Abstract In this study the response of ionospheric F-region to 18–21 September 2014, 19–24 January 2016, and 07–10 March 2016 CIR-driven storms in the equatorial and low-latitude region of America, Africa, Asia, and Pacific sectors are investigated. TEC data obtained from the Global Navigation Satellite System (GNSS) receivers, located in the four longitude sectors and electron density ( N e ) measurements obtained from Swarm-A satellite were used. The storm time behavior of TEC was analyzed by computing its deviation from quiet monthly median TEC ( Δ TEC ). The rate of change of TEC index (ROTI) and the relative electron density perturbation ( Δ N e / N e ) derived from GPS-TEC and Swarm-A, respectively, were used as ionospheric irregularity proxies. In this study, we have also analyzed the ionospheric current disturbances during the storm events using ground-based magnetic data. The result revealed that significant nighttime positive ionospheric storm reaching about 284% (Africa, nklg), 115% (Africa, dakr), and 191% (Pacific, naur) was observed during the storm main phase 19 September 2014, 20 January 2016, and 06 March 2016, respectively. This could be associated with oscillation in the IMF Bz and minimum value in ionospheric current disturbance ( D iono ). Nighttime negative ionospheric responses were also observed in the American sector during the storm main phase of 18–21 September 2014 and 19–24 January 2016 and in the Asian sector during 18–21 September 2014 events, possibly due to the combined effects of over-shielding/disturbance dynamo electric field and neutral composition change. During the storm recovery phases (21–23 January 2016, 07–10 March 2016), significant positive ionospheric storm were also noticed. The occurrence of ionospheric irregularities was observed over the equatorial and low-latitude region of America and Africa during the main phase of 18–21 September 2014, 19–24 January 2016, and 05–10 March 2016 storm events, possibly related with the enhancement in the zonal electric field observed during dusk period, when oscillation in IMF Bz exists. During main phase of the storms, while the occurrence of ionospheric irregularities over Asian and Pacific longitude sectors are suppressed, it frequently occurs over the American longitude sector. Postsunset behavior of plasma density irregularities observed by Swarm satellites is consistent with the ground-based observation of TEC fluctuations.

中文翻译：

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赤道和低纬度电离层TEC对不同经度扇区CIR驱动地磁暴的响应

摘要 在这项研究中，电离层 F 区对 2014 年 9 月 18-21 日、2016 年 1 月 19-24 日和 2016 年 3 月 7-10 日 CIR 驱动的风暴在美洲、非洲、亚洲和亚洲的赤道和低纬度地区的响应。太平洋部门进行了调查。使用从位于四个经度扇区的全球导航卫星系统 (GNSS) 接收器获得的 TEC 数据和从 Swarm-A 卫星获得的电子密度 (N e ) 测量值。通过计算 TEC 与安静月中值 TEC 的偏差 (ΔTEC) 来分析 TEC 的风暴时间行为。分别来自 GPS-TEC 和 Swarm-A 的 TEC 指数 (ROTI) 变化率和相对电子密度扰动 (Δ N e / N e ) 被用作电离层不规则性代理。在这项研究中，我们还使用地面磁数据分析了风暴事件期间的电离层电流扰动。结果显示，在2014年9月19日、2016年1月20日的风暴主要阶段期间，观测到显着的夜间正电离层风暴达到约284%（非洲，nklg）、115%（非洲，dakr）和191%（太平洋、瑙尔），和 2016 年 3 月 6 日，分别。这可能与 IMF Bz 中的振荡和电离层电流扰动 (D iono ) 中的最小值有关。在 2014 年 9 月 18 日至 21 日和 2016 年 1 月 19 日至 24 日的风暴主要阶段期间，美国部门以及 2014 年 9 月 18 日至 21 日事件期间在亚洲部门也观察到了夜间负电离层响应，这可能是由于过度屏蔽/干扰发电机电场和中性成分变化。在风暴恢复阶段（2016 年 1 月 21 日至 23 日，2016 年 3 月 7 日至 10 日），还注意到显着的正电离层风暴。在2014年9月18日至21日、2016年1月19日至24日和2016年3月5日至10日风暴事件的主要阶段期间，在美洲和非洲赤道和低纬度地区观测到电离层不规则的发生，可能与增强有关在黄昏时期观察到的纬向电场中，当 IMF Bz 存在振荡时。在风暴的主要阶段，虽然抑制了亚太经线段电离层不规则的发生，但在美国经线段频繁发生。Swarm 卫星观测到的等离子体密度不规则的日落后行为与地面观测到的 TEC 波动一致。