Отраслевые подборки (УДК)
Издания подборки 31 - 40 из 55
31.

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

32.

Количество страниц: 4 с.

Asymmetry in substorm development in the earth's northern and southern hemispheres / V. A. Velichko, R. N. Boroyev, M. G. Gelberg, D. G. Baishev, J. V. Olson, R. J. Morris, K. Yumoto // Physics of auroral phenomena : proceedings of the 25th annual seminar, Apatity, 26 February – 1 March 2002. – 2002. – P. 33-36.

33.

Количество страниц: 3 с.

Boroyev, R. N. Dynamics of field-aligned currents during substorms / R. N. Boroyev // Physics of auroral phenomena : proceedings of the 25th annual seminar, Apatity, 26 February – 1 March 2002. – 2002. – P. 9-11.

34.

Количество страниц: 4 с.

The spatial-temporal distribution of westward electrojets in the northern hemisphere has been investigated using geomagnetic ground observation data for November 9-10, 2004 geomagnetic storm. It is shown that the location of the maximum westward electrojet depends on the IMF orientation. It is in the evening or morning sector when Bγ0. With the increase of positive IMF Bγ, the region of intensity maximum shifts to morning hours. Thus, the azimuthal IMF component not only controls the pattern of magnetospheric convection, but also affects the longitudinal location of the westward electrojet pattern during the magnetic storm.

Influence of IMF by on the location of western electrojets during the magnetic storm on Nov. 9-10, 2004 / R. N. Boroev, A. Du, S. I. Solovyev, W.-Y. Xu, G.-X. Chen, V. A. Velichko // Physics of auroral phenomena : proceedings of the 29th annual seminar, Apatity, 27 February–3 March 2006. – 2007. – P. 21-24.

35.

Количество страниц: 5 с.

В течение 2009-2016 гг. на территории с границами 40-80° N, 60-180° E проанализированы вариации грозовой активности, представленной количеством грозовых разрядов по данным Всемирной грозолокационной сети WWLLN. Выделены две области с повышенным уровнем грозовой активности: западный очаг (48-60° N и 60-90° E), восточный очаг (40-55° N и 110-140° E). Плотность грозовых разрядов в этих областях в 10-100 раз превышает плотность разрядов на окружающих территориях. Сравнение вариаций суточного количества грозовых разрядов и потока радиоизлучения Солнца на волне 10.7 см показало слабую линейную корреляцию между ними: коэффициент корреляции от -0.55 до 0.86 для западного региона и от -0.78 до 0.39 для восточного за все летние сезоны. На возрастающей ветви 24-го солнечного цикла происходит пространственное перераспределение количества грозовых разрядов между восточным и западным регионами высокой грозовой активности. В максимумах солнечного цикла и на его спадающей ветви перераспределения становятся не настолько ярко выраженными как во время возрастающей ветви.
We analyze variations of lightning activity presented by the lightning stroke number obtained by the World Wide Lightning Location Network (WWLLN) within the territory with boundaries 40-80° N and 60-180° E in 2009-2016. There are two regions with high lightning activity: western (48-60° N, 60-90° E) and eastern (40-55° N, 110-140° E). The lightning stroke density in these regions is 10-100 times higher than that in surrounding areas. The comparison between daily variations of lightning stroke number and the 10.7 cm solar radio flux shows no correlation: the linear correlation coefficient varied from -0.55 to 0.86 in the western region and from -0.78 to 0.39 in the eastern region during all summer seasons. During the ascending phase of solar cycle 24, there was a spatial lightning redistribution between the western and eastern regions of high lightning activity. During peaks of the solar cycle and its descending phase, the redistribution was not so pronounced as that during the ascending phase.

Tarabukina, L. D. Spatial and temporal distribution of lightning strokes over North Asia and its comparison with solar activity variations in 2009-2016 = Пространственно-временное распределение грозовых разрядов по территории северного региона Азии и его сравнение с солнечной активностью в 2009-2016 гг. / L. D. Tarabukina, V. I. Kozlov // Солнечно-земная физика = Solar-Terrestrial Physics. – 2017. – Т. 3, N 2 : 13-я российско-китайская конференция по космической погоде. – С. 70-74.
DOI: 10.12737/22602

36.

Количество страниц: 4 с.

Moiseyev, A. V. Peculiarities of traveling convection vortices propagation: comparison with sudden geomagnetic impulse / A. V. Moiseyev, S. I. Solovyev, A. Du // Physics of auroral phenomena : proceedings of the 32nd annual seminar, Apatity, 3 – 6 March 2009. – 2010. – P. 75-78.

37.

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.

38.

Количество страниц: 6 с.

This paper uses the plasma data from Cluster and TC-1 and geomagnetic data to study the geomagnetic signatures of current wedge produced by fast-flow braking in the plasma sheet. The three fast flows studied here occurred in a very quiet background and were accompanied by no (or weak) particle injections, thus avoiding the influences from other disturbances. All the geomagnetic signatures of a substorm current wedge can be found in geomagnetic signatures of a current system produced by the braking of fast flows, indicating that the fast flows can produce a complete current wedge which contains postmidnight downward and premidnight upward field-aligned currents, as well as a westward electrojet. The Pi2 precursors exist not only at high latitudes but also at midlatitudes. The starting times of midlatitude Pi2 precursors can be identified more precisely than those of high-latitude Pi2 precursors, providing a possible method to determine the starting time of fast flows in their source regions. The AL drop that a bursty bulk flow produces is proportional to its velocity and duration. In three cases, the AL drops are 200 nT, whether a substorm can be triggered depends mainly on the conditions of the braking regions before fast flows. The observations of solar wind before the three fast flows suggest that it is difficult for the fast flows to trigger a substorm when the interplanetary magnetic field Bz of solar wind is weakly southward.

Geomagnetic signatures of current wedge produced by fast flows in a plasma sheet / Jin-Bin Cao, Chunxiao Yan, Malcolm Dunlop, Henri Reme, Iannis Dandouras, Tielong Zhang, Dongmei Yang, Alexey Moiseyev, Stepan I. Solovyev, Z. Q. Wang, A. Leonoviche, N. Zolotukhina, and V. Mishin // Journal of Geophysical Research: Space Physics. – 1978. – 2010 (August), vol. 115, N 8. – P. A08205.

39.

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

40.

Количество страниц: 4 с.

By global geomagnetic observation data the variations of intensity and dynamics of auroral electrojets, low-latitude disturbances at latitudes ~10-55°, SYM-H and studied. It is shown that positive values of SYM-H and Dst or the decrease of their negative values correspond to the growth period of Pd. The enhancement of magnetic field depression at latitudes Ф'~10-30° with the maximum ∆H in the evening sector is observed at negative values of IMF Bz and is accompanied by the enhancement of auroral electrojets in all temporal sectors and their southward shift. The maximum values of Dst ~-400 nT correspondent to the most intensity of western (eastern) electrojet in the midnight (evening) sector with a current center at the lowest latitudes. The possible sources of Dst and SYM-H variations are discussed.

Dependence of High-Latitude and Low-Latitude Geomagnetic Disturbances on Solar Wind Parameters during the Magnetic Storm of November 7-8, 2004 / S. I. Solovyev, R. N. Boroyev, A. V. Moiseyev, A. Du, K. Yumoto // Solar Extreme Events Fundamental Science and Applied Aspects Nor-Amberd, Armenia 26-30 September 2005 : proceedings of the Second International Symposium / edited by A. Chilingarian and G. Karapetyan. − Erevan : Cosmic Ray Division, Alikhanyan Physics Institute, 2006. − P. 104-106.