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Dynamics of the Tongue of Ionizations During the Geomagnetic Storm on September 7, 2015
Author(s) -
Zhang Kedeng,
Wang Hui,
Liu Jing,
Zheng Zhichao,
He Yangfan,
Gao Jie,
Sun Luyuan,
Zhong Yunfang
Publication year - 2021
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2020ja029038
Subject(s) - geomagnetic storm , thermosphere , ionosphere , atmospheric sciences , plasmasphere , local time , earth's magnetic field , storm , magnetosphere , physics , climatology , geology , geophysics , magnetic field , meteorology , statistics , mathematics , quantum mechanics
The dynamic evolution of the double tongue of ionization (TOI) into a single TOI at 400 km altitude during the geomagnetic storm on September 7, 2015 was studied using the Defense Meteorological Satellite Program observations and Thermosphere Ionosphere Electrodynamic General Circulation model simulations. The double TOIs occurred in the presence of increased southward B z and weak positive B y , while the single TOI occurred in the presence of northward turning of B z and duskward turning of B y . In both double and single TOI events, the plasma at middle latitudes in the afternoon (prenoon) sector was greatly enhanced due to the local upward (upward) and zonal (meridional) E × B drift. The transition process is due to both the northward and duskward turning of interplanetary magnetic field (IMF). The northward turning of IMF B z weakens the storm enhanced density (SED) and the TOI in both afternoon and morning sectors, while the increasing duskward IMF B y strengthens the morning TOI.