The November 2004 superstorm: Comparison of low-latitude TEC observations with LLIONS model results
Abstract
We investigate the effects of penetration electric fields, meridional thermospheric neutral winds, and composition perturbation zones (CPZs) on the distribution of low-latitude plasma during the 7–11 November 2004 geomagnetic superstorm. The impact on low-latitude plasma was assessed using total electron content (TEC) measurements from a latitudinally distributed array of ground-based GPS receivers in South America. Jicamarca Radio Observatory incoherent scatter radar measurements of vertical E×B drift are used in combination with the Low-Latitude IONospheric Sector (LLIONS) model to examine how penetration electric fields and meridional neutral winds shape low-latitude TEC. It is found that superfountain conditions pertain between ∼1900 and 2100 UT on 9 November, creating enhanced equatorial ionization anomaly (EIA) crests at ±20° geomagnetic latitude. Large-amplitude and/or long-duration changes in the electric field were found to produce significant changes in EIA plasma density and latitudinal location, with a delay time of ∼2–2.5 h. Superfountain drifts were primarily responsible for EIA TEC levels; meridional winds were needed only to create hemispherical crest TEC asymmetries. The [O/N2] density ratio (derived from the GUVI instrument, flown on the TIMED satellite) and measurements of total atmospheric density (from the GRACE satellites), combined with TEC measurements, yield information regarding a likely CPZ that appeared on 10 November, suppressing TEC for over 16 h.
Description
Date
2009-04-07
Keywords
EIA , CPZ , Superstorm , Superfountain , GPS , TEC
Citation
Hei, M. A., & Valladares, C. E. (2009). The November 2004 superstorm: Comparison of low-latitude TEC observations with LLIONS model results. Journal of Atmospheric and Solar-Terrestrial Physics, 72 (4), 334-343. https://doi.org/10.1016/j.jastp.2009.03.025
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Authors
Publisher
Elsevier