Alfven waves or more generally transverse magneto-hydrodynamic waves (kink waves) would play a key role in coronal heating and solar wind acceleration (e.g. Suzuki & Inutsuka, 2006). Spectro-polarimetric observation is very important to study the dynamics of MHD waves in the magnetic flux. Clear strong fluctuations in the line-of-sight magnetic flux, the line-of-sight velocity, and the intensity are found both in pores and in inter-granular magnetic structure at 25-49 degrees west away from the disk center with SP (Spectro-Polarimeter), and the phase relation between the fluctuations in the line-of-sight magnetic field and the velocity from the observation is consistent with that of both the standing kink wave and the standing sausage wave (Fujimura and Tsuneta, 2009, ApJ, 702, 1443) For further study, we want to identify the mode of MHD wave (i.e. kink mode or sausage mode) in the magnetic flux. For that reason, we would like to perform center-to-limb observation for wide range of -angle, say 0|60 degrees. We are also interested in the dynamics of MHD waves between the photosphere and the corona. Velocity fluctuations in the coronal loop, which can be considered to be the kink waves, have been detected by Van Doorsselaere et al. (2008), Mariska et al. (2008), Doschek et al. (2007), Hara et al. (2008), and Taroyan et al. (2008) using EIS. EIS will perform a repeated scan with the narrow slit to detect the fluctuations in the Doppler velocity and in the intensity in the transition region and the lower corona. SP will perform a repeated scan with high time cadence, which allows us to observe apparent fluctuations in the line-of-sight magnetic flux, in the velocity, and in the intensity at lower photosphere. The collaboration between SP and EIS allows us to study the properties of MHD waves, such as the type of MHD wave (standing or propagating, kink or sausage, and so on) and physical parameters in a flux tubes (Photospheric seismology is possible from the observables (Fujimura and Tsuneta, 2009, ApJ, 702, 1443)) |
|