Magnetosheath study: INTERBALL observation Original Research Article

The fundamental question of the solar wind magnetosphere coupling is how the solar wind and IMF are modified before they hit the magnetopause. Various models have been proposed to describe the magnetosheath flow but none of them includes the presence of the foreshock region. However, due to the curvature of the bow shock, the foreshock can affect a part of magnetosheath flow nearly for all IMF orientations.This study presents results of the multipoint study of the relationship between solar wind and magnetosheath fluxes based on the measurements of the WIND, INTERBALL-1 and GEOTAIL spacecraft. The magnetosheath ion flux profile was found to be well (with an accuracy ±40%) described by the gasdynamic model on the scale of hours but on the shorter scale it exhibits random fluctuations which can exceed the gasdynamic prediction by a factor of 5. The amplitude of the fluctuations is a function of the interplanetary magnetic field cone angle.