Аннотация:This study examines the main features of the initial auroral arc brightening and the localization of substorm onset. Our findings challenge the traditional large-scale magnetospheric dynamics framework, which predominantly relies on the idealized magnetohydrodynamic (MHD) model and the frozen-in condition—typically assumed to be violated only at a few specific points along certain magnetic field lines. Through detailed analysis, we demonstrate that the observed auroral breakup phenomena can be described by the existence of a high level of turbulence in the Earth’s magnetotail and the penetration of large-scale interplanetary magnetic field into the magnetosphere.
