Absorption Altitude - The altitude where solar radiation reaches in the Earth's atmosphere. Red areas receive full sunlight, black areas see none at that wavelength.

Solar irradiance between 122 and 200 nm (FUV wavelengths) creates the atomic oxygen that flows up to form the thermosphere and the ozone that forms the ozone layer. Changes in the FUV irradiance are smaller than those in EUV wavelengths. Solar Cycle Changes at 700 km: Neutral Temperature: 2 times; Neutral Density: 50 times; Electron Density: 100 times.

Temperature Change - The change in temperature of the outer layer of the Earth's atmosphere caused by the Sun (labeled F10.7) and the geomagnetic activity of the Earth (labeled Ap) in the Jacchia model. The F10.7 variation is much larger than Ap. When the temperature is higher the atmosphere expands. This increases satellite drag.

Living With a Star research will allow us to build accurate, data-assimilation models of the thermosphere and ionosphere. Users of space weather data would like a picture of today’s ionosphere to allow them to anticipate radio outages and GPS navigation errors.

Higher density & temperature leads to more drag. Higher electron density leads to more interference with radio communications.