Devbrat Pundhir, Dr.Birbal Singh, O. P. Singh and Saral Kumar Gupta
ABSTRACT
The recording of total electron content (TEC) data has been in progress at a low latitude station Agra (27o N, 78o E), India since 01 March, 2006. In the present study, we analyze the GPS-TEC data for a period of 12 months from 1 January to 31 December, 2011 for the first time during the ascending phase of solar cycle 24. We find a good correlation between vertical total electron content (VTEC)and solar activity (solar flux F10.7 cm). A statistical study employing mean (m) and standard deviation (s) approach is adopted to show the variations of the data. The peak value of daytime TEC is found in the month of October above mean + s whereas the depletions are seen in the months of January, February and April below mean – s. The variations in the nighttime data show similar results as the daytime. We compare our results with the IRI-2007 model and find strong correlation with variations during each of the three seasons (summer, equinox, and winter). These results are well supported by the results of earlier workers (Sharma et al., 2010; Kumar et al., 2010).
Keywords: GPS-TEC; morphological study; low latitude; IRI-2007 model.