Outstanding Questions on Auroral Radiation Fine Structure

极光辐射精细结构的悬而未决的问题

• 批准号: 1043230
• 负责人: James LaBelle
• 金额: $ 19.33万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1043230&HistoricalAwards=false
• 关键词: Outstanding; Questions; Auroral; Radiation; Fine

This proposal is funded to continue study of plasma waves and radiation that play key roles in controlling the charged particle transport, loss rates, and energy exchange in the Earth's magnetosphere. These waves also directly or remotely sense space plasma processes, structures, and boundaries that interact with the solar wind plasma flow. Operating a digital radio receiver (100 KHz -5 MHz) at the South Pole station in the Antarctic will answer some outstanding questions regarding the fine structure of above radio emission: What is the relationship between the recently discovered fine structures of low frequency (LF) auroral hiss and middle-frequency (MF) burst: two types of radio emissions that occur together at the onset of the auroral substorm? Are the LF auroral hiss and auroral MF burst correlated or anti-correlated temporally and spatially on sub-second time scales? Are structured "AKR-like" emissions at 150-750 kHz, which superficially resemble the Auroral Kilometric Radiation (AKR), evidence of transmission of AKR to ground level? Preliminary comparisons between South Pole radio data and corresponding data from the Geotail satellite deep in the Earth's magnetotail suggest a good correlation between AKR and the ground-level "AKR-like" events, which if confirmed will support previously ignored theories of mode conversion and downward propagation of AKR. The proposed experiments must be performed in the Antarctic, because critical portions of the LF/MF radio environment are impossible to observe at Northern Hemisphere locations due to man-made electromagnetic interference. This proposal will provide education and training to both the undergraduate and graduate students at Dartmouth College, forming the major part of a PhD dissertation. It will also provide the basis for multiple undergraduate internships. Researchers at Dartmouth College will participate in public outreach as a part of this work, including public talks or visits to schools.

该提案的资助是为了继续研究等离子体波和辐射，这些波和辐射在控制地球磁层中的带电粒子传输、损失率和能量交换方面发挥着关键作用。这些波还直接或远程感知与太阳风等离子体流相互作用的空间等离子体过程、结构和边界。在南极南极站上运行一台数字无线电接收机（100 KHz-5 MHz）将回答有关上述无线电发射精细结构的一些悬而未决的问题：最近发现的低频（LF）极光嘶嘶声和中频（MF）爆发的精细结构之间的关系是什么？在亚秒级时间尺度上，低频极光嘶嘶声和极光中频爆发在时间和空间上是相关的还是反相关的？在150-750 kHz处的结构化“AKR样”发射，表面上类似于极光千米辐射（AKR），是AKR传输到地面的证据吗？南极无线电数据和地球磁尾深处Geotail卫星的相应数据之间的初步比较表明，AKR和地面“类AKR”事件之间存在良好的相关性，如果得到证实，将支持以前忽略的模式转换和AKR向下传播的理论。拟议的实验必须在南极进行，因为由于人为的电磁干扰，在北方半球的位置不可能观察到LF/MF无线电环境的关键部分。该提案将为达特茅斯学院的本科生和研究生提供教育和培训，并构成博士论文的主要部分。它还将为多个本科实习提供基础。达特茅斯学院的研究人员将参与公共宣传，作为这项工作的一部分，包括公开讲座或访问学校。