GUVI Biblio

Effects of the 12 May 2021 Geomagnetic Storm on Georeferencing Precision

In this work, we present the positioning error analysis of the 12 May 2021 moderate geomagnetic storm. The storm happened during spring in the northern hemisphere (fall in the south). We selected 868 GNSS stations around the globe to study the ionospheric and the apparent position variations. We compared the day of the storm with the three previous days. The analysis shows the global impact of the storm. In the quiet days, 93\% of the stations had 3D errors less than 10 cm, while during the storm, only 41\% kept this level o ...

Valdés-Abreu, Juan; Díaz, Marcos; Báez, Juan; Stable-Sánchez, Yohadne;

Published by: Remote Sensing      Published on: jan

YEAR: 2021     DOI: 10.3390/rs14010038

Geomagnetic storms; total electron content; global navigation satellite system; Global positioning system; precise point positioning; rate of change of the tec index

Effects observed in the equatorial and low latitude ionospheric F-region in the Brazilian sector during low solar activity geomagnetic storms and comparison with the COSMIC measurements

The main objective of the present investigation has been to compare the ionospheric parameters (NmF2 and hmF2) observed by two ground-based ionospheric sounders (one at PALMAS- located near the magnetic equator and the other at Sao Jose dos Campos-located in the low-latitude region) in the Brazilian sector with that by the satellite FORMOSAT-3/COSMIC radio occultation (RO) measurements during two geomagnetic storms which occurred in December 2006 and July 2009. It should be pointed out that in spite of increasing the lati ...

Sahai, Y.; de Jesus, R.; Fagundes, P.R.; Selhorst, C.L.; de Abreu, A.J.; Ram, Tulasi; Aragon-Angel, A.; Pillat, V.G.; Abalde, J.R.; Lima, W.L.C.; Bittencourt, J.A.;

Published by: Advances in Space Research      Published on: 11/2012

YEAR: 2012     DOI: 10.1016/j.asr.2012.07.006

COSMIC satellite; F-region; geomagnetic storm; Ionosphere; Low solar activity

The global thermospheric and ionospheric response to the 2008 minor sudden stratospheric warming event

This paper presents a study of thermospheric and ionospheric response to the 2008 minor sudden stratospheric warming (SSW) event. This period was characterized by low solar and geomagnetic activity. The study was performed using the Global Self-consistent Model of Thermosphere, Ionosphere, and Protonosphere (GSM TIP). Model results were compared with ionosonde data from Irkutsk, Kaliningrad, Sao Jose dos Campos, and Jicamarca. The SSW event was modeled by specifying the temperature and density perturbations at the lower b ...

Korenkov, Y.; Klimenko, V.; Klimenko, M.; Bessarab, F.; Korenkova, N.; Ratovsky, K.; Chernigovskaya, M.; Shcherbakov, A.; Sahai, Y.; Fagundes, P.; de Jesus, R.; de Abreu, A.; Condor, P.;

Published by: Journal of Geophysical Research      Published on: 10/2012

YEAR: 2012     DOI: 10.1029/2012JA018018

Electric field; Ionosphere; sudden stratospheric warming; thermosphere

Studies of ionospheric F-region response in the Latin American sector during the geomagnetic storm of 21--22 January 2005

Sahai, Y.; Fagundes, P.; de Jesus, R.; de Abreu, A.; Crowley, G.; Kikuchi, T.; Huang, C.-S.; Pillat, V.; Guarnieri, F.; Abalde, J.; Bittencourt, J.;

Published by: Annales Geophysicae      Published on: Jan-01-2011

YEAR: 2011     DOI: 10.5194/angeo-29-919-2011

Effects of geomagnetic super storms on the ionospheric F-region in the South American sector using a GPS technique: A review

Sahai, Y; De Abreu, AJ; Fagundes, PR; De Jesus, R; Crowley, G; Klimenko, MV; Klimenko, VV; Brunini, C; Gende, M; Pillat, VG; , others;

Published by: Asian Journal of Physics      Published on:

YEAR: 2011     DOI:

Numerical modeling of ionospheric effects in the middle-and low-latitude F region during geomagnetic storm sequence of 9--14 September 2005

This study presents the Global Self-Consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP) numerical simulations of the 9–14 September 2005 geomagnetic

Klimenko, MV; Klimenko, VV; Ratovsky, KG; Goncharenko, LP; Sahai, Y; Fagundes, PR; De Jesus, R; De Abreu, AJ; Vesnin, AM;

Published by: Radio Science      Published on:

YEAR: 2011     DOI:

Seasonal variations in ionospheric F-region parameters during the low solar activity period in the Brazilian sector and comparison with ionospheric models

Sahai, Yogeshwar; de Jesus, Rodolfo; Fagundes, Paulo; de Abreu, Alessandro; Crowley, Geoff; Pillat, Valdir; Guede, Jose; Bittencourt, Jose;

Published by: 38th COSPAR Scientific Assembly      Published on:

YEAR: 2010     DOI:

Response of the Ionospheric F-region in the Latin American Sector During the Intense Geomagnetic Storm of 21-22 January 2005

Sahai, Y; Fagundes, PR; De Jesus, R; De Abreu, AJ; Crowley, G; Pillat, VG; Guarnieri, FL; , Abalde; Bittencourt, JA;

Published by:       Published on:

YEAR: 2009     DOI:

Effects observed in the Latin American sector ionospheric F region during the intense geomagnetic disturbances in the early part of November 2004

Sahai, Y; Becker-Guedes, F; Fagundes, PR; De Jesus, R; De Abreu, AJ; Paxton, LJ; Goncharenko, LP; Brunini, C; Gende, M; Ferreira, AS; , others;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2009     DOI:

Unusual ionospheric effects observed during the intense 28 October 2003 solar flare in the Brazilian sector

Sahai, Y.; Becker-Guedes, F.; Fagundes, P.R.; Lima, W.L.C.; de Abreu, A.J.; Guarnieri, F.L.; Candido, C.M.N.; Pillat, V.G.;

Published by:       Published on:

YEAR: 2008     DOI:

Brazilian ionosphere behavior during an intense solar flare

The 28 October 2003 solar flare was one of the most intense solar flares observed in the recent past. In the present investigation we show the ionospheric effects observed in the

Becker-Guedes, F; Sahai, Y; Fagundes, PR; Abreu, A; Pillat, VG; Lima, WLC;

Published by:       Published on:

YEAR: 2007     DOI: https://doi.org/10.3997/2214-4609-pdb.172.SBGF0393_07

Unusual ionospheric effects observed during the intense 28 October 2003 solar flare in the Brazilian sector

Sahai, Y; Becker-Guedes, F; Fagundes, PR; Lima, WLC; De Abreu, AJ; Guarnieri, FL; Candido, CMN; Pillat, VG;

Published by:       Published on:

YEAR: 2007     DOI: