A simulation experiment has studied the magnetospheric boundary for high Alfv¿n Mach numbers. The artificial magnetosphere was produced as a result of interacting supersonic and super-Alfv¿nic flow of collisionless plasma with the magnetic field of a dipole. In the presence of southward magnetic field components, a ''visor'' forms at the day side in the plasma flow, preventing reconnection at the front side of the magnetosphere. Field lines of the plasma flow envelop the polar cap, forming the mantle. In the presence of northward field components the convection in the polar cap is sunward, while with southward components convection is antisunward.

Simultaneously with the convection caused by reconnection, convection due to viscous interacting is observed along the boundary, and clearly in the region of closed field lines.