Total Electron Content Variability in the African Ionosphere Observed during Ascending and Decaying Geomagnetic Storms

The geomagnetic storms of October 1, 2012, and May 28, 2017, of the mid- and equatorial-latitude ionosphere responses of the African sector at cycle 24 solar ascending and descending levels are presented. The relative total electron content (rTEC) anomalies at the initial commencement until recovery...

Full description

Saved in:
Bibliographic Details
Published in:Geomagnetism and Aeronomy 2023-12, Vol.63 (6), p.839-853
Main Authors: Anoruo, Chukwuma Moses, Okeke, Francisca Nneka, Okpala, Kingsley Chukwudi
Format: Article
Language:English
Subjects:
Anomalies
Earth and Environmental Science
Earth Sciences
Electric fields
Equatorial ionization anomaly
Geomagnetic storms
Geomagnetism
Geophysics/Geodesy
Global navigation satellite system
Ionization
Ionosphere
Ionospheric electron content
Ionospheric plasma
Latitude
Magnetic fields
Magnetic storms
Navigation satellites
Navigation systems
Phases
Recovery
Satellites
Solar activity
Solar activity cycles
Storms
Total Electron Content
Wind speed
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The geomagnetic storms of October 1, 2012, and May 28, 2017, of the mid- and equatorial-latitude ionosphere responses of the African sector at cycle 24 solar ascending and descending levels are presented. The relative total electron content (rTEC) anomalies at the initial commencement until recovery phases of storms present interesting results. We employed a 15-day sliding average window to study rTEC using 7 (Global Navigation Satellite Systems) GNSS stations from the Africa Geodetic Reference Frame (AFREF) to characterize both storm ionospheric phases over the sector. The recovery phase of both storms lasted 17 h for October 1 and 14 h for May 28 with IMF Bz < 0 when the solar plasma wind speed recorded values of 353 km/s and 336 km/s, respectively. The results showed a significant equatorial latitude response of the ionosphere during both the main and recovery phases of storms that occurred at different solar activity cycles, where prestorm TEC changes occurred during the daytime. Again, positive storms observed during the prestorm events place less emphasis on the solar activity cycle mostly observed at the equatorial latitude. In addition, the magnetic field lines are shaped by the injection of a prompt penetration electric field (PPEF) that prompts prestorm rTEC enhancements, where the phenomenon of the equatorial ionization anomaly (EIA) governs the midlatitude Africa ionospheric plasma distribution based on gradients and is more pronounced in the poststorm effect.
ISSN:0016-7932
1555-645X
0016-7940
DOI:10.1134/S001679322360042X