This paper demonstrates and assesses the capability of the advanced three-dimensional (3-D) ionosphere tomography technique, during severe conditions. The study area is northeast Asia and quasi-Japan-centred. Reconstructions are based on total electron content data from a dense ground-based global navigation satellite system receiver network and parameters from operational ionosondes. We used observations from ionosondes, Swarm satellites and radio occultation (RO) to assess the 3-D picture. Specifically, we focus on St. Patrick’s day geomagnetic storm (17–19 March 2015), the most intense in solar cycle 24. During this event, the energy ingested into the ionosphere resulted in Dst and Kp and reaching values ~ − 223 nT and 8, respectively, and the region of interest, the East Asian sector, was characterized by a ~ 60% reduction in electron densities. Results show that the reconstructed densities follow the physical dynamics previously discussed in earlier publications about storm events. Moreover, even when ionosonde data were not available, the technique could still provide a consistent picture of the ionosphere vertical structure. Furthermore, analyses show that there is a profound agreement between the RO profiles/in-situ densities and the reconstructions. Therefore, the technique is a potential candidate for applications that are sensitive to ionospheric corrections.

本文展示并评估了先进的三维 (3-D) 电离层断层扫描技术在恶劣条件下的能力。研究区域为东北亚，准以日本为中心。重建基于来自密集地基全球导航卫星系统接收器网络的总电子含量数据和来自操作电离探空仪的参数。我们使用电离探测器、群卫星和无线电掩星 (RO) 的观测来评估 3-D 图片。具体来说，我们关注圣帕特里克日地磁风暴（2015 年 3 月 17 日至 19 日），这是太阳活动周期 24 中最强烈的一次。在此事件中，吸收到电离层的能量导致 Dst 和 Kp 并达到值 ~ − 223 nT 和8，分别是感兴趣的区域，东亚部门，的特点是电子密度降低了约 60%。结果表明，重建的密度遵循先前在有关风暴事件的早期出版物中讨论的物理动力学。此外，即使在电离层数据不可用时，该技术仍然可以提供电离层垂直结构的一致图像。此外，分析表明 RO 剖面/原位密度与重建之间存在深刻的一致性。因此，该技术是对电离层校正敏感的应用的潜在候选者。该技术仍然可以提供电离层垂直结构的一致图像。此外，分析表明 RO 剖面/原位密度与重建之间存在深刻的一致性。因此，该技术是对电离层校正敏感的应用的潜在候选者。该技术仍然可以提供电离层垂直结构的一致图像。此外，分析表明 RO 剖面/原位密度与重建之间存在深刻的一致性。因此，该技术是对电离层校正敏感的应用的潜在候选者。