Predicting the Bow Shock Position for Average and Unusual Upstream Conditions

The positions, shape and motion of the Earth's bow shock have been extensively studied for the last four decades. Although many bow shock models have been developed, they still do not sufficiently describe the observed bow shock. The models fail because they are intrinsically steady-state and (semi)empirical. On the other hand, physics-based 3-dimensional global MHD models of the Earth's magnetosphere are resident at the Community Coordinated Modeling Center (CCMC). These MHD models compute the configuration and evolution of the magnetosphere in response to the actual solar wind parameters. We will compare and discuss differences between the bow shock observations for average and unusual upstream conditions and predictions provided by the MHD numerical simulations or by the (semi)empirical models.