Radar Studies of the Low Latitude Disturbed Ionosphere

这是一个为期四年的研究方案，利用阿雷西博和基卡马卡的高层大气研究卫星非相干散射雷达设施对电离层等离子体漂移的测量。拟议的研究项目之一涉及在扰动条件下低纬电离层对基本磁层-电离层耦合过程的电动力学响应。来自阿雷西博的改进的等离子体漂移测量与高纬度、磁层和太阳风数据将结合使用全球对流模式的数值模拟。目的是定量了解屏蔽效率随风暴位相、行星际电场(IMF)、动压和IMF-by变化的低纬瞬时穿透电场和扰动发电机电场，并首次获得亚暴的影响。最终，这被认为导致了基于太阳风和通量参数的预测性低纬经验电场模型的发展，该模型解释了基本的磁层过程。另一个项目涉及强扰动低纬电场对高纬度等离子体密度分布的时间依赖效应。将通过全球定位系统(GPS)接收器全球网络测量的中低纬总电子含量(TEC)的影响来调查后者。第三个项目将通过将Jicamara测量结果与使用海军研究实验室(NRL)三维等离子体不稳定模型的数值模拟进行比较，研究赤道等离子体气泡在不同播撒机制和电动力学条件下的演变。最后，将开展一项研究项目，以量化电离层等离子体漂移和热层中性风的季节和太阳通量依赖的风暴时间耦合。该项目的目标是对美国地段赤道垂直漂移的高度和经度变化进行经验模拟。这些高度研究将包括新的Jicamara漂移测量，覆盖的海拔范围比过去大得多(高达约1500-2000公里)。建议包括学生培训和参与的重要组成部分。研究生和本科生都将得到这笔助学金的资助，并将参与研究项目。具体地说，学生将接受关于雷达观测的高度先进的分析技术的培训。通过这种方式，该项目将有助于在大气学社区内建立和保持这一非常可取的专业知识。大学参与UARS雷达设施的使用是设施方案的一个重要方面，该项目将在实现这一目标方面发挥重要作用。此外，这项拟议的研究涉及与几个机构的广泛科学家进行跨学科的广泛合作。

This is a four-year research program utilizing measurements of ionospheric plasma drifts from the Upper Atmosphere Research Satellite incoherent scatter radar facilities at Arecibo and Jicamarca. One of the proposed research projects concerns the electrodynamic response of the low-latitude ionosphere to fundamental magnetosphere-ionosphere coupling processes during disturbed conditions. Improved plasma drift measurements from Arecibo together with high latitude, magnetospheric, and solar wind data will be used in combination with numerical simulations using global convection models. The objective is to obtain a quantitative understanding of the low latitude prompt penetration and disturbance dynamo electric fields due to the effects of the variation of the shielding efficiency with storm phase, interplanetary electric field (IMF), dynamic pressure, and IMF-By and, for the first time, due to substorms. Ultimately this is believed to lead to the development of a predictive low latitude empirical electric field model based on solar wind and flux parameters, which accounts for essential magnetospheric processes. Another project concerns the time dependent effects of the strongly disturbed low latitude electric fields on the plasma density distribution at higher latitudes. The latter will be investigated by means of the effects on mid and low latitude total electron content (TEC) as measured by a global network of Global Positioning System (GPS) receivers. A third project will examine the evolution of equatorial plasma bubbles in response to different seeding mechanisms and electrodynamic conditions by comparing the Jicamarca measurements with numerical simulations using the Naval Research Laboratory (NRL) three-dimensional plasma instability model. Finally, a research project will be carried out to quantify the season and solar flux dependent storm time coupling of ionospheric plasma drifts and thermospheric neutral winds. The goal of this project is to model empirically the altitudinal and longitudinal variation of the equatorial vertical drifts in the American sector. These altitudinal studies will include new Jicamarca drift measurements covering a much larger range of altitudes (up to about 1500-2000 km) than has been possible in the past.The proposal includes a significant component of student training and participation. Graduate as well as undergraduate students will be supported under this grant and will participate in the research projects. Specifically, the students will be trained in highly advanced analysis techniques for the radar observations. In this way the project will contribute to building and sustaining this highly desirable expertise within the aeronomy community. University participation in the utilization of the UARS radar facilities is an important aspect of the facility program and this project will play an important role in meeting this goal. In addition, the proposed research involves widespread, cross-disciplinary collaborations with a broad range of scientists at several institutions.