Improving the ionospheric specification in the Global Ionosphere Thermosphere Model

The Global Ionosphere Thermosphere Model (GITM) is a relatively new model that describes the new-Earth space environment in a different way than many of the other existing coupled models. First, it uses an altitude grid that stretches from 100 km to 500–800 km depending on F10.7, with roughly 1/3 scale-height resolution. Second, it solves the more-complete momentum equation in the vertical direction of the thermosphere, allowing non-hydrostatic solutions to form. Third, the code is parallel in such a way that the number of grid cells in the latitude and longitude direction can be specified at run-time, so that the resolution is highly adjustable. The ionosphere within GITM is treated in spherical coordinates, so is limited in altitude. Recently, the ionosphere has been modified in three ways: (1) the ion and electron temperatures have been improved; (2) a nightside EUV flux was implemented in the code; and (3) the Eddy diffusion has been modified to allow a more realistic electron density.