DISSIPATIVE STAGNATION-POINT FLOWS AT A CURRENT SHEET WITH SHEAR IN THE PLASMA VELOCITY

The process of magnetic field annihilation is described using the framework provided by the MHD equations. An incompressible plasma is considered, and anomalous transport parameters in the form of uniform resistivity and viscosity are included. The planar stagnation-point geometry which we present models a cuff ent sheet separating two counterstreaming plasmas. One possible application of this configuration is the magnetopause, where coupling processes give rise to an exchange of energy and momentum between the magnetosheath and magnetospheric plasma. We allow for the possibility of a generally inclined plasma flow towards the current sheet so that, for example, the flow in the neighbourhood of the Earth's magnetospheric cusp and flank regions can be modelled as well as the subsolar region. A distinguishing feature of the exact solutions of the MHD equations which we present is that the flow is not irrotational and therefore viscous forces play an important role in the plasma behaviour.