Ionospheric scintillations detected by SCINDA-Helwan station during St. Patrick’s Day geomagnetic storm

Abstract

We report about our observations during one of the major storms of the solar cycle, the so-called St. Patrick’s Day storm, which happened on 17 March 2015. The St. Patrick’s Day storm was the first storm of the current solar cycle that reached the level “Severe” on the NOAA geomagnetic storm scale. The CME arrived at the Earth about 04:30 UT on the 17th, the sudden storm commencement (SSC) was recorded at ∼04:45 UT followed by a quick drop of the SYM-H index. The Kp planetary index of the geomagnetic activity had reached the maximum value of 8. The z-component of the interplanetary magnetic field (IMF) was strongly northward at the storm’s day and altered to southward direction on the next day. The ionospheric response to that severe geomagnetic storm was detected using processed data from GPS-SCINDA receiver installed at Helwan station (Egypt; Geographic coordinates: 29.86°N, 31.32°E) with a dual frequency (f1 = 1.5 GHz, f2 = 1.2 GHz). Our results show that the Vertical Total Electron Content (VTEC) and the ionospheric scintillation index S4 reached the maximum value on the 17th. The ionospheric features during the storm are described within this study.