Summer Research Fellowship Programme of India's Science Academies

Impact of X class solar flares on the TEC of the ionosphere

Shreeyesh Biswal

Indian Institute of Science Education and Research, Pashan, Pune, 411008

Dr. Anil Bhardwaj

Physical Research Laboratory, Navrangpura, Ahmedabad, 380009


The ionosphere is a layer of the Earth's atmosphere which extends from about 80 to 1000 km above the Earth's surface. It contains a large number of ions and free electrons by virtue of which, it has the ability to reflect a certain segment of electromagnetic wave spectrum, especially the radio waves, thereby aiding us in radio propagation. The ionosphere is treated as a gaseous plasma medium and the theoretical principles of plasma physics have been used to describe ionospheric phenomena. The ionosphere apart from being of practical use in radio propagation, affects the functioning of GPS (Global Positioning System). The ionospheric TEC (Total Electron Content) impacts the functioning of GPS. Hence it is imperative on our part understand the reasons for which the TEC value of the ionosphere changes. TEC of the ionosphere is a quantity that changes with time and is subject to several space weather conditions. An assessment is conducted on how solar flares try to impact the TEC of the ionosphere by studying experimental data. It is a known fact that EUV rays are primarily responsible for the variation of TEC in the Earth's ionosphere and the bulk of the ionization done by EUV rays occurs in the F region of the ionosphere. Hence we have undertaken an experiment to see how the change in EUV flux and change in XRS flux correlate to a change in VTEC values. During a solar flare event, it has been observed from experiments done in the past that there is a spike in the variation of EUV flux, X-ray flux and the TEC of the Earth’s ionosphere with respect to time. We try to investigate if there is some strong mutual correlation between these quantities.

Keywords: Plasma Physics, Geophysics, GPS, GOES, SOHO, Solar Cycle

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