Authors: Evangelia Samara (NASA/GSFC), Elena Provornikova (JHU/APL), C. Nick Arge (NASA/GSFC), Viacheslav Merkin (JHU/APL)

In this work, we use the coupled WSA model of the solar corona and the GAMERA model of the inner heliosphere to perform time-dependent (TD) solar wind simulations. We show that TD predictions, although better than steady state (SS) predictions, substantially mispredict the solar wind conditions at different points of the heliosphere because of mainly three reasons: (1) the uncalibrated WSA semi-empirical velocity formula that provides the solar wind speeds at the inner boundary of MHD models, (2) the distance from the Sun at which the WSA solution is being calculated for input into the MHD models, and (3) the abrupt and partial emergence of active regions from the east limb of the Sun. We evaluate one year of TD predictions at the ACE and STEREO-A locations according to the Dynamic Time Warping (DTW) method and we show that by tuning accordingly the WSA velocity formula when used with MHD models, and by taking into account a different height at which the WSA boundary conditions are generated (other than the typical height of 21.5 Rs), can lead to improved TD solar wind results. However, the abrupt emergence of active regions from the east limb of the Sun which can highly disrupt the magnetic field topology in the solar corona and lead to false connectivities with the sub-satellite points, is a difficult task to deal with and requires special treatment since we do not have knowledge of the conditions on the back side of the Sun. We also show how the frequency with which we update the magnetograms in TD simulations matter, especially for the phi-angle of the interplanetary magnetic field.