SHINE: Eulerian Decorrelation Functions Derived from Multispacecraft Observations of Interplanetary Magnetic Field Fluctuations

作为该项目的科学动机，首席研究员（PI）解释说，磁欧拉相关函数（ECF）是由于行星际磁场波动导致的太阳风中粒子传输的时间去相关性的度量，他指出ECF直接用于粒子散射理论，以及基本湍流理论，发电机理论和等离子体物理学。为了向严重依赖ECF估计的空间物理建模者提供太阳风去相关函数的精确观测，PI将使用来自多个航天器的数据，提供慢速和快速太阳风中磁场波动的ECF参数的基于观测的测量。这项研究将解决的问题，如何ECF随太阳风的速度和湍流的几何形状在ECF如何随平均磁场变化的作用。这些问题的答案将首次提供与太阳风湍流和宇宙射线传输相关的理论模型的详细尺度依赖约束。更好地了解ECF还将提供更好的时间范围的估计，在该时间范围内可以可靠地模拟太阳风的传播，这些结果将有益地应用于空间天气预报，并将有助于改进美国航天局未来的“太阳探测器”航天器观测的规划和数据分析。这些发现还将有益于正在进行的行星际磁场湍流研究，这些研究适用于比这一努力更广泛的天体物理和空间研究课题。 该研究项目还将支持一名本科暑期学生。PI将在国际会议、会议报告和期刊出版物中向社区传播其研究成果。

As the scientific motivation for this project, the Principal Investigator (PI) explains that the magnetic Eulerian Correlation Function (ECF) is a measure of the temporal decorrelation of particle transport in the solar wind due to interplanetary magnetic field fluctuations, and he notes that the ECF is directly invoked in particle scattering theory, as well as in fundamental turbulence theory, dynamo theory, and plasma physics. In order to provide accurate observations of solar wind decorrelation functions for space physics modelers who rely heavily on ECF estimates, the PI will provide observationally based measurements of ECF parameters for magnetic field fluctuations in both the slow and fast solar wind, using data from multiple spacecraft. This study will address questions concerning how the ECF varies with solar wind speed and the role that turbulence geometry plays in how the ECF varies with respect to the mean magnetic field. The answers to these questions will, for the first time, provide detailed scale-dependent constraints on theoretical models relevant to solar wind turbulence and cosmic ray transport. Better knowledge of the ECF will also provide better estimates of the temporal ranges over which solar wind propagation can be reliably simulated.These results will have beneficial applications to space weather forecasting, and will contribute to enhanced planning and data analysis for observations from NASA's future "Solar Probe" spacecraft. These findings will also benefit ongoing studies of interplanetary magnetic field turbulence which are applicable to a much more extensive range of astrophysical and space research topics than this effort alone addresses. This research project will also support one undergraduate summer student. The PI will disseminate his research findings to the community at international meetings, in conference presentations, and in journal publications.