Search Publications
The Effect of the Betatron Mechanism on the Dynamics of Superthermal Electron Fluxes within Dipolizations in the Magnetotail
Daly, P. W.; Malykhin, A. Yu.; Grigorenko, E. E. +1 more
The dynamics of high-energy electron fluxes (with energies over 40 keV) is analyzed in 13 events of magnetic field dipolization observed by the Cluster satellites in the near-tail of the Earth magnetosphere. In all of the events, the observed energetic electron fluxes are enhanced simultaneously with initial dipolization. Good correlation (correla…
Effect of the meridional velocity gradient on the anisotropy of turbulence in the solar wind
Erofeev, D. V.
In this paper, the heliolatitude dependence of the anisotropy of hourly interplanetary magnetic field fluctuations under conditions characteristic of low solar activity is studied. Measurements carried out by the Ulysses spacecraft in 1992–1994 and 1995–1997 are analyzed. It is found that the minimum fluctuation variance axis has a significant til…
The vorticity of Solar photospheric flows on the scale of granulation
Pevtsov, A. A.
We employ time sequences of images observed with a G-band filter (λ4305Å) by the Solar Optical Telescope (SOT) on board of Hinode spacecraft at different latitude along solar central meridian to study vorticity of granular flows in quiet Sun areas during deep minimum of solar activity. Using a feature correlation tracking (FCT) technique, we calcu…
Observations of long-period oscillations of the solar active regions in the visible and UV spectral intervals
Tlatov, A. G.; Dormidontov, D. V.; Chernov, Ya. O.
The variation of intensity in spectral line wings, which was obtained from observations of the patrol telescope at the Kislovodsk Mountain Astronomical Station of the Pulkovo Observatory, Russian Academy of Science (KMAS) and the Interface Region Imaging Spectrograph (IRIS) space observatory, are considered. A series of observations lasting a few …
Emergence of hard X-rays at weak nonstationary processes in active regions
Livshits, M. A.; Grigor'eva, I. Yu.; Ivanov, E. F. +1 more
Using Suzaku and Reuven Ramaty High Energy Solar Spectroscopic Image (RHESSI) spacecraft data, we study the characteristics of X-ray emission of weak flares at energies when this emission is generated by fluxes of accelerated electrons. Of the 105 events recorded by a broadband monitor of the entire sky (WAM/Suzaku, with an effective area of ~800 …
Konus- Wind and Helicon- Coronas-F observations of solar flares
Frederiks, D. D.; Svinkin, D. S.; Aptekar, R. L. +7 more
Results of solar flare observations obtained in the Konus-Wind experiment from November, 1994 to December, 2013 and in the Helicon Coronas-F experiment during its operation from 2001 to 2005, are presented. For the periods indicated Konus-Wind detected in the trigger mode 834 solar flares, and Helicon-Coronas-F detected more than 300 solar flares.…
Variation in the statistical properties of IMF direction fluctuations during the 22-year solar magnetic cycle
Erofeev, D. V.
The variation in the IMF direction distribution during the 22-year solar magnetic cycle has been studied. Data obtained in near-Earth orbits and measurements in the heliospheric regions located far from the Earth, performed with the Helios and Ulysses spacecraft devices, have been analyzed. It has been found that the correlation between the azimut…
Weak solar flares with a detectable flux of hard X rays: Specific features of microwave radiation in the corresponding active regions
Livshits, M. A.; Grigor'eva, I. Yu.
The emission of very weak flares was registered at the Suzaku X-ray observatory in 2005–2009. The photon power spectrum in the 50–110 keV range for a number of these phenomena shows that some electrons accelerate to energies higher than 100 keV. The corresponding flares originate in active regions (ARs) with pronounced sunspots. As in the case of …
Giant events in the 23rd solar cycle: Common and specific features
Struminsky, A. B.
Giant X-ray events (>X17) in the 23rd solar cycle (October 28 and November 4, 2003, and September 7, 2005) are considered, which were almost completely observed in hard X rays (>150 keV) from the INTEGRAL satellite and partly from the RHESSI satellite. These events are compared with two events completely observed from the RHESSI satellite (X…
Some aspects of modelling the high-latitude ionospheric convection from Cluster/Edi data
Haaland, S. E.; Förster, M.; Gromova, L. I. +3 more
Measurements onboard Cluster satellites are briefly described, which form the base for determining the intensity and direction of the electric field in the magnetosphere. The aim of this paper is to describe (1) the methodology of calculating the potential distribution at the ionospheric level and the results of constructing spatiotemporal convect…