Abstract

This paper presents a statistical analysis of global ionospheric variation during quiet and disturbed geomagnetic conditions from December 2008 to June 2019. The study comprehends ascending and descending solar periods of the 24th solar cycle. The vertical Total Electron Content (vTEC) data of CODE-GIM are utilized to reveal the TEC variation in the regional and global regions. The disturbance storm time index (Dst) with a storm criterion of diurnal Dst_min less than –20 nT was used to identify the magnetically quiet/disturbed conditions, and the geomagnetic storms were identified by diurnal Dst_min less than –50 nT. 36 and 43% of the ascending/descending periods were magnetically disturbed days, respectively. There was no significant change in vTEC variation in the high and middle latitude regions. Still, in the low latitudes, vTECs increased 50 and 25% in the disturbed days of ascending/descending periods, respectively. vTEC values in the low latitudes were found to be 33% higher than the middle latitudes and 100% higher than the high latitudes in quiet days for both periods. vTEC values in the low latitudes were also found to be 50 and 200% higher than the middle and high latitudes in disturbed days, respectively. Also, the Dst and global Total Electron Content (gTEC) variations were compared using the superposed epoch analysis (SEA) for geomagnetic storms. The gTEC values indicate the average vTEC of CODE-GIM grids. The SEA results indicate that the gTEC variation is similar to the Dst pattern of a magnetic storm. The mean gTEC values decreased shortly after when the storm was peaked, corresponding to approximately 20 and 17% in ascending and descending periods, respectively.

中文翻译：

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第24个太阳周期上升和下降期间暴雨时间TEC变化的统计分析。

摘要

本文介绍了从2008年12月到2019年6月，在安静和扰动的地磁条件下全球电离层变化的统计分析。该研究包括第24个太阳周期的上升和下降太阳周期。CODE-GIM的垂直总电子含量（vTEC）数据用于揭示区域和全球区域中TEC的变化。风暴标准为Dst _min小于–20 nT的干扰风暴时间指数（Dst）用于识别静磁/扰动条件，地磁风暴​​通过Dst _{min的最小值}进行识别小于–50 nT。上升/下降期间的36％和43％分别是磁扰天。高纬度和中纬度地区的vTEC变化没有显着变化。尽管如此，在低纬度地区，vTEC在上升/下降时期的受干扰日子分别增加了50％和25％。在这两个时期的安静天数中，低纬度地区的vTEC值均比中纬度地区高33％，比高纬度地区高100％。在低纬度地区，低纬度地区的vTEC值也分别比中高纬度地区高50％和200％。此外，使用叠加纪元分析（SEA）比较了地磁风暴的Dst和全球总电子含量（gTEC）变化。gTEC值表示CODE-GIM网格的平均vTEC。SEA结果表明gTEC的变化类似于磁暴的Dst模式。gTEC平均值在暴风雨达到高峰后不久下降，分别对应于上升和下降时期的20％和17％。