The main purpose of this paper is to investigate the response of the ionospheric F layer in the American and African sectors during the intense geomagnetic storm which occurred on 30 September–01 October 2012. In this work, we used observations from a chain of 20 GPS stations in the equatorial, low- and mid-latitude regions in the American and African sectors. Also, in this study ionospheric sounding data obtained during 29th September to 2nd October, 2012 at Jicamarca (JIC), Peru, São Luis (SL), Fortaleza (FZ), Brazil, and Port Stanley (PST), are presented. On the night of 30 September–01 October, in the main and recovery phase, the h´F variations showed an unusual uplifting of the F region at equatorial (JIC, SL and FZ) and mid- (PST) latitude stations related with the propagations of traveling ionospheric disturbances (TIDs) generated by Joule heating at auroral regions. On 30 September, the VTEC variations and foF2 observations at mid-latitude stations (American sector) showed a long-duration positive ionospheric storm (over 6 h of enhancement) associated with large-scale wind circulations and equatorward neutral winds. Also, on 01 October, a long-duration positive ionospheric storm was observed at equatorial, low- and mid- latitude stations in the African sector, related with the large-scale wind circulations and equatorward neutral winds. On 01 and 02 October, positive ionospheric storms were observed at equatorial, low- and mid-latitude stations in the American sector, possibly associated with the TIDs and an equatorward neutral wind. Also, on 01 October negative ionospheric storms were observed at equatorial, low- and mid-latitude regions in the American sector, probably associated with the changes in the O/N₂ ratio. On the night of 30 September–01 October, ionospheric plasma bubbles were observed at equatorial, low- and mid- latitude stations in the South American sector, possibly associated with the occurrence of geomagnetic storm.

Item Type:	Refereed Article
Keywords:	space weather, geomagnetic storm, ionosphere, ionospheric irregularities, atmospheric electricity, F region, geomagnetism, ionosphere, ionospheric measurement, solar energy, geomagnetic storm, intense geomagnetic storms, ionospheric irregularities
Research Division:	Physical Sciences
Research Group:	Space sciences
Research Field:	Mesospheric, thermospheric, ionospheric and magnetospheric physics
Objective Division:	Environmental Management
Objective Group:	Air quality, atmosphere and weather
Objective Field:	Atmospheric processes and dynamics
UTAS Author:	Bolaji, OS (Dr Olawale Bolaji)
ID Code:	140046
Year Published:	2016
Web of Science® Times Cited:	16
Deposited By:	Physics
Deposited On:	2020-07-22
Last Modified:	2020-08-18
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