Документы 21 - 30 из 70
21.

Количество страниц: 4 с.

Based on the data of longitudinal chain of midlatitude stations in the northern hemisphere, substorm-associated field-alighned currents (FACs) are examined. A comparison of IMF component variations with surface FAC characteristics in substorm sites is performed. It is shown that the ratio between the upward and downward surface FAC intensities depends on By IMF. In this regard, the conditions are discussed that favor currents flowing from the dayside cusp to nightside auroral region. These currents, which position is dependent on By IMF direction, can be responsible for difference between the upward and downward current-wedge-associated FACs.

Effect of Bγ IMF in substorm current wedge formation / V. A. Velichko, R. N. Boroev, I. Ya. Plotnikov, D. G. Baishev // Physics of auroral phenomena : proceedings of the 26th annual seminar, 25 - 28 February 2003. – 2003. – P. 45-48.

22.

Количество страниц: 2 с.

Evidence of the Psi geomagnetic pulsations burst excitation as the direct response to the solar wind pressure pulses : [тезисы докладов] / S. I. Solovyev, A. V. Moiseyev, D. G. Baishev, K. Yumoto, M. Engebretson // Physics of auroral phenomena : 24 annual seminar, 27 February - 2 March 2001. – 2001. – P. 48.

23.

Количество страниц: 4 с.

Evolution of geomagnetic perturbations and aurora dynamics during the strong magnetic storms events / S. I. Solovyev, R. N. Boroev, A. V. Moiseyev, A. Du, K. Yumoto // Physics of auroral phenomena : proceedings of the 32nd annual seminar, Apatity, 3 – 6 March 2009. – 2010. – P. 41-44.

24.

Количество страниц: 2 с.

Evolution of ionospheric current systems for the geomagnetic impulse SI/SC by the magnetometer global network data : [тезисы докладов] / S. I. Solovyev, A. V. Moiseyev, M. Engebretson, K. Yumoto // Physics of auroral phenomena : 24 annual seminar, 27 February - 2 March 2001. – 2001. – P. 36.

25.

Количество страниц: 14 с.

The spatial evolution of vortex-like flow structures induced by a negative sudden impulse (SI-) is studied on the basis of SuperDARN King Salmon HF radar (KSR) with other ground and satellite data. A large dip in the solar wind density induced a fairly large SI- with a SYM-H amplitude of ~40 nT. The SI-induced ionospheric flow signatures in the evening sector (MLT ~ 19 h) were observed by KSR as a westward flow associated with the preliminary impulse (PI) followed by a more intense eastward flow with the main impulse (MI) in the sub-auroral region on the magnetic latitude ~60-70 deg, consistent with the local ground magnetic field observations. Following the first PI-MI flow sequence, KSR saw a second and possibly third sequence of flow variation which were much smaller in flow amplitude than the first pair but showed qualitatively very similar flow variations and latitudinal/longitudinal propagation characterististics/ These observations can be interpreted as aftershocks of the first PI-MI; the same sequence of vortices and field-aligned currents were generated and then drifted anti-sunward with the same mechanism, namely the pumping motion of dayside magnetosphere. These results are qualitatively consistent with predictions suggested by recent numerical simulations.

Evolution of negative SI-induced ionospheric flows observed by SuperDARN King Salmon HF radar / T. Hori, A. Shinbori, N. Nishitani, T. Kikuchi, S. Fujita, T. Nagatsuma, O. Troshichev, K. Yumoto, A. Moiseyev, and K. Seki // Journal of Geophysical Research: Space Physics. – 1978. – 2012 (December), vol. 117, N 12. – P. A12223.
DOI: 10.1029/2012JA018093

26.

Количество страниц: 1 с.

Moiseyev A. V., Excitation of pulsations localized spatially during the sudden geomagnetic impulse: a case study / Moiseyev A., Baishev D. // 10th International conference "Problems of geocosmos", St. Petersburg, Petrodvorets, October 6-10, 2014. – St. Petersburg : [s. n.], 2014. – P. 177.

27.

Количество страниц: 9 с.

