Shape of the magnetosphere

The shape of the magnetosphere has been studied by using a global MHD model of the magnetosphere. It is found that MHD and the Chapman‐Ferraro models agree in total magnetopause current distributions, but that the MHD model presents a very different physical picture from that of the Chapman‐Ferraro model. In the MHD model with B IMF = 0 or northward, the cusp is not exposed directly to the solar wind because the dayside magnetic field lines drape around the nightside magnetosphere. Furthermore, in the MHD model a current sheet exists above the cusp region.