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.

V.M. Mishin et al. superstorm. For each of them, the plots of variation in the FAC intensity in the cells of premidnight and postmidnight sectors of each of three Iijima and Potemra Regions were obtained. On such a basis, we showed that, during the equinox season, one observes two EP types detected recently, and termed "EP summer type" and "EP winter type" [Mishin et al., 2015]. Within the latter, the FAC space distribution and dynamics during EP differ dramatically. We offer a scenario, in which the winter-type EP starts with the collapse (decrease) of FAC that downflows into the ionosphere of the winter hemisphere in theRl premidnight sector. Simultaneously, and with almost at the same rate, there occurs the FAC increase in in the adjacent R1 postmidnight sector. Thus, in the proposed scenario, the substorm EP starts simultaneously in two hemispheres, but in different MLT sectors of the nightside I-P Region 1. The M-I feedback instability in the premidnight sector of the summer hemisphere sereves as an initiator and organizer of the global EP (see, e.g., [Atkinson, 1970]. Acknowledgements. We thank the ISTP SB RAS MIT group members and Dr. E.V. Mishin for stimulating discussions. The AE index was obtained from the World Data Center for Geomagnetism, Kyoto. We are grateful to Pis of the CANOPUS, INTERMAGNET, GIMA, MACCS, IMAGE projects and of magnetic networks in Arctic and the Antarctic (the Shafer Institute of Cosmo-Physical Research and Aeronomy SB RAS, Arctic and Antarctic Research Institute, and DMI), and individual magnetic observatories for providing magnetic data used in this study. Work was supported by the RFBR under Grants 14-05-91165 and 15-05-05561. C. and J.Y. Wang are supported by NSFC Grant 413111039. References Akasofo SI (2013) The relationship between the magnetosphere and rnagnetospheric/auroral substorms. Ann Geophys 31 (3):387-394. doi: 10.5194/angeo-31-387-2013 Atkinson G (1970) Auroral arcs: Result of the interaction of a dynamic magnetosphere with the ionosphere. J Geophys Res 75 (25):47464755. doi:10.1029/JA075i025p04746 Anderson BJ, Korth H, Waters CL, Green DL, Merkin VG, Barnes RJ, Dyrud LP (2014) Development of large-scale Birkeland currents determined from the Active Magnetosphere and Planetary Electrody-namics Response Experiment. Geophys Res Lett 41 (9):2014GL059941. doi: 10.1002/2014gl059941 Cowley SWH (2000) Magnetosphere-ionosphere interactions: A tutorial review. In: Magnetospheric Current Systems, vol 118. Geophys. Monogr. Ser. AGU, Washington, DC, pp 91-106. doi: 10.1029/GM118p0091 Kabin K, Rankin R, Rostoker G, Marchand R Rae U, Ridley AJ, Gombosi IT, Clauer CR DeZeeuw DL (2004) Open-closed field line boundary position: A parametric study using an MHD model. J GeophysRes 109. doi: 10.1029/2003ja010168 Kamide Y, Baumjohann W (1993) Magnetosphere- ionosphere coupling. Springer-Verlag, Berlin Korth H, Rastatter L, Anderson BJ, Ridley AJ (2011) Comparison o f the observed dependence o f large-scale Birkeland currents on solar wind parameters with that obtained from global simulations. Ann Geophys 29 (10): 1809-1826. doi:10.5194/angeo-29-1809-2011 Laundal KM, Ostgaard N (2009) Asymmetric auroral intensities in the Earth/'s Northern and Southern hemispheres. Nature 460 (7254):491-493. doi: 10.1038/nature08154 Lyatsky WB, Maltsev YP, Leontyev SV (1974) Three- dimensional current system in different phases of a substorm. Planet Space Sci 22 (8):1231-1247. doi: 10.1016/ 0032-0633(74)90007-5 Lui ATT, Kamide Y (2003) A fresh perspective o f the substorm cun-ent system and its dynamo. Geophys Res Lett 30 (18):1958. doi: 10.1029/2003gl01 6 April 2000 Figure 3. Variations in the FAC intensities in cells of three I-P Regions in the premidnight (dusk) and postmidnight (dawn) sectors. Vertical lines mark the EP maximum time for Event 1 (0255 UT) and Event 2 (0355 UT). Also, the AE index plot is provided. Event 1 is at (02-03) UT. Event 2 - at (03-04) UT. Figure 4. Event 3 within the 12-15 UT interval. The designations are the same as those in Fig. 3 26