Physics of auroral phenomena : proceedings of the 33rd Annual seminar, Apatity, 02 - 05 March, 2010 / [ed.: A.G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2011. - 206 с. : ил.

expands up to about 5° of latitude. The AOP region displays an opposite pattern: weak widening of the precipitation region in the morning sector (about 1° of latitude) and expansion of the structured precipitation region in the evening sector. Such pattern in the auroral precipitation is observed for both storms on 10 and 11 January and defined by both the magnetic activity (AL-index) and storm intensity (Dst variations). Thus, during two magnetic storms under a long-lasting depression of the Dst index, a significant latitudinal displacement of the DAZ and the AOP region was observed. The expansion of the DAZ precipitation occurred in the morning sector and the AOP region expanded in the evening sector. Morning - evening asymmetry o fauroralprecipitation during magnetic storms Figure 3. The boundary displacements (a) and the changes of the size of the precipitating zones (b) in the morning (solid lines) and in the evening (dashed lines) sectors on January 10-11, 1997. Figure 2. The dynamics of the global precipitation for four time intervals marked by the dashed lines. For the magnetic storms of moderate (October 21-22, 2001; a, b) and strong (July 15-16, 2000: c,d) intensities the displacement of the boundaries and changes in the size of the precipitation zones in the morning and evening sectors are more expressively and presented in Fig. 4. a b с d Figure 4. The boundary displacements (a, c) and the changes of the size of the precipitating zones (b, d) in the morning (solid lines) and in the evening (dashed lines) sectors for October 21-22, 2001 (the moderate storm) and July 15-16 2000 (the strong storm). 51