Physics of auroral phenomena : proceedings of the 38th annual seminar, Apatity, 2-6 march, 2015 / [ed. board: A. G. Yahnin, N. V. Semenova]. - Апатиты : Издательство Кольского научного центра РАН, 2015. - 189 с. : ил., табл.

Substorm injection at THEMIS satellite and near-conjugate auroral luminosity in pre-midnight sector magnetic field from 108s-smoothed values, the most appreciable dBx and dBy components of the magnetic field is shown here; and also the Ex and Ey components of the electric field. Horizontal lines note the energetic ion injections observed at THD and THE. Vertical lines note the moments: 't ^ t { and Texp. From Fig. 3 one can see the oscillations of В and E field with several quasi-periods. Both before and after Tap, the quasi-period of 1.5 min (panels 'а' и 'f) has the signature at THD and THE. The oscillations with quasi-period o f 30-40 s appear firstly at THE 1 min before Тыр and then - at THD on Texp. Besides, the one oscillation with quasi-period o f 2.5 min occurs at THE. For this oscillation at the interval 18:22-18:25 UT at THE (panels 'e' and 'h'), the perpendicular fluctuations of the magnetic field and the electric field dBx and dEy are ~90° out of phase as for standing Alfven waves (SAW), which may be associated with intensification auroral arc near THE (r~6.8 RE). <" m Ё шо у 0.1 а 20 g t 10 "6 xm !- -15 s 40 £ = 20 gaF 0 Jf 104 r* :° Ht4oJ £ -140 -220 -400 -500 Q I t St- 10400 a. Sc Ц *.10360 I 10320 18:30 18:45 : a — i k rv i : ЧА1 Л2 L f A3| и i — T \ v / t I — -j ' f Л Н _d i i i i i 4 Iй— '1 e t i ШЦ m /2 /3 ] г 11 Ml ~\s 1 Л \ \ N 1 -—4 H I I 11 \ 4 V 19:00 UT Figure 2. Ground-based and THD observations on 19 December 2014 at 18:00-20:00 UT. Ion pressure gradient and upsurge in the duskward ion flux. Fig. 4 show from top to bottom the data at THD (panels 'a'-'f) and the data at THE (panels 'g'-'P): the ion density (integrated from 5 eV to 25 keV); evolution of the electron spectrum (from 6 eV to 30 16 keV); three components of velocity o f plasma flow ( Vx, Vy, V,) in GSM system and Pa component of the ion pressure tensor. Figure 3. E- and В-field variation observed at THD and THE. First, we consider the data at THD. After tu one can see weak increases in Vx and Vy, decrease of Pa presure and weak the B2 increase. After Tap, the sharp drop in the Ni and P„ of ion are observed simultaneously with sharp upsurge in the duskward ion flux. These signatures coincide with the increase o f electron Ecu, from Wcul -10 keV to Wcul - 20 keV (here Wcu, is the cutoff energy), indicated that new “fresh ” electrons at the opened drift trajectories convect toward the spacecraft position from the tail [Kerns et al., 1994]. Simulteneously, the fluxes of “old” trapped electrons of 0.03-0.8 keV, which originated from previous activity, sharp decrease during the local dipolarization. Now, we consider the data at THE (panels ’g'-T). Fig. 4 show slow increase in N-t and Pa after /, and then (1 min before Texp) sharp drop of the ion pressure and simulteneous sharp upsurge in the duskward ion drift velocity Vy. Pressure drop and the Vy upsurge last 30 s and were observed during rapid decrease o f the magnetic field B2 component (magnetic field stretching) at THE. Sharp drop of the ion pressure during magnetic field stretching may indicate on the