A two-dimensional radial outflow model of plasma at Jupiter

An analytic solution illustrating the behaviour of incompressible irrotational plasma outflow in two dimensions is given for application to the Jovian magnetosphere. Plasma is assumed to emanate from the Alfvén surface and is channeled downtail by the confining magnetopause surface. Conformal transformation methods are used to map this complex magnetotail geometry into a rectangular box for which the solution to Laplace's equation is expressed in simple form. The model suggests that a dipole layer is formed on the dawn side in the vicinity of the Alfvén surface where the flow bifurcates into clockwise and counterclockwise motion. An electric field discontinuity of this type fixed in local time may be able to account for several anomalous spin-periodic phenomena, namely, the modulation of Io-independent radio emissions and the injection of energetic electrons into interplanetary space.