Auroral electrojet dynamics during magnetic storms, connection with plasmaprecipitation and large-scale structure of the magnetospheric magnetic field

Effect of the equatorward shift of the eastward and westward electrojets du ring magnetic storms main phase is analyzed based on the meridional chains of magnetic observatories EISCAT and IMAGE and several Russian observatorie s (geomagnetic longitude similar to 110 degrees, corrected geomagnetic lati tudes 74 degrees > Phi > 51 degrees.) Magnetic storms of various Dst index intensity where the main phase falls on 1000 UT - 2400 UT interval were sel ected so that one of the observatory chains was located in the afternoon - near midnight sector of MLT. The eastward electrojet center shifts equatorw ard with Dst intensity increase: when Dst similar to -50 nT the electrojet center is located at Phi similar to 62 degrees, when Dst similar to -300 nT it is placed at Phi similar to 54 degrees. The westward electrojet center during magnetic storms main phase for intervals between substorms shifts eq uatorward with Dst increase: at Phi similar to 62 degrees when Dst similar to -100 nT and at Phi similar to 55 degrees when Dst - -300 nT. During subs torms within the magnetic storms intervals the westward electrojet widens p oleward covering latitudes Phi similar to 64 degrees - 65 degrees. DMSP (F0 8, F10 and F11) satellite observations of auroral energy plasma precipitati ons at upper atmosphere altitudes were used to determine precipitation regi on structure and location of boundaries of various plasma domains during ma gnetic storms on May 10-11, 1992, February 5-7 and February 21-22, 1994. In terrelationships between center location, poleward and equatorward boundari es of electrojets and characteristic plasma regions are discussed. The elec trojet center, poleward and equatorward boundaries along the magnetic obser vatories meridional chain were mapped to the magnetosphere using the geomag netic field paraboloid model. The location of auroral energy oxygen ion reg ions in the night and evening magnetosphere is determined. Considerations a re presented on the mechanism causing the appearance in the inner magnetosp here during active intervals of magnetic storms of ions with energy of tens KeV. In the framework of the magnetospheric magnetic field paraboloid mode l the influence of the ring current and magnetospheric tail plasma sheet cu rrents on large-scale magnetosphere structure is considered.