This paper studies the ionosphere's response to the annular solar eclipse on 26 December 2019, utilizing the following ground‐based and space‐borne measurements: Global Navigation Satellite System (GNSS) total electron content (TEC) data, spectral radiance data from the Sentinel‐5P satellite, in situ electron density and/or temperature measurements from DMSP and Swarm satellites, and local magnetometer data. Analysis concentrated on ionospheric effects over low‐latitude regions with respect to obscuration, local time, latitude, and altitude. The main results are as follows: (1) a local TEC reduction of ∼4–6 TECU (30–50%) was identified along the annular eclipse path, with larger depletion and longer recovery periods in the morning eclipse compared to midday. (2) The equatorial electrojet current was significantly weakened when the eclipse trajectory crossed the magnetic equator in the morning (India) sector, which contributed to large and prolonged TEC depletion therein. (3) At midday, equatorial ionization anomaly exhibited enhancements of 20–40% as well as poleward shifting of 3–4°, likely triggered by modified neutral wind and electrodynamics patterns. (4) The behavior of equatorial ionospheric electron density showed considerable altitudinal differences in the topside, exhibiting ∼30% reduction around 500 km and ∼30% enhancement with 300–500 K Te reduction around 850 km, before the arrival of maximum eclipse. This may have been caused by the enhanced eastward electric field and equatorward neutral wind, and other possible factors are also discussed.

中文翻译：

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2019年12月26日电离层对环状日食的电离层响应的地基和空星协调观测

本文利用以下基于地面和空间的测量方法研究了电离层对环形日食的响应：2019年12月26日：全球导航卫星系统（GNSS）的总电子含量（TEC）数据，前哨的光谱辐射数据5P卫星，DMSP和Swarm卫星的原位电子密度和/或温度测量以及本地磁力计数据。分析集中在低纬度地区的电离层影响方面，包括遮蔽，当地时间，纬度和高度。主要结果如下：（1）局部TEC降低〜沿环形蚀路径发现了4–6 TECU（30–50％），与中午相比，早晨蚀的损耗更大，恢复期更长。（2）当日食轨迹在早晨（印度）越过磁赤道时，赤道电喷电流显着减弱，这导致其中的TEC耗竭时间延长。（3）在中午，赤道电离异常表现出20–40％的增强以及3–4°的极向偏移，这可能是由于中性风和电动力学模式的改变引起的。（4）赤道电离层电子密度的行为在顶面上显示出相当大的高度差异，在500 km附近表现出约30％的减小，在300–500 K T e下表现出约30％的增强。在最大月食到来之前减少约850公里。这可能是由增强的东向电场和赤道中性风引起的，并且还讨论了其他可能的因素。