Open AccessSolar Origins of August 26, 2018 Geomagnetic Storm: Responses of the Interplanetary Medium and Equatorial/Low‐Latitude Ionosphere to the Storm
Author(s) -
Akala A. O.,
Oyedokun O. J.,
Amaechi P. O.,
Simi K. G.,
Ogwala A.,
Arowolo O. A.
Publication year - 2021
Publication title -
space weather
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 56
ISSN - 1542-7390
DOI - 10.1029/2021sw002734
Subject(s) - geomagnetic storm , ionosphere , coronal mass ejection , atmospheric sciences , storm , interplanetary spaceflight , solar wind , geology , geophysics , interplanetary magnetic field , physics , meteorology , plasma , quantum mechanics
This study investigates the solar origins of August 26, 2018 geomagnetic storm and the responses of the interplanetary medium and equatorial/low‐latitude ionosphere to it. We used a multiinstrument approach, with observations right from the solar surface to the Earth. Our results showed that the G3 geomagnetic storm of August 26, 2018 was initiated by a solar filament eruption of August 20, 2018. The storm was driven by an aggregation of weak Coronal Mass Ejection (CME) transients and Corotating Interaction Regions/High Speed Streams (CIR/HSSs). The solar wind energy which got transferred into the magnetosphere drove electrical currents, that penetrated down into the ionosphere to produce weak Prompt Penetration Electric Field (PPEF) (0.3 mV/m). For this reason, during the storm, at daytime, plasma densities of the Equatorial Ionization Anomaly (EIA) crests were localized within the inner flank of ±15° magnetic latitude strip. We attributed this to the extreme quietness of year 2018. There was a clear hemispherical asymmetry, with higher Total Electron Content (TEC) in the northern hemisphere. The major determining factors of the ionospheric responses during the various phases of this storm were the local time of the storm's onset, local time of storm's minimum SYM‐H, and changes in thermospheric O/N 2 .