的非线性动力学行为，即湍流，其尺度范围很广，可以用磁流体动力学（MHD）模型来描述。 在扩展日冕中的许多现象，包括太阳风，磁层和星际介质中的许多现象都可能涉及湍流。 湍流可能在日冕加热、太阳风加速以及高能粒子的加速和扩散方面具有重要意义。 将采用一种综合办法，利用磁流体动力学和流体模拟技术、输运理论、湍流和粒子扩散的分析理论以及对航天器观测的相关分析和解释。 基本MHD理论的工作将包括MHD弛豫和衰变过程的现象学的发展和改进，MHD谱各向异性的性质的进一步表征，以及基于信息论的尝试，以推进MHD湍流中相干结构的描述。 现象学和传输模型的进展将用于进一步发展宇宙射线的散射和传输理论。 长期目标是日冕加热和太阳风加速和演变的自洽模型。