일시: 2022년 5월 19일 목요일 오전 10시 세미나실(자4514호)
연사: Valery M. Nakariakov 교수님(University of Warwick)
제목: MHD Seismology of the corona of the Sun
초록:
Processes operating in the outer part of the atmosphere of the Sun, the fully-ionised and magnetically-dominated plasma of the solar corona, remain one of the major puzzles of the Solar System. The intensively debated research topics are enigmatic problems of coronal heating, rapid release of a huge amount of magnetic energy in solar flares and coronal mass ejections, microphysical processes responsible for effective acceleration of charged particles and anomalous values of transport coefficients, and so on. The solar physics research community is well supported by a number of ground-based and spaceborne observational facilities providing us with a wealth of high-precision data throughout the electromagnetic wave spectrum, from radio to gamma-rays. However, several key parameters of the solar corona, such as the magnetic field and coronal heating function, as well as effective coefficients of thermal conduction, viscosity and resistivity, are not open to direct observations. The method of magnetohydrodynamic (MHD) seismology, based on the estimation of plasma parameters by MHD waves, provide us with a paradigm changing diagnostic tool for probing the plasma in the corona. Modern MHD seismology utilises confidently detected kink, sausage and slow MHD modes of various plasma structures to reveal key parameters of the corona, and processes operating there. In the talk, we present the current state-of-the-art in MHD seismology.
