The magnetostatic equilibrium in high latitude magnetosphere and the selection of coordinate system for high latitude processes description

The coordinate system employing isosurfaces of magnetic flux tube volume as the coordinate surfaces was used for the reconstruction of azimuthal magnetospheric plasma pressure gradients on a basis of the data of large scale field aligned currents distribution and the Tsyganenko magnetic field models. The integral plasma pressure changes are compared with the satellite measurements of plasma pressure. It was shown that Region I and Region II currents can be maintained by azimuthal hot plasma pressure gradients. The localization of the Region I currents in the inner magnetosphere creates the mechanism of dawn-dusk electric field formation which does not require the reconnection or viscous interaction of the solar wind with the magnetosphere.