Amplitude Scintillation Severity and Fading Profiles Under Alignment Between GPS Propagation Paths and Equatorial Plasma Bubbles
Amplitude Scintillation Severity and Fading Profiles Under Alignment Between GPS Propagation Paths and Equatorial Plasma Bubbles
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DOI：
10.1029/2022sw003243
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发表时间：
2022-11
期刊：
影响因子：
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通讯作者：
J. Sousasantos;B. Affonso;A. Moraes;F. Rodrigues;M. A. Abdu;L. A. Salles;B. Vani
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文献类型：
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作者：
J. Sousasantos;B. Affonso;A. Moraes;F. Rodrigues;M. A. Abdu;L. A. Salles;B. Vani
低纬地区的电离层闪烁和衰落事件通常是由被称为赤道等离子体气泡的严重耗尽的地磁排列结构引起的。这些事件引起了科学调查和技术应用的关注。在过去的几年里，大多数闪烁研究集中在这些事件与密度梯度、位置、当地时间、地磁条件等的依赖关系上。这项工作讨论了信号传播路径与耗尽结构或相当于地磁场线之间的对准对观测到的闪烁和深度衰落特性的影响。利用位于赤道电离异常区附近的3个台站(倾角纬度：16.13°S、19.87°S和22.05°S)的资料，分析了对准和非对准条件下的幅度闪烁严重程度和深衰落事件特征。结果表明，取向条件对强闪烁的发生起着至关重要的作用。研究还表明，当考虑远离环评峰顶的站点时，对准影响似乎增加，强烈的等离子体密度起伏和对准路径增加的组合可能是观测到最严重闪烁和剧烈深衰落事件的构型。结果表明，这种交会通常出现在与巴西地区等离子体密度背景最大的地区不同的区域，因此，在略低于环评峰值的地方观测到了最强的闪烁和最大的深度衰减率。
Ionospheric scintillation and fading events over low‐latitude regions are often caused by severely depleted geomagnetic field‐aligned structures known as Equatorial Plasma Bubbles. These events are subject of interest to scientific investigations and concern to technological applications. Over the past several years, most of scintillation studies have focused on the dependence of these events on density gradients, location, local time, geomagnetic conditions, and so forth. This work presents a discussion about the role of the alignment between the signal propagation path and the depleted structures or, equivalently, the geomagnetic field lines, on the observed scintillation and deep fading characteristics. Data from three stations (dip latitudes: 16.13°S, 19.87°S, and 22.05°S) located around the Equatorial Ionization Anomaly (EIA) region were used to assess the amplitude scintillation severity and the deep fading events features under aligned and nonaligned conditions. The results show that the alignment condition plays a crucial role in the occurrence of strong scintillation. The study also revealed that, as stations far from the crests of the EIA are considered, the alignment influence seems to increase, and that a combination of strong plasma density fluctuation and increased aligned path is, presumably, the configuration under which the most severe scintillation and drastic deep fading events are observed. The results indicate that this conjunction is typically met in regions somewhat distinct from that with largest plasma density background over the Brazilian region, therefore, strongest scintillation and largest deep fading rates were observed by a station slightly off‐the EIA peak.