GPS Derived Ionospheric TEC Response to Annular Solar Eclipse Over Indian Region on 15 January 2010

The dual frequency Global Positioning System (GPS) observation data from International GNSS Services (IGS) stations established at Bangalore (IISC) and Hyderabad (HYDE) are processed to estimate the change in ionospheric total electron content (TEC) in response to the annular solar eclipse of 15 January 2010. This event was unique since it took place during solar minimum. It was a geomagnetically quiet period and the eclipse phase coincided with the peak ionization time at the Indian equatorial and low latitudes. The path of the solar obscuration during the eclipse passed through the Indian Ocean, touching the southern part of India. The sudden collapse of the TEC curve at Bangalore and Hyderabad indicates the effect of of blocked solar radiation on decayed electron content in ionosphere over the region. The magnitude of the depletion in ionospheric TEC over both stations are compared with mean diurnal ionospheric TEC of five quietest days of the month to investigate the eclipse effect on electron density of ionosphere over the stations.