Physics of auroral phenomena : proceedings of the 40th annual seminar, Apatity, 13-17 March, 2017 / [ed. board: N. V. Semenova, A. G. Yahnin]. - Апатиты : Издательство Кольского научного центра РАН, 2017. - 143 с. : ил., табл.

Daytime magnetosphere-ionosphere disturbances in response to sharp increases in the solar wind dynamicpressure density (up to 50-60 cm-3) at a low solar wind speed (350-400 km/s). Only in the third event the growth o f the solar wind speed was recorded from ~400 to ~700 km/s. The nature of variations in the solar wind parameters (long structures with an increased density) indicates that all three Psw jumps were initiated by coronal mass injections (CME). A similar event became possible as a result of a series o f flares of the X-ray class "M" on the Sun on June 21, 2015, which threw the CME toward the Earth. The approach to the magnetopause of the first two dynamic impacts, as can be seen from Fig. 1, did not lead to the development o f a magnetic storm, but caused the development o f high- latitude bays. The main phase of the storm begins only after the approach of the third blow with the rotation of the Bz component o f IMF to the south. MLT 11 17 23 05 11 MLT 21 03 09 IS 21 Figure. 2. Magnetograms of the polar observatories on the IMAGE profile and the antipodal on LT North-American sector for June 21 - 22,2015. Fig 2. shows variations o f X- and Y-component of ground magnetic field, registered by the stations of Scandinavian profile IMAGE and antipodal on LT North-American network of observatories for June 21 - 22, 2015. On magnetograms of high-latitude observatories, the first shock front (at 16:45 UT) was observed in the dusk sector as a sharp impulse in the X-component (negative at higher latitudes and positive at lower latitudes). In the near-noon and post-noon sectors a negative magnetic bay started too. The pulse sign reversal at Ф ~ (67-71)° allows to assume that the boundary of open and closed field lines in the dusk sector was located there. In the daytime sector, at latitudes > 80 °, insignificant bays developed. The second front (at 05:44 UT on June, 22) was weaker, but occurred with negative Bz IMF, and led to the development o f positive polar bay ~ 400 nT in the daytime and night sectors, which changc to negative at the auroral stations of the North-American sector. The third, most powerful, jump of Psw (at 18:38 UT on June, 22) occurred at the beginning of the main phase of the storm. It caused very intensive negative X-bays (up to ~ 1500 nT) in both the night and day sector. The top panel of Fig. 1 shows the local time on the chains of stations, and to the right of each chart the station abbreviated designation and their geographical latitudes are signed. Observations on spacecrafts To trace the dynamics of magnetic disturbances in the ionosphere, we used SWARM A and С satellites data and the auroral oval OVATION model. The SWARM has a circular orbit at an altitude ~ 400 km in the midday-midnight meridional plane with a period of about 1.5 h. To determine the perturbations, the main field IGRF-2015 was subtracted from the measured magnetic field. SWARM A and С satellites orbits are near. Fig. 3 shows examples of the distribution of magnetic perturbation vectors recorded during three flights of SWARM A over the northern polar region on June 21,2015: before the shock arrival, immediately after it and by two hours after. To the right and left o f the vector diagrams, MLT of flight and departure of the satellite is shown. As can be seen from Fig. 3, significant magnetic perturbations appeared in the daytime region o f the polar cap (Ф > 75°) immediately after the arrival o f the shock. In this case, when the By IMF changes from a weak positive to a negative at ~17:30 UT, magnetic vectors 16