Navegando por Assunto "GPS-VTEC"

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    Effects of X2.8-class solar flare on the ionosphere occurred during the recovery phase of a geomagnetic storm over South American and Antarctic sectors
    (Elsevier) Abreu, Alessandro José de; Correia, Emilia; Venkatesh, Kavutarapu; Pignalberi, Alessio; Pezzopane, Michael; Pillat, Valdir Gil; Fagundes, Paulo Roberto; Gende, Mauricio Alfredo; Jesus, Rodolfo de
    In this investigation, we present and discuss the effects of an X2.8-class solar flare occurred on 14 December 2023 on the ionospheric F region and on the geomagnetic field over South American and Antarctic sectors. This flare coincides with the recovery phase of a geomag- netic storm. To this end, we rely on vertical total electron content (VTEC) observations from nearly 250 Global Positioning System (GPS) receiver stations over South American and Antarctic sectors, complemented by in-situ electron density observations from Swarm satellites, magnetometer measurements, and ionospheric sounding observations from ionosondes. The magnetic observations show a large increase in the variations of the horizontal component (DH) of the geomagnetic field and equatorial electrojet (EEJ) currents at all stations, syn- chronized with the increase in X-rays flux, indicating solar flare effects or magnetic crochet on the Earth’s geomagnetic field. VTEC shows how the impact of the solar flare on the ionosphere is enhanced from east to west of South America in the equatorial and low-latitudes. VTEC from a specific GPS satellite-receiver also shows great effects at mid-latitudes. Results are confirmed and further elaborated through Swarm in-situ observations. In addition, an asymmetry is observed in the equatorial ionization anomaly (EIA), in which the eastern South American sector shows an intensified EIA compared to the western sector. Ionospheric sounding observations by ionosondes show total fade out in the echo traces of the ionograms, characterizing blackouts in the radio signals from equatorial to low-latitudes. Overall, our results show that an X-class solar flare occurring near the limb of the solar disk is capable of producing effects on the Earth’s ionosphere with similar or even stronger intensities than flares occurring at the center of the solar disk.