Short term variability in foF2 and TEC over low latitude stations in the Indian sector

Abstract

Since the ionosphere is a typical embedded plasma dominated region of the thermosphere, it may be of interest and relevance to study the association between the two different measured quantities, namely the peak electron density of the F2 layer (foF2) or the total electron content (TEC) of the ionosphere and thermospheric parameters. Both these parameters show a large variability during quiet and disturbed conditions as well as during the low and high sunspot periods. Simultaneous TEC (GPS) and foF2 (ionosonde) data obtained at a low latitude station, Waltair (17.72°N, 83.32°E) and a station, located at the inner-edge of the equatorial ionization anomaly (EIA), Delhi (28.58°N, 77.21°E) during the low sunspot period 2004-2005 (mean Rz = 38.55) have been considered for the present study. The Daubechies class of continuous wavelet analysis has been used in the present study to observe the variability in time. To test the efficacy of the correlation between the variability of foF2 and TEC, the cross correlation analysis has been made. An anti-correlation between the variability of foF2 and TEC is observed around noon hours over Waltair. The relative deviation (%) of day- to-day variability between foF2 and TEC is within the inter quartile range of 40.