Karatay S.2023-04-122023-04-122018-01-0113012894https://hdl.handle.net/20.500.12597/5348Earth’s ionosphere is a dominant factor in space weather and the variability of the ionosphere is important for the ionospheric physics and radio communications. The characterizing property of the ionosphere is the electron density distribution that shows variation as a function of height, latitude, longitude, and geomagnetic, solar and seismic activities. An important measurable quantity about the electron density is the Total Electron Content (TEC), which is proportional to the total number of electrons on a line crossing the atmosphere. In this study, TEC obtained for eleven Turkish National Permanent GPS Network (TNPGN-Active) Global Positioning System (GPS) stations located in Turkey are compared with each other using the Cross Correlation Coefficient (CCC), Symmetric Kullback-Leibler Distance (KLD) and L2-Norm (L2N) for quiet days of the ionosphere, during severe geomagnetic storms, and earthquakes having different magnitudes. It is observed that only KLD and L2N can differentiate the seismic activity from the geomagnetic disturbance and quiet ionosphere if the stations are in a radius of 340 km. When TEC for each station is compared with an average quiet day TEC for all periods using CCC, KLD and L2N, it is observed that, again, only KLD and L2N can distinguish the approaching seismicity for stations that are within 150 km radius to the epicenter.falseEarthquake | Geomagnetic Disturbance | Ionosphere | Total Electron ContentArticle2-s2.0-85065160400