SHINE: Solar Wind Magnetic Field Discontinuities and the Role of Alfvenic Turbulence

首席研究员(PI)将研究磁场不连续与太阳风中湍流消散之间的关系，使用一种新方法来准确识别太阳风中即使是微小的不连续。在一项小型的初步研究中，这种新方法发现了许多厚度与离子动力学标度一致的不连续点，这些不连续点可能是耗散湍流级联能量的位置。PI将把这项初步研究扩展到1998年3月至今的所有高级成分探测器(ACE)航天器数据，涵盖整个太阳活动周期。PI将评估发现的任何不连续的统计特性，并将它们与惯性耗散范围光谱中断处的湍流波动特性进行比较。他还将把不连续频率和其他性质与当地对湍流串联率的估计进行比较。这项工作将有助于描述小尺度结构如何产生并促进太阳风的加热，以及限制在1AU附近的太阳风中湍流涨落的消散和离子的加热的机制。PI的工作将解决决定内日光层太阳风的发展和演化的基本物理过程，以及太阳风中的小尺度过程如何与大尺度动力学相耦合。这个项目对于模拟日冕物质抛射(CME)必须通过的周围太阳风的能量是很重要的。湍流级联的消散被认为是给地球附近的太阳风提供能量的一个重要来源，可能是从日冕到日光层外的太阳风。因此，国际空间局期望这项研究为磁流体动力学太阳风模拟提供新的方法，并提高空间天气预报的准确性。这项研究计划将包括新汉普郡大学本科生和研究生的培训和参与。

The Principal Investigator (PI) will investigate the relationship between magnetic field discontinuities and the dissipation of turbulence in the solar wind, using a new method to accurately identify even small discontinuities in the solar wind. In a small preliminary study, this new method found numerous discontinuities with thicknesses consistent with ion kinetic scales, and these could be locations that dissipate the turbulent cascade energy. The PI will extend this initial study to all Advanced Composition Explorer (ACE) spacecraft data from March 1998 to the present, covering an entire solar activity cycle. The PI will evaluate the statistical properties of any discontinuities that are found and compare them to properties of turbulent fluctuations at the inertial dissipation range spectral break. He will also compare discontinuity frequency and other properties with local estimates of the turbulent cascade rate. This effort will help describe how small scale structures arise and contribute to heating the solar wind, as well as constrain the mechanisms responsible for the dissipation of turbulent fluctuations and the heating of ions in the solar wind near 1 AU. The PI's work will address fundamental physical processes that determine the development and evolution of the solar wind in the inner heliosphere and how small-scale processes in the solar wind couple to large-scale dynamics. This project is important for modeling the energization of the ambient solar wind through which coronal mass ejections (CMEs) must travel.Dissipation of the turbulent cascade is believed to be an important source of energizing the solar wind near Earth, and potentially from the corona to the outer heliosphere. The PI therefore expects this research to provide new approaches for magnetohydrodynamics (MHD) solar wind simulations and to enhance the accuracy of space weather forecasting. This research program will include the training and participation of both undergraduate and graduate students at University of New Hampshire.