International Journal of Physics | Vol. 3, No. 3, March 2012 | pp. 19–26
DOI: 10.46882/2012/IJP/000027
Article Type: Original Research Paper
Title: Ionospheric Total Electron Content (TEC) Disturbance Profiles over Equatorial Latitudes During Severe Geomagnetic Storms
Names of Authors: G. I. Amadi¹, R. S. Greenwald²
Authors’ Affiliations: ¹Department of Physics, University of Lagos, Lagos, Nigeria; ²Space Physics and Engineering Department, Johns Hopkins University, Baltimore, USA
Abstract: Severe geomagnetic storms alter the global distribution of ionospheric plasma, inducing signal scintillation that can disrupt satellite navigation and communication links. This paper analyzes the spatial and temporal variations of Total Electron Content (TEC) across the equatorial ionosphere during the prominent geomagnetic storm events of 2011. Dual-frequency Global Positioning System (GPS) receiver networks situated within the West African equatorial coordinate zone were utilized to extract vertical TEC parameters. The storm dynamics were cross-referenced against solar wind indices and planetary Kp indicators. Our observations show that during the storm main phase, the equatorial ionization anomaly (EIA) expanded significantly, shifting up to 5 degrees poleward. This expansion caused a sharp daytime TEC enhancement of up to 45 TEC units (1 TECU = 10¹⁶ electrons/m²) over the magnetic equator, driven by intensified prompt penetration electric fields (PPEF). Conversely, the storm recovery phase displayed a prolonged negative ionospheric storm effect, with TEC values dropping 35% below quiet-time baseline averages due to thermospheric composition modifications (O/N₂ ratio reductions). These measured variations are valuable for calibrating regional empirical ionospheric models and correcting GPS positioning errors during space weather anomalies.
Keywords: Ionospheric total electron content; Geomagnetic storms; Equatorial ionization anomaly; GPS scintillation; Prompt penetration electric fields; Space weather; Thermospheric composition; Plasma dynamics.
Manuscript Timeline: Received: December 05, 2011; Revised: January 18, 2012; Accepted: February 11, 2012; Published: March 02, 2012.
Citation: Amadi, G. I., & Greenwald, R. S. (2012). Ionospheric Total Electron Content (TEC) Disturbance Profiles over Equatorial Latitudes During Severe Geomagnetic Storms. International Journal of Physics, 3(3), 19–26.
Subscribe to read the full article: https://internationalscholarsjournals.org/subscribe-to-read