Abstract

The variations of the ion spectra in the transition region from dipole to tailward stretched field lines are analyzed on the base of INTERBALL/Tail satellite observations. The simultaneous measurements of the CORALL, DOK-2 and SKA-2 instruments were used for the obtaining the ion spectra in a wide energy range. The events of small spectra variations along the satellite trajectory are selected. Some possibilities to explain the observed feature are analysed including the satellite travelling along single field line, the compensation of the loses of particles due to drift effects by the adiabatic acceleration due to the regular earthward drift in the dawn-dusk electric field, and intense plasma mixing in the conditions of the nonconservation of the magnetic moments of particles. It is shown that the action of turbulent auroral electric fields is the most probable explanation of the observed effect.