Space Plasma and Magnetospheric Physics at Southampton (2021-4)

这项综合拨款申请建议在南安普敦大学进行三个相关项目的研究，所有这些项目都与地球磁层和弓形激波对太阳风的反应方式有关。第一个项目将解决地球磁层对太阳风的大规模反应问题。这种相互作用的性质取决于行星际磁场的方向，而行星际磁场与太阳风有关。这种方向是高度多变的，但也可以被称为“向北”或“向南”。我们将利用卫星观测来测试先前在行星际磁场“向北”期间观测到的磁层复杂结构的机制，寻找该结构与太阳风预测相互作用的特征，并研究全球磁层模拟中存在的等效结构。第二个项目将调查一种名为“湍流”的过程如何影响等离子体中的冲击波。湍流是一个过程，在这个过程中，混沌流动导致能量从大尺度(例如太阳风的整体流动)向下转移到小尺度(加热单个粒子)。激波是在快速流动的等离子体(如太阳风)中存在障碍物(如磁层)时形成的。我们将使用三个卫星任务的观测结果：MMS，它以前所未有的细节测量地球附近的等离子体环境，以及Parker太阳探测器和太阳轨道器，这两个任务都使测量太阳风比以往任何时候都更接近太阳。通过将航天器数据与高性能计算模拟相结合，我们将确定湍流过程和其他太阳风瞬变如何影响等离子体冲击波的结构。最后一个项目将研究在磁层观察到的等离子体湍流与极光(北极光)中存在的湍流结构之间的联系，当极光是在非常精细的尺度上观测到的。等离子体湍流将使用MMS(与项目2相同，但这次是在磁层的不同区域)的测量来观测，而极光湍流将使用由南安普顿大学运营的名为ASK的独特极光仪器来观测。ASK能够观察到几十米尺度的极光结构，以及精确到几分之一秒的时间尺度上的变化--这是ASK独一无二的能力。

This Consolidated Grant application proposes research which will be undertaken at the University of Southampton in three related projects, all of which are connected to the manner in which the Earth's magnetosphere and bow shock respond to the solar wind.The first project will address questions about how the Earth's magnetosphere responds to the solar wind on a large scale. The nature of this interaction depends on the orientation of the interplanetary magnetic field, which is associated with the solar wind. This orientation is highly changeable, but can be referred to as 'northward' or 'southward'. We will use satellite observations to test mechanisms that have been advocated for previously observed complex structure in the magnetosphere during periods when the interplanetary magnetic field is 'northward', to hunt for the signature of that structure's predicted interaction with the solar wind, and to investigate equivalent structure present in global simulations of the magnetosphere.The second project will investigate how a process called 'turbulence' affects shock wave in plasmas. Turbulence is a process whereby chaotic flow causes energy to be transferred from large scales (e.g. the bulk flow of the solar wind) down to small scales (heating individual particles). A shock wave is formed when an obstacle (such as a magnetosphere) is present in a fast-flowing plasma (such as the solar wind). We will use a combination of observations from three satellite missions: MMS, which makes measurements of the plasma environment near Earth in unprecedented detail, and Parker Solar Probe & Solar Orbiter, both of which make measurements of the solar wind closer to the Sun than ever possible before. By combining spacecraft data with high-performance computational simulations, we will determine how the turbulence process and other solar wind transients affect the structure of plasma shock waves.The final project will investigate the link between plasma turbulence observed in the magnetosphere and turbulent structure that is present in the aurora (northern lights) when the aurora is observed on very fine scales. The plasma turbulence will be observed using measurements from MMS (as in Project 2, but this time looking at a different region of the magnetosphere), and the auroral turbulence will be observed using a unique auroral instrument called ASK, which is operated by the University of Southampton. ASK is capable of observing structure in the aurora down to scales of tens of metres, and changes on timescales down to fractions of a second - capabilities that are unique to ASK.