A Numerical Study of the Ionospheric Environment for Different Strengths of the Geomagnetic Main Field

Effects of the strength of the geomagnetic main field on the ionosphere are very complex because almost all the physical parameters in the ionosphere depend more or less on the geomagnetic field either directly or indirectly. The ionospheric conductivities depend on the geomagnetic main field, and therefore, electric currents in the ionosphere change with the strength of the magnetic field. Since auroral precipitation and high-latitude ionospheric convection are associated with magnetospheric processes, change in the strength of the main magnetic field would alter high-latitude ionospheric processes. The thermospheric structure and dynamics are also altered by changes in Joule heating and ion convection, indicating that ionospheric dynamo and magnetosphere-ionosphere interaction are affected by the magnitude of the main magnetic field. Numerical modeling of the magnetosphere-ionosphere-thermosphere system could be a useful tool for understanding such complicated processes, although current models have some assumptions and approximations based on present conditions of geospace environment. We will focus on changes in the ionospheric environment including electrodynamic processes. We will present some results of our study of ionospheric environment for different strengths of the geomagnetic main field using our magnetosphere-ionosphere-thermosphere model.