Аннотация:We report a case study of substorm recovery phase on 14 November 2014 in the interval 20:30-23:00 UT using data from THEMIS-D satellite located in the midnight sector (~2300-0030 MLT) magnetosphere at 6.5-9.25 Re. The substorm recovery phase of interest was not just a decline of previous disturbances, but include also a new intense substorm intensification in the midnight sector of the auroral oval. This new auroral activation presents the eastward expanding auroral (EEA) structures occurred precisely after the substorm intensification onset and concentrated to the midnight sector of the auroral oval.
We show that these EEA structures were observed in diffuse aurora, formed the undulations on the poleward edge of the diffuse aurora similar to of omega bands. The pulsating aurora was observed after the passage of the EEA structures. Rapid poleward expansion of the poleward diffuse region boundary coincided with the occurrence of Pi2 pulsations in the ionosphere and with the large-scale dipolarization and the particle injections in the near-Eart plasma sheet of the magnetosphere at ~7.2 Re. Besides, the THEMIS-D reveals the quasiperiodic variations of electrostatic ELF wave intensity at frequency of <100 Hz coincided with the DC electric field variation. At the moments of more small-scale local dipolarizations, the low-energy electron flux (0.1-3 keV) bursts occur simultaneously with the ELF wave intensity enhancements.