Numerical investigation of high-energy plasmoid behavior in the upper ionosphere. Part 2. Development of the three-dimensional model

We develop a new modification for the monotone conservative variant of the grid-characteristic method of 2-3 order of approximation. The general algorithm of the transition from the known state at $t=t^n$ to the desired one at the instant $t=t^{n+1}$ includes the splitting in spatial variables. If there are discontinuities of great intensity, it includes the splitting in “the physical processes” as well (the “gas-dynamic” stage, the “magnetic” stage, and the stage of calculating the magnetic field diffusion). We carry out the numerical investigations of the evolution of the strong plasma disturbances in the near-Earth space to times of the order of 6 sec. We demonstrate the considerable influence of the nonhomogeneity of the exponential atmosphere and the geomagnetic field on the structure of the plasma flow.