COMPARISON OF TOTAL ELECTRON CONTENT FLUCTUATIONS AND IONOSPHERIC SCINTILLATION AT AKURE, SOUTH WEST NIGERIA

Abstract

Ionospheric Total Electron Content (TEC) and Scintillation index (S4) records of January, March, August and October 2010 were examined to study the fluctuation in the ionosphere over Akure (Geographic Latitude 7.30oN; Geographic longitude 5.15oE; dip latitude -2.62o). The months were chosen to represent December solstice, March-equinox, June solstice, and September-equinox respectively due to limited data availability within the months. The data with sampling of 60 seconds were analyzed to determined TEC, the rate of change of total electron content (ROT) and as well as the standard deviation of the rate of change of total electron content within interval of 5 minutes (ROTI). The scintillation index was compared with TEC index and thereby investigated the evolution of large and small scale irregularities at scale lengths of few kilometers and 0.4 kilometer respectively observed at low latitude station at Akure. Correlation coefficients between ROTI and standard scintillation index were discovered to be in the range of 00.00 to 00.40. The results obtained showed that the relationship between ROTI and scintillation index in the months of January and March, 2010 can be linked with their sources of variations. This research work showed the possibility that ROTI can be used as a proxy of scintillation index during the December solstice and March-equinox but it showed the reverse result during the June solstice and September-equinox.