ABSTRACT
The magnetospheric field points northward at the subsolar stagnation point. The formation of Earth's magnetotail remains one of the fundamental questions in magnetospheric physics. The curves plotted result from a theoretical three-dimensional magnetospheric B-field model. The equatorward shift is consistent with the corresponding shift of the boundary between open and closed magnetic field lines and thus reflects a reconfiguration of the entire magnetospheric B-field during magnetically active periods. Magnetospheric convection, or plasma circulation, is a slowly time-dependent process, whereby closed magnetotail flux tubes near local midnight move adiabatically toward the Earth. The first computational scheme of magnetospheric convection in the inner magnetosphere, and its coupling to the low-latitude ionosphere, is due to Vasyliunas. A magnetospheric substorm is a transient process, initiated on the night side of the Earth, in which a significant amount of energy derived from the solar wind-magnetosphere interaction is deposited in the auroral ionosphere and magnetosphere.
