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Topside Ionospheric Conditions During the 7–8 September 2017 Geomagnetic Storm
Author(s) -
Jimoh Oluwaseyi,
Lei Jiuhou,
Zhong Jiahao,
Owolabi Charles,
Luan Xiaoli,
Dou Xiankang
Publication year - 2019
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2019ja026590
Subject(s) - tec , ionosphere , geomagnetic storm , total electron content , earth's magnetic field , storm , atmospheric sciences , geology , morning , geomagnetic latitude , daytime , geophysics , environmental science , meteorology , physics , magnetic field , quantum mechanics , astronomy
The uplooking total electron contents (TECs) from the GRACE, SWARM‐A, TerraSAR‐X, and MetOp‐A satellites and in situ electron density (Ne) from SWARM‐A were utilized to investigate the topside ionospheric conditions during the 7–8 September 2017 geomagnetic storm. The rate of TEC index (ROTI) and rate of density index (RODI), which are derivative indices of TEC and Ne, respectively, were also used to characterize the topside ionospheric irregularities. The main results of this study are as follows: (1) There were significant enhancements seen in the uplooking TEC during the first main phase of the storm. (2) The uplooking TEC did not show unusual enhancement at the morning and evening local times in the Asian‐Australian sector during the recovery phase of the storm. (3) Prominent TEC hemispheric asymmetry at the middle and high latitudes was observed at both day and night sectors. (4) Long‐duration recovery of topside TEC with respect to the prestorm condition was also detected in this event. (5) Nighttime ROTI enhancements were presented in a wide latitudinal range from the equator to the poles during the main phases of the storm. (6) The ionospheric electric field disturbances associated with IMF‐ B z fluctuations probably played a very important role in triggering ionospheric irregularities during the relatively weak geomagnetic activity on 7 September, which implies that ionospheric irregularities do not necessarily occur under the severe geomagnetic conditions only.