Physics of auroral phenomena : proceedings of the 37th Annual seminar, Apatity, 25 - 28 February, 2014 / [ed. board: A. G. Yahnin, N. V. Semenova]. - Апатиты : Изд-во Кольского научного центра РАН, 2014. - 125 с. : ил., табл.

Thus on the base of these results we can identify general trends in development of unified ionospheric- magnetospheric current system for different geomagnetic storms. By the results of experiments it was found that during magnetic storm main phase there is a strong connection between magnetospheric and ionospheric current systems. Therefore the possibility of acceptable neural network restoration of auroral electrojet intensity indices (AU, AL) under ring current intensity indices (SYM, ASY) exist. Fig. 1 shows an example of AL index restoration under ASY index. О.M. Barkhatova et at R = 0.89, PE= 15.27%, ASY(0) - AL Time, UT Figure 1. Restoration of AL index under ASY index by Elman neural network It should be noted that during geomagnetic storms the mid-latitude and auroral current systems may have a relative time shift in the development due to different mechanisms of their formation [Francia et. al., 2004; Barkhatov et. al., 2007; Barkhatov et. al., 2008]. In this study on the base of non-linear relationships analysis, the time shift in development of ring current symmetric part and auroral electrojets is established. For pair SYM-AU nonlinear correlations were searched with time shifts 0; 30 and 60 minutes and index SYM delayed relative to AU. For pair SYM-AL similar experiments were carried out using neural networks with time shifts 0; 60 and 120 minutes, and the index SYM delayed relative to AL. The obtained results indicate the existence of time delay in development of ring current symmetric part relative to eastward electrojet for 30 minutes and westward electrojet for 60 minutes. This means that the ring current is generally characterized by a time delay in the development relative to auroral electrojets for geomagnetic storms of varying intensity. For pairs ASY, AU and ASY, AL similar analysis was not performed because of executed earlier study [Barkhatov et. al., 2007; Barkhatov et. al., 2008]. It was found that the asymmetric ring current during the main phase of a geomagnetic storm develops synchronously with auroral electrojets. 3. Statistical analysis o f neural network restoration results o f AU, AL indices Statistical analysis of neural network experiments results was performed by calculating the ratio of cases number with satisfactory correlation for each indices pair to the total number of possible combinations for all geomagnetic storms events. For pairs SYM-AU and SYM-AL the analysis was carried out with previously established time delays. The results showed that for pairs of indices SYM-AU and ASY-AL it is the largest number of events with correlation coefficient > 0.4 between the real and restored sequences. This means that the corresponding current systems have a stable relationship and a similar scenario within geomagnetic disturbances of varying intensity. For pair of SYM-AU this may be due to activation of corresponding current systems by a single source. The current system of ring current symmetric part indeed is enclosed and does not need a union with auroral electrojets. For pair ASY-AL significant correlation can be explained by union of corresponding current systems. This conclusion is consistent with results of [Grafe et. al., 1997; Barkhatov et. al, 2007; Barkhatov et. al, 2008]. To establish the additional features of the nonlinear connection of asymmetric ring current with auroral electrojets, it has been calculated a number of satisfactory restored cases. This analysis allows determining how typical for geomagnetic storm main phase development of an event is. 7