Total solar eclipse of July 22, 2009: Its impact on the total electron content and ionospheric electron density in the Indian zone

The longest total solar eclipse during the 21st century occurred in South and East Asia on July 22, 2009. Ionospheric response to this rare total solar eclipse which was observed right from the time of sunrise in the Indian zone, has been studied in terms of the total electron content (TEC) obtained from three global positioning system (GPS) receivers located at Udaipur, Hyderabad and Bengaluru, and electron density obtained using space based GPS-Radio Occultation technique. The study reveals significant reductions in the electron density and TEC that persisted up to 2 h past the last contact even during early morning eclipse. These observations imply that during the early morning eclipse, the production and loss of ionization dominate over the plasma transport processes.

Research Highlights
► Studies during rare sunrise time total solar eclipse from Indian zone presented.
► 40–50% reduction in TEC has been observed even during early morning eclipse.
► During early morning eclipse production and loss processes dominant.
► Electron density profile shows maximum reduction between 300 and 400 km altitude.
► Up to 70% reduction in electron density has been observed.