Observations of moreton waves and EIT waves

Abstract

Abstract We study the relationship between Moreton waves and EIT waves by analyzing Hα images taken with the Flare Monitoring Telescope (FMT) at the Hida Observatory of Kyoto University and EUV images taken with SOHO /EIT. In the event of November 4, 1997 (Eto et al. 2002) , the propagation speeds of the Moreton wave and the EIT wave were approximately 780 km/s and 200 km/s, respectively. The data on speed and location suggest that Moreton waves differ physically from EIT waves in these cases. In the event of November 3, 1997 (Narukage et al. 2002) , the wave is detected in soft X-rays as well as by the Moreton and EIT wave signatures. The propagation speeds of the Moreton wave, X-ray wave, and EIT wave were 490 km/s, 630 km/s, and 170 km/s, respectively, which suggests that we can identify both the X-ray wave and the Moreton wave a coronal fast-mode MHD shock wave, but that the EIT wave is physically different.