11 research outputs found
Relationship of type III radio bursts with quasi-periodic pulsations in a solar flare
We studied a solar flare with pronounced quasi-periodic pulsations detected in the microwave, X-ray, and radio bands. We used correlation, Fourier, and wavelet analyses methods to examine the temporal fine structures and relationships between the time profiles in each wave band. We found that the time profiles of the microwaves, hard X-rays, and type III radio bursts vary quasi-periodically with a common period of 40 – 50 s. The average amplitude of the variations is high, above 30 % of the background flux level, and reaches 80 % after the flare maximum. We did not find this periodicity in either the thermal X-ray flux component or in the source size dynamics. Our findings indicate that the detected periodicity is probably associated with periodic dynamics in the injection of non-thermal electrons, which can be produced by periodic modulation of magnetic reconnection
Study of the extreme location of the penetration boundary of solar energetic particles (protons) into the Earth’s magnetosphere during the magnetic storms in 2001–2005
Effects of the April 1994 Forbush events on the fluxes of the energetic charged particles measured on board CORONAS-I: Their connection with conditions in the interplanetary medium
The SONG instrument on board CORONAS-I satellite (fluxes of protons Ep > 70 MeV and electrons Ee > 55 MeV) observed the effects of the Forbush effects caused by interplanetary magnetic field sector boundary crossing and coronal mass ejection in April 1994. The latitudinal dependence of these effects is analyzed and compared with data from ground-based neutron monitors at different latitudes. It was found that while measurements by SONG instrument over the polar caps were in good agreement with the data of the neutron monitor at polar latitudes, at the middle latitudes during the Dst decreases, the cut-off rigidity variations were probably so strong that instead of the usual short-time decrease the SONG instrument detected a significant enhancement of particle fluxes. The influence of interplanetary medium conditions on the cosmic ray flux is analyzed and discussed. © 2002 Published by Elsevier Science Ltd