Two-dimensional Chapman-Ferraro Problem with neutral sheet: 3. Implied magnetospheric flows and their time dependence

In a magnetosphere with a magnetic tail and a perfect neutral sheet, the steady-state field line configuration is found to depend on two variables: the magnetic flux in the tail and the solar wind momentum flux. Thus, changes in solar wind momentum flux, or transport of magnetic field lines into and from the tail cause a large-scale magnetospheric flow toward the new equilibrium configuration. The solutions to the two-dimensional case are used to study the flows and indicate the following: (1) Changes of the momentum flux of the solar wind are important in producing convective flow, only if they are an order of magnitude in a short time. (2) The large-scale convective flow is usually determined to first order by the rate at which field lines are being carried into the tail and is probably not dependent on occurrences at the neutral sheet. (3) Reconnection and collapse of tail field lines to a dipolar-like configuration could produce significant magnetosphere-wide flow only if it was burst-like in occurrence. The magnetospheric response to forces that produce flows depends on the relative size of three time constants: The time constant of the driving force, the time to set up a stressed magnetosphere, and the time to relax it by motion of field line feet through the conducting ionosphere.