Temporal Variation of Ionospheric Scintillation in Relation with Ionospheric Total Electron Content (TEC) over Ethiopia

Abstract

In this study the amplitude scintillation intensity index (S4) and ionospheric total electron content (TEC) data of the year 2012 obtained from Global Positioning System Scintillation Network and Decision (GPS-SCINDA) receiver was analyzed. The diurnal, monthly and seasonal variation of amplitude scintillation intensity index S4 and ionospheric total electron content (TEC) observed from the analyzed data. It is found that intense scintillation occurred during the day time with a small frequency and very frequent occurrences of relatively moderate scintillation during the night time but the vertical total electron content weak at night time than day time. it is observed that ionospheric scintillation intensity index in March, April, February, September– December recorded scintillation events at moderate and intense levels, and these events were generally localized within 1930 LT–2400 LT and All other months experienced weak scintillation of various degrees of occurrences. The scintillation showed a seasonal variation characterized by intense values in March equinox compare to that of in June solstice season. The diurnal variations of amplitude scintillation intensity index S4 in relation with TEC showed that there is more scintillation and TEC around 15:00 to 20:00 UT and this is may be due to the enhancement of equatorial spread F and formation of plasma bubble during the night.