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After going through the chapters of this book, the reader has come to the point at which we would like to give a sketch of what we expect, and wish for, the future development of ionospheric science to be.

The critical interaction between the magnetosphere and ionosphere during intense geomagnetic storms continues to be important to space weather studies. In this investigation, we present and discuss the ionospheric F-region observations in the equatorial, low- and mid-latitude regions in both hemispheres over American sector during the intense geomagnetic storm on 01–03 June 2013. The geomagnetic storm reached a minimum Dst of −119 nT at 0900 UT on 01 June. For this investigation, we present vertical total electron content (VTEC) and phase fluctuations (in TECU/min) from a chain of 10 GPS stations and the ionospheric parameters foF2 and h′F from a chain of 4 digital ionosonde stations, covering from equatorial to mid-latitudes regions over American sector during the entire storm-time period 31 May–03 June 2013. In addition, the plasma density observed from DMSP satellites is presented. The results obtained show that during the sudden impulse/SSC and throughout the main phase of the storm, a large positive phase was observed in mid-latitudes of the northern hemisphere, which could be due to changes in the thermospheric wind circulation. On the other hand, in the mid-latitudes of the southern hemisphere, no deviations are observed in VTEC and foF2 when compared to the quiet period. During the long recovery phase of the storm on 01–02 June, a north-south asymmetry is observed in the F-region. The study confirms the dominant role of the thermospheric winds on north-south asymmetry in the ionospheric F-region. The ionospheric irregularities are found to be confined in the equatorial region, of the bottomside spread-F type, before and during the geomagnetic storm. It shows that the geomagnetic storm did not affect the generation or suppression of ionospheric irregularities at the stations investigated. Fil: de Abreu, A.J.. Instituto Tecnológico de Aeronáutica; Brasil Fil: Martin, I.M.. Instituto Tecnológico de Aeronáutica; Brasil Fil: Fagundes, P.R.. Universidade do Vale do Paraíba; Brasil Fil: Venkatesh, K.. Universidade do Vale do Paraíba; Brasil Fil: Batista, I.S.. Instituto Nacional de Pesquisas Espaciais; Namibia Fil: de Jesus, R.. Instituto Nacional de Pesquisas Espaciais; Namibia Fil: Rockenback, M.. Instituto Nacional de Pesquisas Espaciais; Namibia Fil: Coster, A.. Massachusetts Institute of Technology; Estados Unidos Fil: Gende, Mauricio Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina Fil: Alves, M.A.. Instituto Tecnológico de Aeronáutica; Brasil Fil: Wild, M.. Science and Technology Facilities Council; Reino Unido

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 hDF 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 6h 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. Fil: de Jesus, R.. Centro de Previsao de Tempo e Estudos Climáticos. Instituto Nacional de Pesquisas Espaciais; Brasil. Universidade do Vale do Paraíba; Brasil Fil: Fagundes, P.R.. Universidade do Vale do Paraíba; Brasil Fil: Coster, A.. Massachusetts Institute of Technology; Estados Unidos Fil: Bolaji, O. S.. University of Lagos; Nigeria Fil: Sobral, J. H. A.. Centro de Previsao de Tempo e Estudos Climáticos. Instituto Nacional de Pesquisas Espaciais; Brasil Fil: Batista, I. S.. Centro de Previsao de Tempo e Estudos Climáticos. Instituto Nacional de Pesquisas Espaciais; Brasil Fil: de Abreu, A. J.. Universidade do Vale do Paraíba; Brasil. Instituto Tecnológico de Aeronáutica; Brasil Fil: Venkatesh, K.. Universidade do Vale do Paraíba; Brasil Fil: Gende, Mauricio Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina Fil: Abalde, J. R.. Universidade do Vale do Paraíba; Brasil Fil: Sumod, S. G.. Mahatma Gandhi University; India