APPROXIMATIONS IN AN IONOSPHERE-MAGNETOSPHERE COUPLING MODEL

Magnetospheric and ionospheric MHD models have been used to study their respective regions for some time. This Magnetosphere-Ionosphere coupling model aims to bridge these two regions and study their interactions. The lower ionosphere is of particular importance for many reasons. The high density of the lower ionosphere presents a challenge for simulations. The stability requirements constrain the time step to ever decreasing values as the density increases. Previously this problem has been dealt with by ignoring the lower ionosphere. This project will apply an approximation in order to study this region while maintaining suitable equations for the magnetosphere. The rather short relaxation times in the lower ionosphere are used to model this region with a steady state assumption. This avoids the unnecessary short integration steps and will enable us to use much longer integration steps for the simulation, thereby achieving much faster execution times.