Документы 31 - 40 из 44
31.

Количество страниц: 4 с.

By using data treatment results of mid-latitude geomagnetic variations, the significant increase of the local current system intensity with the eastern direction current system, arising near the meridian of expected substorm center ~10-30 min before the break-up onset, has been found. A comparison of longitudinal sizes of two current system, forming the substorm disturbance before and after the onset of the substorm expansion phase, has been carried out. The longitudinal size of the current loop of the substorm growth phase is nearly twice as small as azimuth scale of the substorm current wedge, and the current strength is as week as 2.7-12 times.

Boroyev, R. N. Local increase of field-aligned current intensity before a substorm onset / R. N. Boroyev, V. A. Velichko, D. G. Baishev // 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. 279-282.

32.

Количество страниц: 4 с.

Analysis of the global magnetosphere-ionosphere response to solar wind dynamic pressure variations under the negative IMF Bz has been performed. It is shown that an increase in the dynamic pressure leads to a double response of the ionospheric currents and aurora, i.e. simultaneously (within the accuracy of 1 min) and ~5-7 min afterward. Thereby, the eastward and westward convective electrojets are enhanced in the evening and morning sectors respectively, followed by the intensification of the westward current in the near midnight and evening sectors. The intensification of the electrojets is followed by extension of the diffuse precipitation zone and its high latitude boundary movement to the pole and to the east in the midnight-to-morning sector. In our case, no poleward or westward extension of aurora before midnight is observed. The disturbance triggered by a dynamic pressure increase may be considered as a convection disturbance associated with reconstruction of the DP2 current system.

Magnetosphere-ionosphere response to magnetosphere compression by the solar wind / S. I. Solovyev, A. V. Moiseyev, K. Yumoto, M. Engebretson // Physics of auroral phenomena : proceedings of the 26th annual seminar, 25 - 28 February 2003. – 2003. – P. 41-44.

33.

Количество страниц: 2 с.

Magnetospheric-ionospheric response to variations in the solar wind dynamic pressure during positive IMF Bz and a sharp change of IMF By direction : [тезисы докладов] / S. I. Solovyev, A. V. Moiseyev, K. Yumoto, M. Engebretson, A. Du // Physics of auroral phenomena : 29th annual seminar, 27 February – 3 March 2006 : abstracts. – 2006. – P. 36.

34.

Количество страниц: 4 с.

Large-amplitude morning Pc5 magnetic pulsations during the main phase of intense magnetic storm were registered at magnetic stations of 190-200° magnetic meridians on January 21-22, 2005. Magnetic pulsations in the Pc5 frequency range observed at the GOES 10, 12 satellites in the noon and evening sectors exhibited a high degree of magnetic compessibility. A Los Alamos particle detector on board geostationary satellite observed the occurrence of energetic particle flux oscillations in the Pc5 band. The Pc5 pulsations were followed with the VLF-emission and riometer absorption modulation with the same period. The regions of maximal amplitude of Pc5 geomagnetic pulsations and deep modulation of riometer absorptions shifted to high latitudes in the same way. Significant and long-lasting compression of magnetosphere led, probably, to moderate pitch-angle diffusion of particle into the loss cone even at the middle latitudes. Analysis of coordinated data allowed us to suggest that a modulation effects of precipitating particles are caused by a compressional waves.

Manifestation of Magnetosphere Fluctuations during the Large Magnetic Storm of January 21-22, 2005 / D. G. Baishev, E. S. Barkova, V. A. Mullayarov, S. N. Samsonov, S. I. Solovyev, 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. 96-99.

35.

Количество страниц: 4 с.

The results of the hydroxyl and oxygen molecules rotational temperature measurements during two observational seasons 1999-2001 at Maymaga station (φ=63°N;λ=129.50°E) are presented. The rotational temperatures of OH(6,2) and O2 (0,1) bands have been measured with the infrared spectrograph equipped by the cooled CCD registration system. It is shown that the amplitude of seasonal change of hydroxyl rotational temperature is greater than the molecular oxygen variation. OH temperatures have been systematically higher the O2 ones during winter. An abrupt decrease of the O2 intensity connected with the springtime transition of the atmospheric circulation is found in both time series. For the first time a change of the temperature vertical gradient sign caused by mesopause height displacemet to a higher (winter) level was shown in the data of August-September 2001.

Gavrilyeva, G. A. Measurements of the mesosphere temperature by two molecular emissions in Yakutsk (62°N, 129,5°E) / G. A. Gavrilyeva // Physics of auroral phenomena : proceedings of the 26th annual seminar, 25 - 28 February 2003. – 2003. – P. 198-201.

36.

Количество страниц: 3 с.

Statistical analysis of internal gravity wave parameters registered by variations of the hydroxyl molecule emission is presented. The wave structures are detected with an all sky infrared camera at the optical station of Maimaga (φ=63° N; λ=129.50°E geographic). The data obtained for the period of 1998 to 2002 show that the small-scale internal gravity waves propagate predominantly westward. The observed wavelengths vary from 15.4 to 100 km. (the average value is ~40 km), the horizontal phase speeds are between 19 and 166 m s-¹ (the average value is ~63 m s-¹) and the estimated periods are 9-90 min (the average value is ~17 min). The wavelengths and phase speeds at high latitudes is probably due to the large intensities of the filtering winds compared to those in the middle atmosphere. The short waves (wavelengths shorter than 17.5 km) propagate in the same direction as the long ones.

Ammosov, P. P. Observations of short-term waves with an all sky camera in the infrared oh brightness over Yakutsk / P. P. Ammosov, G. A. Gavrilyeva // Physics of auroral phenomena : proceedings of the 26th annual seminar, 25 -28 February 2003. – 2003. – P. 179-181.

37.

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.

38.

Количество страниц: 4 с.

Specific features and development of Pi and Pm impulses at latitudes from the equator to the polar cap are studied. It is shown that formation of Pi and Pm impulses at high latitudes (Ф'=70°) is related to simultaneous intensifications of the westward and eastward currents on the dayside of the magnetosphere with a consequent shift of the eastward current to the pole. It leads to an increase of duration of Pi impulse with the growth of latitude. Inversion of Pi and Pm signs relative to the noon meridian takes place only at Ф'≈36-60°. At these latitudes the duration of Pi impulse also increases with growth of latitude, but the increase velocity is one order of magnitude larger than at Ф'=63-83°. The current system of SI impulse and possible reasons of Pi and Pm formation at different latitudes are discussed.

Moiseyev, A. V. Relation between the formation of preliminary and main SI impulses during a sharp compression of the magnetosphere by solar wind / A. V. Moiseyev, S. I. Solovyev, K. Yumoto // Physics of auroral phenomena : proceedings of the 25th annual seminar, Apatity, 26 February – 1 March 2002. – 2002. – P. 51-54.

39.

Количество страниц: 2 с.

The geomagnetic severe storm on November 7-11, 2004 had Dst=-383 nT and had probably caused by the coronal mass ejection (CME) in interplanetary space. The burst of solar X-ray preceded the halo-ejection of solar plasma. The experimental fact testifying the global response of the geomagnetic field ("crochet" type) observed after the solar flare on November 6, 2004 is given. The reaction in the geomagnetic field lasted for several hours as well as X-ray bursts registered aboard GEOS-12.

Solar X-ray Bursts as a Possible Predictor of the Magnetic Storm in November 2004 / V. A. Velichko, D. G. Baishev, I. Ya. Plotnikov, N. G. Skryabin, R. N. Boroev // 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. 107-108.

40.

Количество страниц: 3 с.

Splitting of auroral electrojets: ground-based and satellite data / D. G. Baishev, V. A. Velichko, E. E. Antonova, L. I. Gromova, M. V. Stepanova, R. A. Kovrazhkin, J. M. Bosqued // Physics of auroral phenomena : proceedings of the 26th annual seminar, 25 - 28 February 2003. – 2003. – P. 9-11.