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

合作研究：赤道等离子体漂移涡中垂直等离子体漂移梯度的原因和后果

• 批准号: 1563025
• 负责人: Cesar Valladares
• 金额: $ 15.75万
• 依托单位: University of Texas at Dallas
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1563025&HistoricalAwards=false
• 关键词: Collaborative; Research; Causes; Consequences; Gradients

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.

在低纬度地区，黄昏期间，由于E区等离子体由于快速化学反应而重新组合，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。在F峰以下的海拔高度上，这种垂直漂移梯度可以是惊人的大，动态的，并且每天都在变化。该奖项将应用电离层-热层-电场的物理模型，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，当稠密流体覆盖在轻质流体上时，就会出现不稳定的等离子体流体现象，从而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，这些无线电波通常被反射离开F区等离子体层的平滑底侧。本研究将使用的数据来自希卡马卡射电天文台和低纬度电离层传感器网络对整个南美洲的电子总含量的观测和电离层探测仪对等离子体密度的测量。 与LISN数据相关的还有赤道磁力计测量值，这些测量值可以被解释为产生傍晚期间向上垂直等离子体漂移率的估计值。这些结果将被用来探索梯度的日常变化，以帮助开发一个更好的理解之间的关系的垂直漂移率和赤道等离子体气泡的产生开始。UTD将利用一名研究生来完成大部分数据分析和建模。与最强信号相关的大赤道等离子体气泡（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运输服务、工业企业和军事行动中的常见任务。除了解决这些重要的科学问题以减轻F区等离子体结构的负面影响外，这些活动将继续并扩大与LISN项目和JRO有关的多国合作。