Solar Activity And EUV Wave Phenomena Research

EUV wave is observed in the extreme ultraviolet spectrum on large-scale distur-bances phenomenon, often accompanied by a coronal mass ejection. Besides, EUVwave is, when displayed in EUVI 195 (A|°) difference image, a bright ring reaching outand the subsequent spread of the dark zone. The disturbance can often cover the w-hole day round. The current study explores the CME-EUV wave events which oc-curred at 05:35 on February 13, 2009, based on the STEREO satellite observations andthe three-dimensional MHD numerical simulation. We know this CME with 340km/sfront velocity and 60°angular width from the STEREO-A-COR1 pictures. Viewing inSTEREO-B-EUVI 195 (A|°) running difference images, a bright toroidal wave front prop-agates from the active region to around, with dimmings area following the bright wavefront. The fitting velocity of EUV wave from the observation data is 247km/s. Thenumerical simulation shows that the (fast-mode) wave, with legible bright front anddimming structure, propagates in speed of 245km/s. The simulation results turn out tobe consistent with the satellite observations and confirm that EUV wave is a fast-modeMHD wave.