As the Sun ionizes atoms and molecules in the Earth’s ionosphere, the region of atmosphere above approximately 100 km in altitude, the created ionization in this region affects many of the systems that we rely on in daily life. This includes cellular service, GPS navigation, weather forecasting, and credit card data. A good measure for the level of ionization in the ionosphere is total electron content (TEC), which is the number of electrons in a square column above a given geographic location. The TEC over a geographic location influences the propagation of radio waves that traverse that section of the ionosphere. With severe enough conditions, radio waves sent through the ionosphere can become corrupt or read back with significant levels of inaccuracy. Thus, monitoring and modeling TEC patterns and variations allows us to better understand and prepare for the constantly changing ionosphere. TEC data is gathered from thousands of ground-based GPS receivers around the globe, and TEC distributions between seasons can be compared to each other. Data analysis showed qualitative trends relating the spring and fall equinoxes as well as the summer and winter solstices.
Knudsen, Jason, "Seasonal Variations in Global Ionospheric Total Electron Content" (2022). Physics Capstone Projects. Paper 103.