Abstract During the August 25, 2018 geomagnetic storm, the new borne CSES-01 satellite and the Swarm A satellite detected a really large equatorial plasma bubble (EPB) in the post-midnight sector over western Africa. We investigated the features of this deep ionospheric plasma depletion using data from the Langmuir probes on-board CSES-01 and Swarm A satellites, and data from the high-precision magnetometer and the electric field detector instruments on-board CSES-01. Using also plasma and magnetic field data from THEMIS-E satellite we found that, during the passage of the magnetic cloud that drove the geomagnetic storm, an impulsive variation lasting about ten minutes characterized the solar wind (SW) pressure. The analysis of the delay time, between the occurrence of such impulsive variation and the detection of the plasma bubble, suggests a possible link between the SW pressure impulsive variation as identified by THEMIS-E and the generation of the EPB as detected by CSES-01 and Swarm A. We put forward the hypothesis that the SW pressure impulsive variation might have triggered an eastward prompt penetrating electric field that propagated from high to equatorial latitudes, overlapping in the nightside region to the zonal westward electric field, causing either a reduction or an inversion, at the base of the EPB triggering.

中文翻译：

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太阳风等离子压力的脉冲变化能否触发等离子泡？基于 CSES、SWARM 和 THEMIS 数据的案例研究

摘要 在 2018 年 8 月 25 日地磁风暴期间，新搭载的 CSES-01 卫星和 Swarm A 卫星在西非后午夜扇区探测到一个非常大的赤道等离子体气泡 (EPB)。我们使用来自 CSES-01 和 Swarm A 卫星上的朗缪尔探测器的数据以及 CSES-01 上的高精度磁力计和电场探测器仪器的数据研究了这种深电离层等离子体耗竭的特征。还使用来自 THEMIS-E 卫星的等离子体和磁场数据，我们发现，在驱动地磁风暴的磁云通过期间，持续约 10 分钟的脉冲变化表征了太阳风 (SW) 压力。分析这种脉冲变化发生与检测到等离子体气泡之间的延迟时间，