Propagation And Forecasting Of Interplanetary Shocks Based On MHD Simulation

In the interplanetary space, there exist two types of large-scale shock structures. One is driven by CMEs (Coronal Mass Ejections) with propagating speeds faster than that of the fast magnetosonic wave in the solar wind, the other results from the interaction between the approaching fast and slow solar winds flowing outwards along the same radial direction. Both of these two types of shocks are investigated numerically in this thesis by solving associated ideal magnetohydrodynamic (MHD) equations with the PPM (Piecewise Parabolic Method) scheme.In the case of CME-driven shocks, we developed a space weather forecasting model, the ForSPA (Forecasting Model of interplanetary Shock PropAgation based on MHD simulation) model, making use of the obtained database of a large number of numerical solutions of CME-shocks propagating in both the solar meridian plane and the equatorial plane. The solutions are given by calculations with prescribed initial shock parameters including the shock strength and the shock location. With ForSPA, we are able to obtain numerical solutions of CME-shocks with freely-specified certain initial parameters, and to estimate the shock arrival time (SAT) as well as other concerned parameters at 1 AU or at the Earth. We then make tentative predictions on SATs for the 68 CME-shock events dated between August 2002 and December 2006, and compare with other contemporary forecasting models of CME-shocks. It is found that the statistical errors of SATs given by ForSPA predictions are in general no larger than that given by other models.In the preliminary studies on the CIR (Corotating Interaction Regions) shocks, we focus on the effect of the solar wind speed on the formation heights of the shocks. Through two sets of parameter studies, we find that, (1) the formation heights decrease with a larger speed of the fast solar wind while the speed of the slow wind is fixed; (2) the formation heights increase with a larger solar wind speed while the speed ratio of the two wind components is fixed.