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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Effects of X2-class solar flare events on ionospheric GPS-TEC and radio waves over Brazilian sector

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Author(s):
de Abreu, A. J. [1] ; Roberto, M. [1] ; Alves, M. A. [1] ; Abalde, J. R. [1] ; Nogueira, P. A. B. [2] ; Venkatesh, K. [3] ; Fagundes, P. R. [4] ; de Jesus, R. [5] ; Gende, M. [6] ; Martin, I. M. [1]
Total Authors: 10
Affiliation:
[1] ITA, Div Ciencias Fundamentais, Sao Jose Dos Campos - Brazil
[2] Inst Fed Educ Ciencia & Tecnol Sao Paulo IFSP, Campus Jacarei, Jacarei, SP - Brazil
[3] NARL, Gadanki - India
[4] Univ Vale Paraiba UNIVAP, Lab Fis & Astron, Sao Jose Dos Campos, SP - Brazil
[5] INPE, Sao Jose Dos Campos, SP - Brazil
[6] UNLP, Fac Ciencias Astron & Geofis, La Plata, Buenos Aires - Argentina
Total Affiliations: 6
Document type: Journal article
Source: Advances in Space Research; v. 63, n. 11, p. 3586-3605, JUN 1 2019.
Web of Science Citations: 0
Abstract

In this investigation, we present and discuss the effects of 6 X2-class solar flare events in the ionospheric F region over Brazilian sector that occurred during 2013 to 2015. For this investigation, we present the vertical total electron content (VTEC) observations from nearly 120 Global Positioning System (GPS) receivers all over the Brazilian sector for each event. Also, ionospheric sounding observations obtained in Sao Jose dos Campos (23.2 degrees S, 45.9 degrees W, dip latitude 17.6 degrees S; hereafter referred to as SJC), under the southern crest of the equatorial ionospheric anomaly (EIA), Brazil, are presented. The observations show that the greatest TEC impact occurs with the EUV fluxes increases lasting for more than one hour and when the solar active region is located close to the solar disc center. We present a detailed study of the efficiency of the EUV flux with wavelengths ranging from 0.1 to 190 nm for the F region ionization. The largest increase of Delta TEC occurs below the magnetic equator line, covering mainly the central, northeast, southeast and south regions, which includes the equatorial ionospheric anomaly (EIA) region. The ionograms show partial or total fade out in the echoes traces observed causing blackouts of radio signals of up to 60 min, which can have serious consequences to technological systems of public and private agencies around Brazilian sector. This study can help to better understand the effects of solar flares in the ionospheric F region. (C) 2019 COSPAR. Published by Elsevier Ltd. All rights reserved. (AU)

FAPESP's process: 12/08445-9 - Study of day-to-day variability of the mesosphere, thermosphere and ionosphere at low latitude and equatorial region, during the solar cycle 24
Grantee:Paulo Roberto Fagundes
Support type: Research Projects - Thematic Grants