HF Backscatter from the Polar and Auroral E-Region Ionosphere: Origin, Conjugacy, and Electric Field Control

来自极地和极光 E 区电离层的高频反向散射：起源、共轭和电场控制

• 批准号: 1139806
• 负责人: Roman Makarevich
• 金额: $ 32.33万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1139806&HistoricalAwards=false
• 关键词: HF; Backscatter; Polar; Auroral; Region

The project will focus on investigations into the largely unexplored subset of coherent echo returns from the polar and auroral E-region plasma waves observed with the first U.S. Antarctic high-frequency ionospheric radar deployed at McMurdo in early 2010 in conjunction with other Antarctic and high northern hemisphere radars within the SuperDARN international program. Recent body of work on auroral E-region irregularities exploring SuperDARN as a global array has clearly demonstrated importance of the aspect angle or, equivalently, magnetic inclination angle conditions for both occurrence and phase velocity of E-region radar aurora. Initial observations by the McMurdo radar show abundance of short-range echoes with properties very similar to auroral E-region echoes but at locations with very high geometric aspect angles. The project's research will address a fundamental question of why E-region echoes from the polar cap are observed at all by the McMurdo radar. These investigations will include further examination of the previously found auroral echoes with unusual properties, e.g., velocities greatly exceeding nominal ion-acoustic speed and independent of the plasma flow angle. They will also evaluate the extent of magnetic conjugacy of the E-region radar aurora and establish the relationship between E-region irregularities and plasma drift velocities. This research will be led by a new young PI and will also contribute to the training and education of a graduate student.

该项目将重点研究极地和极光 E 区等离子体波的相干回波返回的大部分未经探索的子集，这些回波是通过 2010 年初部署在麦克默多的美国第一台南极高频电离层雷达以及 SuperDARN 国际计划中的其他南极和高北半球雷达观测到的。最近关于极光 E 区不规则性的研究工作将 SuperDARN 作为全球阵列，清楚地证明了方位角或等效的磁倾角条件对于 E 区雷达极光的出现和相速度的重要性。麦克默多雷达的初步观测显示，存在大量短程回波，其特性与极光 E 区回波非常相似，但位于几何方位角非常高的位置。该项目的研究将解决一个基本问题：为什么麦克默多雷达能够观测到来自极冠的 E 区回波。这些研究将包括对先前发现的具有不寻常特性的极光回波进行进一步检查，例如，速度大大超过标称离子声速并且与等离子体流角无关。他们还将评估 E 区雷达极光的磁共轭程度，并建立 E 区不规则性与等离子体漂移速度之间的关系。这项研究将由一位新的年轻 PI 领导，也将有助于研究生的培训和教育。