Longitudinal study of the ionospheric response to the geomagnetic storm of 15 May 2005 and manifestation of TADs

Abstract

Abstract.Response of low latitude ionosphere to the geomagnetic storm of 15 May 2005 has been studied using total electron content (TEC) data, obtained from three GPS stations namely, Yibal, Udaipur and Kunming situated near the northern crest of equatorial ionization anomaly at different longitudes. Solar wind parameters, north-south component of the interplanetary magnetic field (IMF B z ) and AE index data have been used to infer the strength of the geomagnetic storm. A large value of eastward interplanetary electric field at 06:15 UT, during the time of maximum southward IMF B z has been used to infer the transmission of an eastward prompt penetration electric field (PPEF) which resulted in a peak in TEC at 07:45 UT due to the local uplift of plasma in the low latitudes near the anomaly crest over a wide range of longitudes. Wave-like modulations superposed over the second enhancement in TEC between 09:15 UT to 10:30 UT have been observed at all the three stations. The second enhancement in TEC along with the modulations of up to 5 TECU have been attributed to the combined effect of super plasma fountain and traveling atmospheric disturbances (TAD). Observed large enhancements in TEC are a cause of concern for satellite based navigation and ground positioning. Increased [O/N 2 ] ratio between 09:15 UT to 10:15 UT when modulations in TEC have been also observed, confirms the presence of TADs over a wide range of longitudes.

Positive and negative GPS‐TEC ionospheric storm effects during the extreme space weather event of March 2015 over the Brazilian sector

“…The second and third positive ionospheric storm peaks were not so strong, but it is possible to see their signatures on EIA in both Brazilian sectors. As suggested by many researchers, the superfountain effect during geomagnetic storms are closely related with PPEF and it leads to stronger EIA [ Lu et al ., ; Sharma et al ., ; Balan et al ., ; Abdu et al ., ; Batista et al ., ; Mannucci et al ., ]. In the present study, it is also noted that the EIA west sector was more affected than the east sector by the PPEF, indicating the existence of significant longitudinal differences in the ionospheric response during this geomagnetic storm.…”

Study of Ionospheric TEC from GPS observations and comparisons with IRI and SPIM model predictions in the low latitude anomaly Indian subcontinental region

“…Variations of TEC in response to geomagnetic storms have been studied by many researchers over Indian region (Dashora et al, 2009;Rao et al, 2009;Sharma et al, 2011;Sreeja et al, 2009;Panda and Gedam, 2012). It is noticed from the Fig.…”

Positive and negative ionospheric storms occurring during the 15 May 2005 geomagnetic superstorm

“…While the TEC time series constructed for Poligan (POL2; 33.72°N, geomagnetic) tracked daytime increases that were due to both storm time PPEF and storm-induced equatorward neutral winds, the TEC time series constructed for Algonquin (ALGO; 55.93°N) detected depletions that were attributed to the midlatitude trough [Galav et al, 2014]. Some earlier studies covering this geomagnetic superstorm focused on the low-latitude regions of the Indian zone [Dashora et al, 2009] and Southeast Asia [Sharma et al, 2011]. Although the findings of all these studies are significant and are potentially useful to system engineers and ionospheric model developers, the observational results are from specific locations.…”