Global MHD Simulation of Mesoscale Structures at the Magnetospheric Boundary

We have continued our modeling of the solar wind/magnetosphere interaction for steady solar Wind conditions by carrying out a series of 3 D global magneto-hydrodynamics (MHD) simulations using a set of predetermined solar wind parameters as input to the code. With the results from the simulations that we ran last year for two other dipole tilts (0 and 35 deg), we have 36 data sets to study the dynamics of mesoscale structures at the magnetospheric boundary. We have started the analysis of these runs to investigate geometrical properties and the topology of the magnetic and electric fields for the different solar wind regimes and orientations considered. Preliminary results indicate that merging sites are consistent with patterns proposed for antiparallel merging at the dayside magnetopause. Another goal of this investigation is to establish the displacement of the cusp region as a function of the solar wind dynamic pressure, IMF direction and magnetic field dipole tilt. One of the difficulties of that study is to locate precisely the cusp in the simulation results. We have used several case studies to establish a series of criteria in to permit a routine identification of that location. We need now to process the rest of the simulation results using these criteria to obtain statistical results.