The variations of Total electron content (TEC) over high latitude regions during the geomagnetic storm on August 26, 2018 were investigated. This study is based on Global Positioning System (GPS-TEC) data obtained by the UNAVCO dual-frequency GPS devices at the northern stations of Hofn and Kiruna, and the southern stations of Mawson and Syog. The results of this study show that the enhancement and variations of total electron content are more noticeable in the northern hemisphere of the Hofn and Kiruna stations than in the southern hemisphere of the Mawson and Syog stations on the August 26, 2018 storm. A solar filament eruption produced an aggregation of weak coronal mass ejections, transients, and Co-rotating Interaction Regions/High Speed Streams, which was the primary source of ionospheric total electron content asymmetries on August 26, 2018. Interestingly, the midnight TEC over both northern and southern stations became equivalent to the daytime TEC, suggesting the absorption of extra plasma from higher latitudes into the northern stations.
Keywords: Ionospheric TEC, Geomagnetic storm, TEC enhancement, TEC variability