3-D mesoscale MHD simulations of a cusp-like magnetic configuration: method and first results

Abstract. We present a local mesoscale model of the magnetospheric cusp region with high resolution (up to 300 km). We discuss the construction and implementation of the initial configuration and give a detailed description of the numerical simulation. An overview of simulation results for the case of strongly northward interplanetary magnetic field (IMF) is then presented and compared with data from Cluster 2 spacecraft from 14 February 2003. Results show a cusp diamagnetic cavity (CDC) with depth normal to the magnetospheric boundary on the order of 1–2 R_E and a much larger extent of ~5–9 R_E tangential to the boundary, bounded by a gradual inner boundary with the magnetospheric lobe and a more distinct exterior boundary with the magnetosheath. These results are qualitatively consistent with observational data.