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Strong Storm-effect behaviors of topside and bottom-side ionosphere under low solar activity: Case study in the geomagnetic storm during 25-27 August 2018
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  • Wang Li,
  • Dongsheng Zhao,
  • Changyong He,
  • Yi Shen,
  • Craig M Hancock,
  • Kefei Zhang
Wang Li
Kunming University of Science and Technology
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Dongsheng Zhao
China University of Mining and Technology

Corresponding Author:[email protected]

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Changyong He
Hunan University of Science and Technology
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Yi Shen
Xinyang Normal University
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Craig M Hancock
School of Architecture, Building and Civil Engineering,Loughborough University
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Kefei Zhang
China University of Mining and Technology
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The 25-27 August geomagnetic storm was the third largest storm in 24th solar cycle, which was a surprising space event that generated in the background of very low solar activity. This study presents an overview of temporal-spatial behaviors of ionospheric plasma irregularities as functions of geographic longitude, latitude and altitude by ground-based (GNSS receivers and ionosonde) instruments and space-borne (Swarm-A and Swarm-B) satellites. The results not only reveal the enhanced equatorial ionization anomaly (EIA) and hemispheric asymmetry over the Asian-Australian and American sectors in a particular time, but also discover the development of hemispheric asymmetric features of global ROTI in the main and recovery phases. In addition, this storm also triggered positive plasma irregularities in altitudes of 100 to 150km near Auroral zone, and the changed ratio of bottom-side plasma irregularities exceeded 250%, which has been cross validated by multiple instrument and TIE-GCM’s simulation. Furthermore, the thermospheric density ratio O/N2, equatorial electrojet and vertical E×B drifts suffered from the storm largely, the equatorial and mid-latitude plasma irregularities may be a combined action of thermospheric composition change, equatorial electrojet and vertical E×B drifts. Finally, the storm also induced positive Joule heating irregularities in Auroral ionosphere in altitudes of 100 to 400km with a maximum changed ratio of >200%, as well as the cross Polar voltage enhanced to ~90kv. The Polar ionospheric irregularities may be associated with the additional energy input through the ways of particle precipitation, Joule heating and ionospheric currents intensification.