GEM-CEDAR Postdoc: Understanding MIC through Tomographic Imaging of the Ionospheric and Plasmaspheric Density Using Ground and Space-Based GPS Receiver

GEM-CEDAR 博士后：使用地面和天基 GPS 接收器通过电离层和等离子体层密度断层成像了解 MIC

• 批准号: 0524711
• 负责人: Endawoke Yizengaw
• 金额: $ 18.01万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-12-01 至 2007-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0524711&HistoricalAwards=false
• 关键词: GEM; CEDAR; Postdoc; Understanding; MIC

This project will examine the global density structure of the plasma in the inner magnetosphere using a combination of techniques that use ground- and space-based Global Positioning System (GPS) receivers. Procedures will be developed for the routine analysis of GPS datasets. The method will be validated and compared with current ionospheric and plasmaspheric models and other independent measurement data. The Low-Earth-Orbit (LEO) satellites equipped with dual-band GPS receivers (FedSat, CHAMP, GRACE, SAC-C, and many more) and ground-based dual-band GPS receivers offer an excellent opportunity for remote sensing and monitoring of the topside ionosphere and plasmasphere. A tomographic reconstruction approach will be used to image the detailed structure of ionospheric and plasmaspheric density. The advantages of these combined observations include: Combining the LEO-GPS data with ground-based GPS allows the explicit measurement of relative contributions of the plasmasphere and ionosphere contribution to the total electron content (TEC). Because there are quite a number of LEO satellites orbiting at different orbital inclinations, a global map of the topside ionosphere and plasmasphere can be made. This is in sharp contrast with purely ground-based GPS TEC measurements that are confined to limited land-based geographic regions. Two separate tomographic reconstructions, ground-based and space-based will be generated. This will make it possible to obtain electron density profiles of the inner magnetosphere, understand the field-line plasma transport which is thought to be the principal agent for the density loss and refilling of the plasmasphere, and infer the role of storm time convection electric fields in the dynamics of M-I coupling. The project will also compare the results of the tomographic reconstructions with images of the plasmapause determined using the IMAGE EUV images. The combined observations will identify the correlation between the ionospheric density depletion in the mid-latitude region (usually called the mid-latitude trough) and the plasmapause. In the future, the analysis tools that will be developed will be able to monitor the ionosphere and plasmasphere in near real time. The spatial resolution of this technique will continue to improve as data from the ever-increasing LEO satellite constellations (e.g., COSMIC) and the upcoming GALILEO satellite constellation for ground- and space-based TEC observation are examined. Such real-time monitoring will be important for future space weather operational systems.

该项目将利用地面和空间全球定位系统接收器的综合技术，研究内磁层等离子体的全球密度结构。将为全球定位系统数据集的例行分析制定程序。将对该方法进行验证，并将其与目前的电离层和等离子体层模型及其他独立的测量数据进行比较。配备双波段全球定位系统接收器（FedSat、CHAMP、GRACE、SAC-C等）和地基双波段全球定位系统接收器的低地球轨道卫星为对顶侧电离层和等离子体层进行遥感和监测提供了极好的机会。层析重建方法将用于电离层和等离子体层密度的详细结构成像。这些综合观测的优点包括：将低地轨道全球定位系统数据与地面全球定位系统相结合，可以明确测量等离子体和电离层对总电子含量的相对贡献。由于有相当多的低地球轨道卫星以不同的轨道倾角运行，因此可以绘制顶部电离层和等离子层的全球地图。这与仅限于有限陆地地理区域的纯地基GPS TEC测量形成鲜明对比。两个单独的断层重建，地基和天基将产生。这将使人们有可能获得内磁层的电子密度分布，了解场线等离子体传输，这被认为是主要的代理商的密度损失和再填充的等离子体，并推断风暴时间对流电场的作用，在动力学的M-I耦合。该项目还将把层析重建的结果与使用IMAGE EUV图像确定的等离子体层顶图像进行比较。综合观测将确定中纬度地区电离层密度耗尽（通常称为中纬度槽）与等离子体层顶之间的相关性。今后，将开发的分析工具将能够近真实的实时监测电离层和等离子体。随着来自不断增加的LEO卫星星座（例如，COSMIC）和即将推出的GALILEO卫星星座的地面和空间为基础的TEC观测进行审查。这种实时监测对于未来的空间气象业务系统将是重要的。