SHINE: Statistical Analysis of Magnetic Helicity of the Solar Wind Turbulence at Kinetic Scales

SHINE：动力学尺度上太阳风湍流磁螺旋度的统计分析

• 批准号: 1357893
• 负责人: Bernard Vasquez
• 金额: $ 32.96万
• 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: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1357893&HistoricalAwards=false
• 关键词: SHINE; Statistical; Analysis; Magnetic; Helicity

The research agenda of this project directly addresses the SHINE goal of "understanding or characterizing the background solar wind and how it evolves." The outcome of the research work will advance the understanding of interplanetary turbulence at the kinetic scales. This project is expected to provide fundamental new insights in space physics regarding how collisionless dissipation of large-scale magnetohydrodynamic turbulence actually proceeds in the solar wind. The overall effort includes the participation of students from the University of New Hampshire. The research and EPO agenda of this SHINE project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research. The main goal of this 3-year SHINE project is to study the magnetic helicity associated with interplanetary turbulent fluctuations in the proton kinetic range. The magnetic helicity is a sensitive indicator of the physical processes responsible for the turbulent energy cascade. The project team will use spacecraft data from Wind to determine the statistical properties of the magnetic helicity. The distribution of the helicity with the scale convected past the spacecraft will be described by the value and position attained at the peak and also its width at half maximum. These properties will be studied as functions of the amplitude of the fluctuations, the plasma beta, and the cross-helicity. The spectral properties of the magnetic helicity will be calculated using both global and local mean magnetic fields from the same data sets. This will allow a direct comparison between the obtained statistical results of these two techniques. Three-dimensional hybrid numerical simulations with particle ions and fluid electrons will also be used to interpret the results found in each approach.

该项目的研究议程直接解决了“理解或表征背景太阳风及其演变方式”的光泽目标。 研究工作的结果将提高对动力学尺度下星际湍流的理解。 预计该项目将提供有关太空物理学的基本新见解，内容涉及在太阳风中实际上进行大规模磁流失动力湍流的无碰撞耗散。 总体努力包括来自新罕布什尔大学的学生的参与。 该Shine项目的研究和EPO议程支持AGS部门在发现，学习，多样性和跨学科研究方面的战略目标。这个为期三年的光泽项目的主要目标是研究与质子动力学范围内的星际湍流波动相关的磁性螺旋。 磁性螺旋度是负责湍流能量级联的物理过程的敏感指标。 该项目团队将使用Wind的航天器数据来确定磁性螺旋的统计特性。 螺旋度与超过航天器的量表的分布将由在峰处获得的值和位置描述，也将其宽度在最大的一半处描述。 这些特性将作为波动，等离子体β和跨效率的振幅的函数进行研究。 磁性螺旋度的光谱特性将使用来自相同数据集的全球和局部平均磁场进行计算。 这将允许在这两种技术的统计结果之间进行直接比较。 与粒子离子和流体电子的三维杂化数值模拟也将用于解释每种方法中发现的结果。