In this article, we present a study of the perturbations occurring in the Earth’s environment on 7 October 2015. We use a multi-instrument approach, including space and ground observations. In particular, we study the ionospheric conditions at low latitudes. Two ionospheric storms are observed at the low latitude station of Tucuman ( $26^{\circ}$ $51'$ S, $65^{\circ}$ $12'$ W). We observe a negative ionospheric storm followed by a positive one. These ionospheric perturbations were triggered by two sudden storm commencements (SSCs) of a strong geomagnetic storm. Preliminary results show that the main mechanism involved in both ionospheric storms is the prompt penetration of electric fields (PPEFs) from the magnetosphere. Furthermore, in the positive storm, disturbed dynamo electric fields are observed acting in combination with the PPEFs. The impact of the solar wind on the Earth’s environment is analyzed using geomagnetic data and proxies, combined with data acquired in the Tucuman Low Latitude Observatory for the Upper Atmosphere. We also investigate the solar and interplanetary drivers of this intense perturbation. We find that, although typically interplanetary coronal mass ejections (ICMEs) are the most geoeffective transient interplanetary events, in this case, a corotating interaction region (CIR) is responsible for these strong perturbations to the geospace.

中文翻译：

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低纬度电离层上太阳风流相互作用区的后果：2015 年 10 月 7 日的事件

在本文中，我们介绍了 2015 年 10 月 7 日发生在地球环境中的扰动研究。我们使用多仪器方法，包括空间和地面观测。我们特别研究了低纬度地区的电离层条件。在 Tucuman 低纬度站观测到两次电离层风暴（$26^{\circ}$ $51'$ S，$65^{\circ}$ $12'$ W）。我们观察到一个负电离层风暴，然后是一个正风暴。这些电离层扰动是由强地磁风暴的两次突然风暴开始 (SSC) 触发的。初步结果表明，这两种电离层风暴的主要机制是来自磁层的电场（PPEF）的快速穿透。此外，在正风暴中，观察到扰动的发电机电场与 PPEF 一起作用。太阳风对地球环境的影响是使用地磁数据和代理，结合 Tucuman 低纬度高层大气天文台获得的数据进行分析的。我们还研究了这种强烈扰动的太阳和行星际驱动因素。我们发现，虽然通常行星际日冕物质抛射 (ICME) 是最具地球效应的瞬态行星际事件，但在这种情况下，共转相互作用区 (CIR) 是造成地球空间这些强烈扰动的原因。