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

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。中纬度电离层比之前想象的要活跃得多。中尺度移动电离层扰动(MSTID)、零星电离层E(ES)层和中纬度扩散F是中纬度电离层动力学的例子，它们发生在地磁条件平静的时期。在活跃的地磁条件下，大的等离子体损耗和增强，以及相关的陡峭的密度梯度，经常形成并通过中纬度。平静时间和风暴时间的动态都对无线电波产生了深远的影响。这对以卫星为基础的导航系统的用户尤其重要，因为电离层的可变性是最大的未纠正的误差。在中纬度观测到的MSTID的起源还没有很好地确定，可能是由于极光的强迫，或者是由于耦合到下面的ES层，甚至可能两者兼而有之。SuperDARN雷达系统向中纬度的扩展使大规模和长期研究这些现象成为可能。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)来充分描述MSTID的影响和小尺度动力学。该项目将利用位于弗吉尼亚州沃洛普斯岛的全天空气辉成像仪和SuperDARN雷达进行一项协调研究，以观察MSTID内电场和离子速度的观测与从气辉推断的密度和高度变化之间的关系。将讨论以下问题：1.MSTID是从极光椭圆形传播出来的地磁伪影，还是由局部不稳定产生的，可能与零星的-E层耦合？2.(所有)MSTID是否带电？3.MSTID通过后对F区的影响是什么？该项目的更广泛影响包括加强沃洛普斯岛的SuperDARN基础设施及其获得的数据集，并支持一名新的研究人员在完成博士学位后的第一次研究工作。研究中纬度电离层的长期成果将有助于这些系统的用户和设计者，特别是WAAS等增强系统的用户和设计者，对严重干扰作出更好的修正，并拟订适当的缓解战略。

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.