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.

nT (Fig. lb) under the positive IMF Bz (up to +25 nT), and the IMF By changed from -15 nT to +20 nT). The solar wind density was strong (up to -4 0 1/cm ), and velocity remained at - 700 km/s. The intense (-400 nT) magnetic bay was recorded in the daytime sector of the polar latitudes (Fig. 2). 29 - 30.05.2003 __S.— i V- Daytime polar magnetic disturbances under extremely strong IMF Bz Discussion The ionospheric currents, which are observed on the Earth’s surface as geomagnetic variations, are closely related to the field-aligned electric currents in the magnetosphere. There are several statistical models of the global distribution of high-latitude field-aligned electric currents, e.g., [Mishin et al., 1978; Dremukhina et al., 1998; Papitashvili et al., 2002; Lukianova and Christiansen, 2006]. The Fig. 3 present the field aligned currents ( FAC) distribution calculated by the IZMIRAN model [Feldstain and Levitin, 1986] in coordinates: geomagnetic latitude - MLT: red - downward currents, blue - upward ones. Figure 2. The OMNI data magnetograms (May 30, 2003). lA k -F A J v 'л >' V,’ -i v /ЛМ tv ; . ,-«•¥ % - 7 r '-t n - , n -Of- - Z " a * " • * Ллг. v^r-v, -* --•■'’‘“‘J a i . . . „...._._ i , (May 29-30, ‘■M SC*< • i >. I "J<cv v'V-T•'W*<Nrr|2 •JO |w . 5 0 *- "Sj*,». >JU> c4 t - j* -----------|:C*i 1 - ^* - v- i ' - *CWt* •VJ4Ш 2003) and IMAGE 24.11.2001 09.43 UT Sy = 10.3 нТя 12 Bz = S4.1 нТл .S O D , Figure 3. The field aligned currents ( FAC) distribution according to IZMIRAN model for Nov 24, 2001. The magnetic variation vectors of high-latitude IMAGE stations (NAL - LUR) were constructed using difference magnetograms based on magneto-quiet 2009 level [ Levitin et al., 2014]. They are shown in Fig. 4 (left) for 02-14 UT on 24 Nov 2001 and Fig. 4 (right) for 0 0 - 1 2 UT on 30 May 2003. The magnetospheric configuration changes substantially when IMF is northward and the corresponding NBZ system o f field aligned currents are formed in this case [Antonova and Ovchinnikov, 1999, 2001]. One can be seen that the vortex with clockwise rotation direction are seen which corresponded downward FAC. The FAC intensification in the dayside polar region (the NBZ system) is seen. For event of 30 May 2003 the vortices with opposite rotation direction are seen which corresponded upward and downward FAC. 24.11.2001 30.05.2003 i j*. NAL 76 . 1 * IYK 75.1 * nos 7 . 1 . 0 * ш.\ 71 . 3 * SCR 67 . 3 * . \ V NAL 76.1 Ш Г ' 02 04 06 08 10 12 14 UT ’/Ai . S0R 67. a 00 02 04 06 08 10 12 Figure 4. The magnetic variation vectors during PE events of 24 Nov 2001(left), and 30 May 2003(right) 16