The Differences in Onset Times of Hemispherically Conjugate Auroral Stations

半球共轭极光站出现时间的差异

• 批准号: 1606014
• 负责人: James Weygand
• 金额: $ 14.55万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1606014&HistoricalAwards=false
• 关键词: Differences; Onset; Times; Hemispherically; Conjugate

This is a one-year pilot study of a project classified as "high risk - high reward". The project will study hemispheric differences in the onset times of individual substorms and other auroral events observed simultaneously in the northern and southern auroral regions. Magnetic substorms (as they are called) reshape the Earth's magnetotail far out in Geospace. This process explosively releases energy powering an immediate intensification of currents and energetic charge particle precipitation closer to Earth in the ionosphere at the foot points of the affected field lines, and an intensification of auroral emissions. The investigation will take advantage of recently completed pairings of magnetometer stations located at the two Earthward ends of magnetic field lines that thread through the Earth's magnetotail where substorms are initiated. Differences in timing as well as the sequence of auroral features that precede the onset in each hemisphere will provide new information about, and place additional constraints on, controversial and still intensely debated theories about the underlying physical process(es) responsible for these extremely dynamic events. Significant closure risk is introduced in this project (which has never before been attempted) by the need to separate out the difference in timing due to the substorm process itself in the magnetosphere from other sources of timing offsets, for example, due to slight inter-hemispheric differences in the propagation path of a substorm onset signature into the magnetometer field of view. Whether these additional sources of timing differences can be removed using auroral images or other information, and the true substorm-related timing differences extracted, is the primary focus of this pilot study. The high reward of this technique, if proven feasible, is a new view into a long standing Geospace puzzle that continues to hinder progress in understanding severe space weather in the Earth's vicinity. Progress is important because in the hazardous radiation environment in near-Earth space, astronauts carry human enterprises into space and satellites that are key to important societal infrastructures orbit. The intense abrupt changes in the magnetic field associated with these explosive events induce currents in the solid Earth threatening long-term damage and shorter-term (potentially dangerous) disruptions in the operation of electric power grids. This pilot study will provide an educational experience to an undergraduate and a graduate student, contributing to the development of the future scientific workforce. The project is a statistical study that aims to identify significant difference between the hemispheres in the onset time for individual substorms as measured by signatures of the onset in ground-based magnetometers. Given this information, it may be possible to determine which of two prominent substorm models are more consistent with the timing observations. The second phase of the project will look to identify causes of the differences by examining the orientation of the interplanetary magnetic field, solar wind conditions, and the Universal Time during the substorm onset. A smaller study will compare onset differences with those observed in a pair of conjugate all-sky imagers, when available.

这是一项为期一年的试点研究，该项目被归类为“高风险 - 高奖励”。 该项目将研究在北部和南部极力区域同时观察到的单个实量和其他极光事件的发病时间的半球差异。 磁性体（称为）在地球上将地球的磁尾重塑。 该过程爆炸性地释放了能量，为电流的直接加强和能量电荷颗粒降水在受影响场线的脚部的电离层中更靠近地球，以及极光排放的强化。 调查将利用位于磁场线的两个接地端的最近完成的磁力计站的配对，这些磁场线线穿过地球的磁尾，在启动的镜头中螺纹。 在每个半球发作之前的定时以及极光特征序列的差异将为有关这些极具动态事件的基本物理过程（ES）提供有关基础物理过程（ES）的辩论，并在对基本的物理过程（ES）上提出其他限制的新信息。 在该项目中引入了显着的封闭风险（从未尝试过），需要将由于磁层中的镜头过程本身与其他计时偏移源的定时差异分开，例如，由于近半球相互差异，由于在磁铁计的磁铁计时场中的传播路径的繁殖相互差异。 这项试验研究的主要重点是，是否可以使用极光图像或其他信息来消除这些定时差异的其他其他来源。 该技术的高度奖励（如果可行的话）是一个长期存在的地理拼图的新看法，它继续阻碍地球附近地球上严重的太空天气的进步。 进步很重要，因为在近地空间的危险辐射环境中，宇航员将人类企业带入太空和卫星，这是重要的社会基础设施轨道的关键。 与这些爆炸性事件相关的磁场的剧烈变化会引起固体地球的电流，威胁到长期损坏和电力网格操作中短期（潜在危险）破坏。 这项试点研究将为本科生和研究生提供教育经验，为未来的科学劳动力的发展做出了贡献。该项目是一项统计研究，旨在确定通过基于地面磁力计发作的特征来衡量的单个质量的开始时间的半球之间的显着差异。 鉴于此信息，可能可以确定哪个两个突出的近代模型中的哪个与时间观察更一致。 该项目的第二阶段将通过检查行星际磁场，太阳风条件和实体开始期间的通用时间来确定差异的原因。 一项较小的研究将将发作差异与在一对共轭的全天空成像器中观察到的差异进行比较。