Reproducing the magnetospheric response to southward turnings in MHD simulations

State-of-the-art numerical models have been developed to reproduce magnetospheric dynamics in response to solar wind variations. However, we do not understand how accurate the predictions of the models would be in different solar wind and magnetospheric conditions. In this study, we consider the two relatively simple cases with southward interplanetary magnetic field turnings which have been simulated by several MHD models (SWMF, LFM, PPMLR-MHD, PLUTO). We compare numerical results with observations in terms of global magnetospheric characteristics such as the polar cap open flux and the indices of magnetospheric activity. Our purpose is to understand why some models can make better predictions. To answer this question we also compare the results of the same MHD model with different numerical resolutions and ionospheric conductances and show that both resolution and conductance are important for accurate predictions. By comparing simulations with observations, we can figure out the optimal parameters in the models which should be used in the future.