In this paper, the variations of ionospheric irregularities have been studied using C/NOFS, ground‐based GNSS and magnetometer measurements in Africa during the St. Patrick geomagnetic storm of March 17, 2013. The latitudinal distribution of irregularities was examined using GNSS‐ROTI maps covering longitude 25°–45°E. Longitudinal characteristics were also investigated along with equatorial plasma bubbles (EPBs) and vertical drift velocity (Vz) from 12 to 21 March 2013. The results show postsunset irregularities from 12°S–27°N with the stronger ones confined within 1°S–7°S and 12°N–22°N in the prestorm period. The observed pre‐reversal enhancement (PRE) with Vz varying from 22.51–59.47 m/s between 20.26 and 20.86 LT corresponded with the occurrence of EPBs. PRE greater than 40 m/s nevertheless, supported long lasting depletions. During the main phase, prompt penetration electric field enhanced the PRE thus, extended the latitudinal range of irregularities to 31°N. It also induced a long duration EPB along 15°E and several depletions over the Eastern sector. During the recovery phase, stormtime wind drove a conspicuous asymmetry in the morphology of the postsunset anomaly. This corresponded with the reduction in the latitudinal extent and strength of irregularities. Westward/eastward disturbance dynamo electric field inhibited/triggered irregularities in the postsunset/postmidnight period on 18 March over the Eastern sector. The difference in the drift accounted for the longitudinal variations of irregularities before the storm. During the main phase however, irregularities were present (reduced) over the Eastern (Atlantic/Western) sectors. This difference might have been related to the changes in the wind inferred from the anomaly shape.

中文翻译：

---

非洲电离层不规则性的地面GNSS和C / NOFS观测：以2013年圣帕特里克节地磁风暴为例

在本文中，我们使用C / NOFS，地面GNSS和非洲在2013年3月17日圣帕特里克地磁风暴期间的磁强计测量研究了电离层不规则性的变化。使用GNSS-ROTI检查了不规则性的纬度分布覆盖东经25°–45°E的地图。还研究了纵向特征以及2013年3月12日至21日的赤道等离子体气泡（EPBs）和垂直漂移速度（Vz）。结果显示，从12°S–27°N的后突不规则性，更强的不平度被限制在1°S–暴风雨前期分别为7°S和12°N–22°N。观察到的逆转增强（PRE）在20.26和20.86 LT之间的Vz在22.51–59.47 m / s之间变化，与EPB的出现相对应。尽管如此，PRE仍大于40 m / s，支持持久耗竭。在主相期间，快速穿透电场增强了PRE，从而将不规则性的纬度范围扩大到31°N。它还在15°E诱发了长时间的EPB，并在东部地区造成了数次损耗。在恢复阶段，暴风时风使后置异常的形态显着不对称。这与纬度范围和不规则强度的减小相对应。在3月18日的后扰动/午夜后，东部地区的西向/东向扰动发电机电场抑制/触发了不规则现象。漂移的差异解释了风暴前不规则性的纵向变化。但是，在主要阶段，东部（大西洋/西部）地区存在（减少）不规则现象。