По данным наземных и спутниковых наблюдений рассматриваются квазипериодические изменения геомагнитного поля и параметров плазмы в диапазоне Pc 5 пульсаций, последовавшие сразу после взаимодействия межпланетной ударной волны (МУВ) с земной магнитосферой в событии 24.04.2009 в 00:53 UT. Пульсации были локализованы на широтах 66-74° в полуденном (11 MLT) и вечернем (20 MLT) секторах. Анализ годографов изменений геомагнитного поля как по спутниковым, так и наземным наблюдениям показал наличие вихревых возмущений. В данном событии фронт МУВ в межпланетной среде и фронт волны сжатия в магнитосфере имели наклон в плоскости ZGSM=0, угол наклона составлял 14° в межпланетной среде и 34° в магнитосфере. Положение вихревых возмущений в магнитосфере на разном радиальном расстоянии: X~5.5 Re в полуденном и X~-6.3÷-7.3 Re в вечернем секторе, согласуется с наклоном фронта. По спутниковым наблюдениям максимальная интенсивность волновых возмущений в обоих секторах регистрировалась в тороидальной компоненте, что соответствовало резонансному механизму возбуждения этих возмущений. Анализ распределения скоростей течения плазмы и распространения фронта волны сжатия в магнитосфере показал, что вихревые возмущения наблюдались в областях, где скорости течения плазмы и распространения фронта значительно различались по величине.
Quasi-periodic changes of the geomagnetic field and plasma parameters in the range of Pc 5 pulsations, which occurred immediately after the interaction of interplanetary shock (IPS) with Earth’s magnetosphere in the event of April 24, 2009 at 00:53 UT are examined using ground and satellite observations. The pulsations were localized at latitudes 66-74° in the noon (11 MLT) and evening (20 MLT) sectors. The analysis of hodographs of the geomagnetic field changes both from satellite and ground observations has shown the presence of vortical disturbances. In this event, both the IPS front in the interplanetary medium and the compression wave front in the magnetosphere had a slope in the ZGSM=0 plane; the inclination angle was 14° in the interplanetary medium and 34° in the magnetosphere. The location of the vortical disturbances in the magnetosphere at different radial distances, i.e. X ~5.5 Re in the noon sector and X ~-6.3 ÷-7.3 Re in the evening sector, is in agreement with the front inclination. As inferred from satellite observations, the maximum intensity of wave disturbances in both the sectors was registered in the toroidal component of the magnetic field. This suggests the resonant mechanism of excitation of these disturbances. The analysis of distribution of velocities of plasma flow and compression wave front propagation in the magnetosphere’s equatorial plane has revealed that the vortical disturbances occurred in regions where these velocities were noticeably different in magnitude.

Features of formation of small-scale wave disturbances during a sudden magnetosphereic compression = Особенности формирования мелкомасштабных волновых возмущений во время резкого сжатия магнитосферы / A. Moiseev, D. Baihsev, V. Mishin, T. Uozumi, A. Yoshikawa, A. Du // Солнечно-земная физика = Solar-Terrestrial Physics. – 2017, т. 3, N 2 : 13-я российско-китайская конференция по космической погоде. – С. 36-44.
DOI: 10.12737/22606

28.

Количество страниц: 2 с.

Features of Pc5 generation in the absence of the high-speed streams and significant changes in solar wind dynamic pressure : [тезисы докладов] / A. Moiseyev, D. Baishev, N. Zolotukhina, A. Du, K. Yumoto // Physics of auroral phenomena : 26th annual seminar, 25-28 February 2003 : abstacts. – 2003. – P. 22.

29.

Количество страниц: 4 с.

In the present study we investigate the undulations at the equatorial boundary of diffuse aurora and their relationship to the development of magnetic and auroral substorms and excitation of Pc5 magnetic pulsation on January 14, 1999. The observed undulations had wave-length of ~200-300 km and amplitude of ~50-250 km and they propagated westward with the velocity of ~0,7 km/s. It is found that the undulations began ~40 min after the substorm onset and lasted for ~80 min, all the way to the end of the substorm. During both active and recovery phases of the substorm the undulations were accompanied by the enhancement of the DP2 equivalent current system and by the formation of WTS. Concurrently with undulations, there were observed Pc5 magnetic pulsations of an oscillation period roughly equal to the ratio of the undulation wavelength to their propagation velocity. Observations are interpreted in terms of the shear/ballooning instability excitation near the plasmapause and subsequent generation of drift hydromagnetic waves.

Formation of large-scale, "giant" undulations at the equatorial boundary of diffuse aurora and Pc5 magnetic pulsations during the January 14, 1999 magnetic storm / D. G. Baishev, E. S. Barkova, S. I. Solovyev, K. Yumoto, M. J. Engebretson and A. V. Koustov // Proceedings of the Fifth International Conference on Substorms : 16-20 May 2000 Congress Centre of the Arctic and Antarctic Research Institute, St. Petersburg, Russia. − Noordwijk, Netherlands : European Space Agency, 2000. − P. 427-430.

30.

Количество страниц: 4 с.

Long-lasting ground based measurements of a polarization jet (PJ) by the latitudinal chain of ionospheric stations in Yakutia (3 < L < 5; MLT = UT + 9 h) and by 5 subauroral Russian stations were analyzed. A number of cases were found when PJ was recorded simultaneously with energetic ion observations by AMPTE/CCE and INTERBALL 2. The data comparison shows that at least in the considered cases of strong magnetic substorms, PJ was accompanied by strong injection of ions with the energy of ~20-50 keV and intensity of ~10 cm-² c-¹ sr-¹keV-¹. Close to the injection region in the near midnight sector no ion dispersion was observed, but in the evening sector nose events were detected. In accordance with the mechanism suggested by Southwood and Wolf (JGR, 1978, 83, 5227) PJ was observed near the equatorial boundary of energetic ion penetration into the magnetosphere. Measurements by ionosonds at different longitudes show that the westward velocity of the frontt of PJ development is close to the gradient drift velocity of 20 keV ions (forming nose events). Thus, the physical mechanism of PJ formation due to energetic ion injection during a strong substorm burst is experimentally confirmed. Satellite measurements show that in the near midnight sector energetic ions reach the shell L=3.0 in 20-30 minutes after a substorm commencement with AE>500 nT.

Formation of polarization jet during injection of ions into the inner magnetosphere / V. L. Khalipov, Yu. I. Galperin, A. E. Stepanov, E. D. Bondar // Physics of auroral phenomena : proceedings of the 25th annual seminar, Apatity, 26 February – 1 March 2002. – 2002. – P. 43-46.
DOI: 10.1016/S0273-1177(03)00016-4