Collaborative Research: Causes and Consequences of the Gradients in the Vertical Plasma Drift in the Equatorial Plasma Drift Vortex

在低纬地区的黄昏时段，由于E区等离子体由于快速化学作用而重新组合，在F区峰值高度以下将出现等离子体密度的强烈垂直梯度。F峰以下高度的垂直漂移梯度可能会令人惊讶地大、动态且每天都是可变的。该奖项将应用电离层-热层-电场的物理模型来研究这些垂直梯度的发展与可能产生的等离子体气泡结构之间的关系。在这种情况下，每当稠密的流体覆盖在轻的流体上时，就会出现不稳定的等离子体流体的现象，这将产生奇怪的三维结构。这些等离子体耗尽区(通常称为“气泡”)严重影响无线电波的通信，而无线电波通常从F区等离子体层平滑的底部反射出来。本研究中使用的数据来自Jicamara射电观测站和低纬电离层传感器网络(LISN)对整个南美洲等离子体密度的总电子含量和电离层探空仪测量的观测数据。与LISN数据相关的还有赤道磁力计的测量，可以解释为产生夜间等离子体垂直向上漂移率的估计。这些结果将被用来探索梯度的逐日变化，以帮助更好地理解垂直漂移速率和赤道等离子体气泡产生开始之间的关系。UTD将利用一名研究生完成大部分数据分析和建模。与最强信号闪烁相关的大型赤道等离子体气泡(EPB)对通信和导航技术有负面影响。社会已经变得依赖这些技术来完成交通服务、工业企业和军事行动中的共同任务。除了解决这些缓解F区等离子体结构负面影响的重要科学问题外，这些活动还将继续并扩大与LISN项目和JRO相关的多国合作。

At low latitudes during the evening twilight period, as the E-region plasma recombines due to fast chemistry, a strong vertical gradient in the plasma density will appear below the F-region peak height. This vertical drift gradient in altitude below the F peak can be surprising large, dynamic, and variable from day-to-day. This award would apply a physics-based model of the ionosphere-thermosphere-electric field to study the relationship between the development of these vertical gradients and a possible production of plasma bubble structure. In these circumstances the phenomenon of unstable plasma fluids that occur whenever a dense fluid overlies a light fluid will generate strange three-dimensional structures. These plasma depletion regions (often called "bubbles") affect severely communications of radio waves that normally are reflected off the smooth bottom side of the F-region plasma layer. The data that would be used in this study are derived from observations by the Jicamarca Radio Observatory and by the Low Latitude Ionosphere Sensor Network (LISN) network of total electron content and ionosonde measurements of plasma density throughout South America. Also associated with LISN data are equatorial magnetometer measurements that can be interpreted to produce estimates of upward vertical plasma drift rates during the evening period. These results would be used to explore the day-to-day variability of the gradients to help develop a better understanding of the relationship between the rate of vertical drift and the onset of equatorial plasma bubble production. UTD will be utilizing a graduate student to accomplish much of the data analysis and modeling.Large equatorial plasma bubbles (EPBs), which are associated with the strongest signal scintillations, have negative impacts on communication and navigation technologies. Society has become dependent on these technologies to accomplish common tasks in transportation services, industrial ventures, and military operations. In addition to addressing these important science questions for the mitigation of negative impacts of F-region plasma structures, these activities will continue and expand multinational collaborations associated with the LISN Project and the JRO.