Документы 51 - 60 из 1341
51.

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.

52.

Количество страниц: 4 с.

The Dst-index obtained by hourly average values of the magnetic field at four stations located in various longitudinal sectors at latitudes Φ′≈20-30° is the index of magnetic field depression at low latitudes during the magnetic storm periods. Recently for the characteristics of magnetic field depression the SYM-H index has been used. It is obtained from 1 min data of the magnetic field at ~10 stations, located mainly at latitudes Φ′≈40-50° [1]. It is considered in [2-4] that the SYM-H index is an analog of Dst but with a better temporal resolution. As shown in [5], during super magnetic storms with Dst variation ≥ 400 nT, the SYM-H variations can considerably differ from Dst behavior and thus the SYM-H index is not always an analog of Dst. In this paper the relation between the Dst and SYM-H variations for magnetic storms of different intensity, with Dst varying from ~ -50 nT to -450 nT is investigated.

Solovyev, S. I. On the relation between the SYM-H and Dst- indices during the development of magnetic storm / S. I. Solovyev, R. N. Boroyev, A. V. Moiseyev // Physics of auroral phenomena : proceedings of the 28 th annual seminar, 1-4 March 2005. – 2005. – P. 48-51.

53.

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.

54.

Количество страниц: 1 с.

Makarov, G. A. Propagation velocities of geomagnetic sudden impulses caused by sharp changes jf solar wind dinamic pressure at high latitudes / G. A. Makarov, V. Moiseev, and S. I. Solovyev // The First S-Ramp Conference, October 2-6, 2000: Sapporo, Japan. – Sapporo, 2000. – P. 122.

55.

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.

56.

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.

57.

Количество страниц: 1 с.

Sources of excitation and damping of PC5 geomagnetic pulsations during the magnetic storms of october 29-31, 2003 influence of the solar wind and auroral electrojets : [тезисы докладов] / Solovyev S. I., Moiseyev A. V., Du A., Engebretson M., Newitt L. R. // International symposium on Solar Extreme Events of 2003 : programme and abstract book. – Москва : УНЦ ДО, 2004. – P. 59.

58.

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.

59.

Количество страниц: 4 с.

The character of geomagnetic and auroral response to solar wind dynamic pressure variation and the dynamics of particles injected into the magnetosphere / S. I. Solovyev, A. V. Moiseyev, K. Yumoto, M. Engebretson, A. Du // Physics of auroral phenomena : proceedings of the 29th annual seminar, Apatity, 27 February – 3 March 2006. – 2007. – P. 112-115.

60.

Количество страниц: 3 с.

Examination of auroral absorption (AA) occurrence rate and AA meridional distribution versus local time and in the course of the solar cycle has been performed by riometer observations from 1985 to 1995 at the longitude of Yakutsk. Geomagnetic latitude of the region of absorption maximum occurrence changes in the course of the solar cycle from 66.5° to 64.4°. The largest displacement of this region to lower latitudes is observed during years of maximum solar activity. The half-width of the region is ~8° at solar minimum and ~10° at solar maximum. It has been also revealed that the region of AA is shifted to higher latitudes at daytime (1000-1400LT), and to lower ones in the evening (1800-2000LT), the displacement from the daily average position being ~1° and ~3° in the years of solar activity maximum and minimum, respectively. In all years at 2000-2100LT a short-term extension of the AA region by 1-4° is observed. The interpretation of the observationa is proposed.

Sokolov, V. D. The dynamics of auroral absorption parameters in the 22nd solar activity cycle / V. D. Sokolov, S. N. Samsonov // Physics of auroral phenomena : proceedings of the 26th annual seminar, 25 - 28 February 2003. – 2003. – P. 95-97.