Studies of the Low-Latitude Ionosphere and Electrodynamics Using Data from the LISN Distributed Observatory

该项目对低纬电离层悬而未决的科学问题进行调查，特别是其电动力学现象，同时为低纬电离层传感器网络(LISN)提供重要的建模和分析支持。LISN是一个分布式电离层观测站，由美国国家科学基金会的主要研究仪器计划资助，监测南美洲西半部的条件。研究计划包括三部分工作：(1)将LISN的多仪器多点观测与电离层和电动力学的物理模型相结合，以产生对南美洲赤道西半部上方电离层、电动力学及其驱动因素的最佳表示；(2)利用JRO非相干散射雷达数据对LISN产生的规格进行校准和验证，并最终将JRO纳入LISN系统；校准和验证工作还将利用该区域现有的气辉法布里-珀罗涉仪；(3)使用所得到的低纬表示来解决以下科学问题：决定日落后F区等离子体垂直漂移和东西漂移的剪切的逆转前增强幅度的源(S)是什么？(通常)太阳同步电离层的纵向变化有多大？是什么控制着电动力学/电离层的纵向趋势？日落后三个关键的F区量对赤道扩展F的发生有什么相对作用？这些量是(A)日落后纬向等离子体漂移的切变，(B)垂直等离子体漂移的逆转前的增强，(C)F区峰值以下的垂直密度梯度。电离层驱动因素的关键状态是什么，以及导致低纬F区电离层高度变率和ESF发生的条件是什么？如果人们能够确定一个关键的可变性，那么如果测量了这个数量，那么可以预测ESF发生的时间有多早？这项研究还有几个更广泛的影响。其中包括它对努力发展低纬电离层预测能力的贡献，该电离层在通信和导航方面有重要的应用，可能有助于减轻赤道扩散F的影响和减少全球定位系统中的不确定性。JRO的观测和模型结果将被纳入LISN数据库，该数据库由来自10个不同国家的科学家使用。PI学院的一名研究生将参与这项研究。

This project undertakes investigations of outstanding science questions on the low latitude ionosphere, particularly its electrodynamic phenomena, while providing significant modeling and analysis support for the Low Latitude Ionosphere Sensor Network (LISN). LISN is a distributed ionospheric observatory funded by NSF's Major Research Instrumentation program that monitors conditions over the western half of South America. The research plan consists of a three part effort that will: (1) combine the multi-instrument multi-point observations of LISN with physics-based models of the ionosphere and electrodynamics to produce an optimal representation of the ionosphere, the electrodynamics, and its drivers above the western half of equatorial South America; (2) utilize JRO incoherent scatter radar data in the calibration and verification of the LISN generated specifications and eventually integrate JRO into the LISN system; calibration and verification efforts will also make use of airglow Fabry-Perot interferometers available in the region; (3) use the resulting low-latitude representation to address the following science questions: What is (are) the source(s) that determine the magnitude of the pre-Reversal enhancement of the vertical plasma drift and the shear in the east-west drift in the post-sunset F region? How strong is the longitudinal variation of the (generally) sun-synchronous ionosphere? What controls the longitudinal trends in the electrodynamics/ionosphere? What are the relative roles of the three key post-sunset F region quantities on equatorial spread-F occurrence? These quantities are (a) the post-sunset shear in the zonal plasma drift, (b) the pre-reversal enhancement of the vertical plasma drift, (c) the vertical density gradients below the F-region peak. What are the key states of the ionosphere drivers and what conditions lead to the high variability of the low-latitude F region ionosphere and the occurrence of ESF? If one can identify a key variability then how early can ESF occurrence be forecast if that quantity is measured? There are several broader impacts of the research. These include its contribution to efforts to develop predictive capabilities for the low latitude ionosphere which has important applications for communications and navigation and may aid efforts to mitigate the effects of equatorial spread F and reduce the uncertainties in the global-positioning system. The JRO observations and model results will be incorporated into the LISN database which is used by scientists from 10 different countries. A graduate student at the PI institution will participate in the research.