Statistical study of geomagnetic storm effects on the occurrence of ionospheric irregularities over equatorial/low-latitude region of Africa from 2001 to 2017
Electric field effects
; Geomagnetism
; Global positioning system
; Ionosphere
; Ionospheric measurement
; Solar wind
; Coronal mass ejection
; Corotating interaction regions
; Disturbance electric field
; Disturbance storm time (Dst)
; Equatorial and low latitudes
; Global Navigation Satellite Systems
; Ionospheric irregularities
; ROTIave
; Storms
英文摘要:
The effect of Coronal Mass Ejection (CME) and Corotating Interaction Region (CIR)-driven storms on the occurrence of ionospheric irregularities (OIIs) over the African equatorial and low-latitude region are studied statistically for the first time. In addition to the CME and CIRs’ catalogs, we have used the disturbance storm time (Dst) ≤ -30 nT and Kp ≥ 3 to identify the storm periods. The study was based on Global Navigation Satellite System (GNSS) total electron content (TEC) observation from three stations (nklg: 8.05°S, 81.05°E; mbar: 10.22°S, 102.36°E; and nazr: 0.25°S, 111.01°E, Geomagnetic) during 2001–2017. Based on the GNSS observations, the rate of change of total electron indices (ROTIROTI and ROTIave) have been used to observe the presence/absence of ionospheric irregularities. To examine the effect of the storms on the OIIs, ratio of ROTIave of the selected storm period to the quiet monthly mean of ROTIave, ROTIratio=ROTIobs/ROTI‾quiet, was applied. Based on our analysis, ROTIratio≥3.2, ROTIratio≤0.16 and 0.16
Entoto Observatory and Research Center, Addis Ababa, Ethiopia; Bule Hora University, College of Natural and Computational Science, Department of Physics, Bule Hora, Ethiopia; South Africa National Space Agency, Space Science, Hermanus, South Africa; Department of Physics and Electronics, Rhodes University, Grahamstown, South Africa; Washera Geospace and Radar Science Laboratory, Physics Department, Bahir Dar University, Bahir Dar, Ethiopia
Recommended Citation:
Dugassa T.,Habarulema J.B.,Nigussie M.. Statistical study of geomagnetic storm effects on the occurrence of ionospheric irregularities over equatorial/low-latitude region of Africa from 2001 to 2017[J]. Journal of Atmospheric and Solar-Terrestrial Physics,2020-01-01,199