We briefly overview the radar observations that have been made for 30 years at Syowa Station, Antarctica for studying small-scale electron-density irregularities in the southern high-latitude Eand F-region ionosphere. Some observational results (i.e., long-term variations of radio aurora, Doppler spectra with narrow spectral widths and low Doppler velocities, and simultaneous observations of ra...

We have examined the ionospheric plasma irregularities that were recorded by using three ground-based receivers of the global positioning system (GPS) located at Brazilian longitudes during the period of a complete solar cycle, 1995–2005. The statistic results show that ionospheric irregularities are very easy to occur in December solstice months but rare to occur in June solstice months. Besid...

In this paper, we investigate anomalies in total electron content (TEC) from 7 stations of the Africa Geodetic Reference Frame (AFREF) during initial and recovery stages geomagnetic storm 19 February 2014. Additionally, study storms under solar activity ascending period March 2012 low May 2017 to emphasize scintillation effects, especially nighttime. We employ a 15-days median-average sliding w...

The study of ionospheric irregularities is important since many technological systems might be influenced by the ionosphere. In this work, we use data from Global Navigation Satellite Systems (GNSS) receiver installed in Abuja, Nigeria, GPS Scintillation Network Decision Aid (SCINDA) TEC Air Force Research Laboratory (AFRL) archive, and geomagnetic World Data Center (WDC) Kyoto, Japan, to inves...

This work presents, for the first time, analysis of occurrence ionospheric irregularities during geomagnetic storms at Tucumán, Argentina, a low latitude station in Southern American longitudinal sector (26.9°S, 294.6°E; magnetic 15.5°S) near southern crest equatorial ionization anomaly (EIA). Three occurred on May 27, 2017 (a month rates spread-F), October 12, 2016 transition from to high spre...