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.

Effect o f the IMF By on daysidepolar geomagnetic disturbances Summary If the IMF Bz is more intensive than the IMF By, DP2 current system predominates over other dayside current systems and produces magnetic dayside magnetic bays. May 24, 2000 b Figure 4. a) IMF Bz and By components and the horizontal vectors of the geomagnetic field; b) DMSP F13 precipitating particle data. Blue arrow marks moment when DMSP F13 located above high latitude IMAGE stations. When the IMF By predominates over the IMF Bz, the high latitude DPY current system controlled by the IMF By sign intensified, penetrating deep into the polar cap [Vennerstrom et al., 2002] and produced sequence o f dayside polar magnetic bays. We suppose that the IMF By effect on dayside polar geomagnetic disturbances substantially depends on the IMF \Bz\l\By\ ratio. References Feldstein, Y.I. (1976), Magnetic field variations in the polar region during magnetically quiet periods and interplanetary magnetic fields, Space Sci. Rev., 18, no. 5/6, 777-861. Feldstein, Y.I., Popov, V.A., Cumnock, J.A., Prigancova, A., Blomberg, L.G., Kozyra, J.U., Tsurutani, B.T., Gromova, L.I., and Levitin, A.E. (2006) Auroral electrojets and boundaries of plasma domains in the magnetosphere during magnetically disturbed intervals, Ann. Geophys., 24,2243-2276. Friis-Christensen, E., and J. Wilhjelm (1975), Polar cap currents for different directions of the interplanetary magnetic field in the Y-Z plane. J. Geophys. Res., 80(10), 1248 - 1256. Friis-Christensen, E., Y. Kamide, A.D. Richmond, and S. Matsushita (1985), Interplanetarymagnetic field control ofhigh-latitude electric fields and currents determined from Greenland magnetometer data. J. Geophys. Res., 90(A2), 1325 - 1338. Iwasaki, N. (1971), Localized abnormal geomagnetic disturbance near the geomagnetic pole and simultaneous ionospheric variation, Rep. Ionos. Space Res. Japan., 25, 163-286. Iijima, Т., and T. A Potemra (1976), Field-aligned currents in the dayside cusp observedby Triad, J. Geophys. Res., 81(34), 5971-5979. Levitin, A.E., Gromova, L.I., Gromov, S.V., and Dremukhina, L.A. (2014), Quantitative estimation of local geomagnetic activity relative to the level of the magnetically quiet period in 2009, Geomagn. Aeron. (Engl.Transl.), 54(3), 292-299. Troshichev, O.A., Gizler V.A., Shirochkov A.V. (1982), Field-aligned currents and magnetic disturbances in the dayside polar region, Planet. Space Sci. V. 30. P. 1033-1042. Vennestrom, S., T. Moretto, N. Olsen, Frii-Christensen E., Stampe E., and Watermann J. (2002), Field-aligned currents in the dayside cusp and polar cap region during northward IMF, J. Geophys. Res., 107(A8), 1188-1193. 22