Response of low latitude ionosphere to the space weather event of November, 2012 in the Asian Sector

Abstract

Ionospheric response to geomagnetic storms is determined by the efficiency of the solar wind-magnetosphere-ionosphere coupling that underlies the transfer of tremendous amount of mass and energy. The response of the equatorial and low latitude ionosphere to the moderate geomagnetic storm of 14 November 2012 is investigated. This study is carried out using vertical total electron content (VTEC) measured by Global Positioning System (GPS) receivers along the ~ 115°-121°E longitude. The GPS TEC observations show pronounced positive storm effects in the Asian sector (~115°-121°E) during the main phase of the storm for the low latitude and crest of anomaly stations. During the main phase of the storm the interplanetary electric field (IEF) penetrated to the equatorial ionosphere and caused significant density changes in the equatorial ionization anomaly (EIA) region. The eastward prompt penetration electric field associated with southward interplanetary magnetic field (IMF) augmented the normal daytime eastward dynamo electric field resulting in intensification of equatorial ionization anomaly (EIA) and VTEC enhancements observed over the anomaly crest stations. Results show that EIA region is significantly affected during geomagnetic storms in comparison to the low latitude ionosphere.