Fast magnetoacoustic wave trains in the solar corona

Series: 
Astronomy Unit Seminars
Speaker: 
Valery Nakariakov
Host: 
David Tsiklauri
Date: 
January 15th, 2016 at 14:30
Room: 
GO Jones Room 610
Abstract: 

Analysis of high-precision EUV observations of the solar corona, performed by the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO) allowed for the confident detection of rapidly-propagating quasi-periodic wave trains of the variation of EUV brightness. Typical periods of these waves are about one minute, and the characteristic apparent speeds are about 1,000 km/s. It is found that the wave trains are associated with impulsive energy releases characterised by radio bursts. It is established that the fast wave trains may co-exist with well-known slow waves of the EUV brightness variation. Magnetohydrodynamic theoretical modelling demonstrates that the observed properties of fast wave trains are well-consistent with the dispersive evolution of fast magnetoacoustic wave trains guided by field-aligned plasma non-uniformities. Fast wave trains can hence be used as probes of physical parameters in the wave-guiding plasma structures.