Physics of auroral phenomena : proceedings of the 39th annual seminar, Apatity, 29 February-4 March, 2016 / [ed. board: N. V. Semenova, A. G. Yahnin]. - Апатиты : Издательство Кольского научного центра РАН, 2016. - 167 с. : ил., табл.

О. V. Sapunova el al. 4. Fine structure o f the IP ramp region An example of the front fine structure is illustrated on Fig. 4 taken from 09.09.2011 event. The figure shows its parameters: the duration of the front by plasma measurements: t6=0.37; magnetic field measurements: t5=0.48 s; thickness: 5=161 km; front speed: IPve(=410 km/s. ■2S s 24 u 3 16 U a SPEKTR-R = 0.37 s Front: : 4 5*161 km p = 6.7 / 0 b „ = 26° Mms = 2.3 ГР *410 km/s VS I 12 w10 SPEKTR-R Front; - fi« 5 1 km x, t X = 0.44 s Precursor: X, = 100 km tX^.28 3 . p P = 1.9 68 M m s я 1.5 ® B n ' 45685 456S6 45687 45688 45689 33367 12 33368 33369 tS = 0.17 s — Г" ■ 1 33370 33371 10 с Г 8QD Front: -4- 8 = 68 km f Precursor: X 1 * 64 km U, 4 0.18 s . . . . ■ •• l i -j- tX. = 0.4Б s ... r a . ... I е \ v I Witio 4045,4!s shift I ----- -----t-------- i -I------ ------- 1 ------ ------- 1 Time (UT)(s; 0 9 , 0 9 . 2 0 1 1 33367 33368 33369 33370 T im e (U T ) (s) 01 . 11.2011 33371 Figure 4. Ion flux and magnetic field measurements for 09.09.2011. Main classification parameters are given. Figure 5. Ion flux and magnetic field measurements for 01.11.2011. Main classification parameters are given. S 500 An example of the precursor wave presented on Fig. 5 (01.11.2011 event). 4 peaks are clearly visible in the flow before front, with an amplitude rising up while approaching to the front. This oscillations was also observed in magnetic field. Fig. 6a shows comparison of front thickness by plasma flux and front thickness by magnetic field module. There is a good mutual alignment in common. Figure 6b presents the same for precursor waves. 5. Conclusion The SPEKTR-R (highly elliptical orbit satellite) was launched in 2011, with plasma spectrometer BMSW onboard it. Device BMSW was designed to achieve the high time resolution [12] for plasma parameters o f the solar wind - 0.031 s for measurements of magnitude and direction of the solar wind ion flux. According to the BMSW instrument the study of the fine structure of the IP waves fronts was carried out, and with other spacecrafts' data a wide range of IP waves characteristics was received. Classifying IP shocks parameters were determined: (5 (ratio of thermal pressure to magnetic pressure), the angle 0Bn - angle between the normal to the wave front and the direction o f the vector magnetic field in the unperturbed solar wind, magnetosonic Mach number Mms; the IP shocks propagation speed was calculated. The fine structure of IP shock fronts and precursors was studied. According to the fronts duration and their velocity, the fronts thickness was determined (lying in range from 40/35 up to 350/450 km) (by the plasma/magnetic field parameters); the length o f precursors was calculated (from 65/60 to 450/410 km). I 100 - r 100 200 300 400 500 $j Front thickness by plasma flux {km) S’ T- 0 100 200 300 400 500 Upstream wavelength by plasma flux (km; a Figure 6. Comparison magnetic field module. of measurements by b plasma flux and by 72