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.

S.В. Lunyushkinet al. - 46 kV Л*. «66* - 142 pie N _ - 7 U (SuperDARN) 04:06 UT 26/02/2008 I v я iiooo I875 I 750 Г h 5 1 Ц *00 t |37S J (250 I I *25 5000 m /s U (SuoerDARNH 04:30 UT 26/02 /2008 21 22 23 О 1 2 3 U (M IT -ISTP ) 04:06 UT 26/02/2008 AU = 2 kV U (MIT-ISTP) 04:30 UT 12 26/02 /2008 Figure 2. 26 Feb 2008, comparison of maps of distribution in polar ionosphere for wind velocities and electric potentials. Two examples are shown from the SuperDARN data (top) and MIT data (bottom). Isolines with a positive (negative) value are for the counterclockwise (clockwise) plasma vortices. Fig. Id presents additional examples, the plots of the UPc potential extremal value difference from the MIT data and its analog from the SuperDARN data. Based on these data, we make two conclusions: (1) the mesoscale cell system increases the UPc maximal values, and (2) mesoscale cells superpose two comparatively short-time pulses with U maxima on the U growth long-time pulses near 04:30 and 05:30 UT, respectively. The long-term pulse correlates with the variations in IMF Bz, short pulses are the effect of the inner mechanism that generates two substorms based on the first pulse. The short pulses are shown in Fig. lg, where there are the plots o f UPCand o f the polar ionosphere Joule heating power Qj. In general, the addressed two types of the electric potential distributions describe two different components of spatial distribution of termed parameters: the regular component from the SuperDARN data, and the irregular one from the ground-based magnetometer and MIT data. The latter corresponds to substorms, and dominates in mesoscale cells. The maps for these two types do not contradict, but supplement each other. Conclusions In this paper, we compared the maps of the electric potential distributions, obtained by two different methods: on the basis of MIT and by measurements of the SuperDARN radars. The main difference between these two methods is that the radars provide direct measurements in real time in only a few areas available to each of the radars. On the remaining area of each map, the values of the electric potential are obtained by averaging of multiyear measurements and spatial extrapolation o f these average values These operations do not hampering the measure of the regular component, but they smooth out the irregular component of the ionospheric plasma drift velocity, which may play a major role during substorms. 22