Effects of Geomagnetic Storm on Ionospheric TEC Variability over High Latitude Regions
Issue:
Volume 10, Issue 2, June 2022
Pages:
18-27
Received:
24 June 2022
Accepted:
26 July 2022
Published:
10 August 2022
DOI:
10.11648/j.ijass.20221002.11
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Views:
Abstract: The effects of the geomagnetic storm on August 26, 2018 on the ionospheric TEC fluctuations in the high latitude region were investigated. This study is based on 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 variation of TEC is 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. Interestingly, the midnight TEC became comparable to the daytime TEC over both northern and southern stations, indicating the ingestion of additional plasma from higher latitudes into the northern stations. The positive enhancement of ∆TEC values were higher over Hofn and Kiruna on August 26, 2018 by about 170%, and 180% than Mawson and Syog by about 70%, and 150% stations, respectively. During geomagnetic storm of August 26, 2018, the Hofn and Kiruna stations had a much greater negative impact on ∆TEC = -50% than the Mawson and Syog stations ∆TEC = -40%. The ∆TEC over each station are caused by a significant rise in the Kp index and the opposite polarity of the interplanetary electric field (IEF Ey) in the northward direction and the southward decrease of the interplanetary magnetic field (IMF Bz). The decrease in Dst-index and ∆H during the main phase of the storm increased TEC over Kiruna and Mawson stations. Furthermore, the values of changes in TEC was stronger over Kiruna station in the northern hemisphere than over Mawson station in the southern hemisphere, indicating that the northern stations received more additional plasma than the southern stations during the August 26, 2018 geomagnetic storm. During the August 26, 2018 geomagnetic storm, the values of the horizontal component of Earth’s magnetic field decreased more over Kiruna station, about ∆H = -1500 nT, than over Mawson station, about ∆H = -1300 nT. As a result, the changes in TEC are more pronounced over Kiruna station, where ∆TEC = 180%, than over Mawson station, where ∆TEC = 70%. This indicates that during the August 26, 2018 geomagnetic storm, the northern hemisphere receives more energy from the solar wind, which produces particle acceleration and precipitation, higher field aligned currents, and ionospheric electrojets.
Abstract: The effects of the geomagnetic storm on August 26, 2018 on the ionospheric TEC fluctuations in the high latitude region were investigated. This study is based on 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 th...
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