Dispersive evolution of large-scale MHD waves in the solar atmosphereNormal07.8 磅02falsefalsefalseEN-USZH-CNX-NONENormal07.8 磅02falsefalsefalseEN-USZH-CNX-NONE

袁 丁

时间：2013-09-26星期四下午16:20-17:20

Time：September26, 2013，Thursday, pm16:20-17:20

地点：四楼报告厅

摘要：Recent commission of SDO/AIA provides high-cadence, fine-resolution and full-disk observation data. Large-scale MHD waves are revealed to propagate to a distance of up to a solar radius at approximately local Alfven speed. The period and wavelength were varying along its course and were interpreted as dispersive evolution (Yuan et al. A&A 554 (2013) A144). The period and wavelength evolution of these waves reveals the effect of waveguiding by coronal loops and an impulsive energy source (bursty flaring energy releases). Therefore, MHD seismology could be implemented to diagnose the plasma structuring and the spectrum of the initial energy source. Moreover, the random structuring of the solar coronal plasma were demonstrated numerically to cause dispersive evolution of fast MHD pulses (Yuan et al. ApJ 2013, submitted). A fast MHD pulse would resonate with a coronal plasma with a correlation length equivalent to its pulse width, and strongest dispersive effect are detectable. Based on this effect, a novel MHD seismology were proposed to diagnose the correlation length of the quiet Sun plasma.

袁 丁

http://space.wh.sdu.edu.cn/bencandy.php?fid=36&id=596