We present a study concerning a space weather event on 25–29 August 2018, accounting for its ionospheric and magnetic signatures at low latitudes and midlatitudes. The effects of a storm in several longitudinal sectors (Asia, Africa, America, and the Pacific) have been analyzed using various parameters such as total electron content (TEC), geomagnetic field, and column [O/N₂] ratio. Positive ionospheric storms are found in all the longitudinal sectors having its maximum effects in the Asian sector, whereas the negative ionospheric storms have been observed in the summer hemisphere (Northern Hemisphere). A large decrease in [O/N₂] ratio in the Northern Hemisphere is a possible cause of the observed negative storm effects. Ionospheric F2 region maximum electron density (NmF2) and TEC have shown a positive correlation during this storm. The study suggests that storm time‐generated wind does not have a uniform planetary extension and mainly affects dayside (America and Pacific) and duskside (Africa) sectors. During the space weather event, we observe an asymmetric variation of the magnetic field as a function of the longitude. On the other hand, the magnetic variations at midlatitudes are found to be symmetric in both hemispheres. A signature of the disturbance dynamo (anti‐Sq circulation) has been observed, mainly at low latitudes. We emphasize that the partial ring current (PRC), estimated by the ASYM‐H magnetic index, must also be taken into account along with the SYM‐H index for a better approximation of ionospheric currents. The study further suggests existence of several electric current cells in the ionosphere, which is consistent with the Blanc‐Richmond model.

中文翻译：

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2018年8月25-29日太空天气事件的电离层和磁特征：CME和HSSW

我们提出了一项关于2018年8月25日至29日的太空天气事件的研究，考虑了其在低纬度和中纬度的电离层和磁学特征。已使用各种参数（如总电子含量（TEC），地磁场和柱[O / N ₂ ]比）分析了风暴在几个纵向部门（亚洲，非洲，美洲和太平洋）中的影响。在所有纵向扇区中都发现了正电离层风暴，在亚洲地区影响最大，而在夏季半球（北半球）则观测到了负电离层风暴。[O / N ₂大大降低北半球的]比率可能是观察到的负面风暴影响的可能原因。在这场风暴期间，电离层F2区域的最大电子密度（NmF2）与TEC呈正相关。研究表明，风暴时间产生的风没有统一的行星延伸，主要影响白天（美国和太平洋）和黄昏（非洲）部门。在太空天气事件中，我们观察到磁场的不对称变化是经度的函数。另一方面，发现中纬度的磁变化在两个半球都是对称的。主要在低纬度地区，已观察到扰动发电机的特征（反平方环）。我们强调，通过ASYM-H磁指数估算的部分振铃电流（PRC），为了更好地近似电离层电流，还必须将其与SYM-H指数一起考虑在内。这项研究进一步表明，电离层中存在几个电流细胞，这与Blanc-Richmond模型是一致的。