The interrelationship of magnetospheric processes.
Steady-state convection of plasma in the magnetosphere is quantitatively calculated for the case of a non-negligible magnetospheric plasma pressure. The problem is simplified by retaining only the essential physical features of the interplay between the driving processes and the ionosphere; the dominant contributor to the total plasma pressure is assumed to be the proton population of the plasma sheet and the ring current (this entire continuous population is simply called the ring current). This ring current is shown to be the major factor in determining the convection pattern rather than being only a small correction as was supposed in studies that assumed negligible magnetospheric plasma pressure. The effect of the ring current is to virtually exclude convection from the low-latitude region bounded by it, creating a nearly circular convection-free zone.