Huang Liang, Liu Yi, Tang Qiong, Chen Guanyi, Wang Zhuangkai, Zhou Chen
Department of Space Physics, School of Electronic Information, Wuhan University, Wuhan 430072, China.
Sensors (Basel). 2020 Jan 28;20(3):708. doi: 10.3390/s20030708.
By using multi-satellite observations of the L1 signal-to-noise ratio (SNR) from the Cyclone Global Navigation Satellite System (CYGNSS) taken in 2017, we present the occurrence of nighttime topside ionospheric irregularities in low-latitude and equatorial regions. The most significant finding of this study is the existence of longitudinal structures with a wavenumber 4 pattern in the topside irregularities. This suggests that lower atmospheric waves, especially a daytime diurnal eastward-propagating zonal wave number-3 nonmigrating tide (DE3), might play an important role in the generation of topside plasma bubbles during the low solar minimum. Observations of scintillation events indicate that the maximum occurrence of nighttime topside ionospheric irregularities occurs on the magnetic equator during the equinoxes. The current work, which could be regarded as an important update of the previous investigations, would be readily for the further global analysis of the topside ionospheric irregularities.
通过利用2017年从气旋全球导航卫星系统（CYGNSS）获取的L1信噪比（SNR）的多卫星观测数据，我们展示了低纬度和赤道地区夜间电离层顶部不规则现象的发生情况。本研究最显著的发现是电离层顶部不规则现象中存在波数为4模式的纵向结构。这表明低层大气波，特别是白天向东传播的纬向波数为3的非迁移性周日潮汐（DE3），可能在低太阳活动极小期期间电离层顶部等离子体气泡的产生中发挥重要作用。闪烁事件的观测表明，夜间电离层顶部不规则现象的最大发生率出现在二分点期间的磁赤道上。当前的工作可被视为对先前研究的重要更新，将便于对电离层顶部不规则现象进行进一步的全球分析。
