Response of the equatorial ionosphere to the total solar eclipse of 22 July 2009 and annular eclipse of 15 January 2010 as observed from a network of stations situated in the Indian longitude sector

Dual-frequency GPS TEC monitors have been used to study the response of the ionosphere to the solar eclipses of 22 July 2009 and 15 January 2010. The receivers were located at three stations, Calcutta, Kharagpur and Baharampore which are situated outside the umbra zone in the Indian longitude sector with each baseline being ∼200 km. Effects of obscuration of the solar disc were noted in the ambient TEC recorded at the three stations. A series of depletions in TEC along the track of a GPS satellite and associated wave-like structures were identified on some GPS links during both the eclipses.