Документы 41 - 50 из 1376
41.

Количество страниц: 4 с.

The geomagnetic manifestation of sudden impulse (SI) caused by a sharp decrease of the solar wind dynamic pressure due to the plasma density reduction is considered. The observational data of the magnetometer world network have been analysed. The propagation velocities of the SI signal in the meridional direction by using data of the horizontal component of geomagnetic field in the high-latitude region have been calculated. It is found that at a sharp decrease of the solar wind density the meridional propagation of the SI signal is in the northern direction. In this case, on the day side the propagation velocity is constant but there is a tendency of its increasing in the MLT morning sector. It has been established that the meridional propagation velocity of the SI signal at a sharp decrease of the solar wind density depends on the geomagnetic latitude, i.e. with the rise of latitude the velocity in the auroral zone decreases and in the polar cap it increases.

High-latitude peculiarities of the geomagnetic SI impulse propagation meridional velocity during sharp decrease of solar wind density / G. A. Makarov, D. G. Baishev, A. V. Moiseyev, S. I. Solovyev, V. A. Pilipenko, M. J. Engebretson, K. Yumoto // 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. 523-526.

42.

Количество страниц: 3 с.

The Jupiter is a powerful regular source of high-energy electrons (0,2-40 MeV). In this connection their density in the near-Earth space systematically increases with a period of 399 days, which is coincident with the synodic period of Jupiter. According to our estimations, their energy is sufficient to produce a significant local reduction of the magnetic field in the IMF sector connected with the Jupiter. In this paper the evidence is presented that the electron fluxes in the Jovian sector are controlled by the general magnetic field of the Sun. A treatment of 399-day intervals of the electron fluxes and IMF, obtained from spacecraft data for the period of 1963 to 2000 has been performed by superposed epoch technique taking into account the periodic change of the solar magnetic field polarity. Having adopted the Jupiter opposition day to be an epoch zero, the changes in particle intensity and IMF components under different signs of the general magnetic field of the Sun are found by using a large dataset (9925 days). The times of 399-day variation maxima in different periods of solar activity are compared and a character of their displacement relative to Jupiter opposition momentsis discussed.

Skryabin, N. G. Influence of a change in solar magnetic field polarity on the Jovian electron flux intensity / N. G. Skryabin, S. N. Samsonov, I. Ya. Plotnikov // Physics of auroral phenomena : proceedings of the 26th annual seminar, 25 - 28 February 2003. – 2003. – P. 159-161.

43.

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.

44.

Количество страниц: 4 с.

Galactic cosmic ray (GCR) diffusion in interplanetary space depends in a certain way on the degree of regularity of the interplanetary magnetic field (IMF). The sector IMF structure is manifested in inhomogeneous GCR distribution in the heliosphere. In parallel with the usual sectors associated with solar activity, one should take into account the sectors, which are caused by the Jupiter activity. It is known that the Jupiter is a powerful regular source of high-energy electrons (0.2-40 MeV), the density of which, on the average, is many times higher than that of solar cosmic rays. The high-energy electrons are systematically registed with the 399-day period in the near-Earth space. According to estimations of the particle energy density their flux is sufficient to decrease the magnetic field in the Jovian sector and can due to corresponding large-scale inhomogeneity in the GKL distribution. Hereby, we present the evidences that the GCR diffusion is noticeably stronger in the sector where there are Jovian electrons. By data on periodic passage of those sectors near the Earth, we have treated neutron monitor data using the superposed epoch technique. The day of the Earth and Jupiter opposition is taken as a zero epoch. At large statistical data (9925 days) it is found that the GCR intensity in that period increases with an amplitude near 1%. The groud effect is manifested with the period of 399 days and its maximum time is in a certain way shifted relative to the planet opposite moment.

Skryabin, N. G. Influence of Jupiter on cosmic ray intensity variations / N. G. Skryabin, S. N. Samsonov, I. Ya. Plotnikov // Physics of auroral phenomena : proceedings of the 25th annual seminar, Apatity, 26 February – 1 March 2002. – 2002. – P. 137-139.

45.

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.

46.

Количество страниц: 1 с.

MAGDAS-9 magnetometers observations of strong earthquakes : [тезисы докладов] / Baishev D. G., Moiseev A.V., Bondar E. D., Kobyakova S. E., Yumoto K. // 10th International conference "Problems of geocosmos", St. Petersburg, Petrodvorets, October 6-10, 2014. – St. Petersburg : [s. n.], 2014. – P. 106.

47.

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.

48.

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.

49.

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.

50.

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.