CEDAR Postdoc: Coordinated Optical and Radar Observations of the Ionosphere and Thermosphere

CEDAR 博士后：电离层和热层的协调光学和雷达观测

• 批准号: 0924914
• 负责人: Elsayed Talaat
• 金额: $ 23.81万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0924914&HistoricalAwards=false
• 关键词: CEDAR; Postdoc; Coordinated; Optical; Radar

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The mid-latitude ionosphere is considerably more dynamic than previously thought. Medium-scale traveling ionospheric disturbances (MSTIDs), sporadic-E (Es) layers, and mid-latitude spread F are examples of mid-latitude ionospheric dynamics that occur during periods of quiet geomagnetic conditions. During active geomagnetic conditions, large plasma depletions and enhancements, along with associated steep density gradients, often form and move through the mid-latitudes. Both quiet- and storm- time dynamics have profound effects on radio waves. This is especially crucial for users of satellite-based navigation systems, for which ionospheric variability is the largest uncorrected error. The origins of MSTIDs observed at mid-latitudes are not well established and may be due to forcing by the aurora or by coupling to Es layers below, perhaps even both. The expansion of the SuperDARN radar system to mid-latitudes has made large-scale and long-term study of these phenomena possible. However, the radars lack spatial resolution and photochemical information (notably plasma density and altitude information) to fully characterize the effects and small-scale dynamics of the MSTIDs. This project will perform a coordinated study utilizing an all-sky airglow imager in conjunction with the SuperDARN radar at Wallops Island, VA, to observe the relationship between observations of the electric fields and ion velocities within MSTIDs and variations in density and altitude inferred from the airglow. The following questions will be addressed: 1. Is the MSTID a geomagnetic artifact that propagates out of the auroral oval or is it generated by a local instability, perhaps coupled to a sporadic-E layer? 2. Are (all) MSTIDs electrified? 3. What is the effect of the MSTID on the F region after it passes? The broader impacts of the project include enhancing the SuperDARN infrastructure at Wallops Island and the datasets obtained by it and supporting a new researcher in his first research effort after completion of the Ph.D. The long-term results of studying the mid-latitude ionosphere will help users and designers of these systems, especially augmentation systems such as WAAS, produce better corrections and prepare appropriate mitigation strategies for severe disturbances.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。中纬度电离层比以前想象的要活跃得多。中尺度移动电离层扰动（MSTIDS）、零星的E（Es）层和中纬度扩展F是在地磁平静期间发生的中纬度电离层动力学的例子。在活跃的地磁条件下，大的等离子体耗尽和增强，沿着相关的陡峭的密度梯度，往往形成和移动通过中纬度地区。平静时间和风暴时间的动力学对无线电波都有深远的影响。这对于卫星导航系统的用户尤其重要，因为电离层的变化是最大的未校正误差。 在中纬度地区观测到的MSTID的起源还没有很好的确定，可能是由于极光的强迫或与下面的Es层耦合，甚至可能是两者兼而有之。SuperDARN雷达系统扩展到中纬度地区，使得对这些现象进行大规模长期研究成为可能。然而，雷达缺乏空间分辨率和光化学信息（特别是等离子体密度和高度信息），无法充分描述MSTID的影响和小尺度动态。 该项目将利用全天空气辉成像仪与弗吉尼亚州沃洛普斯岛的SuperDARN雷达进行协调研究，以观察MSTID内电场和离子速度观测值与从气辉推断的密度和高度变化之间的关系。 以下问题将得到解决：1。MSTID是一个传播出极光椭圆的地磁伪影，还是由局部不稳定性产生的，也许与零星的E层耦合？ 2.（所有）MSTID都通电了吗？ 3. MSTID通过后对F区有什么影响？ 该项目的更广泛的影响包括增强Wallops Island的SuperDARN基础设施及其获得的数据集，并支持新研究人员在完成博士学位后的首次研究工作。 对中纬度电离层的长期研究结果将有助于这些系统的用户和设计者，特别是诸如广域增强系统等增强系统的用户和设计者进行更好的校正，并为严重干扰制定适当的减缓战略。