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Persistence of the Long‐Duration Daytime TEC Enhancements at Different Longitudinal Sectors During the August 2018 Geomagnetic Storm
Author(s) -
Li Qiaoling,
Huang Fuqing,
Zhong Jiahao,
Zhang Ruilong,
Kuai Jiawei,
Lei Jiuhou,
Liu Libo,
Ren Dexin,
Ma Han,
Yoshikawa Akimasa,
Hu Lianhuan,
Guo Jiapeng,
Li Wenbo,
Zhou Xu,
Cui Jun
Publication year - 2020
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2020ja028238
Subject(s) - daytime , ionosphere , tec , dynamo , geomagnetic storm , atmospheric sciences , storm , earth's magnetic field , total electron content , electrojet , environmental science , geostationary orbit , climatology , geology , meteorology , geophysics , satellite , physics , magnetic field , astronomy , quantum mechanics
Abstract In this study, the ionospheric responses in the Asian‐Australian, American, and African sectors during the August 2018 geomagnetic storm were investigated based on the Beidou geostationary orbit (GEO) satellite and Massachusetts Institute of Technology (MIT) Madrigal total electron contents (TECs), combined with measurements from ionosondes, magnetometers, and Global Ultraviolet Imager (GUVI). The middle‐ and low‐latitude TECs were dominated by positive responses over the three longitudinal sectors during the storm on 26–29 August. It is unique that daytime TECs at the Asian‐Australian, American, and African sectors displayed large enhancements larger than 10 TEC units (TECu) on 27–29 August, during the recovery phase, when the ionosphere is usually dominated by plasma depletions due to the ionospheric disturbance dynamo and/or disturbed thermospheric compositions. The combination and competition of the disturbed vertical plasma drifts through the solar wind‐magnetosphere‐ionosphere (SW‐M‐I) coupling and disturbed neutral compositions contribute significantly to the daytime TEC responses at different longitudinal sectors on 26 August during the main and early recovery phases. The eastward equatorial electrojet and O/N 2 during the recovery phase on 27–29 August are larger than the quiet reference, which suggest that the enhanced upward vertical plasma drifts combining with higher O/N 2 make an important contribution on the daytime positive ionospheric storm during the recovery phase. The enhanced vertical plasma drifts could not be driven by the SW‐M‐I coupling or ionospheric disturbance dynamo associated with the geomagnetic storm. Further studies should be untaken to explore the dominant sources for the enhanced upward vertical drifts during the recovery phase